Radiation injuries of the thoracic spine after irradiation of carcinoma of the esophagus

The data given relate to 175 patients with carcinoma of the esophagus for which they were treated with Bremsstrahlung irradiation on a 4.3 MeV linear accelerator. Radiation injuries to the bodies of the irradiated vertebrae were diagnosed in 12 of these patients (6.9 +/- 2.0 percent). The minimal focal dose causing injury to the vertebrae was 3,800 rads. Besides osteoporosis, other radiological manifestations of radiation injury include structural changes, namely indistinctness and discontinuity of the closing laminae of the vertebral bodies, the formation of Schmorl's nodes, and compression fractures of the vertebral bodies; considerable sclerotic changes may also be seen in the bodies. After a number of years the process stabilizes and gradual restoration of the normal structure of the vertebra can be observed. Despite the fact that the doses given during irradiation are high, the endosteum reacts with considerable sclerosis, and the anterior longitudinal ligament develops massive areas of ossification. By contrast with radiation changes, metastases of carcinoma of the esophagus in bone are manifested as foci of osteolysis and are never accompanied by sclerotic changes such as those accompanying spontaneous restoration of normal structure of the bone