From September 1968 to March 1974, a randomized clinical trial was carried out, using conventional fractionation, i.e., five treatments per week, in 233 patients with advanced cancers of the uterine cervix–Stages IIB, IIA, IIIB and IVA. The age limit was 70 years and all patients had medical clearance. Lymphangiography and, in some patients, an exploratory laparotomy with selective lymphadenectomy, were done prior to treatment to determine the extent of nodal disease. The staging has not been changed either by lymphangiogram or lymphadenectomy findings. A few patients with bulky Stage I and IIA lesions were entered into the trial because of extensive nodal disease demonstrated either by lymphangiogram and/or lymphadenectomy. First, the patients were grouped according to the clinical stage. The secondary stratification was according to the lymphangiogram and/or selective lymphadenectomy findings. The patients were then randomized to air or hyperbaric oxygen within each group. The patients were pressurized in a Vickers chamber at 3 atmosphere absolute, using a 20-minute soak time prior to the irradition. The size of the external beam portal was determined by the status of the nodes. The difference in absolute NED (no evidence of disease) survival rates for both groups as a whole and by stages is not statistically significant. There is no difference in the incidence of failures in the irradiated area between the HPO and air patients. There is no increase in distant metastases in the HP group. It does not seem that the HPO has had an effect on the major complications. However, there was an increase in the incidence of complications with extended fields. The addition of lymphadenectomy had increased the incidence of fatal complications, even with routine pelvic portals. The negative results of this trial with conventional fractioantion should not lead to the conclusion that HPO could not be useful with schemes using a few high dose fractions.

Fletcher, Lindberg, Caderao, Wharton, , , , , (1977). Hyperbaric oxygen as a radiotherapeutic adjuvant in advanced cancer of the uterine cervix: preliminary results of a randomized trial. Cancer, 1977 Feb;39(2):617-23. https://www.ncbi.nlm.nih.gov/pubmed/402186