Image Interpretation Details : Interpretation will be performed at the Martinos Center for Biomedical Imaging. 5.4 General Concomitant Medication and Supportive Care Guidelines NA 5.5 Criteria for Taking a Participant Off Protocol Therapy Patient s may remain on study (i.e. continue with MR- PET imaging) until one of the following criteria applies: • Intercurrent illness that prevents further participation in the imaging studies • Unacceptable adverse event(s) Protocol A pilot study to evaluate PBR PET as an indicator of inflammation in brain tumor patients treated with chemoradiation or immunotherapy. Version Date: June 20, 2018 16 • Participant demonstrates an inability or unwillingness to comply with the documentation requirements or imaging stud ies. • Participant decides to withdraw from the protocol (i.e. does not want to undergo further imaging studies) • General or specific changes in the participant's condition render the participan t unacceptable for further imaging studies in the judgment of the treating investigator Participants will be removed from the protocol therapy when any of the se criteria apply. The reason for removal from protocol therapy, and the date the participan t was rem oved, must be documented in the case report f orm (CRF) . Alternative care options will be discussed with the participant. A QACT Treatment E nded/Off Study Form will be filled out when a participant is removed from protocol therapy. This form can be found on the QACT website or obtained from the QACT registration staff. In the event of unusual or life- threatening complications, treating investigators must immediately notify the Overall PI, Elizabeth Gerstner , at . 5.6 Duration of Follow Up Participa nts will be followed for 3 years after removal from protocol therapy or until death, whichever occurs first. Participants removed from protocol therapy for unacceptable adverse event (s) will be followed until resolution or stabilization of the adverse event. 5.7 Criteria for Taking a Participant Off Study Participants will be removed from study when any of the following criteria apply: • Lost to follow-up • Withdrawal of consent for data submi ssion • Death The reason for taking a participant off study, and the date the participant was rem oved, must be documented in the case report f orm (CRF) . A QACT Treatment E nded/Off Study Form will be filled out when a participant comes off study.