Mahapatra S, Seltzer L, Osorio N, Miller M, Janssen A, Mitra R, Keen J, Smith C, Ware M
Abstract
IntroductionMetastatic brain tumors (MBTs) are the most common intracranial tumors, affecting up to 40% of cancer patients. Traditional treatments such as Whole Brain Radiotherapy (WBRT) and Stereotactic Radiosurgery (SRS) have limitations, including neurocognitive decline and potential tumor regrowth. Minimally invasive keyhole craniotomy (MIKC) and Cesium-131 (Cs-131) brachytherapy offer promising alternatives due to their precision and reduced side effects. This prospective study aims to evaluate the safety and efficacy of combining MIKC with Cs-131 brachytherapy in treating newly diagnosed brain oligometastases.MethodsTwenty-one adults with newly diagnosed brain metastases were enrolled from 2019 to 2021. Preoperative T1 MRI with gadolinium was used to calculate the gross tumor volume (GTV). Minimally invasive craniotomies were performed with resection of these tumors, followed by the implantation of Cs-131 seeds. Postoperative imaging was conducted to verify seed placement and resection. Dosimetric values (V100, V200, D90) were calculated. Patients were followed every two months for two years to monitor local progression, functional outcomes, and quality of life. The primary endpoint was freedom from local progression, with secondary endpoints including overall survival, functional outcomes, quality of life, and treatment-related complications.ResultsThe median preoperative tumor volume was 10.65 cm3, reducing to a resection cavity volume of 6.05 cm3 post-operatively. Dosimetric analysis showed a median V100 coverage of 93.2%, V200 of 43.9%, and D90 of 89.8 Gy. The 1-year local freedom from progression (FFP) was 91.67%, while the distant FFP was 53.91%. Five patients remained alive at the study's end, with a median survival duration of 5.9 months, a duration likely impacted by the concurrent COVID-19 pandemic. Only one patient experienced local recurrence, and no cases of radiation necrosis were observed. Significant improvements were seen in neurological, functional, and cognitive symptoms.ConclusionCombining MIKC with Cs-131 brachytherapy is effective for local tumor control and improving functional outcomes in patients with brain oligometastases. Further studies with larger cohorts are needed to validate these findings and refine treatment protocols.
