Treatment planning structure and process in the United States: a "Patterns of Care" study

To conduct a study of the structure and process of treatment planning in the United States.

A Patterns of Care treatment planning consensus committee developed a survey form that was used to gather data for 106 items relating to the structure and process of treatment planning. These questions were general in nature and not specific to any particular disease site. Seventy-three facilities were randomly selected for site visits from the 1321 radiation therapy facilities in the United States: 21 academic, 26 hospital, and 26 free-standing. During the site visit the facility physicist, assisted by the site-visit physicist, completed the form.

Twenty-nine percent of facilities have cobalt-60 machines; 25% have 4 MV linacs; 75% have photon energies in the range of 5-8 MV; and less than 10% have energies greater than 20 MV. Academic facilities led hospital and free-standing facilities by about 30 percentage points in the availability of all electron energies (88 vs. 58%, approximately, in the range 4-13 MeV and scaling downward to about 60 vs. 30% at the highest energies). The national averages for the availability of Cs-137, Ir-192, and I-125 were 87, 73, and 44%, respectively. Computerized tomography (CT) scanning is not available or not used in 15% of hospital and free-standing facilities. Ninety-six percent of facilities have treatment planning computers; at 10% of facilities physicians do not participate in treatment planning. The estimated national averages of facilities having formal quality assurance (QA) programs for treatment planning systems, simulators, film processors, and blocking systems are 44, 79, 62, and 55%, respectively. Sixty-three percent of facilities obtain independent machine calibrations.

This is the first patterns of treatment planning study carried out in the United States and the results reported here will establish a baseline for future studies. The present study has identified some elements that were unexpected, such as the percentage of facilities lacking formal QA programs for treatment planning systems; however, it has not established any impact of such findings. It is recommended that future studies include the availability of new technologies such as multileaf collimation, dynamic wedges, digital portal imaging, and CT simulation. With the increasing nationwide concern with the cost of health care, we must continue to monitor the implementation, use, and impact on treatment outcome of new and expensive technologies.