Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
2394 - Toxicity and Survival Analysis of Vertebral-Body-Sparing Proton Craniospinal Irradiation in Pediatric Patients
Presenter(s)
Chuyu Xia, MD - Peking University First Hospital, Beijing,
C. Xia1, S. Zhang2, X. Gao1, S. Shimizu3, Z. Wang2, C. Liu1, and M. Ma1; 1Department of Radiation Oncology, Peking University First Hospital, Beijing, China, 2Department of Radiation Oncology, Yizhou Pronton Therapy Center, Zhuozhou, Hebei, China, 3Department of Radiation Oncology, Hebei Yizhou Cancer Hospital, Zhuozhou, China
Purpose/Objective(s):
This study aims to evaluate the acute toxicities and the influencing factors associated with vertebral-body-sparing proton craniospinal irradiation (VBSpCSI) utilizing pencil beam scanning (PBS) in pediatric patients, and to assess subsequent spinal growth and survival outcomes.Materials/Methods:
A retrospective analysis was conducted on 70 pediatric patients treated with VBSpCSI using PBS at Hebei Yizhou Cancer Hospital between January 2020 and December 2022. The study evaluated acute toxicities and spinal growth post-treatment. Linear regression analysis and receiver operating characteristic (ROC) were employed to evaluate the vertebral dose-effect relationship. Spinal growth was assessed by measuring the Cobb angle on magnetic resonance imaging (MRI) during follow-up. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.Results:
The median age at the time of irradiation was 6 years (range,2-16 years). During treatment, the nadir of white blood cells, absolute neutrophils counts and absolute lymphocyte counts were significantly negatively linearly correlated with vertebral V5 Gy(WBC:P=0.009;ANC:P=0.006;ALC:P=0.001) and V20 Gy(WBC:P=0.007;ANC:P=0.011;ALC:P?0.001). When vertebral V5 Gy?86.5% and V20 Gy?73.2%, the incidence of grade =3 myelosuppression was significantly reduced (P?0.001; P=0.001). Additionally, younger age (in months) and concurrent chemotherapy were significantly associated with increased acute hematological toxicity. Two patients (3%) experienced grade =3 gastrointestinal toxicity, and seven patients (10%) developed grade 1 radiation esophagitis. Among the 43 patients with MRI follow-up, no instances of scoliosis, kyphosis, or chronic lumbosacral pain were observed. The 3-year OS and PFS rates were 95.7% and 86.4%, respectively.Conclusion:
The use of PBS technology for VBSpCSI in pediatric patients demonstrates manageable acute toxicities, with a clear dose-effect relationship between vertebral V5 Gy/V20 Gy and hematological toxicity. The incidence of non-hematological toxicities was low. However, longer follow-up is required to fully assess the long-term impacts on spinal growth and overall survival.| RTOG radiation morbidity score | Grade 0 | Grade 1 | Grade 2 | Grade 3 | Grade 4 |
| Myelosuppressionn | 0(0) | 1(1) | 29(41) | 36(51) | 4(6) |
| Leukopenia | 2(3) | 5(7) | 33(47) | 28(40) | 2(3) |
| Neutropenia | 8(11) | 9(13) | 21(30) | 28(40) | 4(6) |
| Lymphopenia | 0(0) | 11(16) | 52(74) | 7(10) | 0(0) |
| Anemia | 14(20) | 22(31) | 32(46) | 2(3) | 0(0) |
| Thrombocytopenia | 60(86) | 7(10) | 2(3) | 1(1) | 0(0) |
| Gastrointestinal reaction | 25(36) | 12(17) | 31(44) | 2(3) | 0(0) |
| Esophagitis | 63(90) | 7(10) | 0(0) | 0(0) | 0(0) |