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PO-164 SEED MIGRATION IN PROSTATE BRACHYTHERAPY DEPENDS ON EXPERIENCE AND TECHNIQUE
World Congress of Brachytherapy 2012 Purpose/Objective: To assess the impact of radiation dose on biochemical failure in intermediate-risk prostate cancer patients treated with brachtherapy (BT) alone or combined with external beam irradiation (EBRT). Materials and Methods: From a prospectively collected database of 1290 men treated at Tokyo Medical Center from 2003 to 2009 with I125 BT for prostate cancer, 688 men with intermediate-risk patients with either one or more intermediate-risk features (PSA level 10-20 ng/mL, Gleason score 7, or Stage T2b/2c) were identified who had a minimum follow-up of 24 months. Patients with low-tier of intermediate risk (PSA < 10 ng/mL and Gleason score 3+4 with positive core rates less than 1/3 ) were treated with BT alone and the rest upper-tier patients were treated with BT followed by EBRT. Gleason score was 7 in 76% of patients. PSA ranged from 1.4 to 20 ng/mL (median, 7.6 ng/mL). Seventy per cent of patients received neoadjuvant hormone therapy (median, 7 months) while 30 % of patients did not. Biologically effective dose (BED) values were calculated to compare doses of treatment regimens. BED ranged from 105 to 250 Gy2 (median, 206 Gy2). Patient- and treatment-related factors were analyzed with respect to freedom from biochemical failure (FFbF). The effects of multiple variables were tested by logrank and linear regression. Results: The median follow-up was 60 months (range, 24–100 months). The overall FFbF using the ASTRO definition for all patients was 93 % at 5 years and 91 % at 7 years. Of the eight factors tested (age, Tstage, PSA levels, Gleason score, positive core rate, use of hormone, use of EBRT, and BED), only BED (BED <= 180 Gy2 vs. > 180 Gy2) was found to be significant (p=0.003). To analyze the effect of increasing BED on FFbF, patients were devided in to three BED dose groups. The dose groups were <=180 Gy2 (n=66), >180-210 Gy2 (n=368), and >210 Gy2 (n=254). The 7-year FFbF rate for BED groups was 81%, 91% and 94%, respectively (p=0.010). Cox regression revealed that T-stage (p=0.049), Gleason score (p=0.018) and BED (p=0.007) were significant predictors of FFbF when age, PSA, T-stage, Gleason score, positive core rate, hormone and BED were considered continuous variables. Conclusions: Radiation dose is an important predictor of 5-year FFbF in intermediate-risk prostate cancer. With the use of high BED radiotherapy setting, neoadjuvant hormone therapy did not have a significant impact on 5-year FFbF rates. Individualized treatment using I-125 brachytherapy alone or boost should be a good option for intermediate-risk prostate cancer patients. PO-163 PSA RESPONSE TO TRI-MODALITY PREDICTS BIOCHEMICAL PROGRESSION FREE SURVIVAL IN LOCALIZED PROSTATE CANCER M. Aoki1, K. Miki2, Y. Yamamoto2, M. Kido2, S. Takaki1, M. Kobayashi1, C. Kanehira1, S. Egawa2 1 Jikei University School of Medicine, Department of Radiology, Minato-ku, Japan 2 Jikei University School of Medicine, Department of Urology, Minatoku, Japan Purpose/Objective: High dose rate (HDR) brachytherapy combined with external beam radiation therapy (EBRT), neoadjuvant androgen suppression therapy (NAST) and adjuvant androgen suppression therapy (AAST) (Tri-modality) have been used to treat localized high risk prostate cancer. To define prognostic factors of biochemical relapse free survival (bRFS), an analysis of patients treated with Trimodality were performed. Materials and Methods: Between May 2005 and Oct. 2008, 109 highrisk prostate cancer patients (D'Amico classification) were treated with NAST prior to HDR brachytherapy combined with hypofractionated EBRT. Among 108 patients, 107 patients (99%) had completed AAST for 24 months after whole radiotherapy. The median age was 69 years (range, 59-82). The median initial PSA was 23.5 ng/ml (range, 3.9-365). The median Gleason score was 8 (GS 6/7/8/9/10 : 7/23/35/23/4). The median follow up was 52 months (range, 36-74). The median NAST was 9 months (range,1-29). The median AAST was 24 months (range, 3-24). 74 patients:HDR brachytherapy (PTV: 5Gy, 6Gy, 2fx/day) and hypofractionated EBRT (45Gy : 3Gy×15fx/3weeks). 35 patients:HDR brachytherapy (PTV: 9Gy, 9Gy, 2fx/day) and hypofractionated EBRT (40Gy : 2.5Gy×16fx/3weeks). Hypofractionated EBRT was performed 1weeks
