[Show abstract][Hide abstract] ABSTRACT: Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor originating in the parafollicular cells (C cells) of the thyroid and secretes both calcitonin and carcino-embryonic antigen (CEA). Genetic and biochemical testing allow early pre-clinical identification of familial forms. Sporadic MTC usually presents as a solitary thyroid nodule; the diagnosis can be made preoperatively by fine-needle aspiration or by calcitonin assay, though it is usually established at the time of surgery. In the diagnostic assessment of MTC, nuclear medicine imaging provides its contribution mainly in the post-operative work-up to detect residual/recurrent tumor. For such purpose a number of radiopharmaceuticals, which take advantage of the specific expression of receptors (the somatostatin analogue (111)In-octreotide), hormone transporters (radiolabelled MIBG) or molecular targets (radiolabelled anti-CEA monoclonal antibodies) by MTC lesions are available; these tracers may be used also for the palliative treatment of advanced MTC. Interesting perspectives for MTC imaging are offered by PET radiopharmaceuticals.
[Show abstract][Hide abstract] ABSTRACT: (1) To identify myocardial perfusion abnormalities in a cohort of patients having coronary artery disease (CAD) risk factors, with either suspected or clinical evidence of ischaemic heart disease (IHD), and with varying degree of coronary artery stenosis. (2) To evaluate the clinical significance of the extent and severity of perfusion abnormalities assessed by myocardial perfusion scintigraphy (MPS) in relation to the anatomical location of coronary stenosis demonstrated by five-vessel selective coronary angiography (SCA).
One hundred and thirty-eight patients (106 male, 32 female) with suspected or clinical evidence of IHD underwent diagnostic evaluation at the Central Hospital of Nicosia, between November 2002 and August 2003. The diagnostic work-up included clinical examination, exercise tolerance test, SCA and myocardial perfusion scintigraphy (MPS) using either Tl chloride or Tc-tetrofosmin.
Based on the results of SCA, patients were divided into five groups on the basis of stenosis as cross-sectional area of coronary artery lumen and its haemodynamic significance, ranging from group 1=less than 50% coronary stenosis to group 5=100% stenosis (occlusion). Nine of 11 (40.9%) patients with angiographically normal coronary arteries (group 1) had moderate inducible reversible ischaemia on MPS and 9/47 (19.1%) patients with insignificant coronary stenosis (less than 75% stenosis=group 2) had fixed perfusion defects, compatible with previous myocardial infarction. The extent of perfusion abnormalities in post-stress MPS patients from group 2 was not found to be statistically significant (P>0.05) when compared to patients belonging to groups 3, 4 and 5. However, the extent of perfusion abnormalities between patients from group 2, when compared to groups 3, 4 and 5 demonstrated significant statistical difference (P<0.05) on post-rest MPS studies. Furthermore, there was no significant statistical correlation between anatomical location of coronary stenosis and severity of perfusion abnormalities in the corresponding myocardial segments.
Patients with CAD risk factors, and coronary arteries with insignificant stenosis on angiography, may demonstrate inducible reversible myocardial ischaemia. This is suggestive of coronary endothelial dysfunction. Patients with insignificant coronary artery stenosis and no previous history of adverse coronary events may demonstrate features of previous myocardial infarction on MPS. The severity of perfusion defects demonstrated by MPS may be independent of the anatomical location of coronary artery stenosis.
Nuclear Medicine Communications 02/2008; 29(2):129-36. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We present a case of a 52-year-old woman with beta-thalassaemia intermedia under investigation for pulmonary hypertension. V/Q scan demonstrated bilateral pulmonary emboli. In addition there was evidence of central, posterior matched defects. CT pulmonary angiogram confirmed the presence of extramedullary haematopoiesis (EMH) in the paravertebral region. Although a few case reports of pulmonary emboli in thalassaemia intermedia have been published, to the best of our knowledge there have been no reports of matched defects caused by extramedullary haematopoiesis. This may be mistaken for enlarged pulmonary arteries, which are also seen in patients with pulmonary hypertension.
Nuclear medicine review. Central & Eastern Europe: journal of Bulgarian, Czech, Macedonian, Polish, Romanian, Russian, Slovak, Yugoslav societies of nuclear medicine and Ukrainian Society of Radiology 02/2008; 11(1):34-6.
[Show abstract][Hide abstract] ABSTRACT: In this case report we describe an unusual appearance seen on a ventilation-perfusion (V/Q) scan in a woman with pulmonary hypertension. Although the pulmonary hypertension was not caused by pulmonary emboli, the V/Q scan suggested several cardiac anomalies which may lead to pulmonary hypertension. Most of the cardiac anomalies, including right-sided aortic arch and right-to-left shunt, can be deduced from careful examination of the V/Q scan. A subsequent cardiac MRI scan confirmed the anomalies.
Nuclear medicine review. Central & Eastern Europe: journal of Bulgarian, Czech, Macedonian, Polish, Romanian, Russian, Slovak, Yugoslav societies of nuclear medicine and Ukrainian Society of Radiology 02/2008; 11(1):37-9.
[Show abstract][Hide abstract] ABSTRACT: In breast cancer, neoadjuvant chemotherapy needs early indication for responsiveness. Tc-99m sestamibi scintimammography provides comprehensive information about the extent of disease including multiple foci in one or both breasts and possible involvement of nodes. In the present case, X-mammography was positive for a suspicious mass in the upper quadrant of the left breast only. On the other hand,Tc-99m Sestamibi scintimammography was able to depict the full extent of the disease, including its spread to the axillary lymph node, and gave useful information on the effectiveness of neoadjuvant chemotherapy. The case reported here demonstrates that Tc-99m sestamibi scintimammography was useful in detecting bilateral breast cancer and could provide additional information on possible axillary lymph node involvement. Furthermore, Tc-99m sestamibi scintimammography was effective in monitoring response to chemotherapy in the studied case.
Nuclear medicine review. Central & Eastern Europe: journal of Bulgarian, Czech, Macedonian, Polish, Romanian, Russian, Slovak, Yugoslav societies of nuclear medicine and Ukrainian Society of Radiology 02/2008; 11(2):70-2.
[Show abstract][Hide abstract] ABSTRACT: We present a case of a 58-year-old woman with papillary carcinoma of the thyroid and elevated thyroglobulin. Whole body 123I scan with SPECT images demonstrated focal uptake in the thoracic spine, reported as bone metastases. Subsequent (18)FDG PET and (99m)Tc HDP bone were normal. MRI and CT scans confirmed the presence of vertebral haemangiomas corresponding to the uptake seen on the (123)I scan. False-positive uptake of (123)I in benign vertebral haemangiomas should be considered in the differential diagnosis of focal vertebral uptake.
Nuclear medicine review. Central & Eastern Europe: journal of Bulgarian, Czech, Macedonian, Polish, Romanian, Russian, Slovak, Yugoslav societies of nuclear medicine and Ukrainian Society of Radiology 02/2008; 11(1):30-3.
[Show abstract][Hide abstract] ABSTRACT: When HCC is diagnosed at an early stage or liver is affected by a solitary metastasis they can be curable by surgical resection, but this may not be feasible when an extensive tumoural involvement is present. In these cases, possible non-surgical therapies include systemic chemotherapy, chemical ablation (ethanol or acetic acid), radiofrequency ablation, microwave ablation, cryotherapy and transarterial chemoembolisation. All the above mentioned treatments have advantages and disadvantages. In the present paper we reported our experience with selective internal radiation therapy (SIRT) of non-operable HCC and metastatic liver using 99Yttrium (99Y) radioactive microspheres, and our data are compared and discussed with those reported in the literature. A MEDLINE-based review of the literature has been made in the period between 1990 and April 2007. Detailed information on patients selection criteria, SIRT procedure, dose calculation, safety and adverse reactions, follow-up schedule, and clinical efficacy are provided. On the basis of our data, in agreement with those of the literature, SIRT has added another effective method for treatment of primary and secondary liver tumours, being successful in a large number of patients in different experiences. Moreover, SIRT is well tolerated and has minimal adverse effects. Despite being regarded as non-curative, it has been associated with improved survival, reduction in tumour marker, and regression in the number and size of lesions. Follow-up with imaging is essential to assess the response to therapy, and in this respect FDG PET has been shown to be more sensitive than CT, particularly in the early stages.
