Whole breast proton irradiation for maximal reduction of heart dose in breast cancer patients.

PURPOSE: In left-sided breast cancer radiotherapy, tangential intensity modulated radiotherapy combined with breath-hold enables a dose reduction to the heart and left anterior descending (LAD) coronary artery. Aim of this study was to investigate the added value of intensity modulated proton therapy (IMPT) with regard to decreasing the radiation dose to these structures. METHODS: In this comparative planning study, four treatment plans were generated in 20 patients: an IMPT plan and a tangential IMRT plan, both with breath-hold and free-breathing. At least 97 % of the target volume had to be covered by at least 95 % of the prescribed dose in all cases. Specifically with respect to the heart, the LAD, and the target volumes, we analyzed the maximum doses, the mean doses, and the volumes receiving 5-30 Gy. RESULTS: As compared to IMRT, IMPT resulted in significant dose reductions to the heart and LAD-region even without breath-hold. In the majority of the IMPT cases, a reduction to almost zero to the heart and LAD-region was obtained. IMPT treatment plans yielded the lowest dose to the lungs. CONCLUSIONS: With IMPT the dose to the heart and LAD-region could be significantly decreased compared to tangential IMRT with breath-hold. The clinical relevance should be assessed individually based on the baseline risk of cardiac complications in combination with the dose to organs at risk. However, as IMPT for breast cancer is currently not widely available, IMPT should be reserved for patients remaining at high risk for major coronary events.

Left-sided breast cancer radiotherapy with and without breath-hold: does IMRT reduce the cardiac dose even further?

PURPOSE: In radiotherapy for left-sided breast cancer, Active Breathing Control enables a decrease of cardiac and Left Anterior Descending (LAD) coronary artery dose. We compared 3D-Conformal (3D-CRT) to Intensity Modulated Radiotherapy (IMRT) treatment plans based on free-breathing (FB) and breath-hold (BH). We investigated whether IMRT enables an additional decrease of cardiac dose in radiotherapy plans with and without BH. METHODS AND MATERIALS: Twenty patients referred for whole breast irradiation were included. The whole breast, heart and LAD-region were contoured. Four treatment plans were generated: FB_3D-CRT; FB_IMRT; BH_3D-CRT; BH_IMRT. Several doses were obtained from Dose Volume Histograms and compared. Results were compared statistically using the Wilcoxin Signed Rank Test. For heart and LAD-region, a significant dose reduction was found in BH (p<0.01). For both BH and FB, a significant dose reduction was found using IMRT (p<0.01). By using IMRT an average reduction of 5% was noted in the LAD-region for the volume receiving 20Gy. In 5 cases, the LAD-region remained situated in the vicinity of the radiation portals even in BH. Nevertheless, with IMRT the LAD dose was reduced in these cases. CONCLUSION: IMRT results in a significant additional decrease of dose in the heart and LAD-region in both breath-hold and free-breathing.

Preradiotherapy calcium scores of the coronary arteries in a cohort of women with early-stage breast cancer: a comparison with a cohort of healthy women.

PURPOSE: Breast cancer radiotherapy has been associated with an increased risk of cardiac toxicity. However, no data are available on the probability of developing coronary artery disease (CAD) in breast cancer patients when compared with healthy women. Therefore, baseline coronary artery calcium (CAC) scores, as an accepted tool to predict CAD, were determined and compared with the CAC scores of a healthy, asymptomatic cohort, the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. METHODS AND MATERIALS: Eighty consecutive patients with ductal carcinoma in situ or infiltrative breast cancer referred for radiotherapy after breast-conserving surgery were included in our study. Their cardiovascular risk profile was registered, and a 64 multislice CT scan was performed. The CAC scores of an unselected (Caucasian only) Radiotherapy Centre West (RCWEST) cohort, as well as of those of a selected (comorbidity and race adjusted) RCWEST cohort, were determined. The scores of both cohorts were compared with those of the female (Caucasian only) MESA cohort. RESULTS: For the unselected RCWEST cohort (n = 62) we found significant (p < .01) higher scores for women in the 55-64 age category compared with those of the MESA cohort. In the selected cohort (n = 55) the CAC scores of the women in the age category 55-64 were significantly (p = .02) higher compared with the MESA cohort. No significant differences were noted in the other age categories. CONCLUSION: Both cohorts revealed that CAC scores in the 55-64 age category were significantly higher than the CAC scores in the asymptomatic (female) MESA population. These data suggest that breast cancer patients bear a higher risk of developing coronary heart disease before the start of radiotherapy. Therefore, measures to decrease cardiac dose further in breast cancer radiotherapy are even more important.

Relationship between obstructive coronary artery disease and abnormal stress testing in patients with paroxysmal or persistent atrial fibrillation.

Atrial fibrillation (AF) has been linked to the presence of underlying coronary artery disease (CAD). However, whether the higher burden of CAD observed in AF patients translates into higher burden of myocardial ischemia is unknown. In 87 patients (71% male, mean age 61 ± 10 years) with paroxysmal or persistent AF and without history of CAD, MSCT coronary angiography and stress testing (exercise ECG test or myocardial perfusion imaging) were performed. CAD was classified as obstructive (≥50% luminal narrowing) or not. Stress tests were classified as normal or abnormal. A population of 122 patients without history of AF, similar to the AF group as to age, gender, symptomatic status and pre-test likelihood, served as a control group. Based on MSCT, 17% of AF patients were classified as having no CAD, whereas 43% showed non-obstructive CAD and the remaining 40% had obstructive CAD. A positive stress test was observed in 49% of AF patients with obstructive CAD. Among non-AF patients, 34% were classified as having no CAD, while 41% showed non-obstructive CAD and 25% had obstructive CAD (P = 0.013 compared to AF patients). A positive stress test was observed in 48% of non-AF patients with obstructive CAD. In conclusion, the higher burden of CAD observed in AF patients is not associated to higher burden of myocardial ischemia.

Automated quantification of stenosis severity on 64-slice CT: a comparison with quantitative coronary angiography.

OBJECTIVES: This study sought to demonstrate the feasibility of a dedicated algorithm for automated quantification of stenosis severity on multislice computed tomography in comparison with quantitative coronary angiography (QCA). BACKGROUND: Limited information is available on quantification of coronary stenosis, and previous attempts using semiautomated approaches have been suboptimal. METHODS: In patients who had undergone 64-slice computed tomography and invasive coronary angiography, the most severe lesion on QCA was quantified per coronary artery using quantitative coronary computed tomography (QCCTA) software. Additionally, visual grading of stenosis severity using a binary approach (50% stenosis as a cutoff) was performed. Diameter stenosis (percentage) was obtained from detected lumen contours at the minimal lumen area, and corresponding reference diameter values were obtained from an automatic trend analysis of the vessel areas within the artery. RESULTS: One hundred patients (53 men; 59.8 +/- 8.0 years) were evaluated, and 282 (94%) vessels were analyzed. Good correlations for diameter stenosis were observed for vessel-based (n = 282; r = 0.83; p < 0.01) and patient-based (n = 93; r = 0.86; p < 0.01) analyses. Mean differences between QCCTA and QCA were -3.0% +/- 12.3% and -6.2% +/- 12.4%. Furthermore, good agreement was observed between QCCTA and QCA for semiquantitative assessment of diameter stenosis (accuracy of 95%). Diagnostic accuracy for assessment of > or =50% diameter stenosis was higher using QCCTA compared with visual analysis (95% vs. 87%; p = 0.08). Moreover, a significantly higher positive predictive value was observed with QCCTA when compared with visual analysis (100% vs. 78%; p < 0.05). Although the visual approach showed a reduced diagnostic accuracy for data sets with moderate image quality, QCCTA performed equally well in patients with moderate or good image quality. However, in data sets with good image quality, QCCTA tended to have a reduced sensitivity compared with visual analysis. CONCLUSIONS: Good correlations were found for quantification of stenosis severity between QCCTA and QCA. QCCTA showed an improved positive predictive value when compared with visual analysis.

Diagnostic accuracy of 64-slice multislice computed tomographic coronary angiography in patients with an intermediate pretest likelihood for coronary artery disease.

Data on the diagnostic accuracy of multislice computed tomographic coronary angiography (CTA) have been mostly derived from patients with a high pretest likelihood of coronary artery disease. Systematic comparisons with invasive angiography in patients with an intermediate pretest likelihood are scarce. The purpose of the present study was to determine the diagnostic accuracy of CTA in patients without known coronary artery disease with an intermediate pretest likelihood. A total of 61 patients (61% men, average age 57 + or - 9 years) who had been referred for invasive coronary angiography underwent additional 64-slice CTA. A total of 920 segments were identified by invasive coronary angiography, of which 885 (96%) were interpretable on CTA. Invasive coronary angiography identified a significant stenosis (> or = 50% luminal narrowing) in 29 segments, of which 23 were detected on CTA. Thus, the sensitivity, specificity, positive predictive value, and negative predictive value was 79%, 98%, 61%, and 99%, respectively, for CTA. On a patient level, the sensitivity, specificity, positive predictive value, and negative predictive value was 100%, 89%, 76%, and 100%, respectively. CTA correctly ruled out the presence of significant stenosis in 40 (66%) of the 61 patients. In conclusion, the results from the present study have confirmed that CTA has excellent diagnostic accuracy in the target population of patients with an intermediate pretest likelihood. The high negative predictive value allowed us to rule out significant stenosis in a large proportion of patients. CTA can, therefore, be used as a highly effective gatekeeper for invasive coronary angiography.

Combined non-invasive anatomical and functional assessment with MSCT and MRI for the detection of significant coronary artery disease in patients with an intermediate pre-test likelihood.

