Nuclear Medicine - Science topic

I like your "Future trends in health professions education" chapter because the education of a healthcare professional is of foremost relevance in his or her functioning as that professional. And the future should rely on the past to mold the techniques in schooling. I wish you success in your chapter-writing as some of my published papers have been referenced in chapters in books. Good luck!

Great! Maybe we can have a chat.

Dear Fitri, I am recently doing a study about cost utility analysis among ischemic stroke patients in Malaysia. In this context, I will need SF36 malay version for data collection. Did you find out any ways to get the source? Appreciate your help

Hello Frank P. Dawry

You raise a very interesting idea. I have heard that Xe-133 is much more common in USA and less in some places. For example, for V/Qs in Europe, there are a lot of places and practices that use Technegas. Does your suggestion also apply to Technegas?

Dear all

This is the latest info I have - from a review article in Seminars on Oncology (ahead of print):

”Whole-body low-dose Computed Tomography is now recommended over the conventional skeletal survey, and more sophisticated functional imaging methods, such as 18F-Fluorodeoxyglucose Positron Emission Tomography , and diffusion-weighted Magnetic Resonance Imaging are proving effective in the assessment and monitoring of MM disease.”

Dear Rame Miftari and others

I apologise for not joining the discussion sooner! I agree with the point made by Laurens Swart that the situation depends a lot on pre-test probability. I agree with Teik Hin Tan that both functional and anatomical information is required - and Maurício L. Prudente made a good point that FFR is ideal. In the interval between the start of the discussion to now, I believe IFR is even more popular.

All of these points leads to my observation: access is an important issue. It depends on what is available in which place. I have worked in a number of places that MPI is only available two days each week. Even in larger institution, stress echo waiting list is about 8-12 weeks. Both are big problems. Many interventional cardiologists performing angiography unfortunately, do not also perform FFR. All of these types of issues will influence what “functional” assessment will be most used.

I have found that I should make topics relevant to my own place of practice. I ask myself what is/are common at this place and how can I improve it? What you choose should be what other people do in a similar practice (eg bone scan, FDG-PET scan) so your own population would be similar to them and your results and findings could be applicable to them. It is, of course, not the same everywhere but what you do must be similar to what someone else does "out there"?

I have been asked this question at my work quite frequently. I think the general agreement is that it is difficult to overgeneralise - cannot use the answer from one hospital/facility/practice to another. Some places have a very specific type of population/patient and it can be much more tedious than another that reports a lot of "normal" studies - which would be much easier/faster.

I was even more surprised after the comment by Deborah Jean Verran that no answers/comments have been made in the five years after that!

Dr Darel E Heitkamp raises a very interesting point. In my community, a lot of academic departments have followed the trends of radiology practices/facilities in the private sector and have lost the "ethos" that was highlighted. The consultant/attending staff are pushed to report more and more. Nobody stands up, they just leave and take the "if you can't beat them, join them" approach. Those of us left behind get even more disillusioned.

Another value-add activity I have found is multi-disciplinary conferences.

Hello Dear,

I hope this link helps you, get your answers,

nuclear-medicine-for-diagnosis-and-treatment.pdf (iaea.org)

Best regards

Take a look in our database in our new free medical imaging question and answer forum ( www.imagingQA.com ). You can filter on 'ct' and 'spect' as needed at the link below:

Feel free to sign up too, and join the growing community.

If you can't find what you're looking for, please feel free to open a new topic at the link below :

This is free software you can use for NM dosimetry.

The degree of the portal vein thrombosis is important since in cases with severe abnormality you cannot perform SIRT.

As you have mentioned, FDG is not a valuable tool for evaluation of most of HCC cases. FCH PET/CT would be a good choice where it is available.

Lu-177- PSMA

Lu-177-EDTMP

Dear Asra, what is your absolute cross-section definition? Can you explain more? Also, why do you prefer to un-collimation? Is there any special reason?

Even if your question is three years ago, I think I will answer for this. In a nuclear medical world now almost exclusively devoted to PET, dealing with conventional nuclear medicine is still very current. First of all, since conventional techniques are not at all all overcome by PET but in many fields, such as cardiology and neurology, not only are they still current, but neither can they be substituted by PET in routine. We must also think about the real possibilities of using a PET system, in particular for the procurement of radiopharmaceuticals in poor and poorly served areas, unless there are abundant economic resources to establish a complete PET center with cyclotron and radiopharmacy. Therefore I fully agree with the colleague who wants to be informed about the SPECT radiopharmaceutical tracer theory. If you want, you can write me since I taught this subject for years at the nuclear medicine specializing school at the University of Rome.

radiolabeling of compounds and their distribution in humans

Please read this pdf.

Gagan Saini found a very interesting article after your reply. Thank you!

"once better understood and properly exploited, the strategy of combining radiotherapy with an immune modulator may prove to be a watershed event that transforms the role of radiation from a local therapy to an endogenous vaccine

generator, leading to dramatic systemic antitumor immune responses in patients with aggressive tumors."

