Laser Interstitial Thermal Therapy (LiTT) With Cemiplimab or Other Chemotherapy in Recurrent Glioblastomas

Inclusion Criteria: * Histologically confirmed WHO grade 4 GBM (IDH-wt). Note: GBM variants, including histone-mutant and molecular-defined gliomas per WHO 2021 are allowed. Any number of recurrences are permitted. * Unequivocal evidence of tumor progression as documented on the screening biopsy. * At least 12 weeks post-completion of standard frontline therapy. Standard frontline therapy in this population includes maximal feasible surgical resection (biopsy alone is allowed), radiotherapy, and temozolomide chemotherapy. There is no restriction on the number of adjuvant temozolomide cycles. * Candidate for LITT based on the size, location, and shape of the recurrent tumor as determined by the performing neurosurgeon. Surgical resection/debulking prior to LITT is allowed per standard of care but is not required; if the patient undergoes resection or debulking, it must have occurred at least 3 weeks prior to the start of any study treatment. * At least 18 years of age. * Karnofsky performance status ≥ 60% * Adequate bone marrow and organ function as defined below: * Absolute neutrophil count ≥ 1.5 K/cumm * Platelets ≥ 100 K/cumm * Hemoglobin ≥ 9.0 g/dL * Total bilirubin ≤ 1.5 x IULN * AST(SGOT)/ALT(SGPT) ≤ 3.0 x IULN * Creatinine clearance \> 30 mL/min by Cockcroft-Gault * INR or PT ≤ 1.5 x IULN (unless patient is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants) * aPTT ≤ 1.5 x IULN (unless pat…