Combination of Rotte Y applicator and standard tandem for medically inoperable endometrial cancer

Abstract Herein, we report a novel technique of combination of Rotte “Y” applicator and standard tandem (three-channel) brachytherapy (BT) for endometrial cancer (EC). We treated an older adult patient with medically inoperable EC using radiation therapy (RT) alone. External beam radiation therapy (EBRT) was administered, followed by four sessions of brachytherapy. However, there was insufficient dosimetric coverage of the uterine body in the first two conventional Rotte Y applicator BT sessions (conventional sessions). For the remaining two BT sessions, we combined the Rotte Y applicator with a tandem (hybrid sessions), and the dosimetric parameters of the clinical target volume (CTV) improved significantly. The average CTV D90, D98, and V100 values for the conventional sessions were 5.7 Gy, 4.6 Gy, and 87.14%, respectively; those for the hybrid sessions were 7.4 Gy, 5.5 Gy, and 96.7%, respectively. Using the hybrid technique of BT administration, we could provide a higher dose to the CTV and a lower dose to the organs at risk, especially the sigmoid colon, than the doses provided with the conventional method of administration. Our novel and simple technique, combining the Rotte Y applicator and standard tandem BT, is easy to perform three-channel BT for patients with medically inoperable EC.