Heart disease following radiation

Cardiac function, perfusion, and morbidity in irradiated long-term survivors of Hodgkin's disease

PURPOSE

The incidence of cardiotoxicity and clinical cardiac events following mantle irradiation (RT) in patients with Hodgkin's disease using modern techniques is controversial. The use of quantitative, prognostically validated noninvasive tests to assess systolic and diastolic cardiac function and regional myocardial blood flow may reveal preclinical abnormalities associated with subsequent clinical events of myocardial infarction, cardiac death, or angina. The goals of this study are to determine, through noninvasive measures, the presence and time course of alterations in cardiac systolic and diastolic function and of relative myocardial blood flow in long-term survivors of Hodgkin's disease, and assess their correlation with subsequent clinical cardiac end points.

METHODS AND MATERIALS

Equilibrium radionuclide angiocardiography (ERNA) was used to assess left ventricular (LV) systolic and diastolic function by measuring LV ejection fraction (LVEF) and peak filling rate (PFR), respectively, in patients without known ischemic heart disease who received RT. Electrocardiography was performed to assess electrical cardiac function under conditions of rest and either exercise or dipyridamole vasodilator stress. Quantitative rest/stress myocardial perfusion imaging with thallium-201 and/or Tc-99m sestamibi was used to assess myocardial perfusion. Patients at least 1.0 year after RT were eligible if they were <50 years old at RT, had no known cardiac disease, and remained free of clinical recurrence of Hodgkin's disease. Fifty patients, ages 10.2-46.1 years (mean 26.0 +/- 8.6) at RT, were tested 1.1 to 29.1 years (mean 9.1 +/- 7.5) after RT. Seventeen of these patients were tested two times separated by 1.1 to 8.1 years. The mean central cardiac RT dose was 35.1 +/- 7.8 Gy (range 18.5-47.5) in daily 15-2.0 Gy fractions. Twelve patients were concomitantly irradiated to the left ventricle, usually through partial transmission left lung shields (mean 17.0 +/- 2.2 Gy, range 14.3-21.3).

RESULTS

No patients had signs or symptoms of cardiac disease at the time of evaluation. The mean LVEF at the time of initial testing was 59.6 +/- 6.2% (n = 50; range 42-73%; normal > or =50%), and the mean peak filling rate (PFR) was 3.46 +/- 0.88 end diastolic volumes per second (EDV/s) (range 1.5-5.4 EDV/s; normal > or =2.54 EDV/s). The 12 patients also treated to the left ventricle had a normal mean ejection fraction that was lower (56.6 +/- 5.0%) than that of the other 38 patients (LVEF = 60.6 +/- 6.3%, p = 0.051) when initially evaluated. Average PFR was similar in the two groups. For the 15 patients who had repeat tests, changes in LVEF were generally modest in individual patients, and there was no change in the group mean. For all patients, no significant association was found between cardiac function indices and age at RT, dose, or interval from RT to testing. Myocardial perfusion scintigraphy demonstrated mild ischemia in one or more segments in two patients, and borderline normal perfusion in three patients. Rest and stress ECG testing demonstrated mild repolarization abnormalities in three, and one patient was abnormal at rest and had nondiagnostic changes with stress.

CONCLUSIONS

Patients irradiated to the heart incidental to the treatment of Hodgkin's disease using modern techniques have generally normal measures of left ventricular function and myocardial perfusion. Modest differences in the normal left ventricular ejection fraction observed may be attributable to the cardiac volume irradiated. Some patients may manifest improved cardiac function as time from RT elapses, while a significant deterioration of ejection fraction was not observed and reduction in diastolic peak filling rate is uncommon. The previously reported increased risk of cardiac death may relate to use of older techniques of RT employing higher doses and lack of cardiac shielding, and uncontrolled patient selection with additional behaviors and cardiac risk factors.

Symptomatic coronary artery disease after mantle irradiation for Hodgkin's disease

PURPOSE

a) To assess the age-related incidence of morbid cardiac events including cardiac death (CD), nonfatal myocardial infarction (MI), and angina pectoris (AP) in all patients treated for Hodgkin's disease at a single institution; b) to examine the prevalence of cardiac risk factors and presence of coronary artery disease (CAD) in affected patients.

METHODS AND MATERIALS

475 patients were treated for Hodgkin's disease in our institution between 1954 and 1989. The status of 97% of the cohort was established either by patient visit and examination in 1992-1993, personal telephone contact, or documentation of death. The 326 of these patients who had mantle irradiation (RT) and survived 3 years formed the study population. Patients who experienced AP, MI, or CD secondary to CAD were assessed for the presence of specific cardiac risk factors. Cardiac catheterization and necropsy data were reviewed to determine the presence and degree of coronary artery stenosis.

