Treatment planning for Hodgkin's disease: a patterns of care study.

PURPOSE: To conduct a survey of the process of treatment planning for the radiation treatment of Hodgkin's Disease in the United States, and to compare survey results with consensus guidelines as determined by recognized experts. METHODS AND MATERIALS: A consensus committee developed guidelines for the radiotherapeutic management of Hodgkin's Disease. A series of survey forms were designed to evaluate the standards of practice and compare these with the consensus guidelines. A total of 61 facilities divided evenly into the strata of academic, hospital based, and free standing had eligible Hodgkin's Disease cases. There were 275 eligible cases of Hodgkin's Disease evaluated. Data collected from the radiation oncology records included treatment-specific parameters such as energy, dose, blocking, and calculations, as well as treatment planning practices. Statistical analysis was performed on each data element and for all institution strata.
RESULTS: For a number of treatment parameters, there were some discrepancies note between the current United States practice and the consensus guidelines. Some significant differences were found in practice between the stratified institution types. A representative sample of results are: the majority of Hodgkin's Disease patients are treated with x-ray energies in the recommended range, between 4 and 10 MV. Standard mantle (for upper extended field treatment) and modified spade (for lower extended field treatments) are the fields of choice for all types of facilities. The consensus guidelines recommended that dose calculations at multiple points be obtained; however, 15% of patients in the survey received only a single point calculation. Current irregular field dosimetry calculation software does not take account of inhomogeneities. Thirty percent of Hodgkin's Disease patients do not receive a gap calculation for the abutment of upper and lower extended fields. In 70% of treatment fields, no compensation is used. Very few patients receive any kind of in vivo dosimetry check.
CONCLUSION: The survey served to verify that, in general, Hodgkin's Disease treatment planning at all strata of institution has kept pace with recommended practice as delineated in current literature and texts. Small pockets of practice still need improvement in technique and equipment. Changes in practice were identified that can contribute to improved dose uniformity and accuracy.