Reinhold Graf

Publications of Reinhold Graf

• Contribution of (68)Ga-DOTATOC PET/CT to Target Volume Delineation of Skull Base Meningiomas Treated With Stereotactic Radiation Therapy.

  Authors: Reinhold Graf, Fonyuy Nyuyki, Ingo G Steffen, Roger Michel, Daniel Fahdt, Peter Wust, Winfried Brenner, Volker Budach, Reinhard Wurm, Michail Plotkin

  International journal of radiation oncology, biology, physics. 05/2012;

  PURPOSE: To investigate the potential impact of (68)Ga-DOTATOC positron emission tomography ((68)Ga-DOTATOC-PET) in addition to magnetic resonance imaging (MRI) and computed tomography (CT) forPURPOSE: To investigate the potential impact of (68)Ga-DOTATOC positron emission tomography ((68)Ga-DOTATOC-PET) in addition to magnetic resonance imaging (MRI) and computed tomography (CT) for retrospectively assessing the gross tumor volume (GTV) delineation of meningiomas of the skull base in patients treated with fractionated stereotactic radiation therapy (FSRT). METHODS AND MATERIALS: The study population consisted of 48 patients with 54 skull base meningiomas, previously treated with FSRT. After scans were coregistered, the GTVs were first delineated with MRI and CT data (GTV(MRI/CT)) and then by PET (GTV(PET)) data. The overlapping regions of both datasets resulted in the GTV(common), which was enlarged to the GTV(final) by adding volumes defined by only one of the complementary modalities (GTV(MRI/CT-added) or GTV(PET-added)). We then evaluated the contribution of conventional imaging modalities (MRI, CT) and (68)Ga-DOTATOC-PET to the GTV(final), which was used for planning purposes. RESULTS: Forty-eight of the 54 skull base lesions in 45 patients showed increased (68)Ga-DOTATOC uptake and were further analyzed. The mean GTV(MRI/CT) and GTV(PET) were approximately 21 cm(3) and 25 cm(3), with a common volume of approximately 15 cm(3). PET contributed a mean additional GTV of approximately 1.5 cm(3) to the common volume (16% ± 34% of the GTV(common)). Approximately 4.5 cm(3) of the GTV(MRI/CT) was excluded from the contribution to the common volume. The resulting mean GTV(final) was significantly smaller than both the GTV(MRI/CT) and the GTV(PET). Compared with the initial GTV(MRI/CT), the addition of (68)Ga-DOTATOC-PET resulted in more than 10% modification of the size of the GTV(final) in 32 (67%) meningiomas CONCLUSIONS: (68)Ga-DOTATOC-PET/CT seems to improve the target volume delineation in skull base meningiomas, often leading to a reduction of GTV compared with results from conventional imaging (MRI and CT).

• Interfraction rotation of the prostate as evaluated by kilovoltage X-ray fiducial marker imaging in intensity-modulated radiotherapy of localized prostate cancer.

  Authors: Reinhold Graf, Dirk Boehmer, Volker Budach, Peter Wust

  Medical dosimetry : official journal of the American Association of Medical Dosimetrists. 04/2012;

  To quantify the daily rotation of the prostate during a radiotherapy course using stereoscopic kilovoltage (kV) x-ray imaging and intraprostatic fiducials for localization and positioning correction.To quantify the daily rotation of the prostate during a radiotherapy course using stereoscopic kilovoltage (kV) x-ray imaging and intraprostatic fiducials for localization and positioning correction. From 2005 to 2009, radio-opaque fiducial markers were inserted into 38 patients via perineum into the prostate. The ExacTrac/Novalis Body X-ray 6-day image acquisition system (ET/NB; BrainLab AG, Feldkirchen, Germany) was used to determine and correct the target position. During the first period in 10 patients we recorded all rotation errors but used only Y (table) for correction. For the next 28 patients we used for correction all rotational coordinates, i.e., in addition Z (superior-inferior [SI] or roll) and X (left-right [LR] or tilt/pitch) according to the fiducial marker position by use of the Robotic Tilt Module and Varian Exact Couch. Rotation correction was applied above a threshold of 1° displacement. The systematic and random errors were specified. Overall, 993 software-assisted rotational corrections were performed. The interfraction rotation errors of the prostate as assessed from the radiodense surrogate markers around the three axes Y, Z, and X were on average 0.09, -0.52, and -0.01° with standard deviations of 2.01, 2.30, and 3.95°, respectively. The systematic uncertainty per patient for prostate rotation was estimated with 2.30, 1.56, and 4.13° and the mean random components with 1.81, 2.02, and 3.09°. The largest rotational errors occurred around the X-axis (pitch), but without preferring a certain orientation. Although the error around Z (roll) can be compensated on average by a transformation with 4 coordinates, a significant error around X remains and advocates the full correction with 6 coordinates. Rotational errors as assessed via daily stereoscopic online imaging are significant and dominate around X. Rotation possibly degrades the dosimetric coverage of the target volume and may require suitable strategies for correction.

• Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy - a case series.

  Authors: Reinhold Graf, Michail Plotkin, Ingo G Steffen, Reinhard Wurm, Peter Wust, Winfried Brenner, Volker Budach, Harun Badakhshi

  Head & face medicine. 01/2012; 8(1):1.

  ABSTRACT: Magnetic resonance imaging (MRI) and computed tomography (CT) with 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) were compared retrospectively for their ability to delineateABSTRACT: Magnetic resonance imaging (MRI) and computed tomography (CT) with 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy. Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and 68Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) or PET, and were evaluated further. The respective findings were reviewed independently, analyzed with respect to correlations, and compared with each other. Within the study group, SB transgression was associated with bony changes visible by CT in 14 patients (81%). Tumorous changes of the foramen ovale and rotundum were evident in 13 and 8 cases, respectively, which were accompanied by skeletal muscular invasion in 8 lesions. We analysed six designated anatomical sites of the SB in each of the 16 patients. Of the 96 sites, 42 had infiltration that was delineable by MRI/CT and PET in 35 cases and by PET only in 7 cases. The mean infracranial volume that was delineable in PET was 10.1 ± 10.6 cm3, which was somewhat larger than the volume detectable in MRI/CT (8.4 ± 7.9 cm3). 68Ga-DOTATOC-PET allows detection and assessment of the extent of infracranial meningioma invasion. This method seems to be useful for planning fractionated stereotactic radiation when used in addition to conventional imaging modalities that are often inconclusive in the SB region.

• Residual translational and rotational errors after kV X-ray image-guided correction of prostate location using implanted fiducials.

  Authors: Reinhold Graf, Dirk Boehmer, Volker Budach, Peter Wust

  Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]. 09/2010; 186(10):544-50.

  To evaluate the residual errors and required safety margins after stereoscopic kilovoltage (kV) X-ray target localization of the prostate in image-guided radiotherapy (IGRT) using internalTo evaluate the residual errors and required safety margins after stereoscopic kilovoltage (kV) X-ray target localization of the prostate in image-guided radiotherapy (IGRT) using internal fiducials. Radiopaque fiducial markers (FMs) have been inserted into the prostate in a cohort of 33 patients. The ExacTrac/Novalis Body™ X-ray 6d image acquisition system (BrainLAB AG, Feldkirchen, Germany) was used. Corrections were performed in left-right (LR), anterior-posterior (AP), and superior-inferior (SI) direction. Rotational errors around LR (x-axis), AP (y) and SI (z) have been recorded for the first series of nine patients, and since 2007 for the subsequent 24 patients in addition corrected in each fraction by using the Robotic Tilt Module™ and Varian Exact Couch™. After positioning, a second set of X-ray images was acquired for verification purposes. Residual errors were registered and again corrected. Standard deviations (SD) of residual translational random errors in LR, AP, and SI coordinates were 1.3, 1.7, and 2.2 mm. Residual random rotation errors were found for lateral (around x, tilt), vertical (around y, table), and longitudinal (around z, roll) and of 3.2°, 1.8°, and 1.5°. Planning target volume (PTV)-clinical target volume (CTV) margins were calculated in LR, AP, and SI direction to 2.3, 3.0, and 3.7 mm. After a second repositioning, the margins could be reduced to 1.8, 2.1, and 1.8 mm. On the basis of the residual setup error measurements, the margin required after one to two online X-ray corrections for the patients enrolled in this study would be at minimum 2 mm. The contribution of intrafractional motion to residual random errors has to be evaluated.