Dear Ayman, i understand your question, and believe there are little or no free products to do this. Are you talking educational resources?

We as a company i work for, Hermes Medical solutions have created several regional or international setups on a commercial product TeleHERMES that do allow using databases up to Terabytes and investigate all (even several native fields), and perform a lot of postprocessing. The TeleHERMES account will work as a local Hermes workstation. Depending on your needs, place you work and interests we can have a offline discussion. We have already installed multiple educational cloud accounts (some hundreds) for teaching institutions worldwide. This also for Inholland Hogeschool the Netherlands with 26 students and teachers simultaneous users on a Amsterdam server, Contact me when interested.

thanks https://www.researchgate.net/profile/Albertina_Rusandu2

All workstations and device consoles have the possibility to export the data as a dicom format. Then you will need a program to look into the images. Just google and you can find several.

BW

Thiago

I do not know relevant free software, but the following paper may help

FYI, the predecessor of the OLINDA/EXM (Organ Level INternal Dose Assessment/EXponential Modeling) version 1.0 code was the formerly freely available MIRDOSE 3.0 and 3.1 codes, and these codes were written and rewritten by the same investigator.

nuclear medicine technology

certification board equipment list

Hello!

I would suggest C++. And here are the reasons for such a suggestion:

These are the options that may be useful when it comes to medical imaging, segmentation, etc.

The nuclear medicine service

Plans for the establishment of a nuclear medicine service must address the following points:

(a) Level of service needed;

(b) Equipment specifications;

(c) Human resource development;

(d) Site preparation;

(e) Adherence to building, fire and security codes;

(f) Delivery and testing of equipment;

(g) Procedure manuals and department policy;

(h) Service administration;

(i) Official opening ceremony;

(j) Marketing;

(k) Programmes for:

—Physician interactions,

—Continuous clinical evaluation,

—Quality control,

—Initiation of research projects;

(l) Future developments.

The IAEA document suggested by Dr. George C, Giakos is an excellent document that can be used to answer all questions you may have on this subject.

 I agree with the proposal. On the other hand IAEA has published very good documents in other fields.

Sent you a message Huseyin.

Phil Blower may guide you

Hi Markus, 

This might be prone to [11C]labelling:

 http://www.selleckchem.com/products/pd-1-pd-l1-inhibitor-1.html

Yes i agree with Prof Sanad,receptor persent in lung are the best for diagnosis of particular disease by phramaceutical imaging via SPECT and PET..

Hi Sandor!

Thank you so much for your reply. Hoping that you are well. As you probably have guessed already the lab I mentioned was your lab that I visited some time ago to learn the GTPgammaS assay :) In my last experiment, morphine produced slightly less stimulation, but in the one before, the Emax values were identical for both drugs. I was surprised because you mentioned morphine being a partial agonist and DAMGO giving much more stimulation than 50%. Another thing is that I also get 10-times lower EC50's than I got in your lab. I know that the EC50 values are not accurate when determined in GTPgammaS assays due to the presence of sodium, but this inconsistency still worries me a bit. I don't remember which membranes I used when I visited your lab, but I think I'll try the brain regions you mentioned and see how it goes. Do you also use spinal cord homogenates? Do you see a clear distinction between the efficacy of DAMGO and morphine? 

All the best,

Anna

The fate of Iodine-131 discharged to the sewers has been modeled and quantified by Punt et al. [16]. Once discharged to the sewer, Iodine-131 will be transported to the sewage treatment works where it may become associated with sewage solids or discharges to surface waters with treated sewage effluent. During low flow periods, bio-solids settle out in the sewer and it is possible that some of the Iodine-131will be retained in the sewage system. Approximately one third of the iodine activity received at the treatment works is believed to become associated with solids during initial sewage treatment and hence will not be discharged with treated effluent [16].

[16] PUNT, A., WOOD, M., ROSE, D., TITLEY, J., COPPLESTONE, D., Assessment of Radioiodine Discharges to Sewer. Royal Society Of Chemistry- 10th International Symposium, Oxford Press (Sept. 2006).

The answer depends on what you mean by "reliable", and whether you are searching for a general answer or are looking at one specific situation.

To my knowledge, the MIRD formalism will describe quite precisely the absorbed dose in target organs for known activity in the source organ(s), for standard geometries. Deviation from standard geometries will make the prediction less precise. More uncertainties will be introduced by the description of distribution and retention of the radiopharmaceutical within the different body tissues. You will have to check the MIRD documents and other relevant literature to get more detailed information on the case you are interested in.

Here are a few papers...should lead you in the right direction.

The MIRD system is a good practical system for dosimetry of radionuclides in the human body.  It is well suited to radiation protection applications where organ doses are of interest, and it may not be possible to determine the exact shape and biological performance of the organs of interest.  Idealised organ shapes may be used, and microscopic variations in does are not reckoned.  The weaknesses of the system are in the way real biology may depart from the assumptions.  This is particularly evident in the mass and shape of organs, the uptake and distribution of radionuclides in the organs, the kinetics of uptake and elimination, microdosimetry and so on.  However, it is a good methodology, provided you are alert to its limitations.

I also believe it reliable within the scope of the errors of the underlying measurements.

An excellent reference would be George Sgouros papers. I am assuming by best you mean most reliable (accurate and precise). Your question has multiple aspects, including what is the best software tool to perform dosimetry, or what is the best way to provide inputs from the patients (e.g. radiotracer uptake) to these software tools. For the latter, several methods are available, such as imaging, blood samples, etc., and finding out which method is the best is an area of active research. Perhaps you might be interested in the following publication: https://www.ncbi.nlm.nih.gov/pubmed/26982626

Since  direct measurement of the absorbed dose to target organs   from nuclear medicine procedures is rarely possible,  most estimates rely on the  Monte Carlo simulation or numerical calculation based on indirect measurements/radiopharmaceutical data.

Here in the  US MIRD method  has been  developed by Medical Internal Radiation Dose Committee (http://www.snmmi.org/AboutSNMMI/CommitteeContent.aspx?ItemNumber=12475)  that allows the calculation of dose to target organs, see e.g. http://ozradonc.wikidot.com/methods-of-dose-estimation,

http://www.arpapress.com/Volumes/Vol11Issue1/IJRRAS_11_1_17.pdf,

you can find more references on the MIRD webpage under MIRD publications.

Dedicated MIRDose software is developed by M.G. Stabin that simplifies the calculations.

(M.G. Stabin, and G.D. Flux. "Internal Dosimetry as a Tool for Radiation Protection of the Patient in Nuclear Medicine". Biomedical Imaging and Intervention Journal, 2007; 3(2) 28)

Hi Daryoush,

you'll find lots of information in the RADAR website: http://www.doseinfo-radar.com/. This is also the website of the creators of OLINDA (primarily Michael Stabin). Regarding the literature, you might find interesting to read the ICRP report n. 106: http://www.icrp.org/publication.asp?id=ICRP%20Publication%20106

Check this articles from one of my colleague they may be of help

Yes, scintigraphy can guide for deciding for splenectomy, however, in most cases, first splenectomy is done and when patient does not improves, the patient is send for scan to rule out spleneculus or accessory spleen.

I agree with Dr. Morez, labelled platelets can be used for deciding whether to go for splenectomy or not and for prognostication. Another cause for chronic ITP is hepatic sequestration which can also be very well studied with labelled autologous platelet scintigraphy. Though these scan, using In-111 / Cr-51 labelled studies are rare due to logistic issues, but can be very helpful at times..

you are wellcome but how do you practice nuclear médicine in the Sudan? Teleradiology is not the good answer as you need facilities not only  in terms of Equipment  (detectors, radiopharmaceuticals,...) but also with regard to the medical and paramedical staff. This is a high tech spacialty with very special needs. Best regards

Ionizing radiation interacts randomly with molecules along charged particle tracks and may damage DNA either through direct events in the molecule (ionization or excitation) or, more frequently, through indirect mechanisms mediated by reactive oxygen species produced by radiogenic hydrolysis. Reactive oxygen species also derive abundantly from oxygen metabolism. The life of aerobic organisms would have been impossible without defenses against reactive oxygen species. Irradiated cells protect themselves (1) by immediate defense, repair, and damage removal mechanisms and (2) by delayed and temporary protection also against renewed DNA damage, irrespective of its causes that is, through adaptive responses. The carcinogenic risk induced by low doses of ionizing radiation is controversial. It cannot be assessed with epidemiologic methods alone because at low doses the data are imprecise and often conflicting. Since the 1970s, the radiation protection community has estimated the risk of low doses by means of extrapolation from the risk assessed at high doses, generally by using the linear no-threshold (LNT) model.

The LNT relationship implies proportionality between dose and cancer risk. This approach is based on one set of data and two hypotheses: (1) The relationship between dose and DNA damage in vivo seems linear from 1 mGy to 100 Gy with use of H2AX foci as a marker for DNA double-strand breaks (DSBs).However, this marker is not specific; (2) each DSB is hypothesized to have the same probability of inducing cell transformation, irrespective of the quantity of DSBs present simultaneously in the cell; and (3) each transformed cell is hypothesized to have the same probability of developing into an invasive cancer, irrespective of the dose delivered to the tissue. The advances during the past two decades in radiation biology, the understanding of carcinogenesis, and the discovery of defenses against carcinogenesis challenge the LNT model, which appears obsolete.

The LNT model was introduced as a concept to facilitate radiation protection. But the use of this model led to the claim that even the smallest dose (one electron traversing a cell) may initiate carcinogenesis for instance, from diagnostic x-ray sources. This claim is highly hypothetical and has resulted in medical, economic, and other societal harm.

