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Biomedical subjects

Salvador Borges-Neto

Publications and source records attributed to Salvador Borges-Neto.

At least 19 recordsLinked to original sources
PubMed2006

Relation of ventricular premature complexes during recovery from a myocardial perfusion exercise stress test to myocardial ischemia.

Ventricular premature complexes (VPCs) during exercise have long been believed to be harbingers of increased mortality. A recent study has shown that VPCs during the recovery phase of a treadmill exercise test are more predictive of mortality than VPCs that develop during exercise. However, no study to date has examined the relation of VPCs in recovery to the presence of ischemia on myocardial perfusion imaging. We examined the database of perfusion imaging at the Duke University Medical Center from September 1993 to July 2003. We examined the incidence of VPCs during exercise, during the recovery phase, and during the 2 phases. Logistic regression modeling was used to evaluate the significance of VPCs during stress and during recovery in predicting ischemia. VPCs developed during recovery in 561 of 2,828 patients (19.8%). Compared with patients without VPCs during recovery, those with VPCs during recovery were more likely to have a history of hypertension (64.0% vs 56.9%, p = 0.002) and previous coronary artery bypass grafting (25.3% vs 17.1%, p = 0.001). They were also more likely to be older, men, and Caucasian, and to have 3-vessel coronary artery disease (31.9% vs 21.0%, p = 0.001). After adjusting for differences in patient characteristics, VPCs during recovery were significantly associated with ischemia (odds ratio 1.27, 95% confidence interval 1.04 to 1.56, p = 0.017), whereas VPCs during stress were not (p = 0.128). In conclusion, VPCs during the recovery phase of an exercise study are predictive of ischemia on myocardial perfusion imaging.

Adult↗
PubMed2006

Cardiovascular disease risk stratification with stress single-photon emission computed tomography technetium-99m tetrofosmin imaging in patients with the metabolic syndrome and diabetes mellitus.

The metabolic syndrome represents a constellation of risk factors caused by insulin resistance, dyslipidemia, hypertension, and obesity, resulting in elevated coronary disease risk. From a multicenter prospective registry of 7,849 patients, the relation among the metabolic syndrome, diabetes, and risk stratification with stress technetium-99m tetrofosmin single photon-emission computed tomography (SPECT) was evaluated. The percentage of stress myocardial defects was calculated as < or = 5%, 5.1% to 10%, 10.1% to 15%, and > 15%. A Cox proportional-hazards model was used to estimate cardiovascular death or myocardial infarction (n = 752). Of 7,849 patients, 42% had the metabolic syndrome. Patients with the metabolic syndrome had an 84% 2-year event-free survival rate, lower than patients with normal metabolic status (p <0.0001). In patients with the metabolic syndrome, the percentage of moderate to severely abnormal SPECT findings ranged from 11% to 44% for those with 3 to 5 risk factors for the metabolic syndrome. There was an additive relation between the number of risk factors for the metabolic syndrome and the extent and severity of abnormalities in SPECT findings (p <0.0001). Patients with 5 risk factors for the metabolic syndrome were at the greatest risk, with hazard ratios from 7.8- to 14.1-fold for mild to severely abnormal SPECT findings. For diabetic patients requiring combined oral and insulin therapy, relative risk ratios increased from 15 to 21.4 for patients with > 5% to > 15% stress myocardial perfusion defects. In conclusion, cardiovascular prognosis is affected by the degree of metabolic dysfunction, and stress-induced reductions in myocardial perfusion provide an accurate means for near-term risk stratification.

Aged↗
PubMed2006

Predicting significant coronary artery disease in patients with left ventricular dysfunction.

