A commonly held belief is that patients with collagen vascular diseases (CVD) have a greater risk of radiation therapy complications than patients without CVD. This impression is based on anecdotal reports, however.

A group of 61 patients with CVD were compared with a matched control group of 61 patients without CVD. The CVD group included 39 patients with rheumatoid arthritis (RA), 13 with systemic lupus erythematosus (SLE), 4 with systemic sclerosis (scleroderma) (SSc), 4 with dermatomyositis, and 1 with polymyositis. The control group was matched with respect to age, sex, tumor site and histologic characteristics, treatment aim, general treatment method, radiation therapy technique, site irradiated, radiation dose, date of treatment, and follow-up.

Overall, there was no significant difference between the CVD and control groups in terms of acute (11% versus 7%, respectively) or late complications (10% versus 7%, respectively). This was also true when only patients who were treated definitively were considered. Furthermore, none of the patients treated palliatively had complications. Three patients in the CVD group had fatal complications, compared with none in the control group. RA was associated with a slight increase in late complications in the definitively treated patients, whereas SLE was associated with a slight increase in acute reactions. No significant acute or late reactions were observed in the patients with SSc, dermatomyositis, or polymyositis.

In general, these differences are less than expected and not statistically significant. Consequently, from these data, the authors could not show a significant increase in radiation therapy complications for patients with CVD.