Co60 May be the Acceptable Alternative Radionuclides of Ir192 used in HDR Brachytherapy for the Treatment of Inoperable Carcinoma Cervix in the Treatment Modality of Concurrent Chemoradiation

Background: Cancer of the uterine cervix is the eighth most common cancer among women worldwide and third among all malignancies and the second most common cancers in female in Bangladesh. The treatment of cervical cancer requires multidisciplinary approaches Concurrent chemoradiation is the treatment of choice in locally advanced carcinoma cervix uteri. Radiotherapy is the primary local treatment for most patients having FIGO stage IIB to IVA diseases. The success of treatment depends on a careful balance between EBRT and Brachytherapy that optimizes the dose to tumor. Iridium192 is highly used radionuclide for modern remote after loading HDR brachytherapy till date. Recently Co60 source is available with miniature size and identical physical properties for remote after loaders. Methods: 60 patients with biopsy proven locally advanced carcinoma of the uterine cervix were enrolled in the study. Arm A was formed comprising 30 patients who were treated by Ir192 HDR brachytherapy and Arm B formed with equal number of 30 patients who received HDR brachytherapy treated with Co60 radionuclide. This prospective observational study was carried out to compare the treatment effect between two Arm. Results: 60 patients were enrolled in this study with age range from 35 to 63 years. Most of the patients presented with stage IIB disease, consisting of 39 patients (65.3%). Among them 48 patients had squamous cell carcinoma (80.60%), adenocarcinoma trailing with 9 patients (15.3%) and rest were adenoidsquamous carcinoma 2 and small cell carcinoma. In all three insertions, urinary bladder dose distribution was slightly smaller by HDR Co60 irradiation than HDR Ir192 exposure. These differences were statistically significant in first two insertions but not in third one Conclusion: In this study radiation dose distribution at OARs i.e. urinary bladder and rectum were compared between Arm A and Arm B. In all three insertions in urinary bladder the mean dose distribution was slightly smaller in HDR Co60 irradiation than HDR Iridium192 exposure. These differences were statistically significant in first two insertions but not in third one. In case of rectum point, the mean dose distribution was significantly lower in all three insertions of Co60 exposure than Ir192 exposure.