Fibrosis after radiation therapy

Fig. 6.160a,b. Radiation fibrosis, a Short-axis and b long-axis 12-5 MHz US images of the brachial plexus nerves (white arrows) in the supraclavicular region obtained 1 year after radiation therapy for breast carcinoma in a patient with reversible brachial plexopathy. There is mild homogeneous swelling of the nerve fascicles (arrowheads) which appear less defined. No focal mass is observed. SA, subclavian artery... 

Radiation fibrosis typically occurs 6 months or more after radiation therapy. Fibrotic changes are variably present between 30 and 40 Gy, and are always seen after 40 Gy. Permanent scarring resulting in respiratory compromise may develop if the dose and volume of lung irradiated are excessive. The HRCT findings consist of a reticular pattern with associated traction bronchiectasis limited to the radiation portal (Worthy et al. 1997 Wah et al. 2003) (Fig. 6.2.20). 

Fig. 6.2.20a,b. Radiation fibrosis in a 48-year-old man after radiation therapy for lymphoma, a Chest radiograph obtained 1 year after radiation therapy shows bilateral fi-brotic changes in the paramediastinal lung zone (arrows). b CT scan confirms bilateral paramediastinal fibrosis in the field of irradiation (arrowheads). (With permission from Franquet et al. 2005a)... 

Eibrosis is rare in brain tissue. It occurs around abscesses (see Eig. 20.4), in granulomas, and in desmoplastic and sarcomatous tumors. Fibrosis is more common in meninges. Meningeal fibrosis develops after traumatic injuries, meningitis, vasculitis involving meningeal vessels, and radiation therapy and as a desmoplastic response to a tumor. 

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