Brain Imaging Changes Following Proton Therapy for Pediatric Primary Central Nervous System and Base of Skull Tumors

Study Overview
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Brief Summary
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This trial gathers information from patients with primary central nervous system or base of skull tumors that receive proton beam therapy and see if certain imaging techniques can help detect radiation-related changes over time. This study may help providers learn more about proton beam radiotherapy and how to improve the way it is delivered.

Detailed Description
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PRIMARY OBJECTIVE: I. To establish linear energy transfer (LET)-based models as early predictors for white matter changes on magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) sequences in pediatric patients following proton beam therapy for primary central nervous system (CNS) and base of skull tumors. OUTLINE: Patients' medical charts are reviewed.

Official Title
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Assessment of Predicted LET and Dosimetry in Relation to White Matter Changes in Pediatric Patients Following Proton Therapy for Primary Central Nervous System and Base of Skull Malignancies: A Pilot Study

Conditions
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Malignant Central Nervous System Neoplasm, Malignant Skull Base Neoplasm

Intervention / Treatment
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* Other: Medical Chart Review


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients must have histologically confirmed central nervous system of skull base tumors Patient is going to undergo central nervous system (CNS) or base of skull proton beam therapy Exclusion Criteria: Patients who have received prior therapeutic radiotherapy to the primary brain tumor site Patients who are unable to maintain follow-up through the Phoenix Children's Hospital and Mayo Clinic Arizona

Ages Eligible for Study
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Maximum Age: 21 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Observational (medical chart review)<br>Patients' medical charts are reviewed. | Other: Medical Chart Review<br>* Review of medical chart<br>* Other names: Chart Review;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| White matter changes within the central nervous system (CNS) following proton beam therapy using magnetic resonance imaging (MRI) sequences | The concordance of predicted linear energy transfer linear (LET) values with radiographic white matter changes will be analyzed utilizing a one sample t-test. Will the compare concordance over time to evaluate if there is an increase, utilizing repeated measures mixtures models. | At 18 months | 
| White matter changes within the CNS following proton beam therapy using diffusion tensor imaging (DTI) sequences | The concordance of predicted LET values with radiographic white matter changes will be analyzed utilizing a one sample t-test. We will the compare concordance over time to evaluate if there is an increase, utilizing repeated measures mixtures models. | At 18 months | 
| Relative biological effectiveness (RBE) predictions | Will compare concordance over time to evaluate if there is an increase, utilizing repeated measures mixtures models. | Up to 18 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| White matter changes within the CNS following proton beam therapy using DTI and MRI | Will assess the white matter changes within the CNS following proton beam therapy using DTI and MRI and determine concordance with predicted RBE values and biological dose. | Up to 18 months | 
| Dose-volume effect and predicted LET distribution | Will be correlated. Will evaluate the percent of concordance of isodose volumes with white matter changes utilizing pairwise t-tests and repeated measures mixed models. | Up to 18 months | 
| White matter changes identified on imaging, and predict concordance | Will be described with both clinical acute and late toxicities following proton beam therapy. Exploratory analyses utilizing tests for association and appropriate regression techniques will be conducted to determine the association of dose volume histogram, LET, RBE, and clinical factors on acute and late toxicities caused by white matter changes. | Up to 18 months |