Journal of experimental & clinical cancer research: CR 01/2008; 26(4):561-70. · 1.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The imaging of Bremsstrahlung radiation is performed after hepatic radioembolization to assess the distribution of the injected radioactive material. This review assesses the role of Bremsstrahlung imaging and its relation to the angiographic procedure and technique in hepatic selective internal radiation therapy on 21 patients undergoing this procedure at a single center.
CardioVascular and Interventional Radiology 01/2008; 31(3):643-9. · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recombinant human TSH (rhTSH) has been recently suggested for radioiodine ablation in patients with differentiated thyroid cancer (DTC). To date, studies are still not available about the effectiveness of rhTSH stimulation depending on the age, since serum TSH clearance may be different in younger and in older patients. The aim of this study was to investigate the influence of age to serum TSH levels after rhTSH stimulation and thyroid hormone withdrawal (THW). We retrospectively evaluated two groups of consecutive DTC patients: group 1 (311 patients, age 49.0+/-13.6 years, ranging 15-86) underwent rhTSH stimulation 6-12 months after thyroid ablation (rhTSH-group); group 2 (84 patients, age 46.9+/-13.5 years, ranging 20-77) was followed by THW (THW-group). The influence of age, gender, body mass index and body surface area to serum TSH levels were evaluated in both groups. RhTSH-group: on day 5 (d5), TSH levels were 32.7+/-21.4 microU/ml (range 0.8-136.6). By univariate analysis, d5-TSH was positively related to age (r=0.27, p=0.0001) and no correlations were found with the other parameters. At multivariate analysis, both age and gender (female) were independently associated with d5-TSH levels. THW-group: after thyroid hormone withdrawal, TSH levels were 71.1+/-36.4 microU/ml (range 8.5-200). At univariate analysis, only age was significantly and negatively related to serum TSH levels (r=-0.31, p=0.004). Our data indicate that age and gender seem to positively influence serum TSH levels after rhTSH stimulation. An opposite effect of age on serum TSH levels has been observed after THW. Therapeutic implications ((131)I-treatment) of these findings have to be better investigated in prospective studies.
[Show abstract][Hide abstract] ABSTRACT: Early experience with positron emission tomography (PET) has provided exciting results in the evaluation of a broad spectrum of neoplasms, to include primary adrenal tumors, their metastases and metastatic disease to the adrenal glands. By virtue of the well-recognized propensity of malignancies to preferentially use glycolysis as an important energy source and the stimulation of mechanisms designed to absorb substrate glucose, the glucose analog, [18F]fluorodeoxyglucose, has become a successful radiopharmaceutical in the scintigraphic evaluation of adrenal tumors. Building upon prior experience gained with imaging the adrenal gland, other positron-labeled radiopharmaceuticals are finding their way into clinical use. The 11b-hydroxylase inhibitor, metomidate labeled with 11C has been used to scintigraphically identify tissues of adrenocortical origin, to accurately identify recurrent and metastatic adrenocortical carcinoma and may be useful in assessing the malignant potential of these tumors and predicting survival in afflicted patients. Adrenomedulla imaging with 11C- and 18F-labeled catecholamines and catecholamine analogs draws heavily from the experience gained from predecessor compounds, labeled with single photon emitting isotopes and, in some instances, single photon emission tomography, and has been shown to depict with high efficacy pheochromocytomas, neuroblastomas and other neoplasms of neural crest origin. Additional structural and functional information provided by computed tomography (CT), performed as part of hybrid PET/CT imaging directly complements PET and adds measurable diagnostic value in the evaluation of adrenal tumors.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... 10/2007; 51(3):272-83. · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lymphoma has become one of the most successfully treated malignancies. The success of treatment and long-term prognosis depend on accurate staging in which imaging plays a pivotal role. In addition to staging, imaging assists in the evaluation of early and late response to therapy, detecting disease activity in a residual mass and locating sites of recurrence. The mainstay of imaging remains computed tomography (CT), which has replaced lymphangiography, and staging laparotomy. Magnetic resonance imaging (MRI) has additional value in detecting disease in bone marrow, the musculoskeletal and central nervous system. Recent technical developments in CT and MRI have improved acquisition times and resolution, but the main drawback of cross-sectional imaging techniques is their reliance on size criteria to define disease, with