BACKGROUND: Because coronary artery disease (CAD) is a prevalent comorbidity in patients with low ejection function (EF), a number of patients with heart failure undergo diagnostic cardiac catheterization. The objective of this study was to develop a model to assist clinicians in determining the likelihood of CAD before cardiac catheterization. METHODS: This study was a retrospective analysis using the Duke Databank for Cardiovascular Disease. From the databank, 2054 patients who underwent cardiac catheterization between 1992 and 2002 that was preceded by echocardiography with an EF of < 45% were identified. The patients' median age was 63 years, and the median EF was 30%. Patients were considered to have significant CAD if any major epicardial vessel had > or = 75% stenosis. A multivariable model of CAD was generated using stepwise logistic regression. We included demographic, clinical, electrocardiographic, and echocardiographic parameters, including segmental wall motion abnormality. RESULTS: Of the patients who met the criteria, 1184 (58%) had significant CAD and 870 (42%) did not. Significant predictors of CAD, in the order of their ability to predict significant CAD, included history of myocardial infarction, age, diabetes mellitus, Q wave on electrocardiogram, male sex, and segmental wall motion abnormality (all P < .0001). The area under the receiver operating characteristic curve was 0.865. CONCLUSIONS: By using baseline demographic and clinical characteristics, we developed a highly discriminatory diagnostic model for predicting CAD in patients with heart failure. Given the high prevalence of patients without CAD in this cohort, accurate baseline assessment of patients with left ventricular dysfunction for CAD might avoid unnecessary invasive procedures.

Cardiac Catheterization↗
PubMed2005

The incidence and functional consequences of RT-associated cardiac perfusion defects.

PURPOSE: Radiation therapy (RT) for left-sided breast cancer has been associated with cardiac dysfunction. We herein assess the temporal nature and volume dependence of RT-induced left ventricular perfusion defects and whether these perfusion defects are related to changes in cardiac wall motion or alterations in ejection fraction. METHODS: From 1998 to 2001, 114 patients were enrolled onto an IRB-approved prospective clinical study to assess changes in regional and global cardiac function after RT for left-sided breast cancer. Patients were imaged 30 to 60 minutes after injection of technetium 99m sestamibi or tetrofosmin. Post-RT perfusion scans were compared with the pre-RT studies to assess for RT-induced perfusion defects as well as functional changes in wall motion and ejection fraction. Two-tailed Fisher's exact test and the Cochran-Armitage test for linear trends were used for statistical analysis. RESULTS: The incidence of new perfusion defects 6, 12, 18, and 24 months after RT was 27%, 29%, 38%, and 42%, respectively. New defects occurred in approximately 10% to 20% and 50% to 60% of patients with less than 5%, and greater than 5%, of their left ventricle included within the RT fields, respectively (p = 0.33 to 0.00008). The rates of wall motion abnormalities in patients with and without perfusion defects were 12% to 40% versus 0% to 9%, respectively; p values were 0.007 to 0.16, depending on the post-RT interval. CONCLUSIONS: Radiation therapy causes volume-dependent perfusion defects in approximately 40% of patients within 2 years of RT. These perfusion defects are associated with corresponding wall-motion abnormalities. Additional study is necessary to better define the long-term functional consequences of RT-induced perfusion defects.

Adult↗
PubMed2005

Ethnic differences in the prognostic value of stress technetium-99m tetrofosmin gated single-photon emission computed tomography myocardial perfusion imaging.

OBJECTIVES: This study was designed to evaluate the differential prognostic value of gated single-photon emission computed tomographic imaging (SPECT) imaging in an ethnically diverse multicenter registry. BACKGROUND: Ethnic minority patient populations have reportedly higher coronary heart disease mortality with greater comorbidity and a clustering of risk factors at a significantly younger age when compared with Caucasian, non-Hispanic patients. Despite our increasingly diverse population, the predictive accuracy of cardiac imaging in ethnic minority patients is ill-defined. METHODS: A total of 7,849 patients were prospectively enrolled in a registry of patients undergoing exercise (44%) or pharmacologic stress (56%) technetium-99m tetrofosmin SPECT. Scans were scored using a 20-segment myocardial model with a 5-point severity index. Multivariable Cox proportional hazards models were employed to assess time to death or myocardial infarction. RESULTS: A total of 1,993 African-American, 464 Hispanic, and 5,258 Caucasian non-Hispanic patients underwent SPECT imaging. African-American and Hispanic patients more often had a history of stroke, peripheral arterial disease, angina, heart failure, diabetes, hypertension, and smoking at a younger age. Moderate or severely abnormal SPECT scans were noted in 21%, 17%, and 13% of African-American, Hispanic, and Caucasian non-Hispanic patients, respectively (p < 0.0001). Cardiovascular death rates were highest for ethnic minority patients (p < 0.0001). Annual rates of ischemic heart disease death ranged from 0.2% to 3.0% for Caucasian non-Hispanic and 0.8% to 6.5% for African-American patients with low-risk to severely abnormal SPECT scans (p < 0.0001). For post-stress ejection fraction <45%, annualized risk-adjusted death rates were 2.7% for Caucasian non-Hispanic patients versus 8.0% and 14.0% for African-American and Hispanic patients (p < 0.0001). CONCLUSIONS: The current results from a large observational registry reveal that exercise and pharmacologic stress SPECT effectively predicts major cardiovascular events in a large cohort of African-American and Hispanic patients evaluated for suspected myocardial ischemia. These results provide further evidence that ethnic minority patient populations have a worsening outcome related to cardiovascular disease.