RESULTS

Eighteen of 326 patients (5.5%) have had a morbid cardiac event directly related to CAD. Seven patients had CD. Seven patients experienced nonfatal MI, and four patients had AP. The mean interval from RT to morbid cardiac event was 13.1 years (range: 4.4-27.0), and the mean age at the time of the event was 39.4 years (range: 24-65). Four of these patients had morbid cardiac events between ages 24-29 years. Based on US statistics of CD secondary to MI, the relative risk of CD for the treated group was 2.8 (3.1 for males and 1.8 for females). Remarkably, no difference was found in the risk of experiencing a morbid cardiac endpoint in patients stratified by either decile of age at which RT was given, or by duration of follow-up. Only one patient experiencing an event (AP) had received an anthracycline. The mean RT dose to the central cardiac volume for the affected patients was 44.3 Gy (range: 35-60.4). Autopsy or catheterization data were available on 15 patients and revealed 90-100% stenosis of at least one major vessel in 11 patients (73%), and no single artery was more commonly stenosed. Specifically, the left anterior descending and right coronary arteries were each greater than or equal to 60% stenosed in 10 out of 15 patients (67%), and either the left main or circumflex arteries were greater than or equal to 50% stenosed in 5 out of 15 patients (33%); triple vessel disease was present in seven patients. Risk factor data were available on all patients experiencing morbid cardiac events: 72% smoked, 72% were male, 78% had hypercholesterolemia, 61% were obese, 28% had a positive family history, 33% had hypertension, and 6% (one) had diabetes. The average number of risk factors per patient was 2.9; seven patients had at least four risk factors, and all patients had at least one risk factor. This frequency of risk factors is elevated when compared to the US population.

CONCLUSIONS

In our institution, 5.5% of patients treated for Hodgkin's disease experienced a morbid cardiac event following RT to the central cardiac volume. The doses given were greater than commonly used today. Some patients experienced events at a young age, and the likelihood of experiencing CD was increased compared to the general population. This observation is consistent with RT as an additional risk factor in the induction of morbid cardiac events. Appropriate cardiac shielding and radiation doses, careful follow-up, which includes monitoring of cardiac function, and a preventative program of sensible dietary habits, exercise, and nonsmoking may be beneficial in reducing cardiac morbidity in long-term survivors of Hodgkin's disease.

Effects of intraoperative irradiation and intraoperative hyperthermia on canine sciatic nerve: neurologic and electrophysiologic study

PURPOSE

Late radiation injury to peripheral nerve may be the limiting factor in the clinical application of intraoperative radiation therapy (IORT). The combination of IORT with intraoperative hyperthermia (IOHT) raises specific concerns regarding the effects on certain normal tissues such as peripheral nerve, which might be included in the treatment field. The objective of this study was to compare the effect of IORT alone to the effect of IORT combined with IOHT on peripheral nerve in normal beagle dogs.

METHODS AND MATERIALS

Young adult beagle dogs were randomized into five groups of three to five dogs each to receive IORT doses of 16, 20, 24, 28, or 32 Gy to 5 cm of surgically exposed right sciatic nerve using 6 MeV electrons and six groups of four to five dogs each received IORT doses of 0, 12,16, 20, 24, or 28 Gy simultaneously with 44 degrees C of IOHT for 60 min. IOHT was performed using a water circulating hyperthermia device with a multichannel thermometry system on the surgically exposed sciatic nerve. Neurologic and electrophysiologic examinations were done before and monthly after treatment for 24 months. Electrophysiologic studies included electromyographic (EMG) examinations of motor function, as well as motor nerve conduction velocities studies.

RESULTS

Two years after treatment, the effective dose for 50% complication (ED50) for limb paresis in dogs exposed to IORT only was 22 Gy. The ED50 for paresis in dogs exposed to IORT combined with IOHT was 15 Gy. The thermal enhancement ratio (TER) was 1.5. Electrophysiologic studies showed more prominent changes such as EMG abnormalities, decrease in conduction velocity and amplitude of the action potential, and complete conduction block in dogs that received the combination of IORT and IOHT. The latency to development of peripheral neuropathies was shorter for dogs exposed to the combined treatment.

CONCLUSION

The probability of developing peripheral neuropathies in a large animal model was higher for IORT combined with IOHT, than for IORT alone. The dose required to produce the same level of late radiation injury to the sciatic nerve was reduced by a factor of 1.5 (TER) if IORT was combined with 44 degrees C of IOHT for 60 min.

Malignancy-related pericardial effusion. 127 cases from the Roswell Park Cancer Institute

BACKGROUND

Malignancy-related pericardial effusions may represent a terminal event in patients with therapeutically unresponsive disease. However, select patients with malignancies sensitive to available therapies may achieve significant improvement in palliation and long term survival with prompt recognition and appropriate intervention.

METHODS

From 1968 to 1994, 150 invasive procedures were performed for the treatment or diagnosis of pericardial effusion in 127 patients with underlying malignancies. These cases were reviewed retrospectively to best identify the clinical features, appropriate diagnostic workup, and optimal therapy for this complication of malignancy.

RESULTS

Dyspnea (81%) and an abnormal pulsus paradoxus (32%) were the most common symptoms. Echocardiography had a 96% diagnostic accuracy. Cytology and pericardial biopsy had sensitivities of 90% and 56%, respectively. Fifty-five percent of all effusions were malignant comprising 71% of adenocarcinomas of the lung, breast, esophagus, and unknown primary site. In 57 patients, a malignant effusion could not be determined, and no definitive etiology could be established for 74% of these effusions. Radiation-induced, infectious, and hemorrhagic pericarditis each were identified in fewer than 5% of cases.

CONCLUSIONS

Subxyphoid pericardiotomy proved to be a safe and effective intervention that successfully relieved pericardial effusions in 99% of cases with recurrence and reoperation rates of 9% and 7%, respectively. Survival most closely was related to the extent of disease and its inherent chemo-/radiosensitivity, with 72% of the patients who survived longer than 1 year having breast cancer, leukemia, or lymphoma.