consequent failure to detect disease in small lymph nodes and exclude disease in large, but treated, masses. Diffuse visceral involvement is likewise difficult to detect by both modalities. Functional imaging with nuclear medicine techniques offers an answer to these problems. Imaging with the fluorinated glucose analogue, [18F]FDG positron emission tomography (PET), can detect metabolically active disease by its increased glycolysis that is proportional to mitotic activity. It can separate high from low-grade tumors and aid in prognostication. Recent publications suggest that imaging with [18F]FDG PET should be an important component in staging; assessment of response to therapy and restaging. Like other imaging modalities, it has its own drawbacks including inability to detect very small lesions (<5 mm) and reduced specificity due to increased uptake in metabolically active inflammatory and infective tissues. The new generation of hybrid PET-CT combines anatomical and functional imaging and is considered the state-of-the-art imaging technique for the assessment of lymphoma and other malignancies.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... 10/2007; 51(3):251-9. · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Primary and secondary liver tumours are common malignancies that are being treated more aggressively nowadays than decades ago. Surgery is the most effective method of treatment but is only suitable for a minority of patients with well-defined and easily accessible tumours. Surgical resection is contraindicated in patients with massive involvement of the liver or in cases where the disease involves the confluence of vessels at the porta hepatis. These patients may benefit from a variety of ablative and embolic therapies including selective internal radiation therapy (SIRT) with Yttrium-90 microspheres. SIRT has been introduced in the 1980's but the technology has been refined and made more available only recently. The microspheres are injected directly into the hepatic arteries, through a trans-femoral angiographic approach, and are delivered selectively to tumours due to their preferential blood supply by hepatic arteries. SIRT can therefore target small volumes disease with a higher dose of radiation compared with external-beam radiation and is associated the relatively low toxicity and a good response irrespective of tumor origin. Assessment of response to therapy is best performed with metabolic imaging using (18)F-FDG PET scanning. Although it is not considered as a cure, it has been shown to improve quality of life and prolong survival, with the main cause of death being extra-hepatic spread. The technical and clinical demands of patient selection, treatment planning, administration, and clinical follow-up require an interdisciplinary team willing to work cooperatively to achieve the best result for the patient.
Reviews on Recent Clinical Trials 10/2007; 2(3):212-6.
[Show abstract][Hide abstract] ABSTRACT: In the present study we investigated the role of radio-guided surgery with Iodine-131 (I-131) in a group of 31 patients with differentiated thyroid cancer (DTC) and loco-regional recurrent disease. The principal inclusion criterion for I-131 radio-guided surgery in our protocol was the presence of an I-131 positive loco-regional disease relapse after previous total thyroidectomy and at least 2 ineffective conventional I-131 treatments. The protocol we used consisted of the following steps. Day 0: all patients were hospitalized and received a therapeutic 3.7 GBq (100 mCi) dose of I-131 after thyroid hormone therapy withdrawal in condition of overt hypothyroidism (serum TSH levels>30 microUI/ml). Day 3: a whole body scan following the therapeutic I-131 dose (TxWBS) administration was acquired. Day 5: neck surgery was performed through a wide bilateral neck exploration using a 15-mm collimated gamma probe, measuring the absolute intra-operative counts and calculating the lesion to background (L/B) ratio. Day 7: post-surgery TxWBS was performed using the remaining radioactivity to evaluate the completeness of tumoral lesions extirpation. The final histologic examination showed the presence of 184 metastatic foci; among them, 98 (53.2%) were evident by both TxWBS and gamma probe evaluation, 76 (41.3%) were demonstrated only by gamma probe, and 10 (5.4%) were negative by both TxWBS and gamma probe evaluation. During follow-up (8 months to 4.9 years, mean 2.8 years), DxWBS, serum Tg levels off l-T4, and US showed absence of loco-regional disease in 25 patients (80.6%) while 6 patients had persistent disease. In conclusion, this protocol allowed us to identify neoplastic foci with high sensitivity and specificity, enabling us to remove loco-regional I-131 disease recurrences resistant to previous conventional I-131 therapies. Furthermore, the gamma probe allowed detection of some additional tumoral foci in sclerotic areas or located behind vascular structures that were not visualized at the pre-surgery TxWBS evaluation.
