Hyperfractionated radiotherapy of carcinoma of the uterine cervix and predictivity of empirical models

Carcinoma of the uterine cervix is the most common malignancy of women in India. Most of the patients attend for treatment at an advanced stage of the disease. The conventional fractionation schedule fails to give satisfactory tumour control rate in advanced malignancies. Twice daily fractionated radiotherapy (RT) with 1.2 Gy/F, 1.4 Gy/F and 1.6 Gy/F was tried in 40 cases each. The six months minimum follow-up shows that tumour control with 1.2 Gy/F twice daily (85.7%) is comparable with that of a conventional fractionation schedule (82.8%), whereas it is poor with 1.4 Gy/F (71.05%) and 1.6 Gy/F (68.0%) schedules. Attempts were made to apply time dose fractionation (TDF) and linear quadratic (LQ) models to observed tumour control rates. It was observed that time dose fractionation fails to correlate with the observed tumour control rate (p > 0.2). The extrapolated response dose (ERD) analysis also fails to correlate with the tumour control rate (p > 0.3). (author). 29 refs., 4 tabs