Radiotherapy quality assurance of gynecologic oncology group (GOG) protocol 165, a cooperative group study of carcinoma of the cervix

Abstract

ABSTRACT: GOG protocol 165 was a randomized phase III trial to evaluate radiation vs. radiation plus weekly cisplatin vs. radiation plus protracted venous infusion 5-FU in patients with stage II-B, III-B and IV-A carcinoma of the cervix. Protocol treatment included external beam therapy and high-dose rate or low-dose rate brachytherapy. Historically, GOG has performed an extensive review of patient treatments on their clinical trials. As HDR had no previously been used in GOG trials, credentialing of institutions and physicians was required prior to entering patients onto the study for the use of HDR, but was not required for external radiation therapy or LDR. Credentialing consisted of a review of the institution’s HDR physics and QA, and a clinical and dosimetric review of the brachytherapy treatment of two patients treated by the same radiation oncologist in a manner similar to the protocol guidelines. The credentialing process not only evaluated the quality of HDR procedures at the institution, but also assured that the institution and participating radiation oncologist had HDR experience. At the same time, it educated the institution as to the specific requirements of the protocol. Retrospective review of radiotherapy of 326 patients entered on the study was performed. A recalculation of patient dose and a review of the records and all planning and verification films were performed by the Radiological Physics Center in conjunction with the GOG HDR subcommittee and the protocol study co-chairs, respectively. Deviations from protocol guidelines were assessed according to predefined criteria. 100% of the patients treated at credentialed institutions were treated without major protocol deviations. In contrast, 81% of patients from non-credentialed institutions completed treatment without major deviations. Minor deviations occurred in both groups with the result that 75% and 50% of patients from credentialed and non-credentialed intuitions respectively were treated in strict compliance with the protocol. A breakdown of protocol deviations appears in table 1. Table 1. Summation of Deviations for Non-Certified and Certified Institutions