Cardiac localization of ⁹⁹Tc(m) (Sn) pyrophosphate following irradiation of the chest

Of 70 consecutive cancer patients referred from radiotherapy for bone scans, 32% showed cardiac uptake of ⁹⁹(m)Tc (Sn) pyrophosphate; only 9% of a control group showed this uptake. Of those with prior left hemithorax irradiation, 60% showed cardiac uptake; only 12% of those with irradiation elsewhere showed this phenomenon (p < .01). The patients who had no increased uptake tended to have shorter irradiation to scan time intervals (less than 10 months) than those who did show increased uptake (mean of 22 months).