Black or African American↗
PubMed2005

Incremental prognostic power of single-photon emission computed tomographic myocardial perfusion imaging in patients with known or suspected coronary artery disease.

Noninvasive stress testing provides prognostic information in patients who have suspected coronary artery disease, but limited data are available on the incremental value of myocardial perfusion testing in high-risk patients. We studied 3,275 patients who underwent cardiac catheterization and single-photon emission computed tomographic (SPECT) perfusion imaging. Median follow-up was 3.1 years for death, cardiovascular death, and a composite of cardiovascular death or nonfatal myocardial infarction. Using Cox's proportional hazards regression models, we examined the relation of SPECT summed stress score (SSS) to each outcome. A 1-unit change in SSS was associated with increased risks of 4%, 7%, and 5% for death, cardiovascular death, and death or nonfatal myocardial infarction, respectively (all p <0.0001). To examine the prognostic utility of SPECT, after baseline adjustments, SSS and angiographic results provided incremental prognostic information for each outcome. Thus, SPECT SSS provides information beyond clinical and angiographic data in patients who have known or suspected coronary artery disease. This information may be useful for stratifying patients into multiple risk categories for future cardiovascular events and potentially guiding therapy.

Aged↗
PubMed2005

Cardiac imaging impaired by a silicone breast implant.

The authors report a case of a left-sided silicone breast implant interfering with nuclear imaging of the myocardium. Cardiac SPECT imaging of a woman documented widespread infarct in the anterolateral, inferior, and posterolateral walls, as well as mixed ischemia/infarct in the anterior wall. Subsequent cardiac MRI revealed just anterolateral and inferolateral infarct. The anterior wall was completely viable. Also apparent on the MR images was a left breast implant overlying the anterior myocardial wall. This case of a left-sided silicone breast implant interfering with nuclear imaging of the myocardium highlights the importance of understanding the potential interference from silicone breast implants.

Aged↗
PubMed2005

Predicting radiotherapy-induced cardiac perfusion defects.

The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/ chestwall patients treated with tangential photon fields. The mathematical models compared were three commonly used parametric models [Lyman normal tissue complication probability (LNTCP), relative serialty (RS), generalized equivalent uniform dose (gEUD)] and a nonparametric model (Linear discriminant analysis--LDA). Data used by the models were the left ventricular dose--volume histograms, or SPECT-based dose-function histograms, and the presence/absence of SPECT perfusion defects 6 months postradiation therapy (21 patients developed defects). For the parametric models, maximum likelihood estimation and F-tests were used to fit the model parameters. The nonparametric LDA model step-wise selected features (volumes/function above dose levels) using a method based on receiver operating characteristics (ROC) analysis to best separate the groups with and without defects. Optimistic (upper bound) and pessimistic (lower bound) estimates of each model's predictive capability were generated using ROC curves. A higher area under the ROC curve indicates a more accurate model (a model that is always accurate has area = 1). The areas under these curves for different models were used to statistically test for differences between them. Pessimistic estimates of areas under the ROC curve using dose-volume histogram/ dose-function histogram inputs, in order of increasing prediction accuracy, were LNTCP (0.79/0.75), RS (0.80/0.77), gEUD (0.81/0.78), and LDA (0.84/0.86). Only the LDA model benefited from SPECT-based regional functional information. In general, the LDA model was statistically superior to the parametric models. The LDA model selected as features the left ventricular volumes above approximately 23 Gy (V23), essentially volume in field, and 33 Gy (V33), as best separating the groups with and without defects. In conclusion, the nonparametric LDA model appears to be a more accurate predictor of radiotherapy-induced left ventricular perfusion defects than commonly used parametric models.

