Large volume was associated with increased risk of acute non-hematologic adverse events in the hybrid of intracavitary and interstitial brachytherapy for locally advanced uterine cervical cancer: preliminary results of prospective phase I/II clinical trial

Abstract Objective This is the preliminary results of a multi-center prospective clinical trial evaluating the feasibility of the hybrid of intracavitary and interstitial brachytherapy for locally advanced cervical cancer. Methods Patients with FIGO stage IB2, IIA2, IIB, IIIA, IIIB and IVA uterine cervical cancer pretreatment width of which was ≥5 cm measured by MRI were eligible. Protocol therapy consisted of 30–30.6 Gy in 15–17 fractions of whole pelvic radiotherapy concurrent with weekly CDDP, followed by 24 Gy in 4 fractions of hybrid of intracavitary and interstitial and pelvic radiotherapy with central shield up to 50–50.4 Gy in 25–28 fractions. The primary endpoint of phase I part was that the rate of grade ≥ 3 acute non-hematologic adverse events related to hybrid of intracavitary and interstitial would be