Cardiac toxicity is one of the most concerning side effects of anti-cancer therapy. The gain in life expectancy obtained with anti-cancer therapy can be compromised by increased morbidity and mortality associated with its cardiac complications. While radiosensitivity of the heart was initially recognized only in the early 1970s, the heart is regarded in the current era as one of the most critical dose-limiting organs in radiotherapy. Several clinical studies have identified adverse clinical consequences of radiation-induced heart disease (RIHD) on the outcome of long-term cancer survivors. A comprehensive review of potential cardiac complications related to radiotherapy is warranted. An evidence-based review of several imaging approaches used to detect, evaluate, and monitor RIHD is discussed. Recommendations for the early identification and monitoring of cardiovascular complications of radiotherapy by cardiac imaging are also proposed.

Cardiac toxicity is one of the most concerning side effects of anti-cancer therapy. The gain in life expectancy obtained with anti-cancer therapy can be compromised by increased morbidity and mortality associated with its cardiac complications. While radiosensitivity of the heart was initially recognized only in the early 1970s, the heart is regarded in the current era as one of the most critical dose-limiting organs in radiotherapy. Several clinical studies have identified adverse clinical consequences of radiation-induced heart disease (RIHD) on the outcome of long-term cancer survivors. A comprehensive review of potential cardiac complications related to radiotherapy is warranted. An evidence-based review of several imaging approaches used to detect, evaluate, and monitor RIHD is discussed. Recommendations for the early identification and monitoring of cardiovascular complications of radiotherapy by cardiac imaging are also proposed.

The incidence of renal artery stenosis (RAS) in patients with coronary artery disease (CAD) has not been well documented. Over a 9-month period, 196 patients who underwent coronary angiography because of clinically suspected CAD had routine nonselective renal cine or digital subtraction angiography. There were 68 females and 128 males with a mean age of 63 years (range 35-85). Angiographically significant CAD was present in 152 patients (78%). Of the total patient cohort, 29 patients (15%) had mild RAS (< 50%), and 36 patients (18%) had significant RAS (> or = 50%). In patients with normal coronary arteries, only three patients (7%) had RAS. Thirty-three patients (92%) with severe RAS also had CAD. Of these 33 patients, 45% had hypertension, 30% had hyperlipidemia, 24% had diabetes mellitus, 24% had renal insufficiency (creatinine > or = 1.5), and 51% were smokers. In addition, it was noted that 20 of these patients (61%) had two or more of the above-listed clinical parameters. However, univariate analysis using the chi-square test revealed that only CAD (22% P < 0.03) and renal insufficiency (29% P < 0.15) were reliable clinical predictors of RAS. In conclusion, RAS is a frequent finding in patients with CAD, particularly when renal insufficiency is also present.

To assess the effects of age on the left ventricular ejection fraction (LVEF), we performed radionuclide angiocardiography at rest and during upright bicycle exercise in 77 healthy volunteers 20 to 95 years of age. Radionuclide measurements included left ventricular ejection fraction, end-diastolic volume, and regional wall motion. Age did not appear to influence any of these indexes at rest. However, during exercise the ejection fraction was less than 0.60 in 45 per cent of subjects over age 60 as compared with 2 per cent of younger subjects (P < 0.001). In addition, there was a decline in the change in LVEF (exercise LVEF minus rest LVEF) with increase in age (r = -0.71). Wall-motion abnormalities during exercise occurred with increasing frequency in patients who were 50 and older. In the older subjects these age-related changes in ejection fraction during exercise were not associated with differences in end-diastolic volume or blood pressure.

Three-dimensional (3D) mode imaging is the current standard for PET/CT systems. Dynamic imaging for quantification of myocardial blood flow with short-lived tracers, such as 82 Rb-chloride, requires accuracy to be maintained over a wide range of isotope activities and scanner counting rates. We proposed new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging. Methods: 82 Rb or 13 Nammonia (1,100-3,000 MBq) was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was obtained over 5 half-lives on 9 different 3D PET/CT systems and 1 3D/2-dimensional PET-only system. Dynamic images (28 · 15 s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with less than 10% bias, from which corresponding dead-time, counting rates, and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-to-myocardium activity ratio. Image quality was assessed via the coefficient of variation measuring nonuniformity of the left ventricular myocardium activity distribution. Results: Maximum recommended injected activity/body weight, peak dead-time correction factor, counting rates, and residual scatter bias for accurate cardiac myocardial blood flow imaging were 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence counting rates, and 2%-10% on the investigated scanners. Nonuniformity of the myocardial activity distribution varied from 3% to 16%. Conclusion: Accurate dynamic imaging is possible on the 10 3D PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit. PETi maging in 3-dimensional (3D) mode has become the standard for new whole-body scanners. The increased sensitivity allows for reduction of injected activity to the patient while maintaining excellent image quality; however, random and scattered photon counts are increased, requiring systems with high counting rate capability and accurate corrections for these physical effects. Current PET instrumentation and National Electrical Manufacturers Association (NEMA) performance evaluation methods (1) have been developed primarily to optimize whole-body oncology imaging with 18 F-FDG. However, dynamic PET imaging for myocardial blood flow (MBF) quantification with short-lived tracers, such as 82 Rb, 15 O-water, or 13 N-ammonia, requires high counting rates and correction accuracy to be maintained over a wide range of measured activities (2). An ideal PET system should allow for conventional relative myocardial perfusion imaging (MPI) of tracer retention without compromising accuracy of first-pass dynamic data (3). Routine MBF imaging is clinically feasible with the 76-s half-life generator-produced tracer 82 Rb, resulting in accurate (4,5) and reproducible measurements (3,6-8), as validated against 13 N-ammonia...