Radiation injury to the heart

For the RTOG Consensus Conference on Late Effects of Cancer Treatment we summarize the clinical manifestations of cardiac complications appearing months to years following incidental irradiation of the heart during treatment of thoracic neoplasms. The most common effects present as pericardial disease, however, it is becoming more clear that precocious or accelerated coronary artery disease is an important late effect, especially in patients treated with radiation before the age of 21 years. To the extent it is known, the pathophysiology of the various syndromes is described and the extensive literature on dose, volume, and fractionation factors is reviewed. Based upon our current understanding of late cardiac effects, a clinical grading system has been developed and is published elsewhere in this issue.

Intraoperative radiation (IORT) injury to sciatic nerve in a large animal model

Peripheral nerve appears to be a dose-limiting normal tissue in the clinical application of intraoperative radiation therapy (IORT). To assess IORT injury to peripheral nerve, three groups of five beagle dogs received doses of 12, 20 or 28 Gy to the surgically exposed and isolated right sciatic nerve in the mid-femoral region using 6 MeV electrons. The left sciatic nerve of each dog served as its own control. As a surgical control five dogs received surgical exposure of the nerve only. Monthly neurologic exams, electromyogram and nerve conduction studies were performed following treatment for 12 months. After that dogs were euthanatized and histologic studies of nerves were done to define the degree of axon and myelin loss as well as presence of fibrosis and vascular lesions for different doses of IORT. Results showed that the threshold dose most likely related to expression of severe radiation damage to the nerve in this model is between 20 and 25 Gy. Radiation injury to peripheral nerve appears to be the result of direct radiation effects on Schwann cells and nerve vasculature and secondary effects resulting from damage to regional muscle and vasculature. A theoretical mechanism of radiation injury to peripheral nerve is proposed.

Severe coronary artery disease after radiation therapy of the chest and mediastinum: clinical presentation and treatment

OBJECTIVE

To define the clinical and angiographic features and the therapeutic problems in patients with coronary artery disease after therapeutic irradiation of the chest.

DESIGN

An observational retrospective study.

SETTING

The cardiac catheterisation laboratory, university medical school.

PATIENTS

15 subjects (8 men and 7 women, aged 25-56 years, mean 44) examined in the cardiac catheterisation laboratory, who had significant coronary artery disease years after having radiation treatment to the chest and anterior mediastinum. In the early stages of the study angiography was performed because of typical symptoms of ischaemic heart disease. Later on it was performed because of a high index of suspicion in people with signs of extensive radiation heart damage.

MAIN OUTCOME MEASURES

Clinical and electrocardiographic evidence of ischaemic heart disease; echocardiographic signs of pericardial, myocardial or valvar involvement; angiographic evidence of coronary arterial stenosis, with special attention to the ostia; haemodynamic and angiographic signs of pericardial, myocardial, and valvar disease. Survival and symptomatic and functional status were ascertained after medical or surgical treatment.

RESULTS

The patients were relatively young and had no risk factors. Seven patients had no signs or symptoms of ischaemic heart disease. Ten patients had ostial stenosis, which was associated with extensive involvement of other cardiac structures in nine of them. Seven required surgical treatment for coronary artery disease. Two died, one at surgery and the other one six months later. Five patients had complications associated with irradiation.

CONCLUSIONS

Coronary arterial disease can be reasonably ascribed to the effects of chest irradiation when the patients are young and free from risk factors, especially if the obstructions are ostial and there is important damage to other cardiac structures. In patients with damage to other cardiac structures angina and infarction are often absent and coronary angiography seems to be mandatory. Patients often require surgical treatment and postoperative complications are common.

The syndrome of 5-fluorouracil cardiotoxicity. An elusive cardiopathy

BACKGROUND

A case of reversible cardiogenic shock linked to 5-fluorouracil (5-FU) was observed. Recognizing the increasing use of 5-FU, the authors tried to map this syndrome.

METHODS

They reviewed 134 additional case reports, retrieved information from literature searches, focused on clinical features, and discussed possible pathophysiologic findings and prevention of this syndrome.

RESULTS

Although angina and electrocardiographic changes were common and reproducible (approximately 90% each), coronary artery disease was found in a few patients. A total of 33 patients had severe left ventricular dysfunction, 28 without evidence of myocardial infarction. The symptoms were responsive to conservative management (90%).

CONCLUSIONS

Cardiac toxicity is a little known complication of 5-FU therapy, with an unknown but significant incidence. It is highly treatable.

Myocardial infarction in young patients with Hodgkin's disease--potential pathogenic role of radiotherapy, chemotherapy, and splenectomy

Among a total of 2147 patients admitted to our hospital for acute myocardial infarction between 1978 and 1987, three young patients aged 24, 29, and 39 years had previously been treated for Hodgkin's disease. Staging laparotomy, including splenectomy, had been performed in all three patients. Two patients had both mediastinal irradiation (21 and 27 months before infarction) and chemotherapy. In the first patient, postmortem histologic examination of the coronary arteries revealed fibrotic changes, which were probably induced by radiotherapy. In our second patient, myocardial infarction developed 5 days after vinblastine treatment; early angiography showed thrombotic occlusion of the proximal right coronary artery, which was recanalized using the diagnostic Sones catheter. Subsequent angiography revealed normal coronary arteries. This is, to our knowledge, the first case of documented coronary artery thrombosis after treatment with vinca-alkaloids. In our third patient, neither mediastinal irradiation nor chemotherapy had been performed prior to myocardial infarction. However, a marked increase in platelet counts following splenectomy was observed in this patient. The role of radiotherapy, chemotherapy, and splenectomy with consecutive thrombocytosis as a third possible pathogenic factor for subsequent development of myocardial infarction is discussed.

