- Email: [email protected]
PO-233 INTENSITY MODULATED HIGH-DOSE-RATE BRACHYTHERAPY AS MONOTHERAPY FOR CLINICALLY LOCALIZED PROSTATE CANCER
S94 PO-232 ARE URETHRAL TOXICITIES CORRELATED WITH DOSE AFTER INTERSTITIAL HDR BOOST BRACHYTHERAPY FOR PROSTATE CANCER? R. Broksch1, F.A. Siebert1, N. Brüske1, B. Kimmig1, R. Galalae2 1 University Hospital S-H Campus Kiel, Radiotherapy, Kiel, Germany 2 University Hospital S-H Campus Kiel, Medical Faculty, Kiel, Germany Purpose/Objective: HDR brachytherapy as boost technique for prostate cancer patients is in our clinic a well established technique. Study aim was a volumetric evaluation stratified by anatomy-related urethral segmentation in correlation with urethral toxicities. Materials and Methods: HDR-BT prescription prostate dose was 2x15 Gy to peripheral zone (CTV1) and 8.5 Gy to the whole prostate gland (CTV2), using 8 ± 1 (SD) implant needles. Dosimetric analyses were performed in 70 consecutive patients i.e. 140 HDR-BT-fractions, treated in 2003. Intra-operative technique based on TRUS images was applied. The echo of an inserted catheter plus 2 mm margin was digitized as urethra structure, and was digitally divided into three anatomical distinct parts. Two very basal TRUS-images + one cranial additional were defined as 'basal urethra', and two very apical slices + one distal additional as 'apical urethra'. The remaining mid part was labeled 'pars prostatica'. For each partial volume D5 and D0.1cc were calculated using the TG-43 formalism and the mean dose indices over the two fractions were used for evaluation. Late urethral toxicities were analyzed for each patient according to RTOG/EORTC classification and compared against the computed urethral doses of the three segments. Results: For basal urethra, the D5 was 10.1 ±3.8 Gy (SD), and for D0.1cc 8.6 ±2.9 Gy. Similar values were measured in the apex: D5 10.2 ±2.8 Gy and D0.1cc 8.4 ±2.3 Gy, while pars prostatica showed higher D5 with 12.4 ±3.7 Gy and D0.1cc 11.6 ±3.7 Gy. Late toxicities of grade 3 cystitis were found in 6%. One patient with grade 4 toxicity developed a bladder fistula. First results show no correlations between dose indices in the distinct urethra segments and toxicities. Conclusions: Dosimetric differences in three sequential anatomyrelated urethral segments were detected. Nevertheless, no correlation between dose and late toxicities in the urethra could be found is this study. PO-233 INTENSITY MODULATED HIGH-DOSE-RATE BRACHYTHERAPY AS MONOTHERAPY FOR CLINICALLY LOCALIZED PROSTATE CANCER N. Tselis1, D. Baltas2, U.W. Tunn3, T. Buhleier1, T. Martin4, N. Milickovic2, S. Papaioannou2, H. Ackermann5, N. Zamboglou1 1 Klinikum Offenbach GmbH, Department of Radiation Oncology, Offenbach am Main, Germany 2 Klinikum Offenbach GmbH, Department of Medical Physics and Engineering, Offenbach am Main, Germany 3 Klinikum Offenbach GmbH, Department of Urology, Offenbach am Main, Germany 4 Klinikum Bremen Mitte, Department of Radiation Oncology, Bremen, Germany 5 J.W. Goethe University of Frankfurt, Institute of Biostatistics, Frankfurt am Main, Germany Purpose/Objective: To report the clinical outcome of intensity modulated (IM) high dose rate (HDR) brachytherapy (BRT) as sole treatment (monotherapy) for localized prostate cancer. Materials and Methods: Between January 2002 and December 2009, 718 consecutive patients with localized prostate cancer were treated with transrectal ultrasound (TRUS) guided IM-HDR monotherapy. Three biologically equivalent treatment protocols were applied; 141 patients received 38 Gy using one implant at 4 fractions of 9.5 Gy with computed tomography based treatment planning [Group A], 351 patients received 38 Gy in 4 fractions of 9.5 Gy using two implants (2 weeks apart) and intraoperative TRUS real-time treatment planning [Group B], and 226 patients received 34.5 Gy using three singlefraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning [Group C]. Biochemical failure was defined according to the `Phoenix consensus´ and toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up was 52.8 months. For the entire cohort, the 36-, 60- and 96 months biochemical control (BC),
World Congress of Brachytherapy 2012 metastasis-free survival, and overall survival rates were 97 %, 94 %, 89 % and 99 %, 98 %, 97 % as well as 98 %, 96 % and 95 %, respectively. For Group A (n=141) and Group B (n=351) the 36-, 60- and 96 (80) months BC rates were 97 %, 94 %, 89 % (96 months) and 99 %, 98 %, and 97 % (80 months), respectively. For Group C (n=226), the 12-, 24and 35 months BC rates were 100 %, 98 % and 95 %, respectively. Toxicity was scored per event with 5.4 % acute Grade 3 genitourinary and 0.2 % acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were 3.5 % and 1.6 %, respectively. Two patients developed Grade 4 genitourinary toxicity. No other instance of Grad 4 or greater acute or late toxicity was reported. Conclusions: Our results confirm IM-HDR-BRT to be a safe and effective monotherapeutic treatment modality for clinically organconfined prostate cancer.
