Radiation therapy for uterine cervix cancer. Importance of evaluation of pre-treatment tumor size with MR imaging

From May 1992 through December 1995, a total of 42 patients with previously untreated squamous cell carcinoma of the uterine cervix were treated by using middle-dose-rate intracavitary therapy, and their previously treated local tumor volume was evaluated with MRI. According to the staging of FIGO, 2 patients were classified as Stage IB, 2 as IIA, 18 as IIB, 1 as IIIA, 14 as IIIB, 2 as IVA and 3 as IVB. Cumulative 3-year survival rates were 89% in Stage IIB and 54% in IIIB. 3-year local control rates were 100% in Stage IIB and 67% in IIIB. On the other hand, the cumulative survival rate for the local control group in all stages was 100% at 2 years and 82% at 3 years. For the pelvic failure group it was 41% at 2 years. All of those in the pelvic failure group had bulky local tumor sizes of more than 60 mm in the previous treatment MRI study. The 3-year cumulative survival rate and local control rate for tumors less than 60 mm were 84% and 100%, but for tumors over 60 mm the respective rates were 45% and 33% (p<0.01). The a results showed that the group with pretreatment of local tumors over 60 mm on MRI had a poor outcome. We concluded that pretreatment tumor volume is an important factor in prognosis and the evaluation of pretreatment tumor volume by imaging study (MRI) is necessary. (author)