Systematic review and meta-analysis of photon radiotherapy versus proton beam therapy for pediatric intracranial ependymoma: TRP-ependymoma 2024
Masashi Mizumoto,
Sho Hosaka,
Kei Nakai,
Yinuo Li,
Yoshiko Oshiro,
Takashi Iizumi,
Takashi Saito,
Masako Inaba,
Hiroko Fukushima,
Ryoko Suzuki,
Shosei Shimizu,
Kazushi Maruo,
Hideyuki Sakurai
Affiliations
Masashi Mizumoto
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan; Corresponding author. Proton Medical Research Center, University of Tsukuba 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8575, Japan.
Sho Hosaka
Department of Pediatrics, University of Tsukuba Hospital, Tsukuba, Ibaraki, 305-8576, Japan
Kei Nakai
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Yinuo Li
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Yoshiko Oshiro
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan; Department of Radiation Oncology, Tsukuba Medical Center Hospital, Tsukuba, Ibaraki, 305-8558, Japan
Takashi Iizumi
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Takashi Saito
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Masako Inaba
Department of Pediatrics, University of Tsukuba Hospital, Tsukuba, Ibaraki, 305-8576, Japan
Hiroko Fukushima
Department of Pediatrics, University of Tsukuba Hospital, Tsukuba, Ibaraki, 305-8576, Japan; Department of Child Health, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Ryoko Suzuki
Department of Child Health, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Shosei Shimizu
Department of Pediatric Radiation Therapy Center / Pediatric Proton Beam Therapy Center, Hebei Yizhou Cancer Hospital, 072750, China
Kazushi Maruo
Department of Biostatistics, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Hideyuki Sakurai
Department of Radiation Oncology, University of Tsukuba, Tsukuba, Ibaraki, 305-8576, Japan
Introduction: Proton beam therapy (PBT) may reduce the number of adverse events in treatment of patients with pediatric cancer. However, it is difficult to evaluate whether the actual therapeutic effect is truly equivalent to that of photon radiotherapy. To compare photon radiotherapy and PBT, a meta-analysis and systematic review were performed. Methods: The meta-analysis used papers from 1990 to 2023 in which postoperative local photon radiotherapy or PBT was performed for pediatric intracranial ependymomas. Fifteen articles (5 PBT, 9 photon radiotherapy, one both) were selected based on administration of radiotherapy as local irradiation. Results: Among the 15 chosen articles, the 1- to 5-year overall survival (OS) rates (photon radiotherapy vs. PBT) were 95.4 % (95 % confidence interval (CI) 92.8–97.1 %) vs. 97.2 % (95.7–98.2 %); 88.3 % (85.0–90.9 %) vs. 93.5 % (91.4–95.1 %); 81.2 % (76.9–84.8 %) vs. 91.1 % (88.4–93.2 %); 76.9 % (71.2–81.6 %) vs. 86.1 % (81.9–89.4 %); and 73.8 % (68.3–78.5 %) vs. 84.7 % (79.9–88.5 %), respectively. The 1- to 5-year local control (LC) rates (photon radiotherapy vs. PBT) were 90.9 % (95 % CI 83.9–94.9 %) vs. 91.0 % (88.7–92.9 %); 81.5 % (68.9–89.4 %) vs. 85.7 % (82.0–88.6 %); 77.3 % (62.8–86.8 %) vs. 82.6 % (79.1–85.5 %); 74.6 % (57.7–85.6 %) vs. 78.3 % (71.6–83.5 %); and 72.6 % (51.4–85.8 %) vs. 79.0 % (73.4–83.5 %), respectively. The meta-regression analysis identified relationships of modality (photon radiotherapy vs. PBT), age at irradiation, pathology (Grade 2 vs. Grade 3), and tumor removal (complete resection vs. none) with significantly better 3-year OS after PBT and better 1- to 5-year LC at a younger age. Conclusion: In postoperative local irradiation of ependymomas in children, proton beam therapy had outcomes comparable to those of photon radiotherapy.
