Surgically targeted radiation therapy (STaRT) trials for brain neoplasms: A comprehensive review.

The mainstays of radiation therapy include external beam radiation therapy (EBRT) and internally implanted radiation, or brachytherapy (BT), all with distinct benefits and risks in terms of local or distant tumor control and normal brain toxicities, respectively. GammaTile® Surgically Targeted Radiation Therapy (STaRT) attempts to limit the drawbacks of other BT paradigms via a permanently implanted, bioresorbable, conformable, collagen tile containing four uniform intensity radiation sources, thus preventing deleterious direct contact with the brain and optimizing interseed spacing to homogenous radiation exposure. The safety and feasibility of GammaTile® STaRT therapy was established by multiple clinical trials encompassing the spectrum of primary and secondary brain neoplasms, both recurrent and newly-diagnosed. Implantable GT tiles were FDA approved in 2018 for use in recurrent intracranial neoplasms, expanded to newly-diagnosed malignant intracranial neoplasms by 2020. The current spectrum of trials focuses on better defining the relative efficacy and safety of non-GT standard-of-care radiation strategies for intracranial brain neoplasm. We summarize the key design and eligibility criteria for open and future trials of GT therapy, including registries and randomized trials for newly-diagnosed and recurrent brain metastases as well as recurrent and newly-diagnosed glioblastoma in combination with approved therapies.

GammaTile for Gliomas: A Single-Center Case Series.

GammaTile® (GT Medical Technologies, Tempe, Arizona) is a surgically targeted radiation source, approved by FDA for brachytherapy in primary and secondary brain neoplasms. Each GammaTile is composed of a collagen sponge with four seeds of cesium 131 and is particularly useful in recurrent tumors. We report our early experience in seven patients with recurrent gliomas to assess this type of brachytherapy with particular attention to ease of use, complication, and surgical planning. This study represents a retrospective chart review of surgical use and early clinical outcomes of GammaTile in recurrent gliomas. The number of tiles was planned using pre-operative imaging and dosimetry was planned based on post-operative imaging. Patients were followed during their hospital stay and were followed up after discharge. Parameters such as case length, resection extent, complication, ICU length of stay (LOS), hospital LOS, pre-operative Glasgow Coma Scale (GCS), immediate post-operative GCS, post-operative imaging findings, recurrence at follow-up, length of follow-up, and dosimetry were collected in a retrospective manner. Seven patients were identified that met the inclusion criteria. Two patients were diagnosed with recurrent glioblastoma multiforme (GBM), one lower-grade glioma that recurred as a GBM, one GBM that recurred as a gliosarcoma, and two recurrent oligodendrogliomas. We found that operation time, ICU LOS, hospital LOS, pre- and post-operative GCS, and post-operative complications were within the expected ranges for tumor resection patients. Further, dosimetry data suggests that six out of seven patients received adequate radiation coverage, with the seventh having implantation limitations due to nearby organs at risk. We report no postoperative complications that can be attributed to the GammaTiles themselves. In our cohort, we report seven cases where GammaTiles were implanted in recurrent gliomas. No implant-related post-operative complications were identified. This early data suggests that GammaTile can be a safe form of brachytherapy in recurrent gliomas.

Rapid Interval Recurrence of Glioblastoma Following Gross Total Resection: A Possible Indication for GammaTileⓇ Brachytherapy.

Glioblastoma recurrence between initial resection and standard-of-care adjuvant chemoradiotherapy (CRT) is a negative prognostic factor in an already highly aggressive disease. Re-resection with GammaTileⓇ(GT Medical Technologies Inc., Tempe, AZ) placement affords expedited adjuvant radiation to mitigate the likelihood of such growth. Here, we report a glioblastoma patient who underwent re-resection and GammaTileⓇ (GT) placement within two months of the initial gross total resection due to regrowth that reached the size of the original presenting tumor. The patient subsequently received concurrent temozolomide and 60 Gy external beam to regions outside of the brachytherapy range, fulfilling the generally accepted Stupp regimen. The patient tolerated the treatment without complication. The dosimetrics and implications of the case presentation are reviewed.