ESTRO 2023 - Abstract Book

S1242

Digital Posters

ESTRO 2023

Conclusion In this phase 1 no DLT were observed during the monitoring period of 12 weeks, allowing the opening of phase II at a dose of 6x6Gy.

PO-1528 SBRT to lymph node in oligometastatic prostate cancer: monoistitutional preliminary report

P. BONOME 1 , D. CAIVANO 2 , V. DE SANCTIS 3 , R. SIGILLO 4 , M. ROTONDI 4 , I. ANGELICONE 4 , M. VALERIANI 4 , M.F. OSTI 4

1 Gemelli Molise Hospital - Università Cattolica del Sacro Cuore, Radiation Oncology Unit, Campobasso, Italy; 2 Ospedale Santa Maria Goretti, Radioterapia Oncologica, Latina, Italy; 3 Sant'Andrea Hospital - Sapienza University of Rome, Radiation Oncology , Roma, Italy; 4 Sant'Andrea Hospital - Sapienza University of Rome, Radiation Oncology, Roma, Italy Purpose or Objective The purpose of this study was to evaluate the efficacy, safety and toxicity of extracranial stereotactic body radiotherapy (SBRT) for lymph node oligometastatic/recurrent/persistent prostate cancer (PCa) Materials and Methods Patients included in this analysis had ≤ 3 metastatic sites and underwent SBRT on nodal metastases. The endpoints were local control of treated metastases (LC), distant local control (DLC), progression-free survival (PFS), overall survival (OS), distant metastases free survival (DMFS). Acute and delayed toxicities were also evaluated. Results Thirty-nine patients carrying out 62 nodal metastases were analyzed. In 16 patients androgen deprivation (AD) was combined with SBRT. Fifty-three lesions (85.4%) were treated by SBRT (multiple fractions), and 9 (14.2%) lesions were treated by single fraction radiotherapy (SRS). The median dose delivered by SBRT was 45 Gy (range 24-50 Gy) with a median BED α / β 10 of 48 Gy (range 45-95.2 Gy). The most frequent schedula for SBRT was 6 Gy x 5 fractions (46%). The median dose delivered by SRS was 12 Gy (range 8-30 Gy), with a median BED α / β 10 of 71.4 Gy (range 33.6-120). The most frequently adopted schedule for SRS was 12 Gy x 1 fraction (33.3%). After a median follow-up of 30 months (range 5 – 116), median PSA decreased from 5.4 ng/ml (range=4.2–9.6 ng/ml) (values at diagnosis) to 0.21 ng/ml (range=0.05–2.28ng/ml) (values at the last follow-up).The LC rate at three and five years was 98% and 93.5%, respectively. The observed median of DNC was 28 months with a five-year rate of 81.9% The median PFS was 12 months; the three-year PFS rate was 33.9%. The median DMFS was 28 months; the five-year DMFS rate was 56.9%. Median OS was 30 months. No grade III or IV toxicity was reported. Conclusion The present study shows the efficacy of SBRT in oligometastatic/persistent/recurrent prostate cancer patients and allows to achieve good results in terms of clinical outcomes with poor toxicity Purpose or Objective Radiation therapy (RT) for prostate cancer (PCa) is a highly effective therapy modality, offering a particular advantage for patients who are unsuitable for surgical treatment of PCa because of advanced age or comorbidities. The Geriatric Assessment is defined as a multidimensional diagnostic process used to measure age-associated parameters that could help to identify vulnerable patients who are at risk of higher radiation toxicity. The aim of this study was to investigate the association between age-associated characteristics and acute radiation induced side effects. Materials and Methods A total of 308 patients treated with primary curative RT for PCa were enrolled in our prospective study. A GA consisting of the Mini-Mental State Examination (MMSE), Mini Nutritional Assessment (MNA), Nikolaus Scale for Social Situation (SOS), Geriatric Depression Scale, Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Timed Up and Go (TUG), Charlson Comorbidity Index (CCI) and survey of polypharmacy (P) was performed before initiation of irradiation. Genitourinary (GU) and gastrointestinal (GI) acute toxicity was classified according to EORTC/RTOG scale. Results Radiation induced acute toxicity grade ≥ 2 was detected in 38 patients (11,8%), GU toxicity grade ≥ 2 in 35 patients (10,9%), and GI toxicity grade ≥ 2 in 8 patients (2,5%), respectively. The pre-treatment CKI, ADL, and GDS significantly correlated with overall toxicity grade ≥ 2 (p=0.029 and p=0.050, and p=0.043). Furthermore, statistical analysis revealed a significant association of the pre-treatment ADL with GU toxicity grade ≥ 2 (p=0.046) as well as of TUG with GI toxicity grade ≥ 2 (p=0.032). Conclusion The results of our study showed a significant relationship between comorbidities, mood state, reduced functionality,and mobility and acute radiation induced side effects of RT for PCa. The tools of GA might be helpful in detecting unidentified health problems that influence the risk of radiation induced toxicity. PO-1529 Association between age-related parameters and acute toxicity in prostate cancer radiotherapy K. Paal 1 , B. Stranz 1 , E. Thurner 1 , T. Langsenlehner 1 1 Medical University of Graz, Department of Therapeutic Radiology and Oncology, Graz, Austria