Interval From Imaging to Treatment Delivery in the Radiation Surgery Age: How Long Is Too Long?
OBJECTIVE
The purpose of this study was to evaluate workflow and patient outcomes related to frameless stereotactic radiation surgery (SRS) for brain metastases.


METHODS
We reviewed all treatment demographics, clinical outcomes, and workflow timing, including time from magnetic resonance imaging (MRI), computed tomography (CT) simulation, insurance authorization, and consultation to the start of SRS for brain metastases.


RESULTS
A total of 82 patients with 151 brain metastases treated with SRS were evaluated. The median times from consultation, insurance authorization, CT simulation, and MRI for treatment planning were 15, 7, 6, and 11 days to SRS. Local freedom from progression (LFFP) was lower in metastases with MRI ≥ 14 days before treatment (P = .0003, log rank). The 6- and 12-month LFFP rate were 95% and 75% for metastasis with interval of <14 days from MRI to treatment compared to 56% and 34% for metastases with MRI ≥ 14 days before treatment. On multivariate analysis, LFFP remained significantly lower for lesions with MRI ≥ 14 days at SRS (P = .002, Cox proportional hazards; hazard ratio: 3.4, 95% confidence interval: 1.6-7.3).


CONCLUSIONS
Delay from MRI to SRS treatment delivery for brain metastases appears to reduce local control. Future studies should monitor the timing from imaging acquisition to treatment delivery. Our experience suggests that the time from MRI to treatment should be <14 days.
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California. Electronic address: seymourz@radonc.ucsf.edu.
Zachary A
ZA
Seymour
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Shannon E
SE
Fogh
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Sarah K
SK
Westcott
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Steve
S
Braunstein
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California; Department of Neurological Surgery, University of California at San Francisco, San Francisco, California.
David A
DA
Larson
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Igor J
IJ
Barani
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Jean
J
Nakamura
Department of Radiation Oncology, University of California at San Francisco, San Francisco, California.
Penny K
PK
Sneed
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D019458:Insurance Coverage; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D061665:Time-to-Treatment; D014057:Tomography, X-Ray Computed; D055815:Young Adult