ESTRO 2025 - Abstract Book

S2113

Clinical - Urology

ESTRO 2025

After a follow-up of 24months the post-PSMA-1007 BR in the positive group occurred in 85% of patients with a median-response of 2 months (95%CI:1.31-4.0) reaching PSA-values <0.003ng/ml. In the negative group, BR occurred in 40% of patients with a median-response of 4.3 months (95%CI:2.56-9.0). (figure-attached)

Conclusion: The PET/CT-PSMA-1007 is a powerful tool that allows for the correct diagnosis of patients with BCR of PC and enables guided metabolic-volume-radiotherapy, achieving early BR in the majority of patients.

Keywords: PSMA-1007, PET/CT, Prostate cancer

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Digital Poster A retrospective single centre review of prospectively collected rectal toxicity after prostate SABR with an iodinated hydrogel spacer: a 3-year review Erica Bennett, Caoimhe Buckley, Karen P Molan, Mohd S Mat Samuji, Paul J Kelly Bon Secours Radiotherapy Cork in partnership with UPMC Hillman Cancer Centre, Bon Secours Hospital, Cork, Ireland Purpose/Objective: Randomised controlled trials have demonstrated the non-inferiority of prostate SABR compared with hypofractionated and conventional radiotherapy in terms of biochemical outcomes with low levels of rectal toxicity 1 . Hydrogel spacers may further reduce rectal toxicity however, a lack of randomised evidence exists for their use in ultrahypofractionated prostate radiation. Iodine-containing hydrogel spacer SpaceOAR VueTM has been CE marked and FDA approved and have an added advantage of aiding image-guidance during treatment delivery. Since 2021, SpaceOAR VueTM has been offered to patients undergoing prostate SABR at our institution. Material/Methods: A retrospective review of prospectively collected acute and late rectal toxicity in men who received SABR prostate between October 2021 and October 2024 was carried out using the electronic patient records. All patients had a SpaceOAR Vue TM device and fiducial markers implanted prior to CT simulation and planning MRI. Treatment was on a Varian Edge TM linear accelerator utilising fiducial tracking with triggered imaging for IGRT purposes. PTV dose was 36.25Gy in 5# (PACE protocol), delivered on alternate days.