[Mechanism of cardiotoxicity associated with Herceptin using (131)I-Herceptin radioimmunoimaging].

OBJECTIVE: To study the mechanism of cardiotoxicity associated with Herceptin. METHODS: Herceptin was labeled with iodine-131 using the Iodogen method. Radioimmunoimaging was performed in 5 rabbits at 3 h to 5 days following (131)I-Herceptin injection to investigate the biodistribution of Herceptin. (131)I-Herceptin uptake in each organ or tissue relative to that in the muscular tissue (O/M ratio) was calculated and compared. On the fifth day following the injection, the organs including the heart, lung, liver and muscles were taken for measurement of the weight and radiocounts. HER2 expression was measured by immunohistochemistry in these organs and tissues. RESULTS: The O/M ratio of the heart was significantly higher than that of the lung (P=0.032) and liver (P=0.019) at 3 h after Herceptin injection, but reduced significantly at 24 h (P=0.001). The uptake of (131)I-Herceptin in the myocardium was slightly higher that that in the muscle and intestine, but lower than that in the lung and spleen. HER2 expression showed no significant difference between the myocardium and the other tissues such as the liver, lung, and kidney (H=3.236, P=0.172). CONCLUSION: Myocardium expresses low levels of HER2 and accumulates Herceptin no more than the other tissues.

[Relationship between fluorodeoxyglucose uptake and vascular endothelial growth factor in early-stage nasophygeal carcinoma].

OBJECTIVE: To study the overexpression of vascular endothelial growth factor (VEGF) and fluorine-18 fluorodeoxyglucose (FDG) uptake in early-stage nasopharyngeal carcinoma (NPC) and evaluate their relationship. METHODS: FDG positron emission tomography (PET) was performed in forty patients with stage I and stage II NPC. The maximum and mean standard uptake values (SUVmax and SUVmean, respectively) were measured in each patient, and the expression of VEGF was measured on paraffin sections using immunohistochemistry. RESULTS: The FDG uptake in the patients were 9.45-/+1.87 (SUVmax) and 6.04-/+1.09 (SUVmean), 8.95-/+1.91 (SUVmax) and 6.04-/+1.09 (SUVmean) in stage I patients, and 11.55-/+1.70 (SUVmax) and 7.98-/+1.1 (SUVmean) in stage II patients. The FDG uptake of stage II patients was higher than that of stage I patients. The FDG uptake of non-keratinizing differentiated carcinoma was 9.74-/+1.82 (SUVmax) and 6.82-/+1.23 (SUVmean) and 10.44-/+2.16 (SUVmax) and 6.68-/+1.35 (SUVmean) in non-keratinizing undifferentiated carcinoma, showing no significant differences between them (SUVmax: t=1.230, P>0.05; SUVmean: t=0.346, P>0.05). The VEGF-positive cells were 60.80% in the tumor. A correlation between VEGF expression and FDG uptake in he tumor was noted (r=0.460, P=0.03). CONCLUSION: VEGF overexpression is correlated to FDG uptake in patients with early-stage NPC. The SUV value reflects the glucose metabolism of NPC, and also shows the degree of oxygen insufficiency in the tumor tissue.

[Analysis of radioactive distribution in the sacrum in whole-body bone scanning].

OBJECTIVE: To analyze the radiogenic distribution in the sacrum in whole-body bone scanning. METHODS: A total of 212 patients receiving whole-body bone scanning without any explicit bone metastases were divided into different age and gender groups. The radioactive distribution in the sacrum in whole-body bone scanning was analyzed statistically. RESULTS: Of these cases, 31.1% presented with thin radioactive distribution in the sacrum and 11.3% exhibited increased radioactive distribution. Normal radioactive distribution in the sacrum was found in 57.6% of the cases. In both male and female elderly patients (>70 years), the rate of normal radioactive distribution in the sacrum was obviously reduced with increased rate of thin radioactive distribution. The female elderly patients showed higher rate of increased radioactive distribution in the sacrum than male elderly patients. CONCLUSION: The radioactive distribution in the sacrum is similar between female and male patients. Elderly male patients over 70 years have generally thin radioactive distribution in the sacrum due to the presence of osteoporosis, which is also associated with latent fracture of the sacrum to result in increased radioactive distribution in the sacrum in whole-body bone scanning.