ESTRO 2024 - Abstract Book

S2550

Clinical - Urology

ESTRO 2024

16 patients have completed 1 year follow up after radiotherapy to the prostate with a rectal spacer in situ using Varian Truebeam linear accelerators. Baseline characteristics are in table 1. Localised and locally advanced patients were included, with median tumour staging of 2, (range 2a – 3b), median gleason score of 7 (range 7-9) and median initial PSA of 10 (range 4.1-89). All patients had 3 fiducial markers inserted transperineally along with the Hydrogel Vue spacer device prior to radiotherapy planning, which were tolerated well with no acute adverse effects. Patients had been assessed on their experiences of rectal toxicity, one year after completing radiotherapy to the prostate. Constipation, diarrhoea, pain, fissure, bleeding, mucus, flatulence and nausea were graded using CTCAEv5. 18.8% (n=3) patients were experiencing grade 1 toxicity of increase of <4 loose stools per day. 6% (n=1) patient experienced grade 1 mild haemorrhage with intervention not indicated. 6% (n=1) patient experienced grade 1 mild presence of mucus and 6% (n=1) patient experienced an increase in flatulence, however no stomach pains were associated with this and symptoms were mild. No patients experienced grade 2 or higher toxicities. No patients experienced any diarrhoea, pain, anal fissures or nausea. There was no difference in toxicity between patients receiving 2Gy or 3Gy per day.

Conclusion:

This evaluation assessed patients with previous bowel surgery, or IBD patients reported late rectal toxicity after receiving radiotherapy to the prostate with the use of a Hydrogel Vue spacer device. A small percentage of patients experience a mild increase in the frequency of opening bowels, however this is well tolerated and less impactful than active inflammation this patient group are used to. Although sample size is small, the preliminary results are promising and reassuring, however, longer term follow up will continue to be assessed.