Radiation-induced coronary artery disease

Excessive unprotected radiation to the heart appears to lead to the development of CAD, even in the absence of significant cardiovascular risk factors. The coexistence of such factors may enhance the probability of CAD. The presence of hypercholesterolemia and concomitant or sequential use of chemotherapeutic agents (especially doxorubicin) could further increase this risk. Therapeutic decisions, as with any other manifestation of CAD, relate to the extent of myocardium at jeopardy and to the overall diffuseness of CAD. Management options possible are PTCA or coronary artery bypass surgery. The latter may be required in left main artery stenosis and complicated ostial lesions. Use of shielding should decrease the associated risk of radiation-induced CAD in future years. However, clinicians should continue to have a high degree of suspicion of CAD in patients treated with thoracic radiation without cardiac shielding.

Radiation-induced heart disease: review of experimental data on dose response and pathogenesis

Clinical and experimental heart irradiation can cause a variety of sequelae. A single dose of greater than or equal to 15 Gy leads to a reversible exudative pericarditis, occurring in dogs, rabbits or rats at around 100 days. Its time-course is very similar in all species investigated, but there are considerable species and strain differences in severity and incidence. After longer, dose-dependent latency times chronic congestive myocardial failure develops. At histological examination myocardial degeneration and necrosis is observed, which in some species is accompanied by a variable degree of interstitial fibrosis. In rabbits and rats, myocardial degeneration becomes apparent at around 70 days after 20 Gy and is preceded by a marked reduction in capillary density as well as ultrastructural endothelial cell degeneration. Simultaneously to structural capillary damage, a focal loss of the endothelial marker enzyme alkaline phosphatase was observed in rats in areas with subsequent myocardial degeneration. Cell kinetic studies in rabbits and rats revealed a radiation-induced wave of increased endothelial cell proliferation at 30-100 days postirradiation. In the rat it is exclusively seen in conjunction with alteration of endothelial cell marker enzymes. The temporal and spatial pattern of proliferative response exludes endothelial cell death in mitosis as the sole pathogenetic mechanism causing capillary loss and myocardial degeneration. Parallel to development of morphological damage, haemodynamic studies in various rats strains revealed a drop in cardiac output and left ventricular ejection fraction to about 64% of normal values after 20 Gy. In vivo, this slightly reduced cardiac function was then maintained in a steady state for many weeks, probably due to a compensatory up-regulation of cardiac beta-adrenergic receptors. In denervated working heart preparations in vitro, however, these compensatory mechanisms are not effective and stroke volume as well as cardiac contractility show a rapid and steady deterioration. In many respects radiation-induced heart disease conforms to radiobiological concepts of late-responding tissues, showing a chronic progressive time-course and a very pronounced fractionation effect. However, pathogenesis cannot be understood in terms of target cell depletion alone, and experimental evidence indicates the importance of alterations of regulatory mechanisms.

Electrocardiographic changes and arrhythmias after cancer therapy in children and young adults

Transient electrocardiographic changes and arrhythmias are known to be acute manifestations of cardiotoxicity secondary to cancer therapy with anthracyclines or cardiac irradiation. However, despite the known risk of late cardiac dysfunction in survivors of childhood cancer therapy, the risk of clinically important electrocardiographic abnormalities and arrhythmias after treatment is unknown. Standard 12-lead and 24-hour ambulatory electrocardiograms were recorded in 73 patients who received anthracyclines alone, 24 who received cardiac irradiation alone, and 27 who received both anthracyclines and cardiac irradiation. The mean age of the patients was 15 years. Mean cumulative anthracycline dose was 282 mg/m2 in patients who received anthracyclines alone and 244 mg/m2 in patients who received both anthracyclines and cardiac irradiation. Analysis of the 12-lead and 24-hour electrocardiograms demonstrated increased frequency of QTc prolongation, supraventricular premature complexes, supraventricular tachycardia, ventricular premature complexes, couplets and ventricular tachycardia (all p less than 0.001) when compared with an age-matched healthy population. Most patients had abnormalities limited to single supraventricular or ventricular premature complexes; however, potentially serious ventricular ectopy, including ventricular pairs and ventricular tachycardia, were noted in patients with cumulative doses greater than 200 mg/m2. Electrocardiographic abnormalities and arrhythmias are not limited to the acute phase of treatment with anthracyclines and cardiac irradiation. Survivors of childhood malignancy who received anthracyclines or cardiac irradiation, or both, probably should undergo ambulatory electrocardiographic monitoring as part of their follow-up to detect potentially life-threatening arrhythmias.

Coronary artery operation in radiation-associated atherosclerosis: long-term follow-up

Radiation-associated coronary atherosclerosis is a potential problem for patients who have had mediastinal irradiation for malignant tumors. This study identified 14 patients with radiation-associated coronary atherosclerosis, defines unique population characteristics, and analyses postsurgical problems and long-term outcome. Fourteen patients with radiation-associated coronary atherosclerosis and class III and IV New York Heart Association symptoms were identified because of mediastinal or chest wall irradiation (30 Gy) associated with anterior epicardial discoloration or fibrosis, aortitis with adventitial thickening, and inflammatory process over a proximal coronary artery. Two distinct treatment groups were analyzed. Coronary artery operation resulted in one hospital death, with vein grafts being used predominantly. The internal mammary artery could only be used in 3 patients because of vessel friability and mediastinal fibrosis. Postoperative right ventricular dysfunction and pulmonary problems were frequent. Severe pericardial inflammatory complications (fibrosis with graft closure, and constrictive pericarditis) present in 2 early patients resulted in routine anterior pericardiectomy after coronary artery operation without further problems. Long-term follow-up (100%) (range, 11 to 74 months) revealed that 1 patient died late and of the remainder (12 patients), 11 were in New York Heart Association class I and 1 in class II, experiencing three myocardial events. Thus, patients with radiation-associated coronary atherosclerosis have a low operative mortality but have risk of early right ventricular and pulmonary dysfunction. The routine use of internal mammary artery may not be possible and anterior pericardiectomy is recommended. Long-term results are excellent and no evidence of accelerated disease has been noted.