The French Academies report concluded that the LNT model and its use for assessing the risks associated with low doses are not based on scientific evidence. In contrast, the Biological Effects of Ionizing Radiation and that of the International Commission on Radiological Protection (ICRP) recommended the use of the LNT model.

Therefore, the Linear No-Threshold Relationship Is Inconsistent with Radiation Biologic and Experimental Data. We wish to update this debate by using recent radiation biologic and epidemiologic data.

A short "summary" about drug excretion, also mentioning drug weight and lipophilocity : http://www.merckmanuals.com/professional/clinical-pharmacology/pharmacokinetics/drug-excretion 

and for those who want to read more: http://classes.biology.ucsd.edu/bimm118.WI11/PPT%20Lecture%20Notes/Lecture%203.pdf

Interesting and good discussion!

 MIBI is not at all the gold standard to rull out arrythmia. MIBI is only one of the diagnostic methods to rull out coronary heart disease. Deadly arrythmia is not allways caused by coronary heart disease, especially in young sportsmen where MIBI study would probably be normal and the patients could still have a deadly arrythmia.

In my experience, in  The Netherlands, no consultancy firm exists, that combines knowledge of the operational size AND of the legal side AND of the radiation protection side. So it is extremily important to find a few experienced professionals [not just physicists, but also physicians] to monitor any such project on the sidelide.

Take for example the impact that the introduction of PET and PET/CT has had on the design / radiation protection requirements.

In 2004 I had the [College Bouw Ziekenhuis Voorzieningen] (Dutch Governmental Advisory committee for hospital building visit our place, because we judged that their rules and regulations were not compatible with modern radiation protection standards. [At that time our government had a large say in these matters, as the government financed hospital buildings. This system has been abandonded.]

Any rules and advises should be judged from the perspective of the time frame in which these were formulated. And most certainly, one should think ahead. When we finalized our plans for a new department in 2008, we based it on a prognosis for 2025.

I totally agree with Farshid Salehzani that architects are a risk factor rather than a source of good advice. I have dealt with three designs, 2 full departments and one PET/CT centre and know for certain, we have avoided a financial catastrophe each time, by insisting on full participation in the design loop.

In the beginning we were considered a nuisance. But once the concrete was poured for the foundation, we started inspections. This led to a number of costly findings, causing serious delays. Several things had to be redone. We explained our the board of directors that we would apply for our licens because we considered the findings so serious that it was not worth the effort of writing the application for a license. The board of directors acted promptly and since then we were timely  invited to comment on all major design issues and at various stages we were activily invited to inspect the details, i.e. of how the issue of shielding was solved arond the plumbing, piping and wiring. The constructor was very keen on giving us an opportunity to inspect BEFORE details were hidden by concrete whereever possible.

That no experienced architect can be found in most countries is no surprise. In The Netherlands, only 1 or 2 hospitals are built each year. Assume 5 consortia that build hospitals, no single architect can acquire the experience needed and at the same time keep up with the legal stuff and the radiation protection stuff and also maintaining an up to date overview of what contemporary nuclear medicine is about.

The IAEA has a whole series of such documents on their website. Both for radiotherapy, radiology, conventional nuclear medicine and for a PET/CT centre. The IAEA safety report 40 is just one of a whole series. The layout of their website is in constant flux and not all documents can be found at any given time, unfortunately.

The AAPM =TG108 work is an excellent starting point for PET/CT shielding [no  one buys a dedicated PET-camera any more].

I have written software [python 2.6]  that can be used to calculate the net effect of  'distributed' shielding that may be used for a nuclear medicine department situated on a single floor. The code starts with a floor plan of the centre-lines of all walls and specifications of what sources and activities take place in which room how often, and for what time. Our physicist has done an independent validation of the code.  

In the past 8 years I have done the shielding designs of 1 PET/CT centre and 2 departments of nuclear medicine with PET/CT and with 131I-iodine treatment facilities. In september we will move into our new department.

In nuclear medicine there is often some room for a trade-off between physical and procedural safety measures. So such shielding calculations should be a team effort and the team should include an experienced nuclear physician. The routing and timing of injected patients must be taken into account.

Shielding is only part of the story. Each design should be very well documented in anticipation of future decommissioning or modification. Working with radio-isotopes implies taking responsibities for the long term very, very seriously..

A lot of the details depend on anticipated number of diagnostic procedures, equipment, local practices, local legislation and local customs. This is not strictly a scientific topic but a major engineering one. Simple answers do not suffice here.

One has to anticipate the patient numbers 10, 20 years from  now and have a good knowledge of the technology involved. For example the required doses in case of 18F-FDG have dropped considerably, but a further drop is not likely anymore.

You ask for far more details than this communication channel is suited for, so i limit myself to a few references that can all be found on line. There are far more on line.

