Optimal Planning Target Volume With Stereotactic Radiosurgery

The 12-month local control rate is the percentage of lesions without recurrence at the lesion site 12 months after SRS. Time to local recurrence was defined as the time between SRS and local recurrence. If local recurrence did not occur, the time to local recurrence was censored at last follow-up (including deaths without local recurrence). Kaplan-Meier methods were used to describe the time to local recurrence.

The rate of radionecrosis is defined as the proportion of lesions with an indication of radiation-associated changes but no evidence of viable tumor on follow-up imaging (and confirmed by tissue biopsy whenever possible).

The 12-month rate of distant brain metastases is defined as the percentage of participants with the appearance of new brain metastasis located away from the previously treated lesion (i.e. distant brain failure) 12 months after SRS. Time to the appearance of new brain metastasis was defined as the time between SRS and distant brain failure. Patients without new distant brain metastases as of the last follow-up were censored at the last follow-up date. Kaplan-Meier methods were used to describe the time to distant brain failure.

Overall survival was defined as the time in months from the start of SRS to the date of death or last contact if alive. Kaplan-Meier methods were used to estimate overall survival.

Quality of life as measured by the change in FACT-Br scores from baseline to 3 months after SRS. The FACT-Br (version 4) is comprised of the Functional Assessment of Cancer Therapy-General (FACT-G), a 27-item core questionnaire evaluating the domains of physical, family/social, emotional and functional well-being, with the addition of 23 brain cancer specific questions. The FACT-G total score is the sum of the four FACT-G domain scores. The Brain Cancer Subscale (BrCS) is the sum of 19 brain cancer specific questions. The FACT-Br Trial Outcome Index (TOI) is the sum of the BrCS score and the physical and family/social domain scores. The FACT-Br total score is the sum of the FACT-G total score and the BrCS score. Change score = score at 3 months after SRS - score at baseline. Positive change scores indicate improved quality of life.

Cognition as measured by the change in MMSE scores from baseline to 3 months after SRS. The MMSE is an 11-item measure that tests five areas of cognitive function: orientation, registration, attention and calculation, recall and language. The minimum score is 0 and teh maximum score is 30 with higher MMSe scores indicating better cognition. Change score = score at 3 months after SRS - score at baseline. Positive change scores indicate improved cognition.

Cognition as measured by the change in scores on the Trail Making Test (TMT) from baseline to 3 months after SRS. The TMT consists of two parts. Part A (TMT-A) requires an individual to draw lines sequentially connecting 25 encircled numbers distributed on a sheet of paper. Task requirements are similar for Part B (TMT-B) except the person must alternate between numbers and letters (e.g., 1, A, 2, B, 3, C, etc.). The score on each part represents the amount of time required to complete the task. Change score = score at 3 months after SRS - score at baseline. Negative change scores indicate improved cognition.

The rate of death due to neurologic causes is defined as the percentage of participants whose death is attributable to the progression of neurological disease.