Introduction:

Image-guided 3D brachytherapy (IGBT) contemplates the volumetric definitions for the calculation of the dose to clinical target volume and the risk organs, such as bladder, rectum and sigmoid, but the value of contouring the bowel has not been proven.

Objective:

To determine the doses received at the D2cc (dosage in 2 cubic centimeters) bowel in IGBT.

Methods:

Retrospective study including 117 applications of intracavitary gynecological IGBT of high dose rate carried out in the General Hospital of Mexico, evaluating the bowel D2cc.

Results:

117 applications of IGBT were made by computed tomography, 61 simultaneous arrangements (tandem and ovoids), and 56 vaginal cylinders. In the simultaneous arrangement group, the values of the bowel D2cc were in the range of 53 to 1153 cGy, mean 324 cGy; in the vaginal cylinder group, the range obtained was 36 to 549 cGy, with a mean of 224 cGy. Applying a multiple linear regression model, larger doses to the bowel were observed (86.4 cGy) in the simultaneous arrangement group compared to the vaginal cylinder group, with statistical significance.

Conclusion:

The bowel dosimetry shows higher doses in simultaneous arrangements, but studies are required that evaluate the dosimetry obtained with acute and late clinical toxicity.