• Heterotopic Ossification And Functional Status Of The Hip Joint Following Total Hip Arthroplasty And Postoperative Prophylactic Irradiation

  Authors: Dalia AM Ahmad†, Chie Hee Cho, Boris Pantchechnikov†, Wolfgang Noack, Volker Budach, Peter Wust, Reinhold Graf

  Journal of Orthopaedics. 01/2010;

  Background and purpose: Heterotopic ossification (HO) is one of the major complications following total hip arthroplasty (THA). The aim of this study is to evaluate HO and functional status (FS) ofBackground and purpose: Heterotopic ossification (HO) is one of the major complications following total hip arthroplasty (THA). The aim of this study is to evaluate HO and functional status (FS) of the hip joint 5 years after THA and prophylactic postoperative irradiation with a single dose of 7 Gy. Methods: We analyzed a random sample of 100 patients 5 years after THA and postoperative radiotherapy with a single dose of 7 Gy. Brooker score (BS) was used to classify the radiographic signs of HO and Harris-Hip Score (HHS) to assess the FS of the hip joint. The range of motion was assessed in all directions and was measured in degrees.Results: 51% of patients had radiographic evidence of HO; mean HHS 84.8 ± 16.5 points. Height (p = 0.025) and weight (p = 0.008) correlated positively with the extent of HO. Men developed significantly higher BS than women (p = 0.009). Duration of surgery correlated with HHS (p = 0.026). In the category BS 0 vs. BS 1 for the range of motion in degrees, there were significant correlations for flexion (p = 0.05), adduction (p = 0.03) and sum of motions (p = 0.04) in favour of BS 0. In the category BS 0 vs. BS 1,2,3,4, there were significant correlations for flexion (p = 0.07), adduction (p = 0.05), and sum of motions (p = 0.05) in favour of BS 0. For the range of motion in points (HHS), no significant correlations with all categories of HO were found. Conclusion: Mild HO of BS 1 can deteriorate the range of motion after THA significantly. The sum of motion in degrees has been proved a more sensitive tool for assessing the clinical outcome than the range of motion in points according to HHS or the total HHS.

• Potential impact of (68)Ga-DOTATOC PET/CT on stereotactic radiotherapy planning of meningiomas.

  Authors: Fonyuy Nyuyki, Michail Plotkin, Reinhold Graf, Roger Michel, Ingo Steffen, Timm Denecke, Lilli Geworski, Daniel Fahdt, Winfried Brenner, Reinhard Wurm

  European journal of nuclear medicine and molecular imaging. 09/2009;

  PURPOSE: Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planningPURPOSE: Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planning radiotherapy. We investigated the input of (68)Ga-DOTATOC-PET/CT on the definition of the "gross tumour volume" (GTV) in meningiomas, in order to assess the potential value of this method. METHODS: Prior to radiotherapy, 42 patients with meningiomas (26 f, 16 m, mean age 55) underwent MRI and (68)Ga-DOTATOC-PET/CT examinations. History: operated n = 24, radiotherapy n = 1, operation and radiotherapy n = 8, no treatment n = 9. PET/CT and MRI data were co-registered using a BrainLAB workstation. For comparison, the GTV was defined first under consideration of CT and MRI data, then using PET data. RESULTS: 3/42 patients were excluded from the analysis (two with negative PET results, one with an extensive tumour, not precisely delineable by MRI or PET/CT). The average GTV(CT/MRI) was 22(+/-19)cm(3); GTV(PET) was 23(+/-20)cm(3). Additional GTV, obtained as a result of PET was 9(+/-10)cm(3) and was observed in patients with osseous infiltration. In some pre-treated patients there were intratumoural areas (as identified in CT/MRI) without SR-expression (7(+/-11)cm(3)). Common GTV as obtained by both CT/MRI and PET was 15(+/-14)cm(3). The mean bi-directional difference between the GTV(CT/MRI) and GTV(PET) accounted to 16(+/-15)cm(3) (93%, p < 0.001). In a subgroup of seven patients with multiple meningiomas, PET showed a total of 19 lesions; nine of them were not recognizable by CT or MRI. CONCLUSION: (68)Ga-DOTATOC-PET enables delineation of SR-positive meningiomas and delivers additional information to both CT and MRI regarding the planning of stereotactic radiotherapy. The acquisition on a PET/CT scanner helps to estimate the relation of PET findings to anatomical structures and is especially useful for detection of osseous infiltration. (68)Ga-DOTATOC-PET also allows detection of additional lesions in patients with multiple meningiomas.

• Potentials of on-line repositioning based on implanted fiducial markers and electronic portal imaging in prostate cancer radiotherapy.

  Authors: Reinhold Graf, Peter Wust, Volker Budach, Dirk Bohmer

  Radiation oncology (London, England). 05/2009; 4(1):13.

