Rectal hydrogel spacers have been shown to decrease rectal radiation dose and toxicity. In this study, we compared prostate and rectal dosimetry and acute toxicity outcomes in patients who had and had not received a rectal hydrogel spacer prior to combination therapy with external beam radiotherapy and low-dose-rate brachytherapy.
All patients with intermediate-risk and high-risk prostate cancer who received combination therapy at our institution were identified between 2014 and 2019. Dosimetric outcomes of brachytherapy implants and quality of life (QOL) outcomes were compared between patients who had and had not received a hydrogel spacer.
A Total of 168 patients meeting our inclusion criteria were identified. Twenty-two patients had received a rectal hydrogel spacer, among whom the mean separation between the rectum and prostate was 7.5 mm, and the V100rectum was reduced by 47% (0.09 cc vs. 0.17 cc, p = 0.04). There was no difference in the percentage of patients achieving a D90 of ≥100 Gy between those who had and had not received a spacer. The mean rate of change in I-PSS and SHIM scores did not differ between the two groups at 2 months after PID.
LDR brachytherapy appears feasible after the placement of a rectal hydrogel spacer. While there was a significantly reduced V100rectum among patients who had received a hydrogel spacer, there was no statistically significant difference in patients achieving a D90prostate of ≥100 Gy. Although there was no difference appreciated in QOL scores, the length of follow-up was limited in the rectal-spacer group.
Brachytherapy. 2020 Nov 13 [Epub ahead of print]
Anthony D Nehlsen, Kunal K Sindhu, Erin Moshier, John P Sfakianos, Richard G Stock
Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY. Electronic address: ., Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, NY.
PubMed http://www.ncbi.nlm.nih.gov/pubmed/33199175