ESTRO 37 Abstract book

S840

ESTRO 37

Conclusion Postoperative radiation therapy provides excellent long- term overall survival with an aceptable BRFS. Pre-RT PSA <0.5ng/ml and adjuvant RT were predictors of better outcomes. NLR was not significantly associated with poor OS or recurrence-free survival or BRFS in our series. EP-1554 Treatment outcomes and toxicities of IMRT for more than 1000 Japanese patients with prostate cancer. H. Tanaka 1 , M. Ito 1 , T. Yamaguchi 1 , K. Esaki 1 , M. Hayashi 2 , S. Ogawa 2 , S. Kamei 3 , S. Ishihara 3 , F. Hyodo 1 , M. Matsuo 1 1 Gifu University, Radiology, Gifu, Japan 2 Kizawa Memorial Hospital, Radiation Oncology, Minokamo, Japan 3 Kizawa Memorial Hospital, Urology, Minokamo, Japan Purpose or Objective Studies on intensity-modulated radiation therapy (IMRT) for prostate cancer using a large sample size (> 1000) in Asia are yet to be conducted. All the large population studies were performed in Western countries.Because the physique and prostate glands of Asians are smaller than those of Westerners, the outcomes and toxicity might differ between Asian and Western patients. This study aimed to evaluate the treatment result of IMRT in a large number of Japanese patients with prostate cancer. Material and Methods A total of 1091 patients with localized prostate cancer were recruited between March 2006 and July 2014. All tumors were histologically confirmed as adenocarcinomas. The median patient age was 70 years (range, 38-80 years). The median PSA level at diagnosis was 8.53 ng/ml (range, 2.65-370.00 ng/ml). A total of 427 (39.1%), 331 (30.3%), 38 (3.5%), 125 (11.5%), 122 (11.2%), 39 (3.6%), and 9 (0.8%) patients had cT1c, T2a, T2b, T2c, T3a, T3b, and T4, respectively. The patients had a Gleason Score (GS) of ≤6 (n=316 [29.0%]), 7 (n=482 [44.2%], 8 (n=175 [16.0%]), 9 (n=104 [9.5%]), and 10 (n=14 [1.3%]).The patients were stratified into low- (n=205 [18.8%]), intermediate- (n=450 [41.2%]), high- (n=345 [31.6%]), very high-risk (n=91 [8.3%]) groups according to the National Comprehensive Cancer Network classification. All patients were irradiated via IMRT at a dose of 74-78 Gy with or without androgen-deprivation therapy. The mean follow-up period was 50 months (range, 2-120 months).

NCCN risk group Low

205 Intermediate 450 High 345 Very High 91

ADT use

Yes

646

No

445

Results The biochemical failure-free rate (BFFR), the clinical failure-free rate, and the overall survival rate at the 5- year follow-up for all patients was 91.3%, 96.2%, 99.1%, respectively. In univariate analysis, the prostate-specific antigen (PSA) levels (≤20 vs. >20 ng/ml) were significantly correlated with BFFR. A trend toward higher BFFR was noted in patients with a Gleason score (GS) of ≤7 than in patients with GS ≥8. In multivariate analysis, only PSA (≤20 vs. >20 ng/ml) was significantly correlated with BFFR. The cumulative incidence rate of gastrointestinal and genitourinary toxicity (≥grade 2) at the 5-year follow-up was 11.4% and 4.3%, respectively.

Conclusion The findings of this study indicate that IMRT is well tolerated and is associated with both good long-term tumor control and excellent outcomes in patients with localized prostate cancer. EP-1555 Multiple re-irradiation for locally recurrent prostate cancer: proof of concept and clinical outcome S. Volpe 1,2 , B.A. Jereczek Fossa 1,2 , D. Zerini 1 , D.P. Rojas 1,2 , C. Fodor 1 , A. Vavassori 1 , P. Romanelli 1 , S. Vigorito 3 , E. Rondi 3 , S. Comi 3 , R. Cambria 3 , F. Cattani 3 , S. Di Cuonzo 1 , P. De Marco 3 , G. Beltramo 4 , G. Musi 5 , O. De Cobelli 5 , G. Marvaso 1 , R. Orecchia 1,6 1 European Institute of Oncology, Department of Radiation Oncology, Milan, Italy 2 University of Milan, Department of Oncology and Hemato-Oncology, Milan, Italy 3 European Institute of Oncology, Department of Medical Physics, Milan, Italy 4 CyberKnife Center CDI, Department of Radiation Oncology, Milan, Italy 5 European Institute of Oncology, Department of Urology, Milan, Italy 6 European Institute of Oncology, Scientific Directorate, Milan, Italy

Median age

73 (38-80)

Median PSA

8.53 (2.65-370.0)

T stage

< T1c

427

T2a

331

T2b

38

T2c

125

T3a

122

T3b

39

T3

9

GS

≤ 6

316

7

482

8

175

9

104

Purpose or Objective

10

14