POstmastectomy radioThErapy in Node-posiTive breast cancer with or without Internal mAmmary nodaL irradiation (POTENTIAL): a study protocol for a multicenter prospective phase III randomized controlled trial

• Published in: BMC cancer Vol. 21; no. 1; pp. 1185 - 10
• Main Authors: Zhao, Xu-Ran, Fang, Hui, Tang, Yu, Hu, Zhi-Hui, Jing, Hao, Liang, Lin, Yan, Xue-Na, Song, Yong-Wen, Jin, Jing, Liu, Yue-Ping, Chen, Bo, Tang, Yuan, Qi, Shu-Nan, Li, Ning, Lu, Ning-Ning, Men, Kuo, Hu, Chen, Zhang, Yu-Hui, Li, Ye-Xiong, Wang, Shu-Lian
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 06.11.2021; BioMed Central; BMC
• Subjects: Anthracycline; Anthracyclines - therapeutic use; Antineoplastic Agents - therapeutic use; Axilla; Biopsy; Breast cancer; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - pathology; Breast Neoplasms - radiotherapy; Breast Neoplasms - therapy; Bridged-Ring Compounds - therapeutic use; Cancer therapies; Cardiovascular disease; Care and treatment; Chemotherapy; Clinical trials; Clinical Trials, Phase III as Topic; Computed tomography; Disease-Free Survival; Dissection; Dose Fractionation, Radiation; Drug dosages; Female; Heart; Humans; Internal mammary node irradiation; Lymphatic Irradiation; Lymphatic Metastasis - diagnostic imaging; Lymphatic Metastasis - radiotherapy; Lymphatic system; Magnetic resonance imaging; Mammography; Mastectomy; Metastasis; Multicenter Studies as Topic; Patient outcomes; Patients; Population studies; Postmastectomy radiotherapy; Postoperative care; Postoperative Care - methods; Prospective Studies; Quality assurance; Radiation therapy; Radiotherapy; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Conformal - methods; Randomized Controlled Trials as Topic; Skin cancer; Study Protocol; Survival; Survival outcome; Taxoids - therapeutic use; Testing; Thyroid gland; Tomography, X-Ray Computed; Toxicity; Tumors; Ultrasonic imaging; China; Breast cancer; Postmastectomy radiotherapy; Toxicity; Survival outcome; Internal mammary node irradiation
• DOI: 10.1186/s12885-021-08852-y
• ISSN: 1471-2407

Various randomized trials have demonstrated that postmastectomy radiotherapy (RT) to the chest wall and comprehensive regional nodal areas improves survival in patients with axillary node-positive breast cancer. Controversy exists as to whether the internal mammary node (IMN) region is an essential component of regional nodal irradiation. Available data on the survival benefit of IMN irradiation (IMNI) are conflicting. The patient populations enrolled in previous studies were heterogeneous and most studies were conducted before modern systemic treatment and three-dimensional (3D) radiotherapy (RT) techniques were introduced. This study aims to assess the efficacy and safety of IMNI in the context of modern systemic treatment and computed tomography (CT)-based RT planning techniques. POTENTIAL is a prospective, multicenter, open-label, parallel, phase III, randomized controlled trial investigating whether IMNI improves disease-free survival (DFS) in high-risk breast cancer with positive axillary nodes (pN+) after mastectomy. A total of 1800 patients will be randomly assigned in a 1:1 ratio to receive IMNI or not. All patients are required to receive ≥ six cycles of anthracycline and/or taxane-based chemotherapy. Randomization will be stratified by institution, tumor location (medial/central vs. other quadrants), the number of positive axillary nodes (1-3 vs. 4-9 vs. ≥10), and neoadjuvant chemotherapy (yes vs. no). Treatment will be delivered with CT-based 3D RT techniques, including 3D conformal RT, intensity-modulated RT, or volumetric modulated arc therapy. The prescribed dose is 50 Gy in 25 fractions or 43.5 Gy in 15 fractions. Tiered RT quality assurance is required. After RT, patients will be followed up at regular intervals. Oncological and toxilogical outcomes, especially cardiac toxicities, will be assessed. This trial design is intended to overcome the limitations of previous prospective studies by recruiting patients with pN+ breast cancer, using DFS as the primary endpoint, and prospectively assessing cardiac toxicities and requiring RT quality assurance. The results of this study will provide high-level evidence for elective IMNI in patients with breast cancer after mastectomy. ClinicalTrails.gov , NCT04320979 . Registered 25 Match 2020, https://clinicaltrials.gov/ct2/show/NCT04320979.