Safety and Efficacy of a New Approach to Delineating Clinical Target Volume of Glioblastoma

Study Overview
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Brief Summary
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Radiotherapy (RT) is one of the most important local treatments besides surgery, but currently, no consensus has been made regarding the optimal radiation volume for high grade gliomas. The most main growth characteristics of glioblastoma is infiltrative growth through the white matter tracts, regions along the white matter tracts especially at the direction of the main fiber bundles would have a higher risk of microscopic tumor cell dissemination. However, in current practice, recommends for the CTV definition is adding a 2 cm symmetrical margin to GTV or peritumoral edema in all directions, which hardly account for the growth characteristics of gliomas that are known from histopathological findings.

Detailed Description
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Patients with glioblastoma were recruited for this study based on the following eligibility criteria: Age between 18 and 70, performance status of 0-1 (Eastern Cooperative Oncology Group performance status), histologically confirmed glioblastoma, no cerebrospinal fluid and distant metastatic disease. All patients had adequate hematologic, hepatic, and renal function. Patients younger than 18 years; patients with a prior (i.e. within 5 years) or synchronous malignancy, other than non-melanoma skin cancer; and those with significant comorbidities were excluded. Eligible patients received chemoradiotherapy (CRT) ( PTV-GTV: 60Gy at 2.0Gy per fraction, 5 fractions per week for 6 weeks; PTV-CTV: 54Gy at 1.8Gy per fraction, 5 fractions per week for 6 weeks) with a Temozolomide (TMZ) regimen（75mg/m2 per day during RT）, followed by 6 additional cycles of TMZ. (150 mg/m2 for the first cycle and 200 mg/m2 for the 2-6th cycles, on days 1-5, every 4 weeks) . The investigators established a detailed protocol for target delineation of the CTV based on brain anatomy, white mater fiber tracts distribution and the growth patterns of tumor. Briefly, along the directions of the main nerve fiber bundles ，the CTV is defined as peritumoral edema plus 1cm. while in other directions, the CTV is defined as GTV plus 2cm and should be adjusted to anatomical borders such as the skull (0 mm, using bone window), ventricles (5 mm), falx (0 mm), tentorium cerebelli (0 mm), visual pathway/optic chiasm and brainstem (each 0 mm) and modified to include all regions of abnormal T2/FLAIR MRI signal. Deep brain white matter is the focus for RT target contour, regions of normal uninvolved gray matter should be modified to be protected.

Official Title
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Safety and Efficacy of a New Approach to Delineating Clinical Target Volume by Referencing the Nerve Fiber Bundles for Radiotherapy of Glioblastoma

Conditions
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Glioblastoma

Intervention / Treatment
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* Radiation: New delineation approach


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 18-70 years performance status of 0-1 (Eastern Cooperative Oncology Group performance status) histologically confirmed glioblastoma no cerebrospinal fluid and distant metastatic disease All patients had adequate hematologic, hepatic, and renal function. Exclusion Criteria: younger than 18 years; patients with a prior (i.e. within 5 years) or synchronous malignancy, other than non-melanoma skin cancer; and those with significant comorbidities

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: New delineation approach （NDA）group<br>use a new method for clinical target volume delineation by referencing the nerve fiber bundles | Radiation: New delineation approach<br>* New delineation approach<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall survival (OS) | Time from the start of treatment to death due to the disease | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| recurrence-free survival (RFS) | Time from the start of treatment to recurrence | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Radiotherapy, clinical target volume, Glioblastoma multiforme (GBM), radiation volume, the white matter tracts.