POSTER: GYNAECOLOGY PO-234 DOSE OPTIMIZATION OF INTRA-VAGINAL BRACHYTHERAPY USING DIFFERENT MULTI-CHANNEL APPLICATORS H. Kuo1, K. Mehta1, R. Yaparpalvi1, L. Hong1, A. Wu1, D. Mynampati1, W. Bodner1, M. Garg1, S. Kalnicki1 1 Montefiore Medical Center, Radiation Oncology, Bronx NY, USA Purpose/Objective: An inflatable applicator (CapriTM, Varian, USA) with thirteen lumens is designed with the advantage of reducing air pocket, and conforming dose to patient tissues. It is arranged in two concentric rings (with six lumens each) surrounding a central lumen. This study investigates the dose distribution in intra-vagina between applicators of Capri, multi-channel cylinder, Contura balloon, and Mammosite balloon (Figure 1). Materials and Methods: Plans for Capri (injected water of 30 cc, 40 cc, and 60 cc which corresponding to 3.5 cm, 3.7 cm, and 4.2 cm respectively) were configured with central lumen activated only (C), middle ring lumens activated only (M), outer ring lumens activated only (O), all lumens activated (CMO), outer ring lumens activated combined with selective dwell positions in middle ring lumens activated (mO). The goals were dose prescribed to 5mm depth (PTV) from surface of each applicator (D90>90%) with minimum dose at normal tissue (OAR) which is another 5mm away. To study the difference of dose to the apex of the vagina and dose to the body of vagina, plans were evaluated at the proximal 2 cm length vagina [PTV_A(V150) & OAR_A(V80)] and the rest of treatment length at vagina body [PTV_B(V150) & OAR_B(V80)]. Results: Compares similar size (3.5cm diameter at mid-body) of different applicators, Contura and Mammosite have lowest OAR_B(V80) but have maximal PTV_B(V150) (12%) as well. Capri planned with 'O' loading or 'mO' loading has slightly better OAR_B(V80) and reasonable PTV_B(V150) (~5%) compared to multi-channel cylinder. At apical vagina, Contura & Mammosite have similar PTV_A(V150) and have better OAR_A(V80) comparing to Capri. Mulitichannel cylinder has the highest value in both of PTV_A(V150) and OAR_A(V80). The sizes of the Contura and Mammosite limit their treatment length to the vaginal body. Compares different configurations of activated lumens in Capri with different sizes, plans in 'C' or 'M' loading show better at PTV( V150) but worse at OAR(V80); on the contrary, plans in 'O' loading show better at OAR( V80) but worse at PTV(V150). Plans in 'CMO' loading have PTV(V150) close to plans in 'C' & 'M' loading but the OAR(V80) are not optimum. To minimize PTV(V150) and OAR(V80) simultaneously, plan in 'mO' loading is the best choice for each size. It offers the least amount of OAR(V80) which is close to plan in 'O' loading yet with moderate value of PTV(150). Conclusions: Post-operative endometrial brachytherapy using Capri applicator which has the potential of eliminating air-surface interface results in excellent intra-vagina dose coverage. A modified-peripheral loading of the total 13 lumens provides tolerable dose to mucosa of vagina, good coverage to vaginal treatment depth, and the best dose sparing at normal tissue.