[Show abstract][Hide abstract] ABSTRACT: Imaging somatostatin receptor status with 68Ga labeled peptides has progressed rapidly over the last several years. It has generated great interest, and stimulated further research into the development of DOTA-derivative peptides. It has expanded our knowledge of receptor imaging and enhanced our appreciation of the difference between receptor-based and metabolic imaging, as well as more in-depth evaluation of tumor biology. The availability of the 68Ge/68Ga generator provides an attractive alternative to cyclotron-based positron-emitters, especially if kit-based radiopharmaceutical formulations based upon 68Ga are developed in the future.
The quarterly journal of nuclear medicine and molecular imaging: official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of... 10/2007; 51(3):244-50. · 1.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Small-animal imaging has become a relevant research field in pre-clinical oncology. In particular, metabolic information provided by small-animal positron emission tomography (PET) is very useful to closely monitor tumour growth and assess therapy response in murine models of human disease. There are various murine models for human lung adenocarcinoma, but those for squamous cell lung carcinoma, the most common form of human cancer, are lacking.
To assess the feasibility of 18F-FDG small-animal PET to monitor tumour growth in a chemically induced model of squamous cell carcinoma of the lung.
Nineteen NIH Swiss mice were skin painted by N-nitroso-tris-chloroethylurea (NTCU) twice a week, with a 3 day interval, for 8 months and 10 NIH Swiss mice skin painted with NTCU solvent (acetone) were used as controls. 18F-FDG PET was performed under sevofluorane anaesthesia and oxygen supplementation at 2, 4, 6 and 8 months from initial treatment. Images were assessed by visual analysis and semi-quantitatively. When a diffuse distribution of tumour was noted, the mean of the counts/pixel measured at three lung levels, corrected for the effective dose injected and for decay, was used for comparison between mutagen-painted and control mice. Pathological evaluation was carried out from the time of the first positive PET results in a subgroup of the whole population to assess correlation with PET findings. Small animal CT was performed at 8 months in another subgroup.
In both terms of visual analysis and measurement of total lung activity, 18F-FDG PET at 2 and 4 months from initial treatment were comparable in mutagen-painted and controls. At 6 months, PET images showed a faint and diffuse uptake over both lung fields in mutagen-painted mice with multiple focal areas of increased tracer uptake that merged into confluent masses at 8 months and seriously subverting lung architecture on computed tomography. Total lung activity was significantly higher in mutagen-painted versus control mice at 6 (P=0.00000668) and 8 months (P=0.00000043) from initial treatment and paralleled the progressive lung involvement and histological severity.
18F-FDG PET may be useful in the assessment of this chemically induced murine model of lung squamous cells carcinoma. The total lung activity may be used as a measure of tumour metabolic activity of the tumour-bearing animals and may be useful in new drug testing studies.
Nuclear Medicine Communications 09/2007; 28(8):647-52. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To (a) assess the accuracy of 18F-FDG PET/CT in distinguishing malignant from benign pelvic lesions, compared to transvaginal ultrasonography (TVUS) and (b) to establish the role of whole-body 18F-FDG PET/CT, compared to contrast enhanced computed tomography (CT), in staging patients with ovarian cancer.
