Time trial: a prospective comparative study of the time-resource burden for three-dimensional conformal radiotherapy and intensity-modulated radiotherapy in head and neck cancers.
INTRODUCTION
An ongoing institutional randomized clinical trial comparing three-dimensional conformal radiotherapy (3D CRT) and intensity-modulated radiotherapy (IMRT) provided us an opportunity to document and compare the time-manpower burden with these high-precision techniques in head and neck cancers.


MATERIALS AND METHODS
A cohort of 20 consecutive patients in the ongoing trial was studied. The radiotherapy planning and delivery process was divided into well-defined steps and allocated human resource based on prevalent departmental practice. Person-hours for each step were calculated.


RESULTS
Twelve patients underwent IMRT and eight patients had 3D CRT. The prerandomization steps (upto and including approval of contours) were common between the two arms, and expectedly, the time taken to complete each step was similar. The planning step was carried out postrandomization and the median times were similar for 3D CRT (312 min, 5.2 person-hours) and IMRT (325.6 min, 5.4 person-hours). The median treatment delivery time taken per fraction varied between the two arms, with 3D CRT taking 15.2 min (0.6 person-hours), while IMRT taking 27.8 min (0.9 person-hours) (P< 0.001). The total treatment time was also significantly longer in the IMRT arm (median 27.7 versus 17.8 person-hours, P< 0.001). The entire process of IMRT took 48.5 person-hours while 3D CRT took a median of 37.3 person-hours. The monitor units delivered per fraction and the actual "beam-on" time was also statistically longer with IMRT.


CONCLUSIONS
IMRT required more person-hours than 3D CRT, the main difference being in the time taken to deliver the step-and-shoot IMRT and the patient-specific quality assurance associated with IMRT.