Mantle irradiation in the upright position: a technique to reduce the volume of lung irradiated in patients with bulky mediastinal Hodgkin's disease.
Many patients with mediastinal Hodgkin's disease radiographically show a wider horizontal width of disease in the supine or prone as compared to the upright position. Yet for most patients mantle treatment in the supine/prone position is still preferable. This position allows good patient immobilization and precise matching between the mantle and paraaortic-splenic pedicle fields that would not be possible in the sitting or upright position. Adequate blocking of the lungs and heart remains possible in the supine position since most patients do not have extensive subcarinal Hodgkin's disease. Even when more extensive disease is present, contoured blocks to protect the heart and lungs can be adjusted to protect a greater portion of normal tissues if the mediastinal nodes respond to treatment. But if sizeable mediastinal disease persists, it may be impossible to protect sufficient heart and lung. Under these circumstances, repositioning the patient upright can shift the configuration of the mass, allowing larger lung blocks to be added. We report the use of a chair to facilitate treatment with mantle irradiation in the upright position for patients whose mediastinal disease when supine is too large to allow adequate blocking of heart and lung. Blocks are made from the initial port films and daily treatment films are taken to confirm an accurate set-up. To avoid excessive dose to the spinal cord, patients who are to receive para-aortic irradiation receive a maximum of 15-20 Gy in the upright position and the remainder of the mantle is given in the supine-prone position. The use of the upright technique allows for the use of radiation in patients who would otherwise be unable to receive adequate doses due to potential lung and cardiac toxicity.