Fifty consecutive patients with a pelvic lesion, already scheduled for surgery on the basis of physical examination, TVUS, and serum Ca125 levels, were enrolled in the study. Patients' age ranged between 23 and 89 years (mean 64). All patients underwent TVUS including a colour Doppler study followed by a thorax and abdominal CT scan, and whole-body 18F-FDG PET/CT within 2 weeks prior to surgery. Histological findings obtained at surgery were taken as the 'gold standard' to compare 18F-FDG PET/CT and TVUS, and 18F-FDG PET/CT vs. CT. When tissue analysis showed ovarian cancer, the accuracy of 18F-FDG PET/CT and CT were compared for the purpose of obtaining a precise staging.
At surgery, the ovarian lesions were malignant in 32/50 patients (64%) and benign in the remaining 18/50 patients (36%). The sensitivity, specificity, NPV, PPV and accuracy of 18F-FDG PET/CT were 87%, 100%, 81%, 100% and 92%, respectively, compared with 90%, 61%, 78%, 80% and 80%, respectively, for TVUS. In staging ovarian cancer, 18F-FDG PET/CT results were concordant with final pathological staging in 22/32 (69%) patients while CT results were concordant in 17/32 (53%) patients. CT incorrectly down-staged four out of six stage IV patients by missing distant metastasis in the liver, pleura, mediastinum, and in left supraclavicular lymph nodes, which were correctly detected by 18F-FDG PET/CT.
PET/CT with 18F-FDG provides additional value to TVUS for the differential diagnosis of benign from malignant pelvic lesions, and to CT for the staging of ovarian cancer patients.
Nuclear Medicine Communications 09/2007; 28(8):589-95. · 1.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 3'-deoxy-3'-[18F]fluorothymidine positron emission tomography ([18F]FLT-PET) has been developed for imaging cell proliferation and findings correlate strongly with the Ki-67 labelling index in breast cancer. The aims of this pilot study were to define objective criteria for [18F]FLT response and to examine whether [18F]FLT-PET can be used to quantify early response of breast cancer to chemotherapy.
Seventeen discrete lesions in 13 patients with stage II-IV breast cancer were scanned prior to and at 1 week after treatment with combination 5-fluorouracil, epirubicin and cyclophosphamide (FEC) chemotherapy. The uptake at 90 min (SUV90) and irreversible trapping (Ki) of [18F]FLT were calculated for each tumour. The reproducibility of [18F]FLT-PET was determined in nine discrete lesions from eight patients who were scanned twice before chemotherapy. Clinical response was assessed at 60 days after commencing FEC.
All tumours showed [18F]FLT uptake and this was reproducible in serial measurements (SD of mean % difference=10.5% and 15.1%, for SUV90 and Ki, respectively; test-retest correlation coefficient>or=0.97). Six patients had a significant clinical response (complete or partial) at day 60; these patients also had a significant reduction in [18F]FLT uptake at 1 week. Decreases in Ki and SUV90 at 1 week discriminated between clinical response and stable disease (p=0.022 for both parameters). In three patients with multiple lesions there was a mixed [18F]FLT response in primary tumours and metastases. [18F]FLT response generally preceded tumour size changes.
[18F]FLT-PET can detect changes in breast cancer proliferation at 1 week after FEC chemotherapy.
European journal of nuclear medicine and molecular imaging 09/2007; 34(9):1339-47. · 5.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report here our experience in a larger series of differentiated thyroid cancer (DTC) patients who had been treated by (99m)Tc-sestamibi radio-guided surgery (RGS) for (131)Iodine ((131)I)-negative loco-regional recurrent disease.
