Peking Union Medical College Hospital Beijing, Beijing
Z. Zeng, F. Zhang, and J. Yan; Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
Purpose/Objective(s): To assess the safety and efficacy of moderated hypofractionated online adaptive radiotherapy (oART) in combination with high-dose-rate (HDR) brachytherapy in patients with locally advanced cervical cancer (LACC). Materials/
Methods: Patients with histologically confirmed LACC were enrolled in a prospective, regulatory-approved phase 1 trial (NCT05994300). Participants received daily oART via intensity-modulated radiation therapy with 43.35 Gy in 17 fractions to the whole pelvis and a simultaneous integrated boost of 54.40 Gy in 17 fractions to gross lymph nodes. Clinical target volumes were contoured separately with 5-10mm margins. HDR brachytherapy began after external beam radiation therapy (EBRT). Concurrent weekly cisplatin chemotherapy was administered to all participants. Treatment response was evaluated approximately one month after treatment was complete. Toxicity was graded using CTCAE version 5.0, while the EORTC-QLQ-C30 questionnaire evaluated quality of life, and urinary and bowel symptoms were accessed according to the EORTC-QLQ-CX24. Results: A total of 26 patients have completed treatment with moderated hypofractionated oART and HDR brachytherapy. All Patients (100%) had a clinical complete response, with no evidence of tumor on magnetic resonance imaging and computed tomography. Acute gastrointestinal toxicity was Grade 1 or Grade 2 in 15 patients and Grade 3 severity in 3 patients; all Grade 3 toxicities resolved within one week. Acute genitourinary toxicity of Grade 1 or Grade 2 was seen in 8 patients, and no patients had Grade 3 toxicity. Grade 3 acute hematologic toxicity was observed in 9 patients. The mean duration of EBRT was 23 days (ranging from 22 to 28 days). Quality of life and urinary and bowel scores during follow-up were comparable to baseline levels. Conclusion: Moderated hypofractionated oART with HDR brachytherapy appears to be a very promising treatment in LACC, leading to high response rates and limited side effects. Longer follow-up is needed to assess the duration of response. The treatment time of EBRT was shortened compared with conventional therapy.