Effect of external beam irradiation on neointimal hyperplasia after experimental coronary artery injury

Human coronary artery restenosis after percutaneous revascularization is a response to mechanical injury. Smooth muscle cell proliferation is a major component of restenosis, resulting in obstructive neointimal hyperplasia. Because ionizing radiation inhibits cellular proliferation, this study tested in a porcine coronary injury model the hypothesis that the hyperplastic response to coronary artery injury would be attenuated by X-irradiation. Deep arterial injury was produced in 37 porcine left anterior descending coronary artery segments with overexpanded, percutaneously delivered tantalum wire coils. Three groups of pigs were irradiated with 300-kV X-rays after coil injury: Group I (n = 10), 400 cGy at 1 day; Group II (n = 10), 400 cGy at 1 day and 400 cGy at 4 days and Group III (n = 9), 800 cGy at 1 day. Eight pigs in the control group underwent identical injury but received no radiation. Treatment efficacy was histologically assessed by measuring neointimal thickness and percent area stenosis. Mean neointimal thickness in all irradiated groups was significantly higher than in the control groups and thickness was proportional to X-ray dose. X-irradiation delivered at these doses and times did not inhibit proliferative neointima. Rather, it accentuated the neointimal response to acute arterial injury and may have potentiated that injury.

Tolerance of normal tissue to therapeutic irradiation

The importance of knowledge on tolerance of normal tissue organs to irradiation by radiation oncologists cannot be overemphasized. Unfortunately, current knowledge is less than adequate. With the increasing use of 3-D treatment planning and dose delivery, this issue, particularly volumetric information, will become even more critical. As a part of the NCI contract N01 CM-47316, a task force, chaired by the primary author, was formed and an extensive literature search was carried out to address this issue. In this issue. In this manuscript we present the updated information on tolerance of normal tissues of concern in the protocols of this contract, based on available data, with a special emphasis on partial volume effects. Due to a lack of precise and comprehensive data base, opinions and experience of the clinicians from four universities involved in the contract have also been contributory. Obviously, this is not and cannot be a comprehensive work, which is beyond the scope of this contract.

Cardiovascular sequelae of therapeutic thoracic radiation

Mediastinal radiation damages endothelial cells, with resulting loss of capillaries and ischemia at the level of the microcirculation. These changes lead to increases in collagen and proliferation of fibrous tissue throughout the heart. Cardiac dysfunction following radiotherapy is surprisingly common and may be due to pericardial, myocardial, valvular, conduction system, or coronary artery disease. Greater awareness of cardiotoxicity has prompted changes in radiation techniques that appear to reduce clinical cardiovascular complications.

Radiation effects on left ventricular function and myocardial perfusion in long term survivors of Hodgkin's disease

We evaluated systolic and diastolic indices of left ventricular performance by radionuclide angiocardiography and myocardial perfusion with exercise/rest thallium scintigraphy in 16 patients previously irradiated for Hodgkin's disease. These commonly used indices of left ventricular (LV) performance included LV ejection fraction (LVEF) as a measure of systolic function, and LV peak filling rate (PFR) as a measure of diastolic function. The presence of coronary artery disease (CAD) was evaluated by ECG treadmill testing (13 patients) and by quantitative planar thallium scintigraphy (12 patients). Patients were 16-38 years old (mean 24.9 +/- SD 6.2) at the tim eof irradiation, and were evaluated 2.5-21.5 years (mean 9.3 +/- 6.3) after radiation therapy (RT). RT was delivered with beam energies of 2-18 MV, equally weighted AP-PA mantle fields with both fields treated daily for most patients (13 patients), and fraction sizes of 1.5-2.0 Gy. Six patients received radiation to th entire cardiac volume, most commonly via left-sided partial transmission lung blocks (PTLB). Patient data were analyzed according to the volume of heart treated. Individuals who had the entire cardiac volume irradiated were assigned to group I (N = 6), and those patients who had some portion of the heart shielded throughout treatment comprised group II (N = 10). In this series, no perfusion defects were evident in either group by quantitative planar thallium scintigraphy. Mean LVEF for all patients studied was 60% (normal LVEF greater than or equal to 50%). Patients in group I had a lower mean LVEF than those in group II, 55 +/- 4% versus 63 +/- 6% (p = 0.01). Mean PFR for all patients studied was normal at 3.5 EDV/sec (normal PFR greater than or equal to 2.54 EDV/sec). Patients in group I had a lower mean PFR than those in group II, 3.0 +/- 0.6 vs 3.8 +/- 0.7 EDV/sec (p = 0.04). Thus, patients irradiated to large cardiac and pulmonary volumes had lower LVEF and PFR within the normal range compared to patients who had some portion of the cardiac volume shielded. These differences are statistically significant in the relatively small groups studied but do not appear to be associated at the present time with clinically significant effects.