Draft regulatory document RD-52 Design Guide for Nuclear Substance Laboratories and Nuclear Medicine Rooms  from Canadian Nuclear Safety Commission  Nov 2008 [or more recent final text]

Shielding of Medical Facilities. shielding design considerations for PET-CT facilities   Juan Cruzate & Adran Discacciatti

The Design of Diagnostic Medical Facilities where Ionising Radiation is used

A Code of Practice issued by the Raduiological Protection Institute of Ireland June 2009

PET/CT shielding design comparisons. Thesis by Audra Lee Coker  Texas A&M Univiersity  May 2007

Nuclear Medicine Resources Manual    IAEA 2006

Safety Report Series No. 58  Radiation Protection in Newer Medical Imaging Techniques: PET/CT  IAEA 2008

Safety Report Series No.  47  Radiation Protection in the Design of Radiotherapy Facilities  IAEA

Safety Report Series No.  40  Applying Radiation Safety Standards in Nuclear Medicine  IAEA

Safety Guide No. RS-G-1.10 Safety of Radiation Generators and Sealed Radioactive Sources.  IAEA 2006

IAEA Human Health series no. 11  Planning a Clinical PET Centre   IAEA 2010

[in this same series several other publications are also of interest,  I suggest you look for those as well]

F. Roesch and D.V. Filosofov have discussed about the nuclear reactions and targetry for production of Ge-68 in IAEA report on PRODUCTION OF LONG LIVED PARENT RADIONUCLIDES FOR GENERATORS: 68Ge, 82Sr, 90Sr AND 188W., IAEA RADIOISOTOPES AND RADIOPHARMACEUTICALS SERIES No. 2, IAEA, Vienna 2010

Germanium-68 can be produced via a variety of nuclear reaction pathways. The most effective route appears to be proton irradiation of Ga targets. The high cross-section values of the (p,2n) reaction allow irradiation of natural Ga without isotopic enrichment in 69Ga at medium proton energies of between 20 and 30 MeV. In addition, if protons of higher energies are available, the (p,4n) process on 71Ga contributes to production yields. High beam intensities in the range of 100 μA or more are required to produce batch activities of >37 GBq of 68Ge. As the number of accelerators with the above features is limited worldwide, the number of 68Ge production sites is also limited. The nuclear centres at LANL (USA), BNL (USA), Cyclotron Corp Obninsk Russia and Faure (South Africa) report successful production. Attempts to establish 68Ge production have recently been reported by a few other centres. Chemical aspects of production relate to target preparation and radiochemical separation of 68Ge. Metallic Ga encapsulated in Nb containments and Ga4Ni alloys are the best choices for target materials. Chemical separation is achieved even for the separation of 68Ge from up to 100 g of Ga target materials.

The radiochemical technique that is currently preferred consists of liquid–liquid extraction of 68Ge from the dissolved target using CCl4. Following backextraction into water, high separation factors of about 106 are achieved. Specific activities obtained reach values of >74 GBq (>2 Ci) of 68Ge/mg. Radionuclidic purity is high owing to the physical decay of the co-produced short lived radionuclides (such as 67Ga and 69Ge) and radiochemical separation of the long lived radionuclides, mainly co-produced within the non-Ga target or target backing materials. Radionuclidic purity of >99.9% is achieved.

iThemba Laboratories (South Africa), Brookhaven and Los Alamos Laboratories (USA) and Cyclotron Co Ltd (Obninsk, Russia) may be contacted for supply of Ga targets, but I think such targets can be made in a small workshop.

Details about targetry can be read in attached report.

For SPECT, many of the the reconstruction algorithms are designed to make pretty pictures rather than quantitative ones. Avoid those. Do a search on "quantitative SPECT reconstruction" on Google to see the variety. Which algorithm is chosen depends a bit on what equipment you have, for example, with or without CT attenuation correction.

With CT reconstruction there is a general problem. Typically, the reconstructed field of view of the CT images is smaller than the bore of the imaging device. Thus, the CT reconstructed field is inside the patient if the patient is large. The solution to this problem would be to do limited angle reconstruction over a larger matrix than the bore of the imaging device, but, I have never seen that done. So, CT correction attenuation correction sometimes uses methods in an attempt to overcome the original sin of doing things, well, stupidly. This could include, for example, Hilbert space reconstruction to follow an attenuation reconstruction pathway that includes only those portions of the patient that are totally within of the field of view. As a consequence of doing things stupidly, attenuation correction coefficients seem sometimes (e.g., GE CT-SPECT of a few years ago) to be set up so that patients totally within the field of view are over corrected for attenuation and those who are partly outside the field of view are correctly attenuation corrected and those who have massive body size are under-corrected.

Without CT, some reconstructive algorithms are more correct than others, for example Review Article: Filtering in SPECT Image Reconstruction. Maria Lyra and Agapi Ploussi, Think the Butterworth filter is superior for quantification, and opinions vary, and iterative techniques are sometimes better. Unfortunately, this is a matter of what is available on your equipment, in your setting. Given that choice, which is always a subset of all possibilities,  there will be one better method for quantification where most of the methods available will be dedicated to making pretty pictures with little thought to doing things to maximize quantitative fidelity. So, you have to think it through for the equipment you have, and doing phantom studies  may be necessary to get a handle on what is less ridiculous, but even that should only be done after doing a literature search on those methods of image reconstruction that you do have available. But, even phantom studies have to be done in such a way as to correspond to actual patient data, for example, think of the CT problems for patient size above.

