ESTRO meets Asia 2024 - Abstract Book

S284

Interdisciplinary – Urology

ESTRO meets Asia 2024

2. Di Muzio N, Fiorino C, Cozzarini C, Alongi F, Broggi S, Mangili P, Guazzoni G, Valdagni R, Calandrino R, Fazio F. Phase I–II study of hypofractionated simultaneous integrated boost with tomotherapy for prostate cancer. International Journal of Radiation Oncology* Biology* Physics. 2009 Jun 1;74(2):392-8. 3.Di Muzio N, Fiorino C, Cozzarini C, Alongi F, Broggi S, Mangili P, Guazzoni G, Valdagni R, Calandrino R, Fazio F. Phase I–II study of hypofractionated simultaneous integrated boost with tomotherapy for prostate cancer. International Journal of Radiation Oncology* Biology* Physics. 2009 Jun 1;74(2):392-8.

139

Digital Poster

Feasibility of Extended Field Radiation using Volumetric Modulated Arc Therapy in Prostate Cancer

Deepak Sharma 1 , Kannan Periasamy 1 , Shikha Goyal 1 , Santosh Kumar 2 , Ravi Mohan S Mavuduru 2 , Rajender Kumar 3 , Ranjit Singh 1 1 Radiation and Clinical Oncology, Post Graduate Institute of Medical Education and Research, Chandigarh, India. 2 Department of Urology, Post Graduate Institute of Medical Education and Research, Chandigarh, India. 3 Department of Nuclear Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India

Purpose/Objective:

The optimal radiotherapy treatment strategy in prostate cancer patients with or at high risk of paraaortic nodal disease without distant metastases is not well defined. This study aims to assess the feasibility of moderately hypo-fractionated extended field radiotherapy [EFRT] with regard to acute gastrointestinal, genitourinary and haematological toxicities in node positive prostate cancer patients.

Material/Methods:

Twenty-nine patients with prostate specific membrane antigen-positron emission tomography/computed tomography [PSMA-PET/CT] avid node positive disease, were recruited after signing informed consent form. These patients were treated between January 2021 to September 2022 with EFRT after 3 to 6 months of androgen deprivation therapy [ADT], with or without docetaxel/abiraterone acetate + prednisolone [AAP]. Moderately hypo fractionated dose of 60Gy to the prostate + seminal vesicles and 44Gy to the pelvic and para-aortic nodal regions was delivered over 20 fractions. Residual nodes persistent on PSMA-PET/CT after neo-adjuvant ADT were boosted with median dose of 54Gy [54-57.6Gy] using simultaneous integrated boost - volumetric modulated arc therapy [SIB-VMAT]. Acute adverse events were monitored weekly during radiation and monthly up to 3 months using common terminology criteria for adverse event [CTCAE] grading. Serum prostate specific antigen [PSA] was measured for up-to median follow up of 15 [10-29] months.

Results:

With median baseline PSA of 32.49 [4-203.4] ng/dl; all patients had multiple pelvic lymph nodes, out of which 18/29 [62.06%] had common iliac and 14/29 [48.27%] had para-aortic nodes. 4/29 [13.79%] received docetaxel and 5/29 [17.24%] received AAP. All patients completed the intended radiotherapy schedule; the upper border for nodal RT was L1/L2 in 15 [51.72%], L2/L3 in 11 [37.93%] and T12-L1 in 3 [10.34%]. 11/14 [78.57%] patients received a boost dose to the residual nodes. Grade 3 gastrointestinal, genitourinary and haematological adverse event rates were