A Phase 2 Trial of Response-Based Radiation Therapy for Localized Central Nervous System Germ Cell Tumors: Patterns of Failure and Radiation Dosimetry for Nongerminomatous Germ Cell Tumors

• Type of Material: Article
• Authors: Erin S Murphy, Cleveland Clinic; Girish Dhall, University of Alabama Birmingham; Jason Fangusaro, Emory University; Ute Bartels, The Hospital for Sick Children, Toronto; Maryam Fouladi, Cincinnati Children’s Hospital Medical Center; Dennis Shaw, Seattle Children’s Hospital; Soumen Khatua, MD Anderson Cancer Center; Chris Williams Hughes, Children’s Oncology Group; Ashok Panigraphy, Children’s Hospital of Pittsburgh of UPMC; Myrsini Ioakeim-Ioannidou, Massachusetts General Hospital; Mark Souweidane, Weill Cornell Med Coll; David Morris, University of North Carolina Chapel Hill; Amar Gajjar, Brigham and Women’s Hospital and Boston Children’s Hospital; Shengjie Wu, St. Jude Children’s Research Hospital; Arzu Onar-Thomas, St. Jude Children’s Research Hospital; Daphne A Haas-Kogan, Brigham and Women’s Hospital and Boston Children’s Hospital; Shannon M MacDonald, Massachusetts General Hospital
• Language: English
• Date: 2022-04-12
• Publisher: ELSEVIER SCIENCE INC
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: Published by Elsevier Inc.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.ijrobp.2021.12.166
• Title of Journal or Parent Work: INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
• Volume: 113
• Issue: 1
• Start Page: 143
• End Page: 151
• Keywords: Oncology; Life Sciences & Biomedicine; Science & Technology; CHEMOTHERAPY; RADIOTHERAPY; Radiology, Nuclear Medicine & Medical Imaging

Abstract

Purpose: Children's Oncology Group study ACNS1123 tested the efficacy of reduced dose and field of radiation therapy (RT) for patients with localized nongerminomatous germ cell tumors (NGGCT) who achieved a complete (CR) or partial response (PR) to chemotherapy. Here, we evaluate the quality of RT and patterns of failure for patients eligible for reduced RT in this phase 2 trial. Methods and Materials: Patients with localized NGGCT with CR/PR after induction chemotherapy received reduced RT to 30.6 Gy whole ventricular irradiation and 54 Gy tumor-bed total dose. An atlas was provided to assist with complex RT volumes. Early interventional review was performed for the initial RT plan. Complete RT plans for all patients and images of relapsed patients were centrally reviewed at completion of therapy. Results: Between May 2012 and September 2016, 107 eligible patients were enrolled and 66 achieved a CR/PR after induction chemotherapy (± second-look surgery) and were eligible for reduced RT. Median follow-up was 4.4 years. Median age was 11.0 years (3.7-21.6), and 75% were male. Progression-free survival and overall survival at 4 years were 87.9% ± 4.0% and 92.4% ± 3.3% for 66 evaluable patients, respectively. Eight patients relapsed: 6 with isolated spinal relapse and 2 with disease in the brain and spine. After central review, 62 (94%) patients had RT targets contoured and dose delivered per protocol. None of the patients with deviations (n = 4) have progressed. Conclusions: Patterns of failure suggest the spine is at risk for recurrence for patients with localized NGGCT who receive reduced RT after a CR/PR to induction chemotherapy. Although survival data are encouraging, the pattern of failure has influenced the next prospective trial design. RT compliance was excellent despite complexity of radiation volumes, suggesting that providing visual guidance in the form of an online atlas contributes to higher quality RT plans.