Yan Xiu

Differential diagnostic value of single-photon emission computed tomography/spiral computed tomography with Tc-99m-methylene diphosphonate in patients with spinal lesions.

PurposeThe objective of this study was to compare the diagnostic value obtained using single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) with Tc-99m methylene-diphosphonate with that obtained using SPECT alone in patients with spinal lesions. MethodsThis was a retrospective study of 56 patients who underwent planar whole-body scintigraphy because of bone pain or osseous lesions that had been detected by other imaging techniques, or for the investigation of bone metastasis in patients with extraskeletal malignancies. Only patients who had hot spots detected in their spine and who had undergone single-photon emission computed tomography/computed tomography (SPECT/CT) imaging were included. One lesion from each patient was resected or biopsied for pathological diagnosis, and lesions for which a pathological diagnosis could be made were included in this study. Single-photon emission computed tomography (SPECT) and SPECT/CT images were independently interpreted by two experienced nuclear medicine physicians who had not been involved in the selection of data for the study. The physicians were aware of patients’ sex, age, history of histologically confirmed extraskeletal malignancy, and whole-body scintigraphy results, but were unaware of the results of other investigations, such as X-ray, MRI, and laboratory tests. SPECT images were analyzed first, followed by SPECT/CT images. Each lesion was graded on a 4-point diagnostic scale (1, benign; 2, likely benign; 3, likely malignant; 4, malignant), and the inter-reviewer agreement and the agreement of the SPECT and SPECT/CT diagnoses with the pathology results were evaluated by &kgr; scores. ResultsThe pathology results revealed 39 malignant bone tumors and 17 benign lesions. In the malignant cases, 20 were bone metastases and 19 were malignant tumors of another histological type. The reviewers rated 67.9% of lesions as equivocal (grade 2–3) by SPECT, but only 19.6% as equivocal by SPECT/CT. The &kgr; scores for inter-reviewer agreement were 0.467 for SPECT and 0.905 for SPECT/CT (both P<0.0001). The &kgr; scores for the agreement of the interpretation of SPECT and SPECT/CT with the pathology results were 0.493 and 0.689, respectively (both P<0.0001). ConclusionCompared with SPECT imaging, SPECT/spiral CT hybrid imaging significantly reduced the number of lesions judged to be equivocal. This reduction allowed for a definitive diagnosis to be made by imaging in the majority of patients.

Added value of SPECT/spiral CT versus SPECT in diagnosing solitary spinal lesions in patients with extraskeletal malignancies.

PurposeThe aim of this study was to investigate the added value of single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) versus SPECT alone in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies. Materials and methodsA total of 90 patients who had a solitary spine ‘hot spot’ that could not be definitively diagnosed using planar scintigraphy were enrolled in the study. SPECT/spiral CT was performed on the indeterminate lesions in the spine. Images were independently interpreted by two experienced nuclear medicine physicians. Each spinal lesion was graded on a four-point diagnostic scale (1, benign; 2, likely benign; 3, likely bone metastasis; 4, bone metastasis). The final diagnosis of each lesion was based on pathological confirmation or follow-up. &kgr; scores were used to evaluate inter-reviewer agreement and agreement of the SPECT and SPECT/spiral CT diagnoses with the final diagnosis. ResultsFinal diagnoses revealed 25 bone metastases and 65 benign lesions. Forty percent (36/90) of the solitary spinal lesions were diagnosed as equivocal (likely benign or likely bone metastasis) according to SPECT, whereas only 5.6% (5/90) were diagnosed as equivocal according to SPECT/spiral CT. For SPECT/spiral CT-based and SPