Dosimetric comparison of MRI-guided and CT-guided intracavitary and interstitial brachytherapy for locally advanced cervical cancer

Purpose To compare the differences in dosimetry and toxicities between Magnetic Resonance Imaging (MRI) and Computed Tomography (CT)-guided intracavitary and interstitial implantation for locally advanced cervical cancer, respectively. Methods We analyzed 40 cases of locally advanced cervical cancer admitted to our hospital from January 2023 to September 2024. Patients underwent CT-guided intracavitary and interstitial implantation followed by MRI scanning. We compared the volume of HR-CTV and IR-CTV, the dosimetric differences of HR-CTV D 90 and IR-CTV D 90 , and the dosimetric differences of D 2cc for the bladder, rectum, and small intestine under the two localization methods. Results The mean HR-CTV and IR-CTV volumes were larger using CT guidance compared with MRI guidance (P