Photobiomodulation for Cancer-Related Cognitive Impairment

This is a single site, pilot randomized, double blinded control trial designed to assess changes in cognitive symptoms in cancer survivors with cancer-related cognitive impairment. Patients will be randomized into one of two Arms: Intervention or Control. * Arm A: Intervention Group: Use of the THOR LED Photobiomodulation helmet 3x per week for 6 weeks. Helmet will be in 'therapeutic setting', 35mW/cm2 = 42J/cm2 * Arm B: Control Group: Use of the THOR LED Photobiomodulation helmet 3x per week for 6 weeks. Helmet will be in 'placebo setting', 0mW/cm2 = 0J/cm2 This study has been designed to assess the hypothesis that Photobiomodulation can have a positive impact on cognitive symptoms in cancer survivors with cancer-related cognitive impairment. 30 participants will be recruited for this study, 15 per group. Self-report questionnaires assessing cognitive concerns, cognitive abilities, quality of life, depression, and anxiety will be administered at three timepoints through the study Baseline, End of Study Visit and 1 Month Follow Up

Inclusion Criteria: * Adults ≥ 18 years * Previous diagnosis of stage I-III non-central nervous system solid tumor malignancy, Hodgkin, or Non-Hodgkin lymphoma * Completed cancer treatment (chemotherapy and/or radiation) more than 6 months ago but less than 5 years ago (Current concurrent endocrine therapy, anti-HER-2 therapy allowed, or other stable maintenance therapies (such as rituximab) will be allowed. * Self-reported cognitive complaints (score ≤ 54 on the Functional Assessment of Cancer Therapy-Cognition, Version 3, Perceived Cognitive Impairment subscale) * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Ability to read, write and understand either English OR Spanish. Exclusion Criteria: * Current pregnancy or nursing status * Current use of Photobiomodulation (PBM) (for any reason) * A lifetime history of any brain tumor or central nervous system metastasis * Previous use of intrathecal chemotherapy, chimeric antigen receptor treatment (CAR-T), or stem cell/marrow transplant * Known history of other neurological conditions involving impaired cognitive function (such as Alzheimer's Disease and related dementias, Parkinson's Disease, or Multiple Sclerosis).