Abdominal irradiation in non-Hodgkin's lymphomas.

The incidence of subdiaphragmatic relapses in a group of 170 patients with non-Hodgkin's lymphomas treated with radiation to lymph-node bearing areas above and below the diaphragm is described. In patients treated with the standard inverted "Y" abdominal radiation portals, subdiaphragmatic relapses occurred in 29% of 132 patients. This high local failure rate may be attributed to the exclusion of many of the mesenteric lymph nodes and most of the liver and intestines from the irradiated fields. A safe and apparently effective radiation technique which treats the whole abdomen, used at Stanford in 38 patients since 1973, is described. Full thickness lead blocks protect the right hepatic lobe during the initial 1500-rad whole abdominal treatment (through anterior-posterior opposed fields). Horizontal decubitus (cross-table) lateral fields are then used to bring the para-aortic and mesenteric lymph node radiation doses to 3000 rads, followed by an additional 1400 rads through wide anterior-posterior ports, for a total central abdominal dose of 4400 rads. Dosimetric considerations, anatomic descriptions of subdiaphragmatic lymphatic drainage, complications of treatment, and the initial results of whole abdominal radiation therapy are also presented.