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Computed tomography analysis of causes of local failure in radiotherapy for cervical carcinoma
Author(s) -
Suyama Sumio,
Nakaguchi Takahiro,
Kawakami Kouichi,
Shou Keizen,
Fushiki Masato,
Taneike Makoto,
Matsui Akira,
Takahashi Masasi,
Morita Rikushi
Publication year - 1998
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/(sici)1097-0142(19981101)83:9<1956::aid-cncr11>3.0.co;2-i
Subject(s) - medicine , cervix , radiation therapy , nuclear medicine , computed tomography , pelvis , radiation treatment planning , carcinoma , radiology , cancer , pathology
BACKGROUND The authors analyzed the radiation dose to the periphery of the cervix and area of the cervix in relation to local failure of radiotherapy for carcinoma of the cervix using computed tomography (CT) images. METHODS Between 1981‐1990, 127 consecutive patients were treated with definitive radiotherapy. Ninety‐nine of these patients had CT images taken at the time of intracavitary therapy. Of these 99 patients, 80 were eligible for this analysis. After CT scanning, isodose curves relative to the point A dose were superimposed on the CT images. The minimum percent dose and minimum dose at the periphery of the cervix were estimated. The area of the cervix also was measured. These factors were examined in relation to the local tumor control rate. RESULTS Histograms of both the minimum percent dose and the cervical area showed significant differences between the local control and local failure groups ( P < 0.001). The local control rates were related to both the minimum percent dose and the cervical area, and differed significantly over and below the values of 60% and 18 cm 2 ( P < 0.001 each), respectively. The local control patients, over and below the line: Y = ‐0.220X + 21.2, in which X (gray [Gy]) and Y (Gy) are the whole pelvis dose and the minimum dose, respectively, could be well differentiated with significance (91.7% vs. 25.0%; P < 0.001). CONCLUSIONS Computed tomography analysis indicated that the local tumor control rate was related strongly to the minimum percent dose, the cervical area, and the pair of whole pelvis and minimum dose values. These factors were found to be more useful than the point A dose in predicting local tumor control. Cancer 1998;83:1956‐1965. © 1998 American Cancer Society.