Summary

This randomized phase II trial studies how well dose-escalated photon intensity-modulated radiation therapy (IMRT) or proton beam radiation therapy works compared with standard-dose radiation therapy when given with temozolomide in patients with newly diagnosed glioblastoma. Radiation therapy uses high-energy x-rays and other types of radiation to kill tumor cells and shrink tumors. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor may kill more tumor cells and cause less damage to normal tissue. Drugs, such as temozolomide, may make tumor cells more sensitive to radiation therapy. It is not yet known whether dose-escalated photon IMRT or proton beam radiation therapy is more effective than standard-dose radiation therapy with temozolomide in treating glioblastoma.

Objectives

PRIMARY OBJECTIVE:
I. To determine if dose-escalated and -intensified photon IMRT or proton beam therapy (using a dose-per-fraction escalation with simultaneous integrated boost) with concomitant and adjuvant temozolomide improves overall survival, as compared to standard-dose photon irradiation with concomitant and adjuvant temozolomide.

SECONDARY OBJECTIVES:
I. To indirectly compare dose-escalated and -intensified photon IMRT to dose-escalated and -intensified proton beam therapy in terms of overall survival.
II. To indirectly compare and record toxicities of dose-escalated and -intensified photon IMRT versus dose-escalated and -intensified proton beam therapy and directly compare the toxicities of these approaches versus standard-dose photon irradiation on the backbone of concomitant and adjuvant temozolomide.
III. To determine if dose-escalated and -intensified IMRT or proton beam therapy (using a dose-per-fraction escalation with simultaneous integrated boost) with concomitant and adjuvant temozolomide improves perceived cognitive symptom severity, as compared to standard-dose photon irradiation with concomitant and adjuvant temozolomide.
IV. To determine if dose-escalated and -intensified photon IMRT or proton beam therapy (using a dose-per-fraction escalation with simultaneous integrated boost) with concomitant and adjuvant temozolomide improves neurocognitive function, as compared to standard-dose photon irradiation with concomitant and adjuvant temozolomide.
V. To indirectly determine if dose-escalated and -intensified proton beam therapy with concomitant and adjuvant temozolomide improves perceived cognitive symptom severity, as compared to dose-escalated and -intensified photon IMRT, and to directly compare symptom burden with these approaches versus standard-dose photon irradiation on the backbone of concomitant and adjuvant temozolomide.
VI. To indirectly determine if dose-escalated and -intensified proton beam therapy with concomitant and adjuvant temozolomide improves neurocognitive function, as compared to dose-escalated and -intensified photon IMRT, and to directly compare neurocognitive function with these approaches versus standard-dose photon irradiation on the backbone of concomitant and adjuvant temozolomide.

EXPLORATORY OBJECTIVES:
I. Tissue banking for future translational science projects that will be determined based on the state of the science at the time the primary endpoint is reported and will be submitted to National Cancer Institute (NCI) for review and approval.
II. To prospectively compare CD4 lymphopenia between dose-escalated and intensified proton beam therapy, dose-escalated and -intensified photon IMRT, and standard-dose photon irradiation and determine whether CD4 lymphopenia impacts overall survival.
III. To explore the most appropriate and clinically relevant technological parameters to ensure quality and effectiveness throughout radiation therapy processes, including imaging, simulation, patient immobilization, target and critical structure definition, treatment planning, image guidance and delivery.
IIIa. To establish feasibility and clinical relevancy of quality assurance guidelines.
IIIb. To evaluate efficacy of quality assurance tools.
IV. To explore the most appropriate and clinically relevant advanced and standard magnetic resonance imaging (MRI) imaging parameters.
IVa. To evaluate the feasibility of differentiating pseudo-progression and true progression in a multi institutional setting using magnetic resonance (MR) diffusion and perfusion imaging.
IVb. To evaluate for early, imaging biomarkers of response and overall survival.

OUTLINE: Patients are assigned to 1 of 2 groups depending on enrolling institution. Within each group, patients will be randomized 1:2 in favor of the experimental arms.

GROUP I (PHOTON IMRT CENTERS): Patients are randomized to 1 of 2 treatment arms.

ARM A1: Patients undergo standard-dose photon irradiation using 3-dimensional conformal radiation therapy (3D-CRT) or IMRT once daily (QD), 5 days a week for 23 fractions plus a boost of 7 additional fractions.

ARM B: Patients undergo dose-escalated and -intensified photon IMRT QD, 5 days a week for a total of 30 fractions.

GROUP II (PROTON CENTERS): Patients are randomized to 1 of 2 treatment arms.

ARM A2: Patients undergo standard-dose photon irradiation using 3D-CRT or IMRT as in Arm A1.

ARM C: Patients undergo dose-escalated and -intensified proton beam radiation therapy QD, 5 days a week for a total of 30 fractions.

In all treatment arms, patients receive temozolomide orally (PO) QD on days 1-49 of radiation therapy. Beginning 4 weeks later, patients receive temozolomide PO QD on days 1-5. Treatment repeats every 28 days for up to 12 cycles in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up every 3 months for 1 year, every 4 months for 1 year, and then every 6 months thereafter.