• Mean changes in executive cognitive function between pre and post application of iTBS treatment protocol [ Time Frame: 1.5 months ]
  Executive cognitive function will be quantified using technician administered Color Word Interference Test, Category Fluency, Tower of Hanoi, Card Sort and Strategy Application Task (Shallice &Burgess) tests, and the self-report Functional Assessment of Cancer Therapy - Cognitive Scale (FACT-COG) (Dyk et al.). Executive Function (EF) is measured by utilizing standardized test scores adapted from the Delis-Kaplan Executive Function Scales (D-KEFS battery) (Homack et al.). FACT-COG, Category Fluency and Strategy Application Task use raw scores. All EF measures used in this battery form a part of a normative database created and maintained by the principle investigator of this study. An overall score of EF is computed by averaging the Z scores of each test. Higher score on each test represents better performance.
• Mean changes in brain metabolite concentrations between pre and post application of iTBS treatment protocol [ Time Frame: 1.5 months ]
  Proton Magnetic Resonance Spectroscopy will be used to quantify brain metabolite concentrations in parts per million. Brain metabolites under evaluation include: glutamine, glutamate, N-acetyl aspartate, choline, and creatine.

Inclusion Criteria:

• Women or men with a history of non-metastatic cancer who have completed definitive curative cancer therapy
• Received cytotoxic chemotherapy as a part of their therapy for cancer and at least one month has passed since the final cytotoxic chemotherapy treatment
• ≥ 18 years of age at time of cancer diagnosis and receipt of chemotherapy
• Patients must report subjective symptoms of "chemo-brain" (memory loss, difficulty with concentration, word-finding difficulties) with a FACT-Cog perceived cognitive impairment score < 60
• Ability to sign informed consent and comply with study procedures

Exclusion Criteria:

• Patients with a recurrence of cancer or those with current metastatic disease
• Patients with a history or current diagnosis of brain metastasis
• Patients with a history or current diagnosis of a primary brain tumor
• Patients with a history of brain surgery or brain radiation
• Patients receiving maintenance systemic therapy for cancer, other than endocrine therapy
• Patients who cannot produce or request adequate medical record documentation to ensure they meet inclusion and exclusion criteria
• Women who are currently pregnant
• History of childhood cancer or receipt of chemotherapy in childhood (<age 18). Developmental insult to the PFC, can be associated with long-term, durable and sometime debilitating cognitive deficits. Hence, we avoid any cognitive confounds that maybe related to this issue.
• Patients with a weight over 250 lbs., as these patients would not fit in the MRI scanner used in the protocol
• Patients who require benzodiazepines for MRI due to claustrophobic anxiety
• Patients with chest wall tissue expanders or other retained 7 Tesla MRI-incompatible metal. Any other specific contraindication to TMS or MRI not already listed above, including:
• (a) any implanted device in the head, neck or upper body (e.g. cochlear implant, cranial or other electrodes, pacemaker or defibrillator, medication pump, stent, aneurysm clip, etc.)
• (b) personal history of seizures or epilepsy, personal history of multiple concussions or unexplained loss of consciousness. This will be determined by physician judgement
• History of adverse reaction to previous TMS or MRI exposure
• Active substance use disorder in the past 6 months, excluding tobacco use disorder, as diagnosed by study physicians

• American Cancer Society-Holden Comprehensive Cancer Society
• Fraternal Order of Eagles (Iowa)