Thallium-201 scintigraphy is not predictive of late cardiac complications in patients with Hodgkin's disease treated with mediastinal radiation.

Abstract

To assess whether abnormalities depicted by Thallium-201 scintigraphy can predict the occurrence of late cardiac complications in patients with Hodgkin's disease treated with mantle field radiation therapy. Thallium scintigraphy was performed in 49 patients at a median of 75 months after initial treatment (range 28-208 months). Initial treatment consisted in chemotherapy, given to two-thirds of the patients and mantle field radiation, delivered to all patients, using a 25-MV linear accelerator. Myocardial perfusion defects were observed in 78% of patients on thallium scintigraphy. These patients had their cardiac status reassessed at a median follow-up of 13.5 years after treatment. Forty-two patients were assessable, as data on the cardiac status were missing in 7 patients. The majority of patients received at least 40 Gy, and 75% of them were treated with one field per day. The median follow-up of patients is 13.5 years (range 9-24.5). Eleven cardiac complications were observed in 9 patients (coronary artery disease [n = 2], conduction-system abnormalities [n = 3], valvular defects [n = 5], and congestive heart disease [n = 1]). The median 15-year actuarial incidence of cardiac complications was 21% (95% confidence interval of 9-40%). The positive and negative predictive value of thallium scintigraphy was 19% and 77%, respectively. The univariate analysis showed that the extent of left ventricle exposure to irradiation was an adverse prognostic factor, and chemotherapy administered before mantle field irradiation was of borderline significance. Thallium scintigraphy is not predictive of late cardiac complications. The extent of left ventricle exposure to radiation and possibly chemotherapy given before radiation treatment are adverse prognostic factors.