Clinical application and safety evaluation of injectable cross-linked sodium hyaluronate isolation gel in radical hypofractionated radiation therapy for prostate cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective:To evaluate the safety and feasibility of applying injectable cross-linked sodium hyaluronate isolation gel in radical hypofractionated radiation therapy for prostate cancer.Methods:In this prospective study, patients at Beijing Hospital who were pathologically diagnosed with clinical stage T 1-2N 0M 0 prostatic acinar adenocarcinoma by puncture and underwent radical radiation therapy were included. All patients received ultrasound-guided cross-linked sodium hyaluronate isolation gel injection and image-guided intensity-modulated radiation therapy (IG-IMRT). The prescription dose was moderately hypofractionated, with a prescription dose of 60 Gy in 20 fractions for 5 times a week, once daily, which was delivered to 95% of the planning target volume (PTV) of prostate and seminal vesicle. Analyze the prostate rectal spacing (PRS) at the baseline, on the day of injection, during the radiotherapy, 1 month and 3 months after radiotherapy, changes in rectal volume before and after injection, and incidence of rectum-related side effects. The changes in all indexes before and after injection were analyzed by using t-test. Results:A total of 13 patients were enrolled from March 2022 to February 2023. The isolation gel maintained morphologic stability without significant spatial changes during radiotherapy, and the mid-prostate had the best effect, with PRS up to 1 cm. At 3 months after radiotherapy, the isolation gel was seen to decreased in volume with a certain absorptive capacity. The irradiated volume of rectum was decreased significantly in all patients after gel injection, and the mean volumes of rectal V 60 Gy , V 50 Gy , V 30 Gy , and V 20 Gy before and after injection were 1.923% vs. 0.280%, 10.255% vs. 3.172%, 29.602% vs. 18.800%, and 49.452% vs. 40.259% (all P<0.005). The average values (range) of rectal V 60 Gy , V 50 Gy , V 30 Gy , V 20 Gy decreases were 84.9%( 29% - 100%), 69.6%(27%-100%), 36.3%(0%-75%), and 17.8%(0%-50%), respectively. No grade 3-4 side effects occurred in all patients, and there were no common grade 1-2 rectal side effects such as diarrhea, rectal bleeding, proctitis and anal pain, etc. Only one patient developed grade 1 constipation during radiotherapy. Conclusion:Injection of Chinese made cross-linked sodium hyaluronate isolation gel can significantly reduce the irradiated volume of rectum and the incidence of rectal toxicities in prostate cancer patients undergoing radical radiotherapy.