International Conference on Occupational Radiation Protection: Strengthening Radiation Protection of Workers – Twenty Years of Progress and the Way Forward

Workload of medical linear accelerator at a high throughput cancer treatment centre in Sri Lanka

Not scheduled

1h 30m

Geneva

Poster 4. Occupational radiation protection in medicine Session 8. Occupational radiation protection in medicine

Speaker

Vijitha Ramanathan (General Sir John Kotelawala Defence University, Sri Lanka)

Description

BACKGROUND
Bunker design and shielding are fundamental to the radiation protection of staff and the public in a radiation therapy department. The workload is an important factor in the design of protective barriers [1]. With the advent of Intensity Modulated Radiotherapy (IMRT), the workload of linac increased significantly since it requires more monitor units (MUs) per treatment [2,3]. The aim of this study was to evaluate the workload of linac at Apeksha Hospital, Maharagama, Sri Lanka.

METHODS
This study was conducted in the Varian (Varian clinic 2300CD) unit of Apeksha Hospital, Maharagama, Sri Lanka. The data was collected from 1st of August 2020 to 30th of November 2020. All the treatment data were accumulated using the Varian ARIA oncology information system. The total workload during the study period (four months) was calculated and then averaged to one week to obtain for the average workload. The physics workload measurement was ignored in this study. There was no any research related workload during this period of measurement.

RESULTS

Table 1: Number of patients treated under each treatment procedure (6 MV) and the total dose delivered at isocentre. The notations are indicated as follows: 3D-CRT – 3-dimensional conformal radiotherapy, IMRT – Intensity modulated radiotherapy.
Month 3D-CRT IMRT
Number of patients Total dose delivered at isocentre (cGy) Number of patients Total dose delivered at isocentre (cGy)
August 2020 742 544251.724 548 584667.019
September 2020 842 577595.859 661 694643.231
October 2020 624 164220.279 706 145698.781
November 2021 541 135562.912 471 98496.459

Table 2: Number of patients treated using 3D-CRT (15 MV) and the total dose delivered at isocentre.
Month 3D-CRT
Number of patients Total dose delivered at isocentre (cGy)
August 2020 492 174388.137
September 2020 709 270901.168
October 2020 513 98529.337
November 2021 270 61328.650

Table 3: Average workload for one week for treatment procedures.
3D-CRT IMRT
Workload for 6 MV (cGy/week) Workload for 15 MV (cGy/week) Workload for 6 MV (cGy/week) Workload for 15 MV (cGy/week)
89 983.056 38 431.764 99 608.964 0

CONCLUSIONS
The average workload for one week was 1918.97 Gy/week for 6 MV photons and the average workload for one week was 403.37 Gy/week for 15 MV photons.

REFERENCES
[1] Kron, T., Aldrich, B., Jovanovic, K., Howlett, S., Hamilton, C., Workload and use factor of medical linear accelerator in radiotherapy, Health Physics, Volume 69, No 6 (1995).
[2] Juraci, P.R., Alvis, V.G., Fairbanks, L. R., Total workload for radioactive facilities with volumetric modulated arc treatment, Brazilian Journal of Radiation Sciences 7(3) (2019).
[3] Saleh, Z.H., Jeong, J., Quinn, B., Mechalakos, J., Germain, J. St., Dauer, L.T., Results of a 10-year survey of workload for 10 treatment vaults at a high-throughput comprehensive cancer center, Journal of Applied Clinical Medical Physics, Volume 18, Issue 3, p 207-214 (2017).