Late side effects of 3T MRI-guided 3D high-dose rate brachytherapy of cervical cancer Institutional experiences
Abstrakt
Purpose This article reports experiences with 3T magnetic resonance imaging(MRI)-guided brachytherapy (BT) for cervical cancer focusing on late side effects. Methods Between June 2012 and March 2017 a total of 257 uterovaginal BT administrations were performed in 61 consecutive patients with inoperable cervical cancer.
All patients were treated with BT combined with external beam radiotherapy. Results The mean HR-CTV (high risk-clinical target volume) D-90 was 87 & x202f;+/- 5.1 & x202f;Gy equivalent dose corresponding to the conventional fractionation using 2 & x202f;Gy per fraction (EQD2, range 70.7-97.9 & x202f;Gy).
The mean doses in OAR (organs at risk), namely rectum, sigmoid and bladder were D2 & x202f;cm(rectum)(3)& x202f;= 62.6 & x202f;+/- 6.9 & x202f;Gy EQD2 (range 38.2-77.2 & x202f;Gy), D2 & x202f;cm(sigmoid)(3)& x202f;= 66.2 & x202f;+/- 6.8 & x202f;Gy EQD2 (43.2-78.6 & x202f;Gy) and D2 & x202f;cm(bladder)(3)& x202f;= 75.1 & x202f;+/- 8.3 & x202f;Gy EQD2 (58.2-92.6 & x202f;Gy). There were no signs of late gastrointestinal (GI) toxicity in 49 patients, grade 3 toxicity was seen in 2 patients and grade 4 toxicity in 3 patients.
There were no signs of late genitourinary (GU) toxicity in 41 patients, grade 3 toxicity was seen in 4 patients and no signs of grade 4 toxicity were seen. After the treatment, 60 patients (98.4%) achieved locoregional remission.
In 54 patients (88.5%) the remission was complete, whereas in 6 patients (9.8%) remission was partial. Conclusion The use of 3T MRI-guided BT leads to achievement of high rates of local control with limited late morbidity as demonstrated in this series of patients.