  ABSTRACT: BACKGROUND: To evaluate the benefit of an on-line correction protocol based on implanted markers and weekly portal imaging in external beam radiotherapy of prostate cancer. To compare theABSTRACT: BACKGROUND: To evaluate the benefit of an on-line correction protocol based on implanted markers and weekly portal imaging in external beam radiotherapy of prostate cancer. To compare the use of bony anatomy versus implanted markers for calculation of setup-error plus/minus prostate movement. To estimate the error reduction (and the corresponding margin reduction) by reducing the total error to 3 mm once a week, three times per week or every treatment day. METHODS: 23 patients had three to five, 2.5 mm diameter spherical gold markers transrectally inserted into the prostate before radiotherapy. Verification and correction of treatment position by analysis of orthogonal portal images was performed on a weekly basis. We registered with respect to the bony contours (setup error) and to the marker position (prostate motion) and determined the total error. The systematic and random errors are specified. Positioning correction was applied with a threshold of 5 mm displacement. RESULTS: The systematic error (1 standard deviation, SD) in left-right (LR), superior-inferior (SI) and anterior-posterior (AP) direction contributes for the setup 1.6 mm, 2.1 mm and 2.4 mm and for prostate motion 1.1 mm, 1.9 mm and 2.3 mm. The ran-dom error (1 SD) in LR, SI and AP direction amounts for the setup 2.3 mm, 2.7 mm and 2.7 mm and for motion 1.4 mm, 2.3 mm and 2.7 mm. The resulting total error suggests margins of 7.0 mm (LR), 9.5 mm (SI) and 9.5 mm (AP) between clinical target volume (CTV) and planning target volume (PTV). After correction once a week the margins were lowered to 6.7, 8.2 and 8.7 mm and furthermore down to 4.9, 5.1 and 4.8 mm after correcting every treatment day. CONCLUSIONS: Prostate movement relative to adjacent bony anatomy is significant and contributes substantially to the target position variability. Performing on-line setup correction using implanted radioopaque markers and megavoltage radiography results in reduced treatment margins depending on the online imaging protocol (once a week or more frequently).

• Postimplantation analysis enables improvement of dose-volume histograms and reduction of toxicity for permanent seed implantation.

  Authors: Peter Wust, Johanna Postrach, Frank Kahmann, Thomas Henkel, Reinhold Graf, Chie Hee Cho, Volker Budach, Dirk Böhmer

  International journal of radiation oncology, biology, physics. 06/2008; 71(1):28-35.

  PURPOSE: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. PATIENTS AND METHODS: We evaluated 197 questionnaires completed byPURPOSE: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. PATIENTS AND METHODS: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis. The index doses and volumes of the dose-volume histograms (DVHs) were determined and categorized with respect to the date of implantation. Differences in symptom scores relative to pretherapeutic status were analyzed with regard to follow-up times and DVH descriptors. Acute and subacute toxicities in a control group of 117 patients from an earlier study (June 1999 to September 2001) by Wust et al. (2004) were compared with a matched subgroup from this study equaling 110 patients treated between October 2001 and August 2003. RESULTS: Improved performance, identifying a characteristic time dependency of DVH parameters (after implantation) and toxicity scores, was demonstrated. Although coverage (volume covered by 100% of the prescription dose of the prostate) increased slightly, high-dose regions decreased with the growing experience of the users. Improvement in the DVH and a reduction of toxicities were found in the patient group implanted in the later period. A decline in symptoms with follow-up time counteracts this gain of experience and must be considered. Urinary and sexual discomfort was enhanced by dose heterogeneities (e.g., dose covering 10% of the prostate volume, volume covered by 200% of prescription dose). In contrast, rectal toxicities correlated with exposed rectal volumes, especially the rectal volume covered by 100% of the prescription dose. CONCLUSION: The typical side effects occurring after permanent seed implantation can be reduced by improving the dose distributions. An improvement in dose distributions and a reduction of toxicities were identified with elapsed time between 1999 and 2003.

• A non-randomised, single-centre comparison of induction chemotherapy followed by radiochemotherapy versus concomitant chemotherapy with hyperfractionated radiotherapy in inoperable head and neck carcinomas.

  Authors: Reinhold Graf, Bert Hildebrandt, Wolfgang Tilly, Hanno Riess, Roland Felix, Volker Budach, Peter Wust

  BMC cancer. 01/2006; 6:30.