Most prostates are bi-laterally symmetric in their external contour.  Asymmetric planning may arise from two causes:

     1.  If the trans-rectal ultrasound (TRUS) volume study has the prostate shifted left or right from midline, you should center the prostate for the treatment plan. The patient is not sedated for the TRUS volume study, but for the implant in the operating room (OR) with the patient anesthetized, the brachytherapist can more accurately align the prostate to the grid.

     2.  If the prostate is asymmetric, your needle placement approach may affect outcomes.  The two dominant philosophies either consider the target as the prostate or as the prostate plus explicit margins.  The latter is recommended by ASTRO, ABS, and GEC-ESTRO guidelines, but many centers still consider the prostate alone as the target.  Our margins are 4, 5, and 6 mm for low, intermediate, and high-risk patients, respectively, but they are also influenced by mapping biopsy results.  If the prostate is centered and margins added, the resulting planning target volume (PTV) can be made bilaterally symmetric by subsuming prostate invaginations and nodules within the PTV.

For reasons of speed, predictability, and simplicity, all of my plans, about 2,800 patients, have needle placements and offsets that are bi-laterally symmetric.  If the plan calls for a needle 2 cm left of midline and 1 cm offset from the base, the brachytherapist will expect a matching needle on the right.  By limiting the parameters that change in the OR you limit the possibility of mistakes.  Even though the needle positions are symmetric, the contents of the needles may differ in terms of number of sources and their spacing.  Not one of my plans has ever been symmetric in terms of seed placement.

I have seen no credible clinical comparisons of symmetric versus asymmetric needle placement, and I expect no difference in outcomes.  There are also no formal comparisons between outcomes of centers treating the prostate plus margins versus those treating prostate alone.  In the latter case, the 100% isodose is often pushed outside the prostate, but the extent is rarely documented.  For low-risk patients, differences in biochemical progression-free survival are within the uncertainty expected in inter-institutional comparisons.  However, for high-risk men, the differences are substantial.  All the brachytherapists, whose outcomes for high-risk men are comparable to ours, treat with large, explicit margins.  (Refer to GS Merrick et al., "Time to failure after definitive therapy for prostate cancer: implications for importance of aggressive local treatment," J Contemp Brachytherapy, 5: 215-221 (2013).)

In-111 oxine and Tc-99m HMPAO are two radiopharmaceuticals that are used clinically to tag white blood cells ex-vivo for reinjection into patients. There are commercial cell membrane intercalating dyes that can be used for optical imaging. There are numerous radiolabeled cell membrane intercalating dyes and phospholipid analogs that also can tag cells. All of these methods have pros and cons which will depend on your particular application.

Fluorine binds to most metals, forming a very strong bond with Al3+, which can form complexes with metal-binding chelates. The aluminum fluoride bond is stronger than 60 other metal-fluoride bonds, e.g., bond energy of 670 kJ/mol. The aluminum-fluoride bond is highly stable in vivo, and small amounts of AlF complexes are compatible with biological systems.

The pH is critically important for the formation of (AlF)2+-chelate complexes. If the pH is too high, metals would form hydroxide complexes and precipitate, and if it is too low, then the preferred fluoride species in the equilibrium would be HF. Studies of AlF complexes suggested that pH 4 would favor a 1:1 aluminum-fluoride complex, and pH 4 was compatible with the metal complex formation.

An example of complex; please see attached file.

Radioactive therapy with iodine 131 (131 I) is indicated to ablate residual normal thyroid and to treat functioning metastases in differentiated thyroid tumors. Because pediatric patients are few and the prognosis is generally excellent, 131I is usually recommended only for patients with extensive unresectable cervical nodal involvement, invasion of vital structures, or distant metastases.

Ample evidence suggests that more extensive surgery is associated with lower rates of recurrence. Surgery is associated with clear and definable rates of complications that can be minimized when surgery is performed by high-volume thyroid surgeons. Evidence shows that, when properly applied, RAI is associated with lower recurrence rates. Evidence also shows that DTC is associated with an increase SPM risk, which reflects intrinsic factors related to having DTC itself. Evidence also suggests that relatively high doses of 131I may contribute to an increased risk of SPM. Thus, the proven benefit of 131I in preventing cancer recurrence and cancer-related deaths needs to be weighed against potential long-term risks.

Based on the constellation of the above information, the following recommendations are made for children with DTC (Figs. 5 and and66).

It depends what functional group of DOX you want to use to make the bond... If the amino group is your choice, then you just need to use your DOX with any DOTA-like compound with a functional group that reacts with amines (DOTA-SA or DOTA with isothiocyanate mojety). You could find protocols for these reactions in the literature

Usually for sentinel node biopsy with surgery to be done same day, 20 MBq is adequate and should be injected at least 2 hours before the surgery. If surgery is planned the next day , then 37-100 MBq is recommended.

