[Clinical application of sentinel lymph node detection to early stage cervical cancer].

BACKGROUND & OBJECTIVE: Sentinel lymph node (SLN) identification has been increasingly used in the treatment design of a variety of solid tumors, particularly breast cancer and melanoma. A negative SLN predicts the absence of tumor metastases in the regional lymph nodes with high accuracy. This study was to investigate the clinical value of combined isotope-dye technique for detecting SLN, and to evaluate the accuracy of SLN in predicting the pelvic lymph nodes status in patients with early stage cervical cancer. METHODS: A total of 27 patients with early stage cervical cancer,scheduled for radical hysterectomy and total pelvic lymphadenectomy, were eligible for the study. Lymphoscintigraphy was performed with injection of radioactivity isotope (99m)Tc-labeled dextran ((99m)Tc-DX) into the uterine cervix 16 h before surgery. Methylthioninium (4 ml) was injected into the same points as (99m)Tc-DX during surgery, and the patients underwent lymphatic mapping with a handheld gamma-detecting probe. After resection of SLNs, standard radical hysterectomy with pelvic lymph node dissection was performed. All removed lymph nodes, including the SLNs, were examined by routine histopathology. The histopathologic results of SLNs and non-SLNs were compared. RESULTS: The detection rates of SLN were 96.3% by blue dye method, and 100% by radiolabeled tracer or combined isotope-dye. Blue dye method identified 61 SLNs, radiolabeled tracer identified 69 SLNs, and combined isotope-dye identified 70 SLNs. Preoperative SPECT/CT fusion images detected 4 SLNs in the parametrium. Seven (25.9%) patients had lymph node metastasis. The sensitivity, accuracy, negative predictive value, and false negative rate of SLN detection were 85.7% (6/7), 96.3% (26/27), 95.2% (20/21), and 14.3% (1/7), respectively. CONCLUSIONS: SPECT/CT imaging not only is superior to planar imaging in detecting SLN but also enables precise localization of SLNs. The combined isotope-dye method can improve the accuracy of SLN detection. SLN detection can accurately predict the pelvic lymph nodes status in early stage cervical cancer.

[Utility of SPECT lung perfusion scans in assessing early changes in pulmonary function of patients with lung cancer after radiotherapy].

BACKGROUND & OBJECTIVE: Radiation-induced lung injury is commonly following radiotherapy (RT)for tumors in,and around the thorax. Lung function is usually assessed by pulmonary function tests (PFTs), but RT-induced regional changes of pulmonary function cannot be accurately evaluated by PFTs. Lung perfusion scintigraphy compared with other radiographic methods can well assess the regional pulmonary physiological function,and 3-dimension conformal radiotherapy (3D-CRT) planning system can quantitatively calculate irradiation dosage. This study was to assess early changes in the pulmonary function of patients with lung cancer receiving thoracic 3D-CRT by lung perfusion scintigraphy. METHODS: Nineteen patients receiving thoracic 3D-CRT for lung cancer were studied. Single photon emission computed tomography (SPECT) lung perfusion scan,and X-ray or CT scan before RT, and after 40-50 Gy radiation were performed. Pre-RT SPECT lung perfusion images were classified by comparing lung perfusion defect with area of radiological abnormality before RT. Grade 0: no lung perfusion defect in the area of radiological abnormality. Grade 1: the size of radiological abnormality is similar to the area of lung perfusion defect. Grade 2: the area of lung perfusion defect is bigger than that of radiological abnormality,and extend to 1 pulmonary lobe. Grade 3: the area of lung perfusion defect exceed 1 pulmonary lobe. The radiation field with more than 20 Gy was drawn as a region of interest (ROI). The proportion of radioactive count within this ROI to total lung count in one slice was calculated to assess changes in pulmonary function after RT. Student's t test was used for statistical analyses. RESULTS: All patients had lung perfusion defect, 9 patients with grade 1 damage, 5 patients with grade 2 damage, and 5 patients with grade 3 damage. All tumors in the 19 patients were reduced with variant degree after 40-50 Gy radiation in CT or X-ray images. The mean radioactive proportions of ROI in 19 patients were (53.7+/-29.8)% before radiation,and (57.6+/-22.6)% during RT, the difference wasn't significant (P=0.280). The relatively decreased post-RT lung perfusion was observed in 6 patients, whereas the relatively increased post-RT lung perfusion was observed in 13 patients. CONCLUSION: SPECT lung perfusion scans is a simple, convenient, and useful method for assessing pre-RT regional lung function,and monitoring the changes in regional lung function after irradiation.