  BACKGROUND: The application of induction chemotherapy failed to provide a consistent benefit for local control in primary treatment of advanced head and neck (H&N) cancers. The aim of this study wasBACKGROUND: The application of induction chemotherapy failed to provide a consistent benefit for local control in primary treatment of advanced head and neck (H&N) cancers. The aim of this study was to compare the results of concomitant application of radiochemotherapy for treating locally advanced head-and-neck carcinoma in comparison with the former standard of sequential radiochemotherapy. METHODS: Between 1987 and 1995 we treated 122 patients with unresectable (stage IV head and neck) cancer by two different protocols. The sequential protocol (SEQ; 1987-1992) started with two courses of neoadjuvant chemotherapy (cisplatin [CDDP] + 120-h continuous infusions (c.i.) of folinic acid [FA] and 5-fluorouracil [5-FU]), followed by a course of radiochemotherapy using conventional fractionation up to 70 Gy. The concomitant protocol (CON; since 1993) combined two courses of FA/5-FU c.i. plus mitomycin (MMC) concomitantly with a course of radiotherapy up to 30 Gy in conventional fractionation, followed by a hyperfractionated course up to 72 Gy. Results from the two groups were compared. RESULTS: Patient and tumor characteristics were balanced (SEQ = 70, CON = 52 pts.). Mean radiation dose achieved (65.3 Gy vs. 71.6 Gy, p = 0.00), response rates (67 vs. 90 % for primary, p = 0.02), and local control (LC; 17.6% vs. 41%, p = 0.03), were significantly lower in the SEQ group, revealing a trend towards lower disease-specific (DSS; 19.8% vs. 31.4%, p = 0.08) and overall (14.7% vs. 23.7%, p = 0.11) survival rates after 5 years. Mucositis grades III and IV prevailed in the CON group (54% versus 44%). Late toxicity was similar in both groups. CONCLUSION: Concurrent chemotherapy seemed more effective in treating head and neck tumors than induction chemotherapy followed by chemoradiation, resulting in better local control and a trend towards improved survival.

• Dose-escalated conformal radiotherapy of glioblastomas -- results of a retrospective comparison applying radiation doses of 60 and 70 Gy.

  Authors: Reinhold Graf, Bert Hildebrandt, Wolfgang Tilly, Geetha Sreenivasa, Renate Ullrich, Roland Felix, Peter Wust, Klaus Maier-Hauff

  Onkologie. 06/2005; 28(6-7):325-30.

  BACKGROUND: Dose escalated three-dimensional conformal radiotherapy with 70 Gy against glioblastomas was compared retrospectively with the standard scheme of 60 Gy using 2-D-planning. PATIENTS ANDBACKGROUND: Dose escalated three-dimensional conformal radiotherapy with 70 Gy against glioblastomas was compared retrospectively with the standard scheme of 60 Gy using 2-D-planning. PATIENTS AND METHODS: In the period from 1994 to 1998, a series of 135 patients with glioblastomas was treated by surgery and postoperative radiotherapy. A conversion from 2-D into 3-D-planning was carried out in 4/1996. The prescribed total dose for the first 65 patients was 60 Gy (group 60). A boost up to 70 Gy was added for the remaining 70 patients (group 70). RESULTS: The median survival time was 8.0 months for group 60 and 8.3 months for group 70. A dependency on the applied dose range was found. The median survival time was 3 months for patients who received a radiation dose of 55 Gy or less, 8.6 months for doses between 56 and 65 Gy, and 9.6 months for patients with a dose between 66 and 75 Gy (p < 0.01). In a multivariate analysis only the performance status maintained significance (p = 0.02) as a prognostic factor, while the dose range reached borderline significance (p = 0.09). CONCLUSION: No statistically significant survival prolongation was reached despite a dose escalation to 70 Gy.

• Regional hyperthermia in conjunction with definitive radiotherapy against recurrent or locally advanced prostate cancer T3 pN0 M0.

  Authors: Wolfgang Tilly, Johanna Gellermann, Reinhold Graf, Bert Hildebrandt, Lothar Weissbach, Volker Budach, Roland Felix, Peter Wust

  Strahlentherapie und Onkologie : Organ der Deutschen Röntgengesellschaft ... [et al]. 02/2005; 181(1):35-41.