World Congress of Brachytherapy 2012 metastasis-free survival, and overall survival rates were 97 %, 94 %, 89 % and 99 %, 98 %, 97 % as well as 98 %, 96 % and 95 %, respectively. For Group A (n=141) and Group B (n=351) the 36-, 60- and 96 (80) months BC rates were 97 %, 94 %, 89 % (96 months) and 99 %, 98 %, and 97 % (80 months), respectively. For Group C (n=226), the 12-, 24and 35 months BC rates were 100 %, 98 % and 95 %, respectively. Toxicity was scored per event with 5.4 % acute Grade 3 genitourinary and 0.2 % acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were 3.5 % and 1.6 %, respectively. Two patients developed Grade 4 genitourinary toxicity. No other instance of Grad 4 or greater acute or late toxicity was reported. Conclusions: Our results confirm IM-HDR-BRT to be a safe and effective monotherapeutic treatment modality for clinically organconfined prostate cancer.
POSTER: GYNAECOLOGY PO-234 DOSE OPTIMIZATION OF INTRA-VAGINAL BRACHYTHERAPY USING DIFFERENT MULTI-CHANNEL APPLICATORS H. Kuo1, K. Mehta1, R. Yaparpalvi1, L. Hong1, A. Wu1, D. Mynampati1, W. Bodner1, M. Garg1, S. Kalnicki1 1 Montefiore Medical Center, Radiation Oncology, Bronx NY, USA Purpose/Objective: An inflatable applicator (CapriTM, Varian, USA) with thirteen lumens is designed with the advantage of reducing air pocket, and conforming dose to patient tissues. It is arranged in two concentric rings (with six lumens each) surrounding a central lumen. This study investigates the dose distribution in intra-vagina between applicators of Capri, multi-channel cylinder, Contura balloon, and Mammosite balloon (Figure 1). Materials and Methods: Plans for Capri (injected water of 30 cc, 40 cc, and 60 cc which corresponding to 3.5 cm, 3.7 cm, and 4.2 cm respectively) were configured with central lumen activated only (C), middle ring lumens activated only (M), outer ring lumens activated only (O), all lumens activated (CMO), outer ring lumens activated combined with selective dwell positions in middle ring lumens activated (mO). The goals were dose prescribed to 5mm depth (PTV) from surface of each applicator (D90>90%) with minimum dose at normal tissue (OAR) which is another 5mm away. To study the difference of dose to the apex of the vagina and dose to the body of vagina, plans were evaluated at the proximal 2 cm length vagina [PTV_A(V150) & OAR_A(V80)] and the rest of treatment length at vagina body [PTV_B(V150) & OAR_B(V80)]. Results: Compares similar size (3.5cm diameter at mid-body) of different applicators, Contura and Mammosite have lowest OAR_B(V80) but have maximal PTV_B(V150) (12%) as well. Capri planned with 'O' loading or 'mO' loading has slightly better OAR_B(V80) and reasonable PTV_B(V150) (~5%) compared to multi-channel cylinder. At apical vagina, Contura & Mammosite have similar PTV_A(V150) and have better OAR_A(V80) comparing to Capri. Mulitichannel cylinder has the highest value in both of PTV_A(V150) and OAR_A(V80). The sizes of the Contura and Mammosite limit their treatment length to the vaginal body. Compares different configurations of activated lumens in Capri with different sizes, plans in 'C' or 'M' loading show better at PTV( V150) but worse at OAR(V80); on the contrary, plans in 'O' loading show better at OAR( V80) but worse at PTV(V150). Plans in 'CMO' loading have PTV(V150) close to plans in 'C' & 'M' loading but the OAR(V80) are not optimum. To minimize PTV(V150) and OAR(V80) simultaneously, plan in 'mO' loading is the best choice for each size. It offers the least amount of OAR(V80) which is close to plan in 'O' loading yet with moderate value of PTV(150). Conclusions: Post-operative endometrial brachytherapy using Capri applicator which has the potential of eliminating air-surface interface results in excellent intra-vagina dose coverage. A modified-peripheral loading of the total 13 lumens provides tolerable dose to mucosa of vagina, good coverage to vaginal treatment depth, and the best dose sparing at normal tissue.