ESTRO 37 Abstract book

S1247

ESTRO 37

Results Between June, 2014 and July, 2017, 58 patients with 84 lesions were treated with HDR. The median age at presentation was 80.4 years and gender was well balanced. Fifty-nine (70.2%) lesions were BCC and 23 (27.4%) SCC. Seventy-one (84.5%) lesions were treated with radical intent and thirteen (15.5%) lesions had adjuvant treatment due to positive margins or perineural invasion. The median follow- up for this study is 20.5 months (0.6-30.9). The actuarial overall survival (OS) and disease specific survival (DSS) at 2 years were 96.3% and 98.3%, respectively. Histological type BCC when compared to SCC was related to better DSS on univariate (p=0,024) and multivare analysis (p=0.041, HR 2.5 (C.I 1.075-1.103). Conclusion HDR offers a convenient treatment schedule for patients with superficial and localized NMSC, but patients with BCC treated with HDR seems to have better DSS than those with SCC. Our results also show that moderate doses, between 24Gy and 55Gy given in 4 to 22 fractions, can be safely used, despite the fact that effective dose and fractionation prescription for superficial HDR remains uncertain. Although cosmesis was not an objective of the study, all patients were satisfied with the final results. EP-2256 Long Term Results - Hdr For Local/Locally Advanced Prostate Cancer - A Uni-Institutional Experience A.C.A. Pellizzon 1 , M. Silva 1 , R. Fogaroli 1 , M. Chen 1 , D. Guedes 1 , G. Godin 1 1 AC Camargo Cancer Center, Radiation Oncology, sao paulo, Brazil Purpose or Objective Many prospective randomized trials have confirmed that dose-escalation is a determinant factor that influences biochemical control (BC) of prostate cancer (PC) and high-dose-rate brachytherapy (HDRB) is one method for given it. Material and Methods Patients with PC and histological diagnosis Gleason scored (GS), clinical stage T1-3a, with no evidence of metastatic disease, prostate volumes <60cc and initial PSAs (PSAi) <60 mg/ml who were treated with combination of external beam radiotherapy (EBRT) plus HDRB, based on a Institutional Policy of Treatment were evaluated. Results From 1997 to 2005 there were 273 patients treated with HDRB plus EBRT at AC Camargo Cancer Center, Sao Paulo, Brazil. The median age and follow up (FU) time were 64.7 and 10.3 years, respectively. Two hundred thirteen (78.0%) patients had FU longer than 5 years. Actuarial 10-year OS, CSS and BC were 89.8%, 63.6% and 71.8%, respectively. On univariate analyses GS<7, clinical stage65 years old, PSAi<10, localized EBRT and three dimensional HDR planning were associated with improved CSS and BC. Low risk (LR) group compared to intermediate (IR), (HR 0.70, 95% CI 0.023-0.213, p<0.001) and high risk (HR) - (HR 0.99, 95% CI 0.052-0.190, p<0.001)-groups, was a favorable predictive factor for BC. The GS >7 (HR 3.09, 95% CI 1.473-6.473, p=0.003) and PSAi >10 (HR 6.18, 95% CI 2.331-16.393, p<0.001) were negative predictive factor for BC. Multivariate Cox regression analyses confirmed LR, GS<7, PSAi<10, as predictors of improved CSS and BC. For OS only LR was confirmed as predictive factor. Electronic Poster: Brachytherapy: Prostate

Conclusion The present data represents a unique uni-institutional study at long FU for the given technique and the comparison of the results with the current literature data with shorter follow ups confirms the excellent results achieved with this treatment combination. EP-2257 Hyaluronic acid: Preserving sexual function in prostate cancer Brachytherapy M. Arangüena Peñacoba 1 , J. Cardenal Carro 1 , A.S. García Blanco 1 , J. Andreescu Yagüe 1 , N. Sierrasesumaga Martín 1 , V. Cañón García 1 , P.G. Pedro José 1 1 Hospital Universitario Marqués de Valdecilla, Radiation Oncology, Santander, Spain Purpose or Objective Sexual dysfunction secondary to neurovascular toxicity remains a serious complication affecting quality of life for prostate cancer patients treated with Brachytherapy. We are performing a new procedure injecting hyaluronic acid (HA) in the neurovascular beam to increase the distance and separate it from the treated volume. Material and Methods Based on our experience of rectal protection with hyaluronic acid in prostate cancer Brachytherapy, this method is also used in this patients, for both with intermediate-or high risk disease treated with External Beam Radiation Therapy (EBRT) with HDR Brachytherapy boost, and also for those with favorable presentations treated with HDR Brachytherapy in monotherapy, with the same injection technique in all patients. A transperineal injection of 3-7 mL of HA is performed under transrectal ultrasound (TRUS) guidance in the neurovascular beam to systematically create a 1.5- 2 cm space between the neurovascular beam and the prostate (treated volume), usually after the needles are in the treatment position, so that the hyaluronic acid will not modify the image when doing the implate and because the fixed position of the prostate with the needles will not influence the injection, as the neurovascular beam is located on the sides of the prostate. TRUS and Magnetic Resonance Imaging are used to assess the dimensions of the new space.

Results We have noticed that the 1.5- 2 cm distance derived from HA injection decreases the neurovascular dose from 76% to less than a 25%, so possibly the toxicity in Brachytherapy will be less, decreasing consequently the probability of sexual dysfunction. Since we began using this method, no acute toxicity has been reported from the HA or the injection. Due to months lasting of compound stability, the same distance is maintained during the course of EBRT. In follow-up with Magnetic Resonance Imaging, the HA injection has not migrated or changed in mass/shape for close to 1 year. Conclusion It is possible to decrease the dose in the neurovascular beam more than a 50% with our technique based on hyaluronic acid injection, however long-term follow-up will be necessary to determine the extent and benefit to the patient with this procedure.