Dosimetry of intracavitary applications in carcinoma of the cervix: rectal dose analysis.

The International Commission on Radiation Units and Measurements (ICRU), in its Report-38, has given certain recommendations regarding the specifications of bladder and rectal reference points in the intracavitary treatment of carcinoma of the cervix. Conforming to this report, 182 intracavitary applications performed in stage I and II cervix cases were analyzed. In 113 applications, the maximum rectal dose was found to be in a point on the anteroposterior line drawn through the centre of colpostat sources. However, for our type of applications, the point on the anteroposterior line drawn through the lower end of the uterine tube seldom gets maximum dose. In addition, it was observed that there are other dose points than the ICRU reference point receiving doses close to maximum dose. It was concluded that doses to multiple rectal reference points should be recorded, in addition to the ICRU-defined rectal reference point.