Bilateral radiation pneumonitis, a complication of the radiotherapy of bronchogenic carcinoma (report and analysis of seven cases with autopsy)

Abstract

Acute radiation pneumonitis lacks any single pathognomonic morphologic feature, but is a diagnosis made from a combination of alveolar septal thickening, proliferation and desquamation of atypical septal cells, hyaline membrane formation, and pulmonary vascular changes. The pathogenesis of radiation pneumonitis is poorly understood. Total radiation dosage, total volume irradiated, and duration of therapy are significant factors but cannot explain all cases. Seven autopsied cases of bilateral radiation pneumonitis following megavoltage therapy for lung carcinoma are reported and analyzed. The use of extensive fields, or of rotational technique, necessitated irradiation of a large volume of lung tissue. The inaccuracy of calculated dosimetry, coupled with possible errors in port placement can result in much higher bilateral radiation doses than anticipated. Infection, by increasing absorption of radiation, probably causes an increased susceptibility to radiation pneumonitis. While the relatively small doses of radiation reaching the contralateral lung are usually innocuous, certain patients are hyperreactive and respond with a severe diffuse radiation pneumonitis.

Migratory organizing pneumonitis "primed" by radiation therapy

“…Strictly unilateral pulmonary irradiation may occasionally result in bilateral pneumonitis [6,7,22,23]. Bronchoalveolar lavage in radiation pneumonitis shows a lymphocytic alveolitis, and cell cycle analysis in one patient has shown that alveolar lymphocytes had a marked increase in their ribonucleic acid (RNA) content, suggesting that they were activated (blood lymphocytes were not) [20].…”

Migratory bronchiolitis obliterans organizing pneumonia after unilateral radiation therapy for breast carcinoma

“…It has been suggested that radiation pneumonitis represents a form of immunologically-mediated hypersensitivity pneumonitis [2,3,9,10]. Indeed, in a few patients, extensive radiographic changes outside the field, even in the contralateral lung, have been observed after lung irradiation [9].…”

“…Indeed, in a few patients, extensive radiographic changes outside the field, even in the contralateral lung, have been observed after lung irradiation [9]. Recently, a prominent lymphocytic alveolitis, more pronounced in patients developing clinical pneumonitis, has been shown to develop in both lung fields after strictly unilateral thoracic irradiation [2,3].…”

Radiation-induced Lung Disease and the Impact of Radiation Methods on Imaging Features

“…Although there have been reports of extensive radiation pneumonitis occurring outside the treatment portals (6,7), the radiographic changes in radiation pneumonitis are generally confined to the field of irradiation. Initially, there is a diffuse haze in the irradiated region with obscuring of vascular outlines.…”