Radiosensitivity syndromes and diseases
General information on CVDs (collagen vascular diseases)/CTDs (connective tissue diseases).
- The terms "collagen vascular diseases (CVD)" and "connective tissue diseases (CTD)", which are often used synonymously in English, describe a diverse group of systemic, immunologically caused, inflammatory diseases of the rheumatic spectrum, which includes, for example, diseases such as systemic lupus erythematosus, systemic scleroderma, rheumatoid arthritis, polymyositis, polyarteritis nodosa and mixed connective tissue disease. Among other things, the connective tissue and the vessels can be affected. Patients with such CVDs often exhibit inflammation of the skin, joints, vessels and/or internal organs. Collagen Vascular Diseases and Disorders of Connective Tissue
CTDs/CVDs and radiosensitivity measurement/radiation consequences.
The group of CVDs has emerged as potentially clinically relevant for radiotherapy.
The potential complication rate and a possible increased risk of radiation sequelae of CVD patients after irradiation in the context of tumor therapy is highly controversial in the literature. Matched-Control Retrospective Study of the Acute and Late Complications in Patients with Collagen Vascular Diseases Treated with Radiation Therapy
- Many case reports have addressed the hypothesis of potentially increased radiosensitivity in patients with CVDs, as these patients sometimes suffered from disproportionate treatment sequelae after radiotherapy. Acute and late toxicities of radiotherapy for patients with discoid lupus erythematosus: a retrospective case-control study
- That the risk of developing radiation sequelae during or after radiotherapy appears to be potentially increased in patients with CVDs, but not as dramatically as initially thought, is postulated in another publication. Consequences of breast irradiation in patients with pre-existing collagen vascular diseases
- A study involving 209 patients concluded that patients with rheumatoid arthritis had normal radiosensitivity, whereas patients with non-rheumatoid arthritis CVDs had an increased risk of late toxicities. Whether radiation should be considered in principle and - if unavoidable - to what extent must be decided individually for each patient with CVD. Irradiation in the setting of collagen vascular disease: acute and late complications
- The risk of developing late effects due to radiotherapy also appears to increase as the severity of the underlying CVD disease increases. Radiotherapy for malignancy in patients with scleroderma: The Mayo Clinic experience
In addition to many publications speaking of an increased risk for CVD patients to suffer radiation sequelae, there is no evidence in another matched-control retrospective study of a difference in the incidence of acute or late complications resulting from radiotherapy between patients with CVD and their control patients matched on the basis of various criteria (dose, age, sex, etc.). Only scleroderma patients had stood out in this study with an increased rate of late complications after radiotherapy. Matched-Control Retrospective Study of the Acute and Late Complications in Patients with Collagen Vascular Diseases Treated with Radiation Therapy
Conclusion
- The information from the literature search listed below on the individual rheumatic diseases often seems to contradict each other, so that no clear statement on the presence or absence of a generally increased radiation sensitivity in patients with a specific rheumatic disease, such as dermatomyositis, can be derived from it.
- Since, according to several case reports, unusually severe radiation sequelae have frequently occurred in patients with CVDs, it seems reasonable to test these patients with regard to their radiosensitivity prior to radiotherapy in order to have the possibility to avoid severe therapy sequelae by reducing the daily radiation dose if an increased radiosensitivity is detected.
- To obtain more accurate information on the radiosensitivity of patients with a specific rheumatic disease, such as rheumatoid arthritis or systemic sclerosis, significantly more patient samples need to be collected for the laboratory's radiosensitivity measurements to examine in terms of individual patient radiosensitivity. In addition, more case reports of irradiated CVD patients need to be collected to supplement existing reports, to support or refute results of radiosensitivity measurements, and to better assess the overall risk of having increased radiosensitivity within a given patient population. (See also General Radiosensitivity Syndromes and Diseases).
- The aim of the various rheumatic diseases listed separately on the following pages is to give an impression of which rheumatic diseases are more likely to have a generally increased sensitivity to radiation than others and which pre-existing conditions therefore make more sense to test for radiosensitivity than others.
If such testing reveals increased individual radiosensitivity, the indication for radiation should be carefully reviewed and, if necessary, the radiation dose adjusted according to the radiosensitivity. Individual radiosensitivity.