Late cardiac effects after mantle radiotherapy in patients with Hodgkin's disease

Twenty-five patients (21-45 years old) treated for Hodgkin's disease with mantle radiotherapy but no chemotherapy underwent cardiac testing with myocardial scintigraphy during exercise, Echo-Doppler cardiography and CT-examination, 10-20 years after treatment. Four of twenty-six (15%) young patients had serious cardiac complications after mantle therapy, and reduced systolic and/or diastolic function; and minor valvular disturbances were often found. One 36-year-old female died of myocardial infarction 4 years after therapy, one 39-year-old male had two non-lethal infarctions after 14 years, one 36-year-old male with no symptoms had severe reversible ischemia and three proximal coronary artery stenoses, and one 32-year-old female with constrictive pericarditis had pericardeictomy 14 years after therapy. In 23/24 patients the pericardial thickness was normal and no pericardial effusion was found. 23/24 patients had normal working capacity, but myocardial scintigraphy was normal in only 9 patients. 11/25 patients had reduced systolic function and in 12/24 patients the diastolic function was reduced. 11/25 patients had abnormal valvular or subvalvular structures. Valvular stenosis was not found but aortic, mitral and tricuspidal regurgitations were found in 1/25, 9/25 and 22/25, respectively. In all but two cases the regurgitations were mild. We conclude that mediastinal irradiation must be considered a risk factor for cardiac disease. It may be advisable to reduce other risk factors in these patients.

Thoracic irradiation in Hodgkin's disease: disease control and long-term complications

A total of 590 patients with Stage IA-IIIB Hodgkin's disease received mantle irradiation at the Joint Center for Radiation Therapy between April 1969 and December 1984 as part of their initial treatment. Recurrence patterns as well as pulmonary, cardiac and thyroid complications were analyzed. Pulmonary recurrence was more frequently seen in patients with large mediastinal adenopathy (LMA); 11% of patients with LMA recurred in the lung in contrast to 3.1% with small or no mediastinal disease, p = 0.003. Hilar involvement, when corrected for size of mediastinal involvement, was not predictive of lung relapse. Patients with LMA also had a high rate of nodal relapse above the diaphragm (40%) following radiation therapy (RT) alone as compared to similarly treated patients with small or no mediastinal adenopathy (6.5%), p less than 0.0001. This risk of nodal recurrence was greatly reduced (4.7%) for LMA patients receiving combined radiation therapy and chemotherapy (CMT), p less than 0.0001. Sixty-seven patients (11%) with hilar or large mediastinal involvement received prophylactic, low dose, whole lung irradiation. No decrease in the frequency of lung recurrence was seen with the use of whole lung irradiation. Radiation pneumonitis was seen in 3% of patients receiving radiation therapy alone. In contrast, the use of whole lung irradiation was associated with a 15% risk of pneumonitis, p = 0.006. The risk of pneumonitis was also significantly increased with the use of chemotherapy (11%), p = 0.0001. Cardiac complications were uncommon with pericarditis being the most common complication (2.2%). Thyroid dysfunction was seen in 25% of patients and appeared to be age-related. These data suggest that the long-term complications of mantle irradiation are uncommon with the use of modern radiotherapeutic techniques. The use of prophylactic whole lung irradiation is no longer recommended since its use did not reduce pulmonary relapse but did increase the risk of pneumonitis. Chemotherapy is also associated with an increased risk of pneumonitis, however, its use in patients with large mediastinal adenopathy appears justified.

Differentiation of restrictive cardiomyopathy from pericardial constriction: assessment of diastolic function by radionuclide angiography

Diastolic filling variables were studied in 12 patients with the hemodynamic features of constriction, of whom 5 had restrictive cardiomyopathy, 5 had pericardial constriction and 2 had combined pericardial constriction and restrictive cardiomyopathy. The values were compared with those in 10 normal subjects of comparable age. The filling fractions between 10% and 70% of the diastolic time interval were greater in patients with pericardial constriction than in those with restrictive cardiomyopathy (p less than 0.01 between 20% and 50%, p less than 0.05 at 10%, 60% and 70%), with no overlap. The filling fractions in patients with pericardial constriction were also greater than those in normal subjects between 10% and 60% of the diastolic time interval. The filling fraction was lower in patients with restrictive cardiomyopathy than in normal subjects at 40% of the diastolic time interval (p less than 0.05). The time to peak filling rate in patients with pericardial constriction was shorter (110 +/- 14 ms) than in those with restrictive cardiomyopathy (195 +/- 45 ms, p less than 0.01) or in normal subjects (173 +/- 32 ms, p less than 0.01). The percent of atrial contribution to left ventricular filling was higher in those with restrictive cardiomyopathy (45 +/- 17%) than in those with pericardial constriction (21 +/- 6%, p less than 0.05) or in normal subjects (24 +/- 9%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Pure infundibular pulmonary stenosis induced by radiation therapy--a case report

A sixty-one-year-old woman developed acquired infundibular pulmonary stenosis eleven years after radiation therapy to the mediastinum. On catheterization, there was a 48 mmHg gradient between the right ventricle and the pulmonary artery. Postmortem examination revealed remarkable narrowing of infundibulum. Histologic examination strongly suggested that muscular hypertrophy of the right ventricular outflow tract had been induced by a high dose of radiation therapy.

Immediate effect of irradiation on microvasculature

The immediate effects of irradiation on microvasculature in muscle in an animal model are described in this paper. By using triple isotopes of 125I, 131I, and 22Na, the transcapillary transfer of albumin from the vascular bed to the extravascular space is determined in terms of mg/g of tissue, after single doses of 2 to 14 Gy. These results reveal an increase in the extravascular albumin immediately after irradiation and suggest an instantaneous compromise in vascular permeability even after 2 Gy. This effect was apparently dose related.

