A prospective observational study with dose volume parameters predicting rectosigmoidoscopic findings and late rectosigmoid bleeding in patients with uterine cervical cancer treated by definitive radiotherapy.
OBJECTIVE
We assessed the value of dose-volumetric parameters predicting rectosigmoid mucosal changes (RMC) and late rectosigmoid complications (LRC).


METHODS
Between January 2004 and February 2006, 77 patients with stage IB-IIIB cervical cancer underwent external beam radiotherapy and computed tomography (CT)-based intracavitary irradiation. Total dose to the rectal point and several dose-volumetric parameters for rectosigmoid colon (D20cc, D15cc, D10cc, D5cc, D2cc, D1cc, and D0.1cc , defined as the minimal doses received by the highest irradiated volumes of 20, 15, 10, 5, 2, 1, and 0.1 cc, respectively), were calculated using the equivalent dose in 2 Gy fractions (α/β = 3, Gy3). The RMC and LRC were graded by rectosigmoidoscopy and Radiation Therapy Oncology Group criteria every 6 months, respectively.


RESULTS
Of 77 patients, 27 (35.1%) patients developed RMC ≥ score 3 and 22 (28.6 %) patients developed LRC ≥ grade 2. There was a positive correlation between RMC score and LRC grade (r = 0.728, p < 0.001). In multivariate analyses, D5cc, among the dose-volumetric parameters, was significant parameter for the risks of RMC ≥ score 3 and LRC ≥ grade 2 (p < 0.05).


CONCLUSIONS
D5cc may be a more reliable estimate than other dose-volumetric parameters for predicting the risk of RMC ≥ score 3 and LRC ≥ grade 2 in CT-based brachytherapy.
Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi, South Korea.
Tae Hyun
TH
Kim
Joo-Young
JY
Kim
Dae Kyung
DK
Sohn
Yeon-Joo
YJ
Kim
Yoon-Seok
YS
Lee
Sung Ho
SH
Moon
Sang Soo
SS
Kim
Dae Yong
DY
Kim
D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D001918:Brachytherapy / Q000009:adverse effects*; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000209:etiology / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011832:Radiation Injuries / Q000209:etiology / Q000473:pathology*; D012002:Rectal Diseases / Q000209:etiology / Q000473:pathology*; D012810:Sigmoid Diseases / Q000209:etiology / Q000473:pathology*; D012812:Sigmoidoscopy; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D002583:Uterine Cervical Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*