ESTRO 2023 - Abstract Book

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ESTRO 2023

Table. Dose-volume parameters of single fraction high-dose-rate (HDR) and low-dose-rate (LDR) brachytherapy of prostate cancer. *Median. **Mann-Whitney-U Test. ***Wilcoxon Matched Pairs Test. Conclusion Both techniques provided acceptable target volume coverage. However, in plans 4 weeks after LDR implantation 5-10% poorer dose-volume parameters were observed, except for dose homogeneity. The dose distributions were more homogeneous and conformal, and both urethra and rectum were better protected with the HDR technique.

PO-2197 Prostate inverse brachy boost - 10 Gy with implantation of gold markers – results and feasibility

M. Hetna ł 1 , A. Romaniszyn 2 , K. Serwa ń ska 3 , M. Tumidajewicz 3 , W. Burchardt 4

1 Andrzej Frycz Modrzewski Krakow University,, Amethyst Radiotherapy Centre, Rydygier Hospital, , Kraków, Poland; 2 Rydygier Hospital, Krakow, Amethyst Radiotherapy Centre, , Kraków, Poland; 3 Rydygier Hospital, Amethyst Radiotherapy Centre, , Kraków, Poland; 4 Greater Poland Cancer Centre, Brachytherapy , Pozna ń , Poland Purpose or Objective Modern external beam radiotherapy (EBRT) of the prostate is performed with implanted markers. The inserting the markers need time, equipment, staff and is cost–consuming for the health care providers. This study aims to assess the effectiveness and toxicity of treatment of intermediate and high-risk prostate cancer patients with 10 Gy inverse brachytherapy (BT) boost with implantation of gold markers and subsequent EBRT. Materials and Methods Between September 2016 and October 2018, 87pts with intermediate (33 pts) or high (54 pts) risk prostate cancer were treated. Median age was 71 (range 47-84.) Median follow-up time was 44 months (range 2-700 . Median BT time was 200 minutes (range 120-285). The endpoints of the analysis were biochemical relapse-free survival (LRRFS), clinical relapse- free survival (CRFS) and overall survival (OS). Kaplan-Meier method was used to calculate survival rates. Toxicity was assessed according to CTCAv4.

Results The ADT was used in all patients form 6 to 24 months.

The 3-year BFS was 90%, CRFS was 94% and OS was 100%. BFS was 94% in intermediate and 88% in high-risk group (p=0,06 ns).

Time to BFS was 17 months. There have been 7 distant and 1 local relapse.

Early genitourinary (GU) toxicity was reported in 40% - G1, 38% - 38% and most common acute toxicities were nycturia and frequency. Late GU toxicity was mild: G1 – 5%, G2 – 3% with most common urinary incontinence. Early gastrointestinal toxicity was noticed in 14%-G1, 14%-G2 and 1%-G3 (bleeding). Late GU were reported in 7%-G1 and in 1%-G2 pts (bleeding).

Conclusion