Impact of Combined Interstitial and Intracavitary Brachytherapy in Locally Advanced Cervical Cancer: A Feasibility, Survival, and Toxicity Profile Assessment

Advancements in role of imaging in brachytherapy in treatment of cervical cancers has seen further improvement in therapeutic ratio. We assessed the impact of combined interstitial and intracavitary brachytherapy in locally advanced cervical cancer in relation to survival outcomes and toxicity profile. A total 125 patients, histopathologically diagnosed as cervical cancer and staged as per FIGO staging, were enrolled for the procedure. After completing external beam radiation therapy (Median dose 50Gy), patients were evaluated for brachytherapy which involved CT based hybrid interstitial-intracavitary brachytherapy using Iridium-192 source and a novel template to facilitate therapy. Parametrial extent of the disease in these patients was judged to exceed the coverage limit of intracavitary brachytherapy alone. ‘Manish Jupiter template’ was used for guidance of parametrial needles to perform high-dose-rate-brachytherapy. Clinical feasibility, treatment outcomes, and toxicity profile were assessed. The patients were followed up as per the institution protocol. There were 57 patients (45.6%) in FIGO stage IIIB and 50 patients (40%) in stage IIB. The median EBRT dose was 50Gy and Brachytherapy dose received was 23Gy. The overall median EQD2 was 85Gy. After a median follow up of 30 months (Range 10 -50 months), local control rate was 95.2% and 11 patients (8.8%) developed distant metastases (9-Lung, 2-brain). Of the distant metastases, 7 were Stage IIIB and 4 had IIB disease. The median total treatment time was 69 days. No adverse events were caused by the procedure. Grade 2 and 3 rectal and bladder toxicities were 7.9% and 2.4% and 5.66% and 2.4% respectively. Disease free survival probability after 1 and 2 years was 94.1% and 93.53%. On multivariate analysis, stage of disease IIB, treatment duration less than 49 days and EQD2 of more than 85Gy were found to improve the rate of local recurrence and distant metastases. Hybrid brachytherapy with the novel template has shown to improve the therapeutic ratio in LACC by enabling a tumor specific dose escalation leading to improved survival outcomes without adding treatment related late morbidity. The procedure was more conformal with improved dosimetry and clinical outcomes.