Fifty-eight patients with loco-regional (131)I-negative recurrent disease from DTC were studied with (99m)Tc-sestamibi directed RGS using a hand-held 11-mm gamma probe as an intra-operative detector. Patients were selected for RGS on the basis of (a) progressive increase of serum thyroglobulin (Tg) levels after first treatment during follow-up, (b) negative high dose (100 mCi, 3.7 GBq) (131)I whole-body scan, and (c) positive pre-operative (99m)Tc-sestamibi scintigraphy for the presence of loco-regional recurrent disease. There were 41 papillary (1 "tall" cell variant), 13 follicular and 4 Hürthle cells tumours. In 14 patients thyroid cancer recurred in the thyroid bed while cervical lymph node metastases were found in 37 patients, and 7 patients had recurrent disease both in the thyroid bed and in cervical lymph nodes.
At bilateral neck exploration, 147 metastatic foci ranging from 4 mm to 51 mm in largest diameter (mean tumour diameter=17.3+/-9.5mm) were removed. Eighty-five of them (58%) had been pre-operatively identified at (99m)Tc-sestamibi scintigraphy. After RGS, serum Tg levels normalised in 43 of 58 patients (serum Tg<2 ng/ml--they were considered disease-free), serum Tg remained slightly increased in 12 patients without evidence of metastatic disease at scintigraphic and radiologic imaging (serum Tg<10 ng/mg--they were considered living with microscopic disease), while serum Tg significantly increased up to values>900 ng/ml in 3 patients who developed lung metastases. The mean lesion to background (99m)Tc-sestamibi uptake ratios decreased in all 58 patients (p<0.0001). Post-surgical follow-up ranged 6-72 months (mean+/-SD=29.6+/-13.5 months). The operating surgeon assessed RGS as very useful in 14 patients in whom metastatic foci were embedded in fibrotic tissues or located behind blood vessels, useful in 22 patients, moderately useful 17 patients and not useful in 5 patients.
Our data suggest that a (99m)Tc-sestamibi intra-operative gamma probe can be used to identify and guide resection of recurrent loco-regional tumour in DTC patients with (131)I-negative loco-regional metastatic foci.
European Journal of Surgical Oncology 09/2007; 33(7):902-6. · 2.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Small-animal PET is acquiring importance for pre-clinical studies. In rodents, radiotracers are usually administrated via the tail vein. This procedure can be very difficult and time-consuming as soft tissue extravasations are very frequent and tail scars can prevent repeated injections after initial failure. The aim of our study was to compare the retro-orbital (RO) versus tail vein intravenous (i.v.) administration of (18)F-FDG and (11)C-choline in mice for small-animal PET studies.
We evaluated four healthy female ICR CD1 mice according to the following protocol. Day 1: each animal underwent an i.v. injection of 28 MBq of (11)C-choline. PET scan was performed after 10 min and 40 min. Day 2: each animal received an RO injection of 28 MBq of (11)C-choline. A PET scan was performed after 10 min and 40 min. Day 3: each animal received an i.v. injection of 28 MBq of (18)F-FDG. A PET scan was performed after 60 min and 120 min. Day 4: each animal received an RO injection of 28 MBq of (18)F-FDG. A PET scan was performed after 60 min and 120 min. Administration and image acquisition were performed under gas anaesthesia. For FDG studies the animals fasted for 2 h and were kept asleep for 20-30 min after injection, to avoid muscular uptake. Images were reconstructed with 2-D OSEM. For each scan ROIs were drawn on liver, kidneys, lung, brain, heart brown fat and muscles, and the SUV was calculated. We finally compared choline i.v. standard acquisition to choline RO standard acquisition; choline i.v. delayed acquisition to choline RO delayed acquisition; FDG i.v. standard acquisition to FDG RO standard acquisition; FDG i.v. delayed acquisition to FDG RO delayed acquisition.
The RO injections for both (18)F-FDG and (11)C-choline were comparable to the intravenous injection of F-FDG for the standard and delayed acquisitions.
The RO administration in mice represents a technical advantage over intravenous administration in being an easier and faster procedure. However, its use requires high specific activity while its value in peptides and other receptor-specific radiopharmaceuticals needs further assessment.
Nuclear Medicine Communications 08/2007; 28(7):547-53. · 1.38 Impact Factor