S 67 after HDR brachytherapy. 66 patients were given total androgen suppression and 16 patiennts were given LH-RH only as NAST. Results: With a median follow up of 52 months, bRFS of all patients was 81%(70mons). bRFS of high dose arm and low dose arm were 100% (48 mon) and 79.5%(76mon) respectively(p=0.24). On multivariate analysis of factors predicting bRFS, dose of HDR and Pre-HDR PSA level were significant respectively (p=0.0003, 0.005). However age, initial PSA, Gleason score, duration of NHT were not significant respectively (p=0.68, 0.065, 0.40, 0.62). Patients in the Pre-HDR PSA<0.1 group have significantly improved bRFS compared to patients in the Pre-HDR PSA>0.1 group (87.9% vs. 68.2%, p=0.014). On multivariate analysis of factors predicting Pre-HDR PSA level, although the term of NAST was not significant (p=0.076), initial PSA tend to be significant (p=0.052). Conclusions: For high-risk prostate cancer patients treated with Trimodality (NAST, HDR plus EBRT, AAST), Dose of HDR and Pre-HDR PSA were important prognostic factors (p=0.0003, 0.005 respectively). Patients in the Pre-HDR PSA<0.1 group have significantly improved bRFS compared to patients in the Pre-HDR PSA>0.1 group (p=0.014). A further study is needed to confirm the importance of Pre-HDR PSA in Tri-modality treatment. PO-164 SEED MIGRATION IN PROSTATE BRACHYTHERAPY DEPENDS ON EXPERIENCE AND TECHNIQUE G. Delouya1, D. Taussky1, C. Moumdjian1, R. Larouche1, D. BéliveauNadeau1, C. Boudreau1, Y. Hervieux1, D. Donath1 1 CHUM - Hôpital Notre-Dame, Radiation Oncology, Montréal, Canada Purpose/Objective: To determine the rate of seed loss and pulmonary migration over time in permanent seed prostate brachytherapy (PB). Materials and Methods: The first 495 patients treated at our department were analyzed. All patients were treated with loose I125seeds using an automated seed delivery system and real-time intraoperative planning. Pelvic fluoroscopic imaging was done 30 days following the implant. Patients were divided into five groups of 100 patients each according to the order treated. The five groups were compared using Chi-square test and One-way analysis of variance (ANOVA). Results: A total of 22.8% of patients lost at least one seed. The highest percentage of patients losing any number of seeds was in the first group of 100 patients. At least one seed was lost in 38% of the patients. This number decreased gradually and reached a rate as low as 9% in the last group of one hundred patients (patients 400 to 499). The mean total seed loss rate (number of seeds lost/number of seeds implanted) changed significantly over time (p<0.001). There was a continuous significant (p<0.001) decline after the first 100 patients (1.25% for first 100 patients) followed by a rise for patients 300-399, followed by another decline (0.21% for the last 100 patients). The pulmonary migration rate also changed significantly over time (p=0.009). The initial rate of 0.25% increased to 0.42% in patients 200299 and 300-399 and declined later to a rate of 0.21% in the last one hundred patients. Conclusions: Seed loss and pulmonary migration are associated with a learning curve. Avoiding implanting seeds outside of the capsule and modern TRUS imaging can help decrease migration. PO-165 FOCAL THERAPY FOR PROSTATE CANCER RECURRENCES: FEASIBILITY, TOXICITY AND QUALITY OF LIFE OF I-125 FOCAL SALVAGE M. van Vulpen1, M. Peters1, M.R. Moman2, U.A. van der Heide3, J.J. Battermann1, S. Franken4, M. van Deursen1, M.A. Moerland1 1 UMC Utrecht, Radiotherapy, Utrecht, The Netherlands 2 UMC Utrecht, Radiology, Utrecht, The Netherlands 3 AvL/NKI, Radiotherapy, Amsterdam, The Netherlands 4 Verbeeten, Radiotherapy, Tilburg, The Netherlands Purpose/Objective: Salvage treatments for prostate cancer recurrences show high failure and severe toxicity rates. Current Magnetic Resonance Imaging (MRI) techniques provide the possibility to localize early recurrences and therefore enable focal salvage, both likely to improve treatment outcome. In this study, feasibility, toxicity and quality of life are described for focal salvage brachytherapy.
