Click here to


Are you sure ?

Yes, do it No, cancel

Workflow Analysis of Frameless Gamma Knife Treatments

J Liu*, E Calugaru, J Chang, Northwell Health, Lake Success, NY


(Sunday, 7/12/2020)   [Eastern Time (GMT-4)]

Room: AAPM ePoster Library

Purpose: To study the patient tolerance, identify the root causes for prolonging treatment time, and improve the efficiency and patient experience for frameless Gamma Knife Icon (GKI) procedures.

Methods: Forty-one frameless GKI patients with 48 plans and 89 treatment fractions were analyzed. The actual treatment time was compared to the planned treatment time to evaluate the patient tolerance of the treatment. The planned treatment time was given by the planning software to deliver a prescribed dose. The actual treatment time was the actual time taken to deliver a fractionated treatment, including the time for CBCT and interruptions due to various reasons. The time spent for switching patients for treatments was also recorded and analyzed.

Results: 75% of the planned treatment time are within one hour. The actual treatment time was longer than the planned time by 4-60 minutes depending on the patients. 88% of the 50 cases with more than 10-minute delay were caused by patients not being able to hold the treatment position and moving out of the tolerance. Most patients with planned treatment time longer than 40 minutes have difficulty maintaining the treatment position. Some patients had to take a break before completion. The time to switch patients varied from less than 5 minutes to 35 minutes with a mean of 15 minutes, during which the therapist documented previous treatment and prepared for the next treatment.

Conclusion: Majority of the patients have difficulty keeping their position within tolerance for longer than 40 minutes. Coaching or additional CBCT scans were frequently required to reposition these patients to continue treatments, which prolongs the treatment time. Scheduled breaks may be considered for these patients to minimize patient discomfort and avoid unexpected delay. The time spent between switching patients can be also shortened to improve workflow efficiency.


Gamma Knife


IM/TH- Formal Quality Management Tools: Root Cause Analysis

Contact Email