Ho Chun Song

Improved Detection of Lung or Bone Metastases with an I-131 Whole Body Scan on the 7th Day After High-Dose I-131 Therapy in Patients with Thyroid Cancer

PurposeThe purpose of this study is to compare post-therapy third day and seventh day I-131 whole body scans (3DWBS and 7DWBS) in detecting lung or bone metastasis from well-differentiated thyroid cancer.Materials and MethodsWe enrolled 52 patients with lung or bone metastasis out of 1,152 patients who were treated with high-dose I-131 therapy from January 2008 to June 2009. All patients underwent 3DWBS and 7DWBS. I-131 avidity was classified into three grades: no uptake, suspicious for uptake, and definite uptake. We compared the presence and grades of metastatic lesions on each scan. We categorized all cases into three groups based on I-131 uptake on each scan and compared several clinical parameters including FDG uptake and thyroglobulin (Tg) level among the groups.ResultsSixty metastatic cases from 52 patients (45 lung and 15 bone metastases) were included. In 35 cases, I-131-avid metastatic lesions were detected by both 3DWBS and 7DWBS (group A). In 15 cases, metastatic lesions were missed on 3DWBS but detected on 7DWBS (group B). In 10 cases, I-131 uptake was not detected on either 3DWBS or 7DWBS (group C). Ten of 45 cases (22.2%) of lung metastasis that were negative on 3DWBS were detected on 7DWBS (p = 0.002). Five of 15 cases (33.3%) of bone metastasis that were negative on 3DWBS were detected on 7DWBS (p = 0.0625). The serum Tg level (TSH stimulated) was significantly different among groups A, B, and C (p = 0.0030). However, after exclusion of cases without a history of I-131 therapy, there was no significant difference in serum Tg level among the groups (p = 0.2330). The number of cases with a prior history of metastasis was higher in group A than in group B (p = 0.0069). However, there was no significant difference in prior history of metastasis between groups A and C (p = 0.8107).Conclusion7DWBS showed more lung or bone metastatic lesions than 3DWBS. After high-dose I-131 therapy, 7DWBS should be considered regardless of the results of the 3DWBS for the diagnosis of lung or bone metastasis from well-differentiated thyroid cancer.

Cardioprotective Effect of Fimasartan, a New Angiotensin Receptor Blocker, in a Porcine Model of Acute Myocardial Infarction

Cardioprotective effect of fimasartan, a new angiotensin receptor blocker (ARB), was evaluated in a porcine model of acute myocardial infarction (MI). Fifty swine were randomized to group 1 (sham, n=10), group 2 (no angiotensin-converting enzyme inhibitor [ACEI] or ARB, n=10), group 3 (perindopril 2 mg daily, n=10), group 4 (valsartan 40 mg daily, n=10), or group 5 (fimasartan 30 mg daily, n=10). Acute MI was induced by occlusion of the left anterior descending artery for 50 min. Echocardiography, single photon emission computed tomography (SPECT), and F-18 fluorodeoxyglucose cardiac positron emission tomography (PET) were performed at baseline, 1 week, and 4 weeks. Iodine-123 meta-iodobenzylguanidine (MIBG) scan was done at 6 weeks for visualization of cardiac sympathetic activity. Left ventricular function and volumes at 4 weeks were similar between the 5 groups. No difference was observed in groups 2 to 5 in SPECT perfusion defect, matched and mismatched segments between SPECT and PET at 1 week and 4 weeks. MIBG scan showed similar uptake between the 5 groups. Pathologic analysis showed similar infarct size in groups 2 to 5. Infarct size reduction was not observed with use of fimasartan as well as other ACEI and ARB in a porcine model of acute MI. Graphical Abstract

Cardioprotective effect of substance P in a porcine model of acute myocardial infarction

BACKGROUND Substance P (SP) may attenuate ischemia-reperfusion injury by reducing inflammation. We assessed cardioprotective effect of SP in a porcine model of acute myocardial infarction (AMI). METHODS AMI was induced by occlusion of the left anterior descending artery on 28 swine, randomized to SP 5 nmol/kg (group 1, n = 14) and normal saline (group 2, n = 14) given intravenously 5 min before reperfusion. Blood samples were collected at baseline, 3 days and 4 weeks. Echocardiography and myocardial perfusion single photon emission computed tomography (SPECT) were performed at 1 week and 4 weeks. Histomorphometric infarct size assessment was done at 4 weeks. RESULTS Left ventricular (LV) ejection fraction (EF) (LVEF) after AMI induction was higher in group 1 than group 2 (37.9 ± 4.6% vs. 29.4 ± 3.2%, p = 0.001) but not different at 4 weeks. No significant difference was observed in perfusion defect extent and total perfusion defect on SPECT at 1 week and 4 weeks. Pathologic infarct size (% LV) was significantly smaller in group 1 than group 2 (2.4 ± 2.3% vs. 5.7 ± 2.5%, p = 0.020). The ratio of neutrophil to lymphocyte on day 3 and serum creatinine concentration at 4 weeks after AMI were lower in group 1. CONCLUSIONS In a porcine model of AMI, SP improved LVEF early post-MI and reduced infarct size. SP may be beneficial in reducing inflammation and ischemia-reperfusion injury after AMI.

888 CARDIOPROTECTIVE BENEFIT OF NEW ANGIOTENSIN RECEPTOR BLOCKER, FIMASARTAN, IN A PORCINE MODEL OF ACUTE MYOCARDIAL INFARCTION

Background: We evaluated the cardioprotective effect of fimasartan, a new angiotensin receptor blocker (ARB), in a porcine model of acute MI. Methods: Twenty-five pigs were allocated to group 1 (sham operation, n = 5), group 2 (no medication post-MI, n = 5), group 3 (perindopril 2 mg daily, n = 5), group 4 (valsartan 40 mg daily, n = 5), or group 5 (fimasartan 30 mg daily, n = 5). Acute MI was induced by occlusion of the left anterior descending artery with a balloon catheter for 50 min. Two-dimensional echocardiography, myocardial perfusion single photon emission computed tomography (SPECT) with technetium-99m sestamibi and F-18 fluorodeoxyglucose (FDG) cardiac positron emission tomography (PET) were performed at baseline, 1 week, and 4 weeks and iodine-123 meta-iodobenzylguanidine (MIBG) scan at 6 weeks for visualization of cardiac sympathetic activity. Results: Baseline LV ejection fraction (EF), infarct size, and viable myocardium size were similar between the 5 groups. LVEF and the number of segments matched and mismatched between SPECT and FDG PET at 4 weeks were not different in groups 2 to 5. The heart/mediastinum count ratios on MIBG images were—although not statistically significantly—lower in group 2 (17.4 ± 4.1), but similar in group 1, 3, 4, and 5 (20.4 ± 3.6, 21.9 ± 5.6, 20.0 ± 5.6, 20.2 ± 4.0, respectively), indicating restored sympathetic nerve activity induced by use of ACEI or ARB. Conclusions: Fimasartan, a new ARB, used post-MI improved cardiac sympathetic nerve activity and this benefit was comparable to that of other ACEI or ARB.