Cardiovascular Toxicities of Radiation Therapy and Recommended Screening and Surveillance.

Radiation therapy is a key part of treatment for many cancers. Vast advancements in the field of radiation oncology have led to a decrease in malignancy-related mortality, which has uncovered some of the long-term side effects of radiation therapy. Specifically, there has been an increase in research looking into the cardiovascular side effects of chest radiation therapy for cancers of the esophagus, breast, and lung tissue as well as lymphomas. The manifestations of cardiac injury from irradiation range from short-term complications, such as pericarditis, to long-term damage including cardiomyopathy, valvular disease, and conduction disturbances. The aims of this article are to describe the cardiovascular side effects and the associated risk factors, to discuss risk reduction strategies, and to provide guidance in pre-radiation screening, post-radiation surveillance, and the management of these conditions.

Validation of the clinical utility of sGaw as a response variable in methacholine challenge testing.

BACKGROUND AND OBJECTIVE: Airway hyperresponsiveness (AHR) is commonly assessed by a methacholine challenge test (MCT), during which a provocative concentration causing a 20% reduction in forced expiratory volume in 1 second (FEV1 ) (PC20 ) < 8 mg/ml is considered a positive response. However, a fall in specific airway conductance (sGaw) may also have clinical significance. The purpose of this study was to assess whether AHR determined by a provocative concentration causing a 40% reduction in sGaw (PC40 ) < 8 mg/ml corresponds to a clinical diagnosis of asthma. METHODS: We analysed the changes in spirometry, lung volumes and sGaw during MCT in 211 randomly selected patients being evaluated for AHR to support a clinical diagnosis of asthma. RESULTS: The mean (SD) age of the group was 53 (15) years, with 141 women (67%). Overall lung function was normal, with FEV1  = 92 (15) % predicted, total lung capacity = 97 (13) % predicted and sGaw = 0.19 (0.15-0.23) L/s/cm H2 O/L, (median, 25-75 IQR). There were many more patients who responded by PC40 only (n = 120) than who responded by PC20 (n = 52). There was no significant difference in asthma diagnosis between the PC20 (98%) and PC40 (93%) groups, and we estimate 34% of patients with a diagnosis of asthma would have been classified as having no AHR if only the FEV1 criterion was used. CONCLUSION: Changes in sGaw during MCT indicate clinically significant AHR in support of a clinical diagnosis of asthma among patients being evaluated for asthma.