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Evaluation of the Leksell Gamma Knife Perfexion Clinical Workload at M.D. Anderson Cancer Center

M Chetvertkov*, D Luo , T Briere , M.D. Anderson Caner Center, Houston, TX


(Sunday, 7/29/2018) 3:00 PM - 6:00 PM

Room: Exhibit Hall

Purpose: To calculate and evaluate the average patient workload and corresponding statistics at Leksell Gamma Knife® Perfexion™ unit.

Methods: 604 patients treated on the Leksell Gamma Knife® unit from May 2016 to May 2017 were evaluated. Before treatment each patient was triaged based on a “star system� to evaluate the treatment complexity based on the number of lesions, expected treatment time and need for anesthesia, with 1 star expected to be the least complex, and 4 star the most complex. Statistics for these treatments, such as overall machine occupancy, treatment times per day, single patient data, completion time were analyzed and evaluated.

Results: During the time of study the dose rate decayed from 2.5 to 2.2 Gy/min. Daily machine occupancy during the selected period of time was 95%, with an average of 2.3 patients treated per day and average star rating of 2 per patient. Average total treatment (elapsed) time was 240 min/day, with the shortest being 20 min, and the longest 732 min. This does not include the time needed for patient set up or the time between patients. The average treatment time was 103 min/pt, with the shortest being 6 min and longest 451 min. Median treatment times with respect to the star rating were 46, 97, 161 and 231 min for 1, 2, 3 and 4 stars, respectively. Nineteen percent of 1 star cases exceeded 90 minutes, while 32% of 2 star cases exceeded 120 minutes. Nearly half (127 out of 261) of working days exceeded 8 hours.

Conclusion: A simple star system to estimate treatment time is helpful to schedule patients in a busy Gamma Knife unit.


Gamma Knife


TH- External beam- photons: gammaknife

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