Daily image-guided radiation therapy benefits patients

Pretreatment daily image-guided radiation therapy (IGRT), which can be efficiently performed, was beneficial to all patients at a radiology facility in Australia, according to a study published online Nov. 23 in the Journal of Medical Imaging and Radiation Sciences.

IGRT, a widely-considered essential technique for ensuring accurate field placement in radiation therapy, is used on all patients across treatment sites at Radiation Oncology Queensland Toowoomba (ROQ) in Australia.

However, ROQ’s Dean Robb and colleagues explained in their study, “There are many variables that can affect the efficacy of an IGRT program and it is noted that the time taken for staff to analyze images is potentially varied, not only because of imaging modality differences but also the experience level of the staff performing IGRT.”

The researchers designed their study to assess the efficiency and consistency of IGRT practice at ROQ by examining its variables and their effects on matching and treatment times across treatment types.

The study included five treatment types: chest (kV), pelvic patients (MV and kV), gold seed pelvis, and head and neck (H&N) (MV and kV). Ten patients were randomly selected for each treatment type from 2007 to 2012. Eight treatment variables were used for 80 patients in total. These variables included treatment type, imaging modality used, and the setup error of each session. Treatment images were taken on a daily basis.

Results revealed that patients treated in the thoracic region had the greatest random setup error. The mean matching times were longer for chest patients at approximately 197 seconds, and there were only very small differences in times regarding the modality used. Treatment times were the longest for head and neck variables, taking about 399 to 405 seconds.

kV provided more consistent match times, while MV provided slightly faster times. The researchers concluded that variables associated with the chest IGRT performed the worst.

“It is expected that these results will drive training and education for that specific anatomic site. This in itself shows the positives of assessing an IGRT program,” wrote the study’s authors. “It has identified both strengths and weaknesses and can be used to further refine the process and outcomes.”