Texture analysis of computed tomography data using morphologic and metabolic delineation of esophageal cancer-relation to tumor type and neoadjuvant therapy response.

The prognostic values of image-based tumor texture analysis based on computed tomography (CT) and of limiting the segmented tumor volume to metabolically active regions using fludeoxyglucose-positron emission tomography (FDG-PET) were studied in 25 patients with esophageal adenocarcinoma and 11 patients with squamous cell carcinoma. The aims of this study are to describe their CT-image-based texture characteristics before and after neoadjuvant therapy and to evaluate whether limiting the examined tumor volume to metabolically active regions detected with FDG-PET image data would further improve their value. Textural parameters (homogeneity, energy, entropy, contrast, and correlation) based on gray-level co-occurrence matrices (GLCM) were calculated for 3D volumes of segmented esophageal tumors before and after neoadjuvant chemotherapy or radiochemotherapy. Histopathological data after surgical resection and textural parameters before and after neoadjuvant treatment were compared using the Mann-Whitney U test. Significant differences in the textural parameters were observed between adenocarcinoma and squamous cell carcinoma for homogeneity, energy, inertia, and correlation. The use of contrast media during scanning resulted in significant differences in homogeneity, energy, entropy, and inertia for adenocarcinoma but not squamous cell carcinoma. There was also a significant difference in all textural parameters between pathological T status for ypT0-ypT2 and ypT3-ypT4 adenocarcinomas, but not in squamous cell carcinoma patients. No additional value was found from using PET image data to aid segmentation of CT images.

Quantitative assessment of 99mTc-depreotide uptake in patients with non-small-cell lung cancer: immunohistochemical correlations.

BACKGROUND: Somatostatin receptor (SSTR) scintigraphy with (99m)Tc-depreotide is used for differential diagnosis of solitary pulmonary nodules. The method is based on SSTR expression in cancer tissue. PURPOSE: To estimate the expression of SSTRs in non-small-cell lung cancer (NSCLC) in vitro, and to determine the correlation between (99m)Tc-depreotide uptake in vivo and different tumor characteristics determined in vitro, such as tumor grade, and presence of SSTR2, MIB-1, and p53. MATERIAL AND METHODS: A total of 127 patients with lung lesions detected on computed tomography (CT) were investigated with SSTR scintigraphy after injection of 740 MBq (99m)Tc-depreotide. This study includes 19 patients with NSCLC with histologically proven diagnosis. The quantitative evaluation of (99m)Tc-depreotide was performed using region-of-interest analysis and includes tumor counts/cm(3), background counts/cm(3), and the ratio between tumor and background counts. RESULTS: 99mTc-depreotide uptake was found in all NSCLC tumors, which expressed SSTR2 defined in vitro by immunochemical methods. SSTR2 expression was negatively correlated to the degree of the tumor's differentiation (P<0.05). 99mTc-depreotide uptake in tumor cells did not correlate with tumor grade, or SSTR2, MIB-1, or p53 expression. CONCLUSION: There is an expression of SSTRs in NSCLC. The degree of tumor differentiation correlates negatively with SSTR2 measured in vitro and positively with MIB-1 expression in tumor tissue. No correlation was found between (99m)Tc-depreotide uptake and possible prognostic factors such as MIB-1 and p53 expression in tumor cells in NSCLC. Lastly, no correlation was found between (99m)Tc-depreotide uptake and tumor grade or SSTR2 expression.

Role of scintigraphy with technetium-99m depreotide in the diagnosis and management of patients with suspected lung cancer.

BACKGROUND: In Sweden, there are over 3000 new lung cancer cases every year. There are still numerous patients with undetermined lesions after routine diagnostic evaluation by clinical examination, chest radiography, computed tomography (CT) of the thorax, and bronchoscopy. An appropriate method for further diagnostic workup is therefore needed. PURPOSE: To evaluate the diagnostic value of the somatostatin analogue depreotide in patients with suspected lung cancer, and to determine in which clinical settings it would be beneficial to use 99mTc-depreotide scintigraphy. MATERIAL AND METHODS: We included 99 consecutive patients referred to our hospital with suspected lung cancer. A clinical examination, bronchoscopy, chest radiography, CT of the thorax and upper abdomen, and scintigraphy were done. Scintigraphy was performed after injection of 740 MBq (99m)Tc depreotide with tomographical imaging of the thorax and whole-body scanning. The diagnostic outcome of the scintigrams was compared to CT, using morphology or clinical outcome as the endpoint. RESULTS: 99mTc-depreotide uptake was found in 62 out of 66 malignancies, including 57 of 58 primary lung cancer cases. Two cases of lung metastasis (one from a colon cancer and one from an adenoid cystic carcinoma originating in the palate) and one rib chondrosarcoma did not show depreotide uptake. There were 33 patients with benign lesions, of whom 16 displayed false-positive 99mTc-depreotide uptake, whereof 11 were pneumonias. Tc-99m-depreotide uptake was absent in 17 patients with benign lesions, including all 10 hamartomas. The sensitivity in detecting malignancy was 94%, and in detecting lung cancer 98%. The specificity was calculated based on two sets of data. When all cases were used, the specificity was 52%. If the 12 pneumonias are excluded, the specificity was 77%. CONCLUSION: 99mTc-depreotide scintigraphy has a high sensitivity in detecting lung cancer. The method is useful in decision-making with respect to surgery.

11C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies.

Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with (11)C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of (11)C-harmine in 13, and 3 samples did not give a significant level of specific binding of (11)C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of (11)C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary.