Abstract
The limiting factor in the treatment of malignant disease with irradiation is the tolerance of normal tissue irradiated. In the present study the right lungs of rats were exposed to single doses of 2000 rad of X-radiation, to 10 × 200 rad, or to 5 × 400 rad. Animals from each group were sacrificed monthly for 6 months post exposure. Sections of lung were examined by light microscopy (LM) and by scanning or transmission electron microscopy (SEM and TEM). A focal exudative lesion was seen at 2 months after the single dose; it progressed to a proliferative and then reparative, fibrotic lesion by 6 months. Changes in epithelial lung components, particularly the presence of Type II pneumocytes, were found with both LM and TM. Vascular changes were less pronounced. A striking finding was the presence of mast cells in the alveolar walls. Neither of the mufti-fraction schedules produced any of these changes, except hyperplasia of Type II cells following 5 × 400 rad. The possible implication of Type II and mast cells in radiation pneumonitis and fibrosis is discussed.
Original language | English (US) |
---|---|
Pages (from-to) | 475-490 |
Number of pages | 16 |
Journal | International journal of radiation oncology, biology, physics |
Volume | 2 |
Issue number | 5-6 |
DOIs | |
State | Published - 1977 |
Externally published | Yes |
Keywords
- Late injury
- Lung
- Mast cells
- Multiple fractions
- Radiation
- Type II pneumocytes
ASJC Scopus subject areas
- Radiation
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research