It depends on center to center on type of injection, usually we prefer peri-areolar as peritumoral lymphatics may be heavily laden with tumoral cells so that lymphatics might not flow leading to failure of technique. Peri-areolar injection concept has come up because of unique nature of superficial lymphatics of breast (Sappy plexus).

Imaging before the surgery, again varies between various centers depending on the time at your disposal. In many busy centers, they do not do imaging and send the patient directly for surgery, but in my opinion, we should do planar imaging and in doubt SPECT- CT for confirmation.

During surgery, with the use of gamma probe, the injection site is marked and any node having more than 10% of injection site count is considered as positive. This should be taken out for frozen section. Again whole axilla should be surveyed for activity and same principle of 10% should be followed till we do not find anything more than background.

Hope this would help...Best of luck

There is a significant difference between the amount of ionised calcium between these two drugs. Anyway, one should prefer ca-citrate in case of histaminoresistent hypochlorhydria, when gastric acid is missing.

If you look on the structure of sestamibi; a small microsphere - and want to coulpe it to a SPION - my guesstimate is that the biological property of Sestamibi (a MPI agent) will be lost. It is like attaching a car to a corn flake and hope to use it in the cereal for breakfast.

Quantification in terms of Bq/ml is usually only performed by a solid state camera (rotating heads are not fast enough to pick up the dynamics involved). Using a DSPECT system with 99mTc-MIBI, peak myocardial activity concentration is on the order of 5 Bq/ml (with injection of 800 MBq), while of course the input function from the ventricle should be much higher. These numbers are patient-dependent, but are certainly on the order of Bq/ml for SPECT (only 2% of MIBI is taken up in the myocardium), even in PET studies a maximum of few hundred kBq/ml are to be expected (depending on tracer of course)

A recent paper from UCL in London explains myocardial perfusion quantification in SPECT further:

Hope it helps

Well, in recents papers (such as Glenn Wells et al. 10.2967/jnumed.114.139782) the potential of fast cardiac SPECT cameras to acquire in a dynamic way to "track" the delivery  and uptake of perfusion agents is investigated (i.e. the tracer is injected while the patient is sitting/lying in/under the camera). Based on such data, quantification of absolute myocardial blood flow similar to PET would be possible. Theoretically this allows - amongst others advantages - the detection of balanced three vessel disease as the stress flow is reduced in absolute terms (ml/min/gram) but the (static) images look almost normal. The problem, however, is that conventional SPECT tracers are much less extracted by the myocardium as typical PET agents - thus this quantification is much less reliable.

In addition to the aforementioned complexities, K1 varies vastly for different (radio)-tracers which are linked to the clinical target, namely the myocardial blood flow - if one uses the Renkin-Crone equation  K1 = E*MBF, E = (1-exp(-PS/MBF)). In other words, for a normal MBF of 0.8, K1 could be 0.8 for 15-O water, 0.75 for N-13 ammonia or 0.5 for 82-Rb (numbers gut feeling...) - depending on the extraction fraction (E) of the particular tracer.

The injected activity would depend on the interval between injection and surgery. In my centre, the elective surgery is only done the next day; about 20-24hr post-injection. So, the dose we used is about 37MBq, injected  at 9 O'clock using peri-areolar approach (single dose/ site).  Image acquisition is performed after 5min post-injection.

It might be possible to distinguish the contribution of the two radioisotopes to the images on the basis of their kinetics in the brain. If you have two ligands with well characterised kinetic profiles, then your tissue concentration of ligand build-up will be comprised of a sum of these two profiles. If sufficiently different, you could model this mathematically: the impulse response in the tissue would be a sum of two exponentials rather than one. Non-linear least squares algorithms are best suited for this sort of component analysis. Spectral analysis and principle component analysis of time-activity curves is already being used to look at PET ligand binding to two separate subtypes of the GABA receptor, so it is doable!

In this kind of analysis, the difference in isotope is not important, just the difference in brain behaviour. In fact, doing it with two different isotopes would make things harder: you could do the ligand comparison, but quantification would be hard given your problem with decay-correction.

I agree with Jesus about the ~ 10% for tail vein injection. I did not read and know if there is any sharp line. It was said there is about 7% blood of the body weight and therefore about 1.4 mL for a 20 g mouse. We used to inject 0.1 mL, more than enough for 99mTc labeled solution, unless low labeling efficiency, specific radioactivity, or concentration becomes an issue. For my own experience with mice, there is not any adverse sign if 0.25 mL is used. If injecting 0.4 mL, a mouse may look inactive for a couple of minutes before getting back to normal and active. We do not like to use more than 0.25 mL. I guess there is no difference with rats. Proportional increase may be made. Please note we recently noticed ionic strength is an additional factor to be considered.

