Montana G S, Martz K L, Hanks G E
Radiology Department, Duke University Medical Center, Durham, NC 27710.
Int J Radiat Oncol Biol Phys. 1991 Jan;20(1):87-93. doi: 10.1016/0360-3016(91)90142-q.
Patterns of Care Study (PCS) conducted the second survey of carcinoma of the cervix in 1978. The data of this survey are derived from 565 patient questionnaires completed from 120 randomly selected facilities. Through these surveys PCS has set out to establish a profile of the practice of radiation therapy in the United States as well as determine the survival, local control rates, patterns of recurrence, complications, and relationship of these events with dose. This study deals with the patterns and sites of failure and relationship with dose to the paracentral and lateral points previously defined. The breakdown of patients according to the stage was as follows: Stage I = 203, Stage II = 243, Stage III = 115, undertermined = 4. Twenty-three percent of the patients failed within the field of irradiation, whereas 9% failed outside of the irradiated field. The infield failure rate increased as a function of stage from 9% in Stage I to 23% in Stage II and 48% in Stage III. Distant metastasis was the first site of failure in 4% of patients with Stage I, 7% for Stage II, 9% for Stage III, and 6% for the entire group. The cervix and vagina were the first site of recurrence in 20% of the patients. The cervical/vaginal recurrence rate increased as a function of stage from 7% in Stage I to 21% in Stage II, and 37% in Stage III. An analysis of the cervical/vaginal recurrences as a function of the average total dose to the paracentral points showed a decreased recurrence rate as a function of dose within the range of less than 6500 to 7999 cGy. The recurrence rate at 4 years decreased from 34% with a dose of less than 6500 cGy to 14% with a dose of 7500-7999 cGy. Above this dose level, this correlation of dose with recurrence was not observed. This correlation was also absent when the patients were studied according to the stage of the disease. The relationship of parametrial/sidewall failure and average dose to the lateral point was studied also, but no correlation was found except for patients with Stage III disease. The disease-free survival was studied for the entire group of patients and for the different stages as a function of average paracentral dose: less than 7500 cGy, 7500 to 8500 cGy, and greater than 8500 cGy. The disease-free survival was lower for the patients in the less than 7500 cGy group.(ABSTRACT TRUNCATED AT 400 WORDS)
