The effects of treatment duration on outcomes of radiation treatment with high-dose-rate brachytherapy in the era of concurrent chemoradiation for cervical carcinoma

This study analyzes the effects of treatment prolongation using a patient population that primarily received HDR-ICBT (high-dose-rate intracavitary brachytherapy) during CCRT (cisplatin-based chemotherapy with radiation).

A retrospective review was performed of 214 patients who were diagnosed with cervical carcinoma and completed radiation therapy with LDR (low-dose-rate)-ICBT (77 patients) or HDR-ICBT (137 patients). Whole pelvic radiation therapy was followed by ICBT. LDR-ICBT was delivered in two to three insertions at an average of 85 Gy to point A. After 2000, the institution transitioned to using HDR-ICBT during CCRT. HDR-ICBT was delivered in four to seven insertions, 300 to 700 cGy per session prescribed to point A. Separate statistical analyses were conducted for the patients who received LDR-ICBT and the patients who received HDR-ICBT.

The LDR-ICBT treatment group included 77 patients. The median TD (treatment duration) of 60 days was used as the cutoff for statistical analyses. Significantly increased pelvic recurrence in the patients treated for TD > 60 days compared to TD ≤ 60 days was observed. There was a significant difference in OS (overall survival) distributions. Upon univariate analysis, age at diagnosis > 51 years old, TD > 60 days, and stage were found to be significant prognostic factors, but on multivariate analysis, the only significant prognostic factors were age at diagnosis > 51 years old and TD > 60 days. The HDR-ICBT treatment group all received CCRT and included 137 patients. A range of TD cutoff thresholds from 60 to 78 days was used. There was a significant difference in CSS (cause-specific survival) between TD ≤ 77 days and TD > 77 days. There was no significant difference in local recurrence, distant metastases, and complications. Stage was the only prognostic factor found on multivariate analysis.

In the present era of HDR-ICBT with CCRT, radiation treatment longer than 8 weeks does not appear to make a significant impact on clinical outcomes. This is a retrospective analysis. Further studies are warranted.