The simple answer is as follwos. You see the physical propety is alsobased on the electronic configuration that in turn depends on number of protons. When alpha or beta decay occurs in any nculeus, its proton number changes and hence the electronic configuration is re-arranged accodingly. Naturaly the physical property also changes

If you do a post filtering or not depends on what you want. Modern PSF reconstructions will enhance your contrast and special resolution (at least they are told to) but it is known that they are more infulenced by noise (e.g. gibbs artefacts). No post filter is good for sharp images but if you use the maximal pixel value (SUVmax) it will be less reproducible than with post filtering. For quantitative measurements post filtering could help. If you do not want post filtering you could use the mean pixel value of an threshold segmentet area or the mean of a fixed area around the max pixel. These values are more stable concerning noise.

TOF reconstructions should reduce noice, but I can't quantivy that reduction.

A common setting for post filtering is a Gaussian filter with 5mm FWHM

In Siemens PET/CTs nowadays monstly the TrueX algorithm (PSF) is used with no post filtering (Allpass). If the "Iterativ" algorithm (without PSF) is used mostly a 5mm FWHM Gaussian filter is used.

GE is using VUE POINT HD or TF(meaning TOF) and you can switch the PSF on and off (SHARP IR on/off). GE uses a Gaussian post filter. I think the recommended FWHM is 6.3mm (entered in the field Cut Off). The Z-Axis filter is a Axial 1:N:1 filter with N=2 (Heavy), N=4 (Standard), N=6 (Light).

For Philips i don't know a common setting. I didn't solve the mysteries of the examination cards till now but i am looking forward that i will somewhen.

The question post filtering or not can't be answert.

The importent thing is that post filtering is changing your measurements. You should be always aware that every change in recon setting or filter setting will influence the outcome. Therefor the choice of settings should be made in accordance with the things (measurements) you want to compare to.

E.g. if you want to monitor therapy response, you must not change the settings between the two studies because you would get values which are not comparable.

greetings

Ivo

From a dutch perspective:

Having been trained in Groningen I also highly recommend UMCG. Siemens mCT and SymbiaT camera's, high production numbers, more than 20 years experience with cyclotron and a very wide scale of types of nuclear imaging.

Depending on what's important to you a good alternative in the Netherlands would be Erasmus Medical Center in Rotterdam for highly new equipment. If expertise in cyclotron-based tracers is relevant stick with UMCG or look at VUMC in Amsterdam. If the dedicated cardiac camera is more relevant you could look at a large peripheral hospital, Isala, in Zwolle. They are the only site in the Netherlands with the GE Discovery NM/CT 570c with CZT solid state detectors.

Nuclear medicine is not really used for quick recovery. It is used in two instances:

1. for diagnostic (SPECT, PET, old fashioned scintigraphy...), and it is used because some of the techniques are simply the best way for identifying a condition

2. for therapy of cancer, when we speak about metabolic radiotherapy, but this is not leading to quick recovery.

For the diagnostic, the doses are higher than in classic radiology, but to the best of my knowledge there is no evidence that SPECT or PET investigations resulted in increased incidence of secondary cancers.

For metabolic radiotherapy, the dose is lower than when using external radiotherapy and even much better localised and targeted, so in fact it saves dose to the patient.

Summing all this, I would say developing a nuclear medicine program saves lives, either through precise diagnostic or through therapy.

Try the http://www.doseinfo-radar.comor Olinda or the older one mirdose 3.1 and you can calculate S

I do not know how is it in other areas, but in Romania the trend is to quit using I-131 in diagnostic procedures exactly because its high half life, compared to other isotopes. For thyroid imaging I-123 is better suited when we speak about half life (only 13 hours, compared to the 8 days of the 131 isotope). The I-131 remains, however, better suited for metabolic radiotherapy due to its beta emission (where yes, Tadeu is right, the doses are high and should be calculated carefully for each procedure - my bad, in my last comment I was thinking only about imaging, and not about metabolic radiotherapy)

Dear Grant

The reason of using direct measurement of the organs after sacrifice is the inaccuracy of imaging methods due to limited ability for scatter correction or attenuation correction. Using standard activity can help but the problem persists

Ramin

Dear Emmanuel. Generally processing software does not allow you to change the information of DICOM files. The suggestion is that you use Matlab and design your own application. I recommend the following functions: "dicominfo" (this reads the file returns), "dicomread" (read the DICOM) and "dicomwrite" (DICOM file type). If you're interested I can send you a function to read the file and one for you to write. Greetings and success.

Dear Mercieca,

you can compare following items in your study:

a-The duration of procedures(under local and/or general anesthesia and total time)

b-patient opinion about them:(painstaking,bothering,unacceptable,acceptable,quite acceptable....e.g)

c-Physician's(user's) opinion about easiness of procedures(difficult,moderate and easy)

d-the cost of procedures..

These factors may give better understanding about the discomfort of each modality...

kind regards

This is the normal range we follow

There are many ways to analyse the hepatic function by semi-quantitative methods. Recently, our research center performed an meta-analysis and you can find several methods in the Table 1 of this study.