Safety and Efficacy of Vertebral Body-Sparing Craniospinal Irradiation With Proton Therapy in Pediatric Tumors (VBS-CSI-PT-PED)

Safety and Efficacy of Vertebral Body-Sparing Craniospinal Irradiation (VBS-CSI) With Proton Therapy in Pediatric Tumors: A Single-Center Prospective Observational Cohort Study

his is a single-center, prospective observational study in children and adolescents with central nervous system tumors who need whole-brain and whole-spine radiation therapy (craniospinal irradiation, CSI). The study uses proton therapy with a special vertebral body-sparing (VBS) technique to protect the front and center of the vertebrae, which helps preserve bone marrow function and growth. The main goals are to find safe dose limits for the vertebrae and check how often severe side effects occur. The study will also look at bone marrow preservation, spinal deformity, tumor control, survival, chemotherapy completion, neurocognitive function, quality of life, and growth and development for up to 5 years after treatment.

Study Overview

• Status: Not yet recruiting
• Conditions: Ependymoma; Medulloblastoma; Germinoma; Atypical Teratoid/Rhabdoid Tumor (AT/RT); Pediatric Central Nervous System Tumors
• Intervention / Treatment: Radiation: Vertebral Body-Sparing Craniospinal Proton Irradiation

• Study Type: Observational
• Enrollment (Estimated): 38

Contacts and Locations

• Study Contact: Name: Jiayi Chen; Phone Number: +86 021 64370045; Email: cjy11756@rjh.com.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This is a prospective observational study enrolling 38 pediatric patients aged >3 years and ≤18 years with histologically confirmed central nervous system tumors requiring craniospinal irradiation (CSI). Patients will be assigned to 2 cohorts: low-dose CSI and high-dose CSI. All participants will receive vertebral body-sparing intensity-modulated proton therapy (IMPT) and standard chemotherapy according to clinical guidelines.

Description

Inclusion Criteria:

• The patient's legal guardian voluntarily signs the written informed consent form.
• Age at diagnosis > 3 years and ≤ 18 years.
• Histopathologically confirmed diagnosis of a central nervous system (CNS) tumor.
• Indication for craniospinal irradiation (CSI) confirmed by multidisciplinary team (MDT) discussion.
• Karnofsky Performance Score (KPS) ≥ 80.
• For postoperative patients, complete healing of the surgical incision with no evidence of wound infection or other complications.
• For women of childbearing potential, effective contraception must be used for at least one month prior to screening, and they must commit to continued contraception throughout the study period and for the required time after study completion.

Exclusion Criteria:

• Previous receipt of any form of spinal radiotherapy.
• Previous major spinal surgery for any reason.
• Presence of clinically significant and confirmed spinal deformity at enrollment (e.g., Cobb angle > 10° measured by MRI or X-ray).
• Presence of medical contraindications to proton radiotherapy.
• Presence of any severe, uncontrolled systemic disease (e.g., active infection, severe cardiac, hepatic, renal, or respiratory insufficiency) that, in the investigator's judgment, makes the subject unsuitable for treatment under this protocol.
• Female patients who are pregnant or breastfeeding.
• Presence of any severe cognitive or psychiatric disorder that prevents understanding of or cooperation with study assessments.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Low-Dose Cohort; Patients in the low-dose cohort receive vertebral body-sparing craniospinal irradiation (VBS-CSI) using pencil-beam scanning proton therapy at a prescription dose of 23.4 Gy(RBE) in 13 fractions or 24 Gy(RBE) in 15 fractions.	Radiation: Vertebral Body-Sparing Craniospinal Proton Irradiation; Vertebral body-sparing craniospinal irradiation (VBS-CSI) using intensity-modulated proton therapy (IMPT, pencil-beam scanning). The treatment actively restricts radiation dose to the anterior and central regions of thoracolumbar vertebral bodies to preserve active bone marrow and spinal growth potential, while ensuring adequate target coverage for the whole brain and spinal cord. Two dose levels are applied: 23.4 Gy(RBE)/13 fractions or 24 Gy(RBE)/15 fractions and 36 Gy(RBE)/20 fractions.
High-Dose Cohort; Patients in the high-dose cohort receive vertebral body-sparing craniospinal irradiation (VBS-CSI) using pencil-beam scanning proton therapy at a prescription dose of 36 Gy(RBE) in 20 fractions.	Radiation: Vertebral Body-Sparing Craniospinal Proton Irradiation; Vertebral body-sparing craniospinal irradiation (VBS-CSI) using intensity-modulated proton therapy (IMPT, pencil-beam scanning). The treatment actively restricts radiation dose to the anterior and central regions of thoracolumbar vertebral bodies to preserve active bone marrow and spinal growth potential, while ensuring adequate target coverage for the whole brain and spinal cord. Two dose levels are applied: 23.4 Gy(RBE)/13 fractions or 24 Gy(RBE)/15 fractions and 36 Gy(RBE)/20 fractions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of ≥ Grade 3 acute adverse events	To evaluate the incidence of treatment-related acute adverse events of grade 3 or higher, assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).	Up to 3 months after completion of radiotherapy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Active Bone Marrow Preservation Rate	The proportion of active bone marrow in the vertebral body is calculated by dividing the width of the low-signal area by the total diameter of the vertebral body, which allows a relatively quantitative assessment of the active bone marrow preservation rate.	Baseline, 3, 6, 12, 24, 36, 48, 60 months
Incidence of spinal deformity	Evaluation is performed using whole-neuraxis MRI or whole-spine anteroposterior and lateral X-ray films. Spinal scoliosis is quantitatively assessed using the Cobb angle measurement method by a radiologist who is blinded to the patient's specific treatment information. The degree of kyphosis is evaluated by assessing the presence of thoracic kyphosis. Additionally, vertebral body change characteristics of the thoracolumbar spine are measured, including the posterior-to-anterior ratio (PARs) of the vertebral body-defined as the ratio of the posterior vertebral body height to the anterior vertebral body height-as well as intervertebral disc height.	Baseline and at 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months after treatment completion

Collaborators and Investigators

• Sponsor: Ruijin Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): April 30, 2026
• Primary Completion (Estimated): June 30, 2029
• Study Completion (Estimated): December 31, 2033

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: May 10, 2026
• First Posted (Actual): May 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 10, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Glioma; Neoplasms, Neuroepithelial; Neuroectodermal Tumors; Neoplasms, Germ Cell and Embryonal; Neoplasms, Nerve Tissue; Neuroectodermal Tumors, Primitive; Neoplasms, Complex and Mixed; Ependymoma; Medulloblastoma; Rhabdoid Tumor; Germinoma
• Other Study ID Numbers: VBS-CSI-Proton-Pediatric

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No