SIMT Stereotactic Radiosurgery Outcomes Study (SIMT)

Outcome in Patients With 4 or More Brain Metastases Treated With Single-Isocenter, Multi-Target (SIMT) Stereotactic Radiosurgery: A Prospective Single-arm Study in Adults With Brain Metastases

The purpose of this study is to determine the effectiveness and efficiency of Single Isocenter Multi-target Stereotactic Radiosurgery (SIMT SRS) in patients with four or more brain metastases

Forty patients with four or more brain metastases will be enrolled prior to radiosurgery. A planning MRI brain scan will be performed with GD-DPTA within one week prior to radiosurgery, per the standard of care. Neurocognitive (Mini-Mental Status Examination (MMSE), Trail-making test A&B, Hopkins Learning Verbal (HVLT)) and functional assessment of cancer therapy-brain (FACT- Br) will be obtained prior to radiosurgery. Dose will be prescribed to the maximum isodose line encompassing the resulting PTV using the dose guidelines as described below. The primary endpoint will be the proportion of patients who live longer than predicted based on the diagnosis-specific GPA score. The Kaplan-Meier estimator will be used to describe the survival of all patients treated with SIMT SRS. Secondary endpoints will be the rate of recurrence at the treated metastases sites, the rate of new brain metastases at a site different from the SRS-treated metastases sites, the rate of death due to neurological causes, and the prevalence of significant adverse events. Exploratory endpoints include change over time in neurocognition and quality of life, quantification of dosimetric measures, the rate of salvage therapy, the rate of radionecrosis at the SRS treatment sites, and the rate and intensity of steroid-usage post-SRS. All patients will be evaluated for neurocognitive function via MMSE, HVLT, and Trail-making tests A & B, quality of life via FACT-Br, and for local recurrence via MRI every 3 months over the course of the study. These evaluations will be done at regular follow-up evaluations or when local recurrence is suspected on the basis of symptoms. Distant recurrence is defined as the appearance of new brain metastases at a site different from that of the original metastases. Recurrence will further be defined as a new area of enhancement that measures greater than 5 millimeters in the axial plane on MRI. The length of time to recurrence of the original brain metastases will be calculated from the date of the brain metastases radiosurgery to the date that a recurrence was detected by MRI. Patients with suspected recurrent tumor and/or who are symptomatic may undergo a stereotactic biopsy to evaluate for radionecrosis versus recurrent brain metastases, as is standard of care.

All subjects will receive stereotactic radiosurgery(SRS) following the RTOG Stereotactic Radiotherapy Guidelines available at http://dx.doi.org/10.1016/j.prro.2011.06.014

Number of Participants Who Live Longer Than Predicted According to the Graded Prognostic Assessment (GPA) Score

Calculated from the time of protocol Stereotactic RadioSurgery (SRS). The GPA incorporates four factors: age, KPS (Karnofsky Performance Score), ECM (extracranial metastases) and number of BM (brain metastases). Each factor is given a score of 0, 0.5 or 1.0 and GPA is calculated as a sum score of all four factors. The GPA has four groups: the GPA 0-1 with median survival of 2.6 months; GPA 1.5-2.5 with survival of 3.8 months; GPA 3 with median survival of 6.9 months and GPA 3.5-4.0 with the best median survival of 11 months.

Local recurrence of brain metastases is based on serial MRIs every 3 months and estimated by Kaplan-Meier analysis.

Time to neurologic death is defined as the time between initiation of SIMT SRS and death due to neurologic causes and is estimated using Kaplan-Meier analysis.

Number of Participants Who Experience a New Brain Metastasis at a Site Different From the Original Brain Metastasis Site 1 Year After SIMT SRS Treatment

Distant recurrence of brain metastases is based on serial MRIs every 3 months and estimated by Kaplan-Meier analysis.

Number of Participants Who Experience Grade 3, 4, or 5 Neurologic Adverse Events Attributable to SIMT SRS

Adverse Events only included those that were deemed by the PI to be related to the SIMT SRS treatment.

Inclusion Criteria: A contrast-enhanced MRI scan showing = or > 4 brain metastases. Age >/=18 years of age. KPS >/= 70 Patient must have a graded prosnostic score (GPA) score 0.5 or greater Life expectancy of at least 3 months Postoperative patients with resected brain metastases are eligible. Largest lesion < 4cm diameter Must be a candidate for MRI imaging Previous cranial stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT) is allowed if > 3 months prior to SIMT Must be capable of providing informed consent Exclusion Criteria: Primary lesion with radiosensitive histology (i.e., small cell carcinoma, germ-cell tumors, lymphoma, leukemia, and multiple myeloma). Metastases within 2 mm of the optic apparatus Patients unable to obtain MRI Evidence of leptomeningeal disease Greater than 10 brain metastases Pregnant women are excluded

Kim GJ, Buckley ED, Herndon JE, Allen KJ, Dale TS, Adamson JD, Lay L, Giles WM, Rodrigues AE, Wang Z, Kelsey CR, Torok JA Jr, Chino JP, Fecci PE, Sampson JH, Anders CK, Floyd SR, Yin FF, Kirkpatrick JP. Outcomes in Patients With 4 to 10 Brain Metastases Treated With Dose-Adapted Single-Isocenter Multitarget Stereotactic Radiosurgery: A Prospective Study. Adv Radiat Oncol. 2021 Jul 23;6(6):100760. doi: 10.1016/j.adro.2021.100760. eCollection 2021 Nov-Dec.