ESTRO 36 Abstract Book

S140 ESTRO 36 _______________________________________________________________________________________________

≤60cc; no use of androgen deprivation and no previous prostate surgery. The patients were monitored prospectively for toxicity (CTCAE v. 3.0) and health-related quality of life (Expanded Prostate Cancer Index Composite [EPIC]). A clinically significant decrement was considered an EPIC score decrease greater than one-half of the SD of the baseline value for each domain. Patient satisfaction was evaluated using a five-category predetermined Likert scale question. Results The median age was 71 years (range 55-78), median initial PSA 7.05 ng/ml (4.2-17.8) and median baseline IPSS was 5 (0-14). Forty-four percent of the patients were low-risk and 56% intermediate-risk. The median prostate volume was 34cc (17-60). Median CTV and OAR doses were: V100: 96.5% (95-99.4), V150 20.5% (13.7-35.1), V200 5.3% (3.1- 10.1), Urethral Dmax 106% (103-111) and rectum 2cc 53 % (45-48) After a median follow-up is 16 months (3-31), acute grade- 2 genitourinary and gastrointestinal toxicity occurred in 4 patients (9%) and 2 patients (2.3%), respectively. Two patients presented late GU grade-2 toxicity (4.6%). No grade-3 toxicity occurred. In terms of QoL, there was a statistically significant decline in EPIC urinary urgency domain between month 1 and month 6 (p=0.006), and returned to baseline by month 12. Mean EPIC urinary irritative-obstructive, bowel, sexual and hormonal domains did not present significant changes. Of patients potent at baseline evaluation, 60% remained potent at last follow-up. Patients rated their satisfaction at 6 months as “very- satisfied” (23%) or “extremely-satisfied” (77%). Conclusion HDR brachytherapy monotherapy administered in a single fraction of 19Gy, demonstrate excellent results in terms of toxicity, tolerance, safety, patient satisfaction and QoL. Longer follow-up is needed to confirm the efficacy of this strategy. OC-0271 The clinical outcome after high dose rate brachytherapy as monotherapy in localized prostate cancer S. Kariya 1 , K. Kobayashi 1 , I. Yamasaki 2 , S. Ashida 2 , K. Inoue 2 , T. Yamagami 1 1 Kochi Medical School, Department of Radiology, Nankoku, Japan 2 Kochi Medical School, Department of Urology, Nankoku, Japan Purpose or Objective The aim of this study is to report the clinical outcome after a single implant, high dose rate (HDR) brachytherapy in localized prostate cancer. Material and Methods Eighty-three patients, 2 with low-risk (T stage < or = 2a, PSA < or = 10 ng/ml, and Gleason score (GS) < or = 6), 28 with intermediate-risk (T stage = 2b or 2c, PSA > 10 and < or = 20 ng/ml, GS = 7), and 53 with high-risk (T stage > or = 3a, PSA > 20 ng/ml, GS > or = 8) prostate cancer who underwent HDR brachytherapy as monotherapy (no external beam radiotherapy) using 27 Gy/2 fractions in one day from July 2011 to October 2014 were analyzed prospectively. Patient age ranged 57 to 81 (median 72 ） years old. Fifty-nine patients were received neoadjuvant hormonal therapy, and 10 patients were also adjuvant hormonal therapy. Acute and late toxicities were assessed as per Common Terminology Criteria for Adverse Events (CTCAE), Version 4.03. The dosimetric factors affecting the acute or late grade 2 to 3 GU toxicity were analyzed by univariate analysis. PSA failure was defined as the Phoenix definition of nadir + 2 ng/mL. Biochemical relapse-free survival was analyzed using the Kaplan Meir method. Results

The median follow-up period was 52 months (range 21 – 64). The 4-year biochemical relapse-free survival rate was 89.0%. Neither acute nor late grade 2 to 3 rectal toxicities developed. Acute grade 2 genitourinary (GU) toxicity occurred in 12.0% (grade 3 in 0.0%). The predictor of acute grade 2 GU toxicity was urethra D90 (the dose that covers 90% volume of the urethra) > 11.5 Gy (p-value < 0.01). Late grade 2 to 3 GU toxicity occurred in 20.5% (grade 3 in 3.6%). However, any predictors of late grade 2 to 3 GU toxicity weren’t founded. Conclusion HDR brachytherapy as monotherapy in localized prostate cancer is a highly effective treatment with minimal side effects. OC-0272 Long-term rectal toxicity following I-125 prostate brachytherapy in 1,260 patients A. Yorozu 1 , S. Sutani 1 , R. Kota 1 , A. Sunaguchi 1 , K. Toya 1 , S. Saito 2 1 Tokyo Medical Centre- NHO, Department of Radiation Oncology, Tokyo, Japan 2 Tokyo Medical Centre- NHO, Department of Urology, Tokyo, Japan Purpose or Objective To analyze factors associated with long-term rectal toxicity in permanent prostate brachytherapy patients. Material and Methods This retrospective cohort study examined 1,260 patients treated with I-125 brachytherapy without external beam radiotherapy between 2003 and 2013. Neoadjuvant androgen deprivation (NAD) was given to 39% of patients. The patient, treatment, and dosimetry factors were examined for an association with rectal toxicity. Toxicity was graded according to the National Cancer Institute’s Common Terminology Criteria for Adverse Events ver 4.0. Rectal dosimetry was calculated through dose-volume histogram of the rectum using day-1 and day-30 CT-based dosimetry, and expressed as volume of rectum in cc receiving 100% and 150% of the prescription dose (RV100 and RV150, respectively), and as dose to 5% and 30% of rectum (RD5 and RD30 respectively). The Kaplan-Meier method and Cox regression model were used for analysis. Results The median follow-up was 6.6 years. Median RV100 was 0.15 cc at day 1, and 0.56 cc at day 30. Any grade of proctitis, rectal bleeding, fecal incontinence, diarrhea, and anal pain was observed in 22.9%, 22.8%, 15.2%, 10.6%, and 9.9% of patients, respectively. Toxicities were categorized as grade 1 in 28.8% of patients and grade 2 in 1.7%. No Grade 3 toxicity was observed. Actuarial risk of grade 2 rectal toxicity was 2.0%. The majority cases (82%) of grade 2 toxicities were diagnosed by the third year. Upon univariate analysis, the likelihood of G2 toxicity was significantly associated with RV150, RV100, RD30, RD5 at day 1, and NAD. Only RV100 at day 1 and NAD fit a Cox regression model. Actuarial risk of grade 2 was 1.4%, 3.1%, 4.8%, and 6.7% for patients with RV100 <=0.2cc, 0.2-0.5cc, 0.5-1cc, >1cc at day 1, respectively (P=0.029). Actuarial risk of grade 2 was 1.1 % for patients with NAD, and 2.2% for patients without NAD (p=0.032). Conclusion I-125 prostate brachytherapy is well tolerated. Rectal dosimetry at day 1 is relevant to long-term rectal toxicity. RV100 and NAD are associated with rectal toxicity. OC-0273 Prostate brachytherapy in African-Caribbean patients: A retrospective analysis of 370 cases V. Atallah 1 , N. Leduc 2 , M. Creoff 2 , P. Escarmant 2 , V. Vinh-Hung 2 1 universitary hospital, radiotherapy, Pointe-a-pitre, Guadeloupe 2 Universitary hospital Martinique, Radiotherapy, Fort- de-france, Martinique