  BACKGROUND AND PURPOSE: Since long-term results of the standard treatment of locally advanced or recurrent prostatic carcinoma are unsatisfactory, the role for additional regional hyperthermia wasBACKGROUND AND PURPOSE: Since long-term results of the standard treatment of locally advanced or recurrent prostatic carcinoma are unsatisfactory, the role for additional regional hyperthermia was evaluated in a phase I/II study. PATIENTS AND METHODS: From 08/1996 to 03/2000, 22 patients were treated by a standard irradiation regimen (68.4 Gy) in combination with regional hyperthermia (weekly, five to six times), and five of 22 patients received short-term (neoadjuvant) hormonal treatment. Of these, 15 patients had primary prostatic carcinoma T3 pN0 M0 and seven a histologically confirmed local recurrence after radical prostatectomy. Feasibility of hyperthermia, and acute/late toxicity as well as long-term follow-up (prostate- specific antigen [PSA] control, overall survival) were analyzed. Clinical endpoints were correlated with thermal parameters. RESULTS: Mean maximum temperatures along the urethra of 41.4 degrees C (41.0 degrees C for the recurrences), and mean T(90) values of 40.7 degrees C could be achieved. Severe acute toxicity of grade 3 occurred at the rectum in three, at the urethra in four, at the intestine in one, and a burn induced by hyperthermia in one of 22 patients. Late toxicity was only observed rectally in one patient (grade 3) and at the urethra in two patients (grade 2). There was no correlation between thermal parameters and any toxicity. The survival curves showed a PSA control for primary prostatic carcinoma > 50% after 6 years, but no long-term PSA control for the recurrences. Overall survival after 6 years was 95% for primary carcinoma, and 60% for the recurrences. There was a clear correlation between higher temperatures or thermal doses with long-term PSA control. CONCLUSION: Regional hyperthermia might be a low-toxicity approach to increase PSA control of common treatment schedules. Further evaluation, in particular employing improved hyperthermia technology, is worthwhile.

• Clinical and physical determinants for toxicity of 125-I seed prostate brachytherapy.

  Authors: Peter Wust, Daniel Wischka von Borczyskowski, Thomas Henkel, Christian Rosner, Reinhold Graf, Wolfgang Tilly, Volker Budach, Roland Felix, Frank Kahmann

  Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 10/2004; 73(1):39-48.

  BACKGROUND AND PURPOSE: To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to workBACKGROUND AND PURPOSE: To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to work out strategies for improvement. PATIENTS AND METHODS: A group of 174 patients with localised prostate cancer was treated with permanent seed implantation between 1999 and 2001, either alone (140 patients) or in combination with external radiotherapy (34 patients). For the majority (114/174, i.e. 66%) a CT was performed four weeks after implantation and analysed in the planning system VariSeed. In the postimplant analysis, dosimetric descriptors (doses, volumes) were determined for the prostate and rectum and compared with the intraoperative values. In addition, a questionnaire was sent to all patients to assess and quantify acute and chronic toxicity (urinary, rectal, sexual) and the impact on subjective acceptance and quality of life (return rate of questionnaires 83%). The derived score changes were correlated with clinical and dosimetric factors. RESULTS: In the mono-brachytherapy group 14% (16/140) required a bladder catheter, of them 8% (9/140) with a manifest urinary obstruction. Long-term rectal toxicity (<5%) and impairment of potency (<30%) are moderate and obviously below other treatment options. Urinary toxicity is dominant with an overall long-term dysuria up to 30% (at a mean observation interval of ten months), and a significant trend to decline with follow-up time. Conversely, the erectile function tends to deteriorate with follow-up time. Nevertheless, quality of life is not significantly reduced and acceptance is high. Our analysis suggests that the main factor for urinary toxicity and impaired erectile function is the dose load to larger portions of the prostate (D(50)>240 Gy), which appears to be attributed to unnecessarily high numbers of seeds (for a fixed activity per seed) and needles. The rectal toxicity is correlated with the high dose regions in the rectum (>/=145 Gy). Urinary toxicity is lower for combined-brachytherapy, while rectal toxicity and impairment of potency are slightly higher. CONCLUSIONS: Toxicity spectrum and quality of life after permanent seed implantation for early prostate cancer are acceptable for nearly all patients (98%). To further improve tolerance we should attempt to achieve a better dose homogeneity, i.e. by reducing D(50). Therefore, special attention should be given to D(50) during the real-time planning process. The necessity of more homogeneous dose distributions might imply a reduction of the activity per seed, e.g. from 0.7 mCi down to 0.6 mCi.