Smitt M C, Stouffer N, Owen J B, Hoppe R T, Hanks G E
Department of Radiation Oncology, Stanford University Medical Center, CA 94305, USA.
Int J Radiat Oncol Biol Phys. 1999 Jan 15;43(2):335-9. doi: 10.1016/s0360-3016(98)00388-5.
To document national standards of care for patients receiving radiotherapy as part of curative treatment for Hodgkin's disease.
A national survey was conducted of 61 institutions treating 275 patients with Stages I-III Hodgkin's disease and representing six facility type strata. Pretreatment evaluation, radiotherapy treatment parameters, and use of combined modality therapy were assessed.
Ann Arbor stage for the 275 patients was as follows: IA, 69 (25%); IB, 7 (3%); IIA, 123 (45%); IIB, 36 (13%); IIIA 23 (8%), IIIB, 14 (5%); unknown, 3 (1%). Pretreatment evaluation included complete blood count for 93%, sedimentation rate in 29%, chest CT in 88%, abdominal CT scan in 87%, and bone marrow biopsy in 81%. Lymphangiograms were obtained in 50% of cases; laparotomy was performed in 46%. The yield of positive findings in the spleen at laparotomy was 6.5 % overall. Facility differences with respect to staging were seen only for the use of gallium scans, which were more commonly used in academic centers (44% vs. 15-23% elsewhere, p<0.001). Radiotherapy was delivered with a linear accelerator in 94% of cases. Treatment simulation was performed for 94% and individualized blocks constructed for 95% overall; however, freestanding facilities had a lower rate of performance of these procedures (78% vs. 98-99% for simulation and 88% vs. 96-99% for customized blocking, p<0.001). The mean supradiaphragmatic dose was 36.74 Gy and the mean subdiaphragmatic dose was 33.81 Gy. Planned combined modality therapy was given in 36% of patients. The use of combined modality therapy by stage was as follows: IA, 11%; IB, 43%; IIA, 30%; IIB, 68%; IIIA, 57%; IIIB, 100%. Chemotherapy was completed prior to radiation in 80% of cases and generally consisted of ABVD (32%), an alternating regimen (25%), or MOPP (22%). Among Stage I/II patients, use of chemotherapy was associated with reduced radiation doses (mean supradiaphragmatic dose 34.53 Gy vs. 38.43 Gy and mean subdiaphragmatic dose 31.27 Gy vs. 34.51 Gy), and reduced volumes of treatment (87% vs. 28% treated to one side of the diaphragm only). Laparotomy was not associated with decreased supra- or subdiaphragmatic radiation doses or decreased volumes of treatment.
With the exception of gallium scans, pretreatment evaluation is relatively uniform across facility strata. Increased understanding of prognostic factors in Hodgkin's disease and greater use of planned combined modality therapy for higher risk patients appears to have contributed to a decreased use of and low yield of positive findings for laparotomy. Laparotomy was not associated with reduced radiation volumes or doses. Freestanding radiation facilities had a lower rate than other facility types for the performance of treatment simulation and customized patient blocking.
