scholarly journals Total Workload for Radioactive Facilities with Volumetric Modulated Arc Treatment

2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Juraci Passos Reis ◽  
Victor Gabriel Alves ◽  
Leandro Rodrigues Fairbanks

In recent years, there have been major changes in radiotherapy, particularly in dose delivery for treatments using the techniques of Three-Dimensional Conformal Radiation Therapy (3D-CRT), Intensity-Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT). However, in the literature, no workload results for radiation therapy treatments performed exclusively with the VMAT technique were found. In this study, a new workload and a new VMAT factor will be proposed. For such, patient data originating from management and planning systems were acquired, such as dose values, monitor units, numbers of arcs per patient and number of hypofractionated treatments. The average clinical workload values for conventional treatments were 328 Gy/week, resulting in a VMAT factor of 1.97; similarly, for hypofractionated treatments, the clinical workload was 33Gy/week and the VMAT factor was 1.54. The total workload has a value of 596 Gy/week, less than the value used in the facility shielding design, 1250 Gy/week, and the average value of VMAT factor for conventional and hypofractionated treatments showed that a smaller amount of C should be used at facilities that perform exclusive VMAT treatment.

2016 ◽  
Vol 34 (26_suppl) ◽  
pp. 211-211
Author(s):  
Matthew Chan ◽  
Robert Anton Olson ◽  
Shilo Lefresne ◽  
Michael R. McKenzie

211 Background: In recent years, there has been a transition from two-dimensional radiation therapy (2DRT) planning towards more advanced techniques such as three-dimensional conformal radiation therapy (3D-CRT), volumetric modulated arc therapy (VMAT), and stereotactic body radiation therapy (SBRT). Our study aim was to analyze these trends in the treatment of bone metastases. Methods: All patients aged 18 and older who had received palliative intent RT for bone metastases between 2009-2014 and referred to any 1 of 6 regional cancer centers in British Columbia, Canada were reviewed. Summary statistics were used to describe radiation technique patterns. Logistic regression modeling was used to assess the influence of demographic, clinical, and health services variables on receipt of types of RT. Results: We identified 8,059 patients and 15,832 courses of RT; overall, 97.9% of courses were achieved by 2DRT and 2.1% by 3D-CRT, VMAT, or SBRT. Despite the low overall use of advanced techniques, its use was significantly higher in all subsequent years compared to 2009 (p < 0.05 for all years). The median age for patients treated with 2DRT was 67.0 (19-99) versus 66.0 years (19-93) for advanced techniques. There did not appear to be a statistically significant difference in age at the time of treatment start (OR 0.99; 95% CI 0.981-1.00, p < 0.05). Compared to lung cancers, thyroid (OR 9.9; 95% CI 5.197-18.724, p < 0.001) and kidney cancers (OR 3.9; 95% CI 2.508-5.911, p < 0.001) were significantly more likely to be treated with advanced techniques, while breast (OR 0.90; 95% CI 0.621-1.306, p = 0.58) and prostate cancers (OR 0.93; 95% CI 0.613-1.410, p = 0.73) were not any more likely. Compared to the Vancouver center, all other treatment centers in the province were utilizing advanced techniques less frequently. Patients were also more likely to complete RT with 2DRT than with advanced techniques (98.3% versus 95.8%, p < 0.05). Conclusions: The vast majority of treatment of bone metastases is still done by 2DRT in British Columbia. Despite these overall statistics though, a trend towards increasing use of more advanced techniques was observed.


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