Prospective study of concomitant chemoradiation vs accelerated radiotherapy with interdigitated brachytherapy in cancer cervix

For decades, a synergistic combination of EBRT and Intracavitary Brachytherapy (ICBT) has been the widely accepted primary modality of treatment for carcinoma cervix. As already stated, concomitant chemoradiation using Cisplatin has become the accepted standard treatment for locally advanced cases. Although concomitant chemoradiation is the standard care, it cannot be administered safely in elderly patients and those with certain comobilities. An alternative radiation schedule, without chemotherapy, that can reduce treatment time is therefore required, especially in those patients who have contraindications to chemoradiations . Yoon SM et al have shown that in patients in whom chemotherapy cannot be used, radiation alone with 6 fractions per week instead of 5 have equivalent results without major toxicities. The aim of this study was to evaluate the feasibility and compare the efficacy of 6 fractions per week of external beam radiotherapy with conventional fraction size with interdigitated brachytherapy starting from third week of EBRT (a total of 5 fractions of interdigitated brachytherapy, each fraction comprising of 6 Gy each). In the test arm, accelerated EBRT is given to a total dose of 46 Gy in 23 fractions (Monday to Saturday 6 days a week) and interdigitated brachytherapy 6 Gy × 5 fractions. From the third week interdigitated brachytherapy is started and on that day EBRT was not given. On the control arm EBRT was given to 50 Gy in 25 fractions followed by intracavitary brachytherapy 7 Gy × 3 fractions. Concomitant Cisplatin was added along with EBRT. The main aim of the study is to assess and compare the response and safety of accelerated EBRT with interdigitated brachytherapy to concomitant chemo-radiation, which is the accepted standard today. The overall response was comparable in both arms at end of treatment and during the period of follow up. Although the percentage of complete responses were slightly higher in the chemo-radiation arm, this was not statistically significant. Moreover the difference in CRs seemed to diminish with time during follow up.The treatment time was also prolonged in the test Arm as most of the patients had repeated treatment breaks. An important aspect of our study was to assess the overall treatment time. It was found that a majority of patients in the study arm did not complete treatment within the stipulated time whereas many in the chemo-radiation arm had delays also. The rationale for accelerated fractionation (AF) is that reduction in overall treatment time decreases the opportunity for tumour cell regeneration during treatment and therefore increases the probability of tumour control for a given total dose. To conclude, findings from this study suggest that accelerated EBRT (six fractions per week) with interdigitatedbrachytherapy is an effective treatment for patients with locally advanced carcinoma of the uterine cervix and can be used as a possible alternative to concomitant chemo-radiotherapy in selected patients keeping in mind about slightly increased rectal and bowel toxicities. The early responses to treatment are non-inferior to concomitant chemotherapy and the acute toxicities lesser but in our study the Test Arm patients had many treatment breaks due to acute toxicities as a result the treatment time got prolonged in the Test Arm. So to conclude accelerated radiotherapy is a great alternative tool but the problem of acute toxicities must be bore in mind while using a conventional radiotherapy machine like Cobalt 60.