Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix

Grigsby PW. Radiation Therapy Oncology Group clinical trials for carcinoma of the cervix. The purpose of this paper is to review the primary data of the clinical trials performed by the Radiation Therapy Oncology Group (RTOG) for patients with carcinoma of the uterine cervix. The trials, their strengths, limitations, and the implications of the results are discussed. During the past 25 years there have been several clinical trials performed by the RTOG to test various hypotheses for improving local control and survival for patients with carcinoma of the uterine cervix. The major research themes that have been appraised are the use of hyperbaric oxygen, altered fractionation radiotherapy, hypoxic cell sensitization, chemo-sensitization, prophylactic paraaortic irradiation, and neutron radiotherapy. There are two general research themes. The initial RTOG trials for cervical cancer attempted to address the issues of tumor volume and hypoxic cells while the latter studies addressed these issues and the issue of micrometastatic disease. The phase III clinical trials performed by the RTOG have not demonstrated a local control or survival advantage in the experimental arm with the use of hyperbaric oxygen, split-course radiotherapy, hypoxic cell sensitization, or neutron radiotherapy. Acceptable toxicity and efficacy results were shown in phase II studies evaluating twice-daily irradiation and chemo-sensitization. The positive phase III trials were RTOG 79-20 which evaluated prophylactic paraaortic irradiation in patients with bulky stages IB, IIA, and IIB disease, and RTOG 90-01 which evaluated concurrent chemotherapy. Results of more recent clinical trials are pending their completion.