Dose-Response Relationship, Radiation↗
PubMed2005

Prediction of death and nonfatal myocardial infarction in high-risk patients: a comparison between the Duke treadmill score, peak exercise radionuclide angiography, and SPECT perfusion imaging.

UNLABELLED: Radionuclide exercise testing provides prognostic information in patients with known or suspected coronary artery disease (CAD). The relative contribution of 3 noninvasive tests--the Duke treadmill score (DTS), first-pass radionuclide angiography with calculation of the ejection fraction (RNA-EF), and perfusion SPECT--has not been comparatively assessed in a high-risk population undergoing all 3 tests. METHODS: We identified 997 patients (75% male; median age, 60 y) who underwent exercise treadmill testing with RNA-EF and SPECT perfusion imaging as a single test. The relative prognostic power of each test was evaluated in both an unadjusted manner and after adjustment for differences in baseline characteristics using Cox proportional hazards models. RESULTS: During a median follow-up of 4.1 y, 175 patients experienced outcome events. Without adjustment for baseline patient characteristics, each of the modalities proved highly predictive of the composite endpoint of cardiovascular death or nonfatal myocardial infarction (MI) (DTS chi(2) = 18.9, P = 0.0001; RNA-EF chi(2) = 34, P = 0.0001; SPECT chi(2) = 11.5, P = 0.0007). In clinically risk-adjusted models, RNA-EF was the most powerful predictor of cardiovascular death compared with the DTS and SPECT (chi(2) = 40.5, 27.6, and 19.8, respectively). Conversely, exercise SPECT perfusion was a stronger predictor of nonfatal MI than the DTS or RNA-EF (chi(2) = 26.7, 15.7, and 16.7, respectively). CONCLUSION: The DTS, perfusion SPECT, and RNA-EF are each significant predictors of cardiovascular events in high-risk patients. The optimal risk stratification of patients for CAD may include all 3 modalities.

Exercise Test↗
PubMed2004

Outcome prediction in patients at high risk for coronary artery disease: comparison between 99mTc tetrofosmin and 99mTc sestamibi.

PURPOSE: To determine if there was any difference in the ability of physicians to predict prognosis with technetium 99m ((99m)Tc) sestamibi or (99m)Tc tetrofosmin in a large consecutive series of patients at high risk for coronary artery disease who underwent coronary angiography. MATERIALS AND METHODS: This study included 1,818 consecutive patients who underwent a rest and stress single photon emission computed tomographic (SPECT) examination with either (99m)Tc sestamibi (n = 915) or (99m)Tc tetrofosmin (n = 903) and cardiac catheterization. A clinical index was generated and consisted of clinical and demographic variables. Information concerning death, cardiovascular death, and nonfatal myocardial infarction was 93% complete during the 1.5-year study period. Cox proportional hazards models were generated to help determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent variable to the clinical index. RESULTS: Exercise was used for stress testing in 473 (52%) patients who received (99m)Tc tetrofosmin and 519 (57%) patients who received (99m)Tc sestamibi (P =.06). Cardiovascular death or myocardial infarction occurred in 130 patients. Resulting P values for chi(2) differences between models for the end points of (a) death from any cause, (b) cardiovascular death, and (c) cardiovascular death or myocardial infarction showed that SSS combined with clinical index was a significantly better model than adjusting for only baseline characteristics (P =.001, P <.001, P =.004, respectively). Incremental addition of either (99m)Tc tetrofosmin or (99m)Tc sestamibi to those models containing SSS and the clinical index did not show further significant improvement (P =.87, P =.88, and P =.26 for death from any cause, cardiovascular death, and cardiovascular death or myocardial infarction, respectively). CONCLUSION: This study shows that the type of clinically available (99m)Tc-labeled myocardial perfusion agents should not affect interpretation of results for risk stratification and prognostic assessment.

Adenosine↗
PubMed2004

The additive value of combined assessment of myocardial perfusion and ventricular function studies.

In addition to providing quantitative ventricular function information, gated SPECT and radionuclide angiocardiographic studies can evaluate regional wall motion and ventricular volumes. This review focuses on the combined assessment of myocardial perfusion and left ventricular function. Two clear roles for nuclear imaging in clinical practice include the diagnosis of coronary artery disease and assessment of prognosis in patients with known coronary artery disease. Ventricular function information can help differentiate an attenuation artifact from an infarct and is helpful in diagnosing 3-vessel coronary disease. Additionally, several studies have highlighted the prognostic benefit to combined assessment of myocardial perfusion and ventricular function. Several new modalities have recently been reported that promise to continue to solidify the place of nuclear imaging in the diagnosis and prognosis of coronary artery disease.

