Effect of Hyaluronate Acid Injection on Dose-Volume Parameters in Brachytherapy for Cervical Cancer.

Purpose: Hyaluronate gel has been injected as a spacer into the rectovaginal fossa and vesicouterine fossa during brachytherapy for patients with cervical cancer at our institution. The effect of hyaluronate gel injection (HGI) on dose-volume parameters was investigated in this study.
Methods and Materials: Between July 2008 to January 2020, a total of 104 patients (non-HGI group: 52 patients; HGI group: 52 patients) who underwent curative radiation therapy for cervical cancer were selected. The total doses of external beam radiation therapy and brachytherapy for high-risk clinical target volume (CTV _HR ) D ₉₀ , bladder D _2cc , and rectal D _2cc were converted to the equivalent dose in 2 Gy fractions (EQD2) and were analyzed for association with HGI.
Results: Median CTV _HR D ₉₀ (EQD2) in the non-HGI group was 76.0 Gy (63.7-99.5 Gy), and in the HGI group it was 79.4 Gy (52.6-97.5 Gy) ( P  = .017). The median bladder D _2cc and rectal D _2cc (EQD2) were 62.9 Gy and 56.0 Gy in the non-HGI group and 63.7 Gy and 54.8 Gy in the HGI group, which had no significant difference.
Conclusions: In cases with HGI, a significant CTV _HR D ₉₀ dose increase was obtained with sufficient bladder and rectal doses suppression.
(© 2022 The Author(s).)