S 67 after HDR brachytherapy. 66 patients were given total androgen suppression and 16 patiennts were given LH-RH only as NAST. Results: With a median follow up of 52 months, bRFS of all patients was 81%(70mons). bRFS of high dose arm and low dose arm were 100% (48 mon) and 79.5%(76mon) respectively(p=0.24). On multivariate analysis of factors predicting bRFS, dose of HDR and Pre-HDR PSA level were significant respectively (p=0.0003, 0.005). However age, initial PSA, Gleason score, duration of NHT were not significant respectively (p=0.68, 0.065, 0.40, 0.62). Patients in the Pre-HDR PSA<0.1 group have significantly improved bRFS compared to patients in the Pre-HDR PSA>0.1 group (87.9% vs. 68.2%, p=0.014). On multivariate analysis of factors predicting Pre-HDR PSA level, although the term of NAST was not significant (p=0.076), initial PSA tend to be significant (p=0.052). Conclusions: For high-risk prostate cancer patients treated with Trimodality (NAST, HDR plus EBRT, AAST), Dose of HDR and Pre-HDR PSA were important prognostic factors (p=0.0003, 0.005 respectively). Patients in the Pre-HDR PSA<0.1 group have significantly improved bRFS compared to patients in the Pre-HDR PSA>0.1 group (p=0.014). A further study is needed to confirm the importance of Pre-HDR PSA in Tri-modality treatment. PO-164 SEED MIGRATION IN PROSTATE BRACHYTHERAPY DEPENDS ON EXPERIENCE AND TECHNIQUE G. Delouya1, D. Taussky1, C. Moumdjian1, R. Larouche1, D. BéliveauNadeau1, C. Boudreau1, Y. Hervieux1, D. Donath1 1 CHUM - Hôpital Notre-Dame, Radiation Oncology, Montréal, Canada Purpose/Objective: To determine the rate of seed loss and pulmonary migration over time in permanent seed prostate brachytherapy (PB). Materials and Methods: The first 495 patients treated at our department were analyzed. All patients were treated with loose I125seeds using an automated seed delivery system and real-time intraoperative planning. Pelvic fluoroscopic imaging was done 30 days following the implant. Patients were divided into five groups of 100 patients each according to the order treated. The five groups were compared using Chi-square test and One-way analysis of variance (ANOVA). Results: A total of 22.8% of patients lost at least one seed. The highest percentage of patients losing any number of seeds was in the first group of 100 patients. At least one seed was lost in 38% of the patients. This number decreased gradually and reached a rate as low as 9% in the last group of one hundred patients (patients 400 to 499). The mean total seed loss rate (number of seeds lost/number of seeds implanted) changed significantly over time (p<0.001). There was a continuous significant (p<0.001) decline after the first 100 patients (1.25% for first 100 patients) followed by a rise for patients 300-399, followed by another decline (0.21% for the last 100 patients). The pulmonary migration rate also changed significantly over time (p=0.009). The initial rate of 0.25% increased to 0.42% in patients 200299 and 300-399 and declined later to a rate of 0.21% in the last one hundred patients. Conclusions: Seed loss and pulmonary migration are associated with a learning curve. Avoiding implanting seeds outside of the capsule and modern TRUS imaging can help decrease migration. PO-165 FOCAL THERAPY FOR PROSTATE CANCER RECURRENCES: FEASIBILITY, TOXICITY AND QUALITY OF LIFE OF I-125 FOCAL SALVAGE M. van Vulpen1, M. Peters1, M.R. Moman2, U.A. van der Heide3, J.J. Battermann1, S. Franken4, M. van Deursen1, M.A. Moerland1 1 UMC Utrecht, Radiotherapy, Utrecht, The Netherlands 2 UMC Utrecht, Radiology, Utrecht, The Netherlands 3 AvL/NKI, Radiotherapy, Amsterdam, The Netherlands 4 Verbeeten, Radiotherapy, Tilburg, The Netherlands Purpose/Objective: Salvage treatments for prostate cancer recurrences show high failure and severe toxicity rates. Current Magnetic Resonance Imaging (MRI) techniques provide the possibility to localize early recurrences and therefore enable focal salvage, both likely to improve treatment outcome. In this study, feasibility, toxicity and quality of life are described for focal salvage brachytherapy.