A novel magnetic resonance-positive emission image registration based on morphology.

Structures were obtained from images with morphological characteristics to register with voxel-based method. We applied simple morphological operations to obtain human brain cortex and chose normalized mutual information as similarity measure for the geometric alignment of PET and MR images. Evaluation used nine patients, and the results showed that sub-voxel accuracy was achieved and the registration process was significantly more rapid. Thus this new automated multi-modality registration method is more robust and has high accuracy.

[Radioimmunodetection of 188Re-labeled anti-carcinoembryonic antigen chimeric antibody in nude mice bearing human colon carcinoma].

BACKGROUND & OBJECTIVE: Carcinoembryonic antigen(CEA), is highly expressed in many kinds of carcinomas, especially in colon carcinoma. Anti-CEA antibodies have great application in diagnosis and therapy of the patients with colon carcinoma. This study was designed to investigate the biodistribution and radioimmunodetection in nude mice bearing human colon carcinoma using 188Re-labeled anti-CEA chimeric antibody. METHODS: CEA chimeric antibody and its parent McAb C50 were labeled with 188Re by a stannous chloride reduction method. The radiochemical purity of them were determined by ITLC. The biodistribution and whole body gamma scintigraphy imaging of 188Re-CEA chimeric antibody in nude mice bearing human colon carcinoma were fulfilled. The effect of radioimmunoimage between these two antibodies was compared. RESULTS: 188Re-CEA chimeric antibody showed high radiochemical purity of more than 95%. The specific reactivity of 188Re-CEA chimeric antibody was 356 MBq/mg. Immunoreactivity of 188Re-CEA chimeric antibody was 61% as determined by ELISA. Tumor/kidney ratio (0.75) and tumor/blood ratio(0.99) of 188Re-CEA chimeric antibody were observed in 24 h; compared to the orther organs, the ration is over 1.78. Tumor/kidney ratio (1.02) and tumor/blood ratio (1.12) of 188Re-CEA chimeric antibody were observed in 48 h; compared to the other organs more than 2.08. High uptake of 188Re-CEA chimeric antibody was observed in 20 hours after injection. The radioimmunodetection effect of these two antibodies was approximately same. CONCLUSIONS: 188Re-CEA chimeric antibody showed high specific tumor uptake and could fast display clear image in the nude mice bearing human colon carcinoma. Comparing with McAb C50, CEA chimeric antibody has good effect in clinic because of reducing of immunogenicity.

The abnormal expression of retinoic acid receptor-beta, p 53 and Ki67 protein in normal, premalignant and malignant esophageal tissues.

AIM: Esophageal cancer remains a significant health problem worldwide. It is important to investigate alterations in expression of retinoic acid receptor-beta, p 53 and Ki67 proteins in esophageal carcinogenesis. METHODS: To find biomarkers for early identification of esophageal cancer, we analyzed the retinoic acid receptor-beta, p 53 protein and the proliferation marker Ki67 in surgical specimens of normal, mildly, and severely dysplastic and malignant esophageal tissues by in situ hybridization of RNA and immunohistochemistry. RESULTS: RAR-beta was expressed in 94.3%(33/35) of normal mucosae, 67.8%(19/28) of the mild, 58.1% (18/31) of the severe lesions and 53.2%(116/218) of tumor samples. RAR-beta mRNA was expressed in 62.7%(42/67), 55.1%(43/78) and 29.2%(7/24) of well, moderated and poorly differentiated SSCs. The p 53 and Ki67 proteins were 5.9%(2/34) of the normal mucosa. P53 and Ki67 stained positively in 10.7%(3/28) and 21.4% (6/28) of mild dysplasia, and 51.6%(16/31) and 58.1% (18/31) of severely dysplasia respectively. Samples from esophageal cancer showed no higher levers of p 53 and Ki67 expression than seen in severely dysplastic lesions. There was significant difference of RAR-beta p 53 and Ki67 expression between normal mucosa and dysplastic tissue or esophageal cancer. CONCLUSION: Loss of RAR-beta expression and accumulation of p 53 and Ki67 proteins may serve as biomarkers for early identification of esophageal cancer in the high-risk populations.