Radiation injury in a patient with unusually high sensitivity to radiation

Radiation therapy is usually given with the assumption that interindividual variations in radiosensitivity are small, except for some patients with hereditary diseases associated with increased sensitivity. Recently, we observed radiation induced pericarditis in a breast carcinoma patient, in whom clinical signs, blood counts and chromosome analysis after in vitro irradiation of blood suggested a state of unusually high radiosensitivity. No evidence of constitutional chromosome abnormality was found in karyotypic analysis with the G-banding technique.

Cardiac disease after mediastinal irradiation for seminoma

One hundred twenty-four patients with seminoma (119 primary testis, five primary extragonadal) were treated between 1968 and 1984 at the Joint Center for Radiation Therapy. Fifty-seven of the 124 patients were treated with irradiation to the mediastinum as well as to an infradiaphragmatic field. One patient received supradiaphragmatic radiotherapy only. The remaining patients had radiation treatment limited to the infradiaphragmatic field only. Median dose to the mediastinum among the 58 patients was 2400 cGy. Four patients developed heart disease (one fatal myocardial infarction, one uncomplicated myocardial infarction, one constrictive pericarditis resulting in permanent total body anasarca, and one patient requiring aortic valve replacement and coronary artery bypass grafting for atherosclerotic disease) and two died suddenly. The two sudden deaths were thought to be cardiac in origin by the patient's primary physicians. All six complications occurred in the group that received mediastinal irradiation. No cardiac disease was manifested in the group not treated with mediastinal irradiation. This difference in the incidence of cardiac disease between the two groups is statistically significant (two sided, P = 0.019). Neither group had a statistically significant difference in cardiac disease rate from a normal population (Framingham study), although the ratio of observed to expected cardiac disease was 1.97 in the group receiving mediastinal radiation. Further experience from this and other institutions is necessary to confirm this finding.

Late cardiac effects of mediastinal radiotherapy in patients with Hodgkin's disease

Twenty-eight patients younger than age 40 years, treated for Hodgkin's disease with mediastinal irradiation, were examined no less than 5 years after the irradiation in order to evaluate the frequency of cardiac abnormalities. Twelve patients (43%) had had some pericardial event after radiation: a diagnosed pericarditis, remarkably increased heart volume, or a conspicuous change of cardiac silhouette, suggesting pericardial fluid. On evaluation, 50% of the patients complained of symptoms, and 13 patients had to stop the exercise test on a low level because of chest pain, dyspnea, or general fatigue. In 13 patients some of the following abnormalities in the electrocardiogram (ECG) was found: right bundle branch block (four), first-degree atrioventricular block (four), abnormal P terminal force (five), or a low voltage (two). In ten patients (38%) an increase of the pericardial fluid was seen in the echocardiogram, and in nine patients the right ventricle wall thickness had increased. In two patients a severe coronary artery disease was found. One died suddenly after an acute myocardial infarction (AMI), and the other had a large anterior AMI. Two patients with chronic pericardial fluid underwent partial pericardectomy. Two cases of mild pulmonary valve stenosis, one pulmonary subvalvular stenosis and two aortic valve deformities were discovered. Eight patients went through cardiac catheterization, and in all but one case the pressures were slightly elevated suggesting diminished diastolic compliance. In summary, 19 of 28 patients had some abnormal cardiac findings, but only three of them were serious ones.

The etiologic spectrum of constrictive pericarditis

Ninety-five consecutive patients with constrictive pericarditis that was documented at the time of surgery during 1970 to 1985 were reviewed. The etiologies included idiopathic (42%), postradiotherapy (31%), post-cardiac surgery (11%), postinfective (6%), connective tissue disease-related (4%), neoplastic (3%) uremic (2%), and sarcoidosis (1%). Post-cardiac surgery etiology was seen only after 1980, but constituted 29% of cases during 1980-1985. Postradiotherapy etiology occurred with equal incidence in 1980-1985 and in 1970-1980, but the interval from radiotherapy to presentation with constrictive pericarditis was longer in the more recent period (11 vs 4.75 years). Effusive constrictive pericarditis occurred in 24% overall with similar prevalence in all of the etiologic groups except the postsurgical cases, which were caused by noneffusive fibrous constrictive pericarditis in all instances. Operative mortality was 12% overall: It was lower in the idiopathic group (8%) and higher in the postradiotherapy group (21%). Thus postradiotherapy constrictive pericarditis continues to occur despite technical changes aimed at reducing its likelihood, but recent cases have a longer latent period: and postsurgical constrictive pericarditis has emerged as an important etiology.

Left atrial mass 16 years after radiation therapy for mediastinal neuroblastoma

Tumors involving the heart during childhood are rare. However, neuroblastoma, a common pediatric malignancy, has been described to involve the cardiovascular system in 3%-12% of patients dying with this tumor. Rarely is such involvement diagnosed ante mortem and never, to our knowledge, has a benign cardiac tumor been reported to present in childhood after successful eradication of neuroblastoma. We describe the identification and surgical resection of a nodular, hypertrophied, calcified, pedunculated left atrial mass in a 16-year-old boy who was complaining of exercise-associated presyncope and headaches 16 years after irradiation and chemotherapy for mediastinal neuroblastoma.

Myocardial hypertrophy, fibrosis and infarction following exposure of the heart to radiation for Hodgkin's disease

A 35 year old man was treated for stage IIA Hodgkin's disease by radiation to the upper thorax, axillae and neck. Three years later he presented with intractable and ultimately fatal congestive heart failure. Autopsy revealed massive biventricular hypertrophy with widespread subendocardial fibrosis and myocardial infarction, but with little coronary artery disease. Such a complex of features has not previously been described after radiation therapy and cannot be adequately explained by other known causes of heart muscle disease. Ventricular hypertrophy with extensive subendocardial fibrosis may be part of the spectrum of radiation heart disease.

Incidence of heart disease and functional significance of changes in the electrocardiogram 10 years after radiotherapy for breast cancer

Late cardiac complications after radiotherapy for breast cancer was studied in 197 patients examined before, 6 months after, and 10 years after treatment. The 10-year follow-up was done by survey of the files of patients who had died and re-examination of patients who were alive and free of cancer. Among 95 patients who died, 3 died of cardiopulmonary diseases. Autopsy in 32 patients showed serious cardiac abnormalities in 3. Of 102 patients alive at follow-up, 3 reported heart symptoms. Sixty-nine patients participated in the re-examination. Electrocardiogram (ECG) abnormalities were found in 19% of these patients before treatment; in 45% at 6 months, essentially due to T-wave changes in patients who had received left-sided irradiation; and in 45% at 10 years, with fewer T-wave abnormalities but more ST depression and ectopic beats. Average working capacity was 83 W before, 81 W at 6 months, and 84 W at ten years. Average heart volume was 680 ml before, 689 ml at 6 months, and 718 ml (P less than 0.01) 10 years after treatment. In conclusion, there was a high incidence of ECG T-wave changes, but they were reversible, and the perimyocardial damage indicated was functionally insignificant. The incidence of serious cardiac complications was low.

The cold pressor test during radionuclide ventriculography: a feasibility study in cancer patients

To monitor the use of cardiotoxic drugs, adequate assessment of myocardial function is required. Although serial radionuclide left ventricular ejection fraction (EF) studies allow a simple and rapid assessment of the myocardial function without risk or discomfort to the patient, they appear not to be sensitive enough. Determination of the EF during cold application may be more sensitive. In this study we tested the feasibility of the cold pressor test (CPT) in relation to EF determination in 23 cancer patients. Only minor side effects were recorded. The response of heart rate to cold was similar to the response reported in healthy volunteers and patients with coronary artery disease. In selected cases EF determination during CPT appeared to be more sensitive than EF at rest. EFCPT may be an attractive alternative for EFexercise in cancer patients who cannot perform enough exercise to stress cardiac function adequately, but for a more definite conclusion a prospective comparative study is required.

Early cardiac changes related to radiation therapy

To investigate the incidence and severity of possible radiation-induced cardiac changes, 21 women without heart disease were investigated serially by echocardiography and by measuring systolic time intervals before and up to 6 months after postoperative radiation therapy because of breast cancer. Radiation was associated with a decrease in fractional systolic shortening of the left ventricular (LV) minor-axis diameter, from 0.35 +/- 0.05 to 0.32 +/- 0.06 (p less than 0.005), and in the systolic blood pressure/end-systolic diameter ratio, from 4.4 +/- 1.2 to 3.9 +/- 0.9 mm Hg/mm (p less than 0.005). The mitral E point-septal separation increased, from 2.8 +/- 1.5 to 4.2 +/- 2.5 mm (p less than 0.005). The preejection period/LV ejection time ratio of systolic time intervals increased, but only the decrease within 6 months after therapy was significant (p less than 0.005). All these changes reflect slight transient depression of LV function, which became normalized within 6 months after therapy. Up to 6 months after therapy, a slight pericardial effusion was found in 33% of the patients. Hence, conventional radiation therapy appeared to cause an acute transient and usually symptomless decrease in LV function, and later, slight pericardial effusion in one-third of the patients.

Late effects of treatment of cancer in children

Over the past two decades, owing to advances in surgical techniques, chemotherapy, and radiation therapy, there has been dramatic improvement in the survival of children with malignancies. Children cured of cancer will soon form a significant fraction of our adult population. As we follow such survivors, we have become more aware of long-term side effects of treatment. Therapy should not be withheld. Instead, careful follow-up of oncology patients is needed to document the adverse late effects, to identify the etiologic agents, and to alter treatment to give the least toxic therapy without sacrificing the quality or duration of survival.

The evolution and summary results of the Stanford randomized clinical trials of the management of Hodgkin's disease: 1962-1984

This is a summary report of the Stanford randomized clinical trials of the management of Hodgkin's disease, initiated in 1962. There have been four major changes in the treatment protocols during this 22 year period. Between 1962-67, 132 patients with CS I, II and III disease were enrolled on various radiation trials. Between 1968-74, 367 patients were enrolled on studies primarily evaluating the role of adjuvant MOPP chemotherapy. Between 1974-80, variations in the chemotherapy regimen and the sequences of the combined modality programs were studied. The current studies, initiated in 1980, have enrolled 102 patients, and test a new mild adjuvant chemotherapy, VBM, (vinblastine, bleomycin and methotrexate) and utilizes ABVD in combined modality and alternating regimens. During the two decades of these studies, involving more than 800 patients, the initial remission rate and duration and the survival of all patients treated have progressively improved.

Aortic insufficiency following mediastinal radiation for Hodgkin's disease

Aortic insufficiency developed 13 months after mediastinal radiation in a patient with Hodgkin's disease. The estimated cardiac dose was 4200 rads. Several years later, a cerebral embolus occurred. The evidence for valvular and endocardial damage due to radiation is reviewed.