CARCINOMA OF THE UTERINE CERVIX .2. LACK OF IMPACT OF PROLONGATION OFOVERALL TREATMENT TIME ON MORBIDITY OF RADIATION-THERAPY

Purpose: Several reports document a negative impact of prolongation of overall treatment time in a course of irradiation on tumor control an d survival. A correlation has been documented of incidence of signific ant treatment sequelae with increasing doses of irradiation, volume of the specific organ, and dose per fraction. However, no data were foun d on the potential correlation of overall irradiation treatment time w ith significant sequelae. Methods and Materials: Records were reviewed of 1269 patients with carcinoma of the cervix (Stage IB to III) treat ed with definitive irradiation (combination of external beam and two i ntracavitary insertions). Follow-up was obtained in 97% of patients (m edian, 12 years; minimum, 3 years; maximum, 28 years). The relationshi ps between overall treatment time and time of brachytherapy and incide nce of treatment sequelae were analyzed for each stage. Results: Overa ll incidence of Grades 2 (moderate) sequelae was 7% and of Grade 3 (se vere) sequelae, 11%. There was no significant correlation of various i ncidences of Grade 2 and 3 sequelae with overall treatment times (8% i n patients treated in less than 7 weeks, 9% in 7.1 to 9 weeks, and 12% when treatment time was longer than 9 weeks) (p = 0.08). In patients with Stage IB and IIA tumors, incidence of rectal toxicity (mostly pro ctitis) was comparable in patients treated in less than 7 or 7.1 to 9 weeks (4.1 and 6%, respectively) and slightly higher in those treated in longer periods (11.5%) (p = 0.24). In patients with Stage IIB and I II, the incidence of Grade 2 and 3 small bowel morbidity was 2% in tho se treated in less than 7 weeks, 6% for 7.1 to 9 weeks, and 4.9% for l onger times (p less than or equal to 0.01). This increased morbidity w as also correlated with total dose of irradiation to the lateral pelvi c wall: 5 of 257 (2%) for less than 60 Gy and 21 of 438 (4.8%) for hig her doses (p less than or equal to 0.01). There was no significant cor relation between the timing of brachytherapy (usually two low dose rat e intracavitary insertions performed within 4.5 to 6.5 weeks of initia tion of external beam therapy) and significant treatment sequelae. Con clusions: We observed a varied average incidence of Grade 2 and 3 morb idity in the bladder, rectum, and small intestine with different overa ll treatment times, without a definite pattern to suggest an impact of prolongation of treatment time on morbidity. Likewise, there was no s ignificant correlation with the timing of intracavitary insertions and morbidity of therapy. Because prolongation of the overall treatment t ime has a well-documented detrimental effect on pelvic tumor control a nd survival in carcinoma of the cervix with no significant impact on m orbidity, it is imperative to deliver radiation therapy in the shortes t possible time and without schedule interruptions.