Coronary Artery Disease↗
PubMed2003

Myocardial perfusion changes in patients irradiated for left-sided breast cancer and correlation with coronary artery distribution.

PURPOSE: To evaluate postradiation regional heart perfusion changes with single photon emission tomography (SPECT) myocardial perfusion imaging in 69 patients treated with tangential photon beams radiation therapy (RT) for left-sided breast cancer. To correlate SPECT changes with percent irradiated left ventricle (LV) volume and risk factors for coronary artery disease (CAD). METHODS AND MATERIALS: Rest SPECT of the LV was acquired pre-RT and at 6-month intervals post-RT. The extent of defects (%) with a severity > 1.5 standard deviations below the mean was quantitatively analyzed for the distributions of the left anterior descending (LAD) artery, left circumflex (LCX) artery, and right coronary artery (RCA) based on computer assisted polar map reconstruction (i.e., bull's-eye-view). Changes in perfusion were correlated with percent irradiated LV receiving > 25 Gy (range 0-32%). Data on patient- and treatment-related factors were collected prospectively (e.g., cardiac premorbidity, risk factors for CAD, chemotherapy, and hormonal treatment). RESULTS: In the LAD distribution, there were increased perfusion defects at 6 months (median 11%; interquartile range 2-23) compared with baseline (median 5%; interquartile range 1-14) (p < 0.001). There were no increases in perfusion defects in the LCX or RCA distributions. In multivariate analysis, the SPECT perfusion changes in the LAD distribution at 6 months were independently associated with percent irradiated LV (p < 0.001), hormonal therapy (p = 0.005), and pre-RT hypercholesterolemia (p = 0.006). The SPECT defects in the LAD distribution at 12 and 18 months were not statistically different from those at 6 months. The perfusion defects in the LAD distribution were limited essentially to the regions of irradiated myocardium. CONCLUSION: Tangential photon beam RT in patients with left-sided breast cancer was associated with short-term SPECT defects in the vascular distribution corresponding to the radiation portals. Factors related to the extent of perfusion defects included the percent irradiated LV, hormonal treatment, and pre-RT hypercholesterolemia.

Adult↗
PubMed2003

Radionuclide viability testing: should it affect treatment strategy in patients with cardiomyopathy and significant coronary artery disease?

BACKGROUND: Ischemic heart failure is a significant source of morbidity and mortality, yet it has an unclear treatment strategy. The assessment of viable myocardium by nuclear imaging studies has shown promise in predicting improvements in ejection fraction and symptoms. However, the relationship of viability to long-term mortality has not been fully established. METHODS: A number of studies have addressed long-term mortality with nuclear viability imaging in patients with impaired left ventricular function and significant coronary artery disease. These studies were analyzed to determine differences in design, results, trends, and limitations. They were then evaluated by use of qualitative criteria established for prognostic studies. RESULTS: Fourteen studies met our criteria. Although the conclusions differed, it appears that patients with viability who undergo revascularization have the highest survival rate, whereas patients with viability who are treated medically have a much lower survival rate. Patients without viability have an intermediate survival rate, regardless of treatment. Several limitations were identified, including a lack of randomization, small sample size, inadequate follow-up, and extensive study protocol and design differences. CONCLUSIONS: The use of viability testing in patients with heart failure and significant coronary artery disease has shown promise in predicting the long-term mortality rate with treatment allocation. However, there is a need for further study involving larger cohorts with a randomized design, longer periods of follow-up, improved study designs, and identification of referral bias and viability prevalence.

Coronary Disease↗
PubMed2003

Revascularization in patients with coronary artery disease, left ventricular dysfunction, and viability: a meta-analysis.