OBJECTIVES: To compare magnetic resonance myocardial perfusion imaging (MRI) with anatomical assessment by multislice computed tomography (MSCT) coronary angiography and conventional coronary angiography. DESIGN AND PATIENTS: In this prospective study, 53 patients (60% male, average age 57+/-9 years, 83% intermediate pre-test likelihood) underwent 1.5 T MRI, 64-slice MSCT and conventional coronary angiography. MAIN OUTCOME MEASURES: The presence of significant stenosis (>or=50% luminal narrowing) was determined on MSCT and conventional coronary angiography. Ischaemia on MRI was defined as a stress perfusion abnormality in the absence of delayed contrast enhancement. RESULTS: A significant stenosis was seen on MSCT in 15 (28%) patients, while ischaemia on MRI was seen in 19 (36%). In the 38 patients without significant stenosis on MSCT, normal perfusion was seen in 29 (76%). In patients with a significant stenosis on MSCT, ischaemia was seen in 10 (67%). In all patients without significant stenosis on MSCT and normal perfusion on MRI (n=29), significant stenosis was absent on conventional coronary angiography. All patients with both MSCT and MRI abnormal (n=10) had significant stenoses on conventional coronary angiography. CONCLUSION: The anatomical and functional data obtained with MSCT and MRI are complementary for the assessment of coronary artery disease. These findings support the sequential or combined assessment of anatomy and function.

Prevalence of coronary artery disease assessed by multislice computed tomography coronary angiography in patients with paroxysmal or persistent atrial fibrillation.

BACKGROUND: Although atrial fibrillation (AF) has been linked to underlying coronary artery disease (CAD), data supporting this association have been based on ECG and clinical history for the definition of CAD rather than direct visualization of atherosclerosis. METHODS AND RESULTS: The prevalence of CAD among patients with paroxysmal or persistent AF and without history of CAD was evaluated using multislice computed tomography. Multislice computed tomography was performed in 150 patients with AF (61+/-11 years, 67% males, 58% asymptomatic) with predominantly low (59%) or intermediate (25%) pretest likelihood of CAD. CAD was classified as obstructive (> or =50% luminal narrowing) or not. A population of 148 patients without history of AF, similar to the AF group as to age, gender, symptomatic status, and pretest likelihood, served as a control group. Logistic regression analysis was applied to evaluate the relationship between demographic and clinical data and the presence of obstructive CAD. On the basis of multislice computed tomography, 18% of patients with AF were classified as having no CAD, whereas 41% showed nonobstructive CAD and the remaining 41% had obstructive CAD. Among patients without AF, 32% were classified as having no CAD, whereas 41% showed nonobstructive CAD and 27% had obstructive CAD (P=0.010 compared with patients with AF). At logistic regression analysis, age, male gender, and the presence of AF were significantly related to obstructive CAD. CONCLUSIONS: A higher prevalence of obstructive CAD was observed among patients with AF, confirming the hypothesis that AF could be a marker of advanced coronary atherosclerosis.

Metastases in supraclavicular lymph nodes in lung cancer: assessment with palpation, US, and CT.

PURPOSE: To compare ultrasonography (US), computed tomography (CT), and palpation for diagnosing supraclavicular lung cancer metastases and to assess the effect of proved metastases on TNM stage and diagnostic work-up. MATERIALS AND METHODS: One hundred seventeen consecutive patients (91 men and 26 women; mean age, 64.0 years) underwent palpation, US, and CT of supraclavicular regions and chest and upper abdominal CT. Fine-needle aspiration cytologic (FNAC) analysis was performed in patients with nodes with a short-axis diameter of 5 mm or greater; cytologic diagnosis was used as the standard of reference. Sensitivities of palpation, US, and CT were compared with McNemar testing. Relationship between size and palpability of nodes with metastasis was evaluated with logistic regression. RESULTS: Supraclavicular metastases were diagnosed cytologically in 30 (26%) of 117 patients: eight (31%) of 26 patients with small cell lung cancer (SCLC) and 22 (24%) of 91 patients with non-small cell lung cancer (NSCLC). Sensitivities of US (1.00; 30 of 30 patients) and CT (0.83; 25 of 30 patients) for detection of metastases were significantly higher (P <.001 and P =.001, respectively) than that of palpation (0.33; 10 of 30 patients). Palpable nodes with metastasis (mean diameter, 25.2 mm) were significantly larger than nonpalpable nodes with metastasis (mean diameter, 13.7 mm) (P =.002). To have a 50% chance of being palpable, nodes with metastasis had to have a diameter of at least 22.3 mm. TNM stage was changed in three of 91 patients with NSCLC, and further invasive diagnostic procedures were prevented in 11 of such patients because it was proved that nonpalpable nodes had metastases. CONCLUSION: Supraclavicular lung cancer metastases were cytologically proved in 26% of patients. Nodes with metastasis were only palpable when markedly enlarged. US tripled the sensitivity of palpation for detection of metastases. Results of US and US-guided FNAC analysis can change the work-up in patients with lung cancer.