ESTRO 2022 - Abstract Book

S496

Abstract book

ESTRO 2022

(p=0.0091) in IMAT, CK, HDR and LDR BT plans, while D 0.1 to urethra was lower with both IMAT and CK than with BTs: 79.9Gy, 88.0Gy, 132.7Gy and 170.6Gy (p<0.001). D 2 to hips was higher with IMAT and CK, than with BTs: 13.4Gy, 20.7Gy, 0.4Gy and 1.5Gy (p<0.001), while D 2 to sigmoid, bowel bag, testicles and penile bulb was higher with CK than with the other techniques (Table).

Conclusion Using single fraction HDR and LDR BT, total dose of the prostate is higher than with IMAT or CK techniques, and accordingly dose to urethra is also higher with both BT modalities using the recommended fractionation scheme. Dose to rectum and bladder is lower with HDR BT than with IMAT, CK or LDR BT, while dose to sigmoid, bowel bag, testicles and penile bulb are higher with CK than using the other examined techniques. Overall, HDR monotherapy yields the most advantageous plans, except for the dose to urethra, where IMAT proves to be the optimal modality in the radiotherapy of low- and selected intermediate risk prostate cancer. This paper was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences and the ÚNKP- 18-4 New National Excellence Program of the Ministry of Human Capacities.

PD-0566 Permanent interstitial brachytherapy for prostate cancer implenting prostatic artery embolization

H. Haddad 1 , H. Hermani 1 , P. Bischoff 2 , H. Hanitzsch 3 , A. Heidrich 3 , A. Schaefer 4 , A. Kovács 2 , M. Pinkawa 1

1 Mediclin Robert Janker Clinic, Department of Radiation Oncology, Bonn, Germany; 2 Mediclin Robert Janker Clinic, Department of Interventional and Diagnostic Radiology and Neuroradiology, Bonn, Germany; 3 Mediclin Robert Janker Clinic, Department of Urology, Bonn, Germany; 4 MediClin Robert Janker Clinic, Department of Interventional and Diagnostic Radiology and Neuroradiology, Bonn, Germany Purpose or Objective Indication for permanent interstitial brachytherapy (PIB) can be limited by prostate volume, commonly decreased using neoadjuvant hormonal therapy. Volume changes and initial clinical results focusing on patients treated with prostatic artery embolization (PAE) were evaluated in this study Materials and Methods A group of 102 consecutive patients were treated with permanent interstitial brachytherapy (PIB), 13 patients received a neoadjuvant PAE (median 12 weeks before PIB) in case of large prostate volume >60cm ³ and moderate to severe urinary problems Results Patients after PAE were treated with significantly larger prostate volumes (52±11 cm ³ vs. 39±11 cm ³ ; p<0.01; 66±17cm ³ before PAE), but larger volume reductions to 44±10 cm ³ vs. 35±10 cm ³ was found at day 30 (p<0.05). International Prostate Symptom Score (IPSS) decreased significantly from 13±5 before PAE to 7±4 after PAE; p<0.01. Initial PSA and first PSA after