Post radiation hysterectomy in locally advanced cervical cancer: Outcomes and dosimetric impact

Abstract

Purposes: Firstly, to evaluate the impact of completion hysterectomy after chemoradiation and image-guided adaptive brachytherapy (IGABT) in locally advanced cervical cancer. Secondly, to assess a potential differential dose-effect relationship for the rectum and bladder according to the realization of hysterectomy.

Material and methods: Two cohorts of patients were identified, differing by the realization of completion hysterectomy. Inclusions were limited to FIGO stage I-II, with no para-aortic involvement. All patients received a combination of pelvic chemoradiation followed by IGABT. Their outcomes and morbidity were reviewed. Log-rank tests were used to compare survivals. Probit analyses were performed to study dose-volume effect relationships.

Results: The two cohorts comprised 54 patients in the completion surgery group and 157 patients in the definitive radiotherapy group. They were well balanced, except for the mean follow-up, significantly longer in the post hysterectomy cohort and the use of PET-CT in the work-up, more frequent in the definitive radiotherapy cohort. Although less local relapses were reported in the hysterectomy group, the 5-year disease-free and overall survival did not differ between groups. The cumulative incidence of severe late morbidity was significantly increased in the hysterectomy cohort: 22.5% versus 6.5% at 5years (p=0.016). Dose-volume effects were observed for the bladder, with the D_2cm3 corresponding with a 10% probability of late severe morbidity urinary events (ED₁₀) of 67.8Gy and 91.9Gy in the hysterectomy and definitive radiotherapy cohorts, respectively. A D₉₀ CTV_HR of 85Gy (planning aim) corresponded with a 93.3% rate of local control in the definitive radiotherapy cohort whereas it corresponded with a 77.3% chance to have a good histologic response (complete response or microscopic residual disease) in the hysterectomy group.

Conclusion: No benefit from completion hysterectomy in terms of overall or disease-free survival rates was observed, which was moreover responsible for an increase of the severe late morbidity. The realization of post-radiation hysterectomy resulted in a shift of the ED₁₀ of 24.1Gy.

Keywords: Cervix cancer; Chemoradiation; Hysterectomy; Image-guided adaptive brachytherapy; Late morbidity.