BACKGROUND: The effects of viability status and treatment allocation on long-term mortality in patients with left ventricular dysfunction and coronary artery disease have not been determined. Several observational studies with significant limitations have addressed this issue, and a recent meta-analysis has attempted to combine these results to increase statistical power. However, the analysis did not test for an interaction between viability status and treatment type, and included extraneous studies. We provide an alternate meta-analysis of this primary literature, utilizing interaction statistical methodology on relevant data and factoring in multiple limitations. METHODS: We examined papers from this prior meta-analysis examining viable and nonviable patients undergoing surgical or medical therapy. We determined an interaction odds ratio for each study and used an empirical Bayes random-effects model to obtain a combined interaction odds ratio that was tested for statistical significance. We compared our results against an interaction odds ratio we estimated from the primary studies included in the previous meta-analysis. RESULTS: Nine relevant studies with 1244 patients and 172 events were identified that utilized all 4 treatment/viability subsets. The interaction odds ratio was 2.76 (P =.0176, 95% CI 1.19-6.38), 2.5 times lower than our estimated interaction odds ratio of 7.27 for the prior meta-analysis. CONCLUSIONS: We found a markedly reduced but statistically significant interaction between viability status and treatment allocation. However, numerous limitations in the primary studies and the application of meta-analysis along with significant improvements in medical therapies render a randomized controlled trial necessary to reach a definitive conclusion to this critical question.

Coronary Artery Disease↗
PubMed2003

Prognostic value of normal exercise and adenosine (99m)Tc-tetrofosmin SPECT imaging: results from the multicenter registry of 4,728 patients.

UNLABELLED: Event rates associated with a normal or low-risk myocardial perfusion SPECT imaging study have been shown by numerous investigators to be associated with <1%/y of follow-up. Thus, the aim of this study was to evaluate the prognostic value of a normal (99m)Tc-tetrofosmin study in a geographically diverse registry of patients undergoing stress myocardial perfusion SPECT. A total of 4,728 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at 5 U.S. hospitals were included in this series. METHODS: Patients were monitored for the occurrence of major cardiac events and hospitalizations. Uniform methods of data collection and standardized epidemiologic methods for follow-up were used at all centers. We used a risk-adjusted, Cox proportional hazards model to assess time to cardiac death. RESULTS: Of the 4,728 patients, one third underwent adenosine stress SPECT and two thirds underwent treadmill exercise. The observed annualized survival rate for those patients with a normal (99m)Tc-tetrofosmin study was 0.6%. Similarly, excellent survival rates were noted for the male and female subsets of this population as well as for patients who could exercise and for those undergoing pharmacologic stress testing. Compared with prior published outcomes studies on stress (201)Tl or (99m)Tc-sestamibi SPECT, the overall survival rates were similar and ranged from 99.3% to 99.7%. CONCLUSION: Results from this large multicenter registry provide further supportive evidence that the excellent prognosis associated with a normal SPECT scan is independent of the radiopharmaceutical used.

Adenosine↗
PubMed2003

Symptomatic cardiac events following radiation therapy for left-sided breast cancer: possible association with radiation therapy-induced changes in regional perfusion.

Our group has demonstrated that tangential radiation therapy (RT) to the left breast or chest wall can cause perfusion changes in the anterior myocardium. We assess if RT-induced perfusion changes are associated with the development of symptoms consistent with cardiac dysfunction. Between 1998 and 2001, 114 patients were enrolled into an institutional review board-approved prospective study and had pre-RT and serial post-RT (range, 6-24 months) single photon emission computed tomography (SPECT) scans to assess changes in regional cardiac perfusion. Thirty-one patients were excluded. The incidence of cardiac symptoms in patients with and without RT-induced perfusion defects was compared using a 2-tailed Fisher's exact test. With a median follow-up of 16 months (range, 6-24 months), 10 of 83 evaluable patients had > or = 1 episode of transient chest pain, occurring 0-14 months after RT (median, 6 months). The rates of chest pain in the patients with and without new perfusion defects were 9 of 31 and 1 of 52, respectively (P = 0.0004). A similar result was found when patients were segregated based on the use of chemotherapy. Two of these 10 cases were diagnosed as pericarditis. No patient had myocardial infarction or congestive heart failure. Cardiac symptoms occur more frequently in patients with perfusion abnormalities by SPECT after RT than in patients with normal SPECT scans, suggesting that such perfusion defects may be clinically significant. One confounding factor is that women who know they have RT-induced perfusion defects may be more likely to report episode of chest pain. Long-term follow-up will be necessary to better assess the clinical significance of RT-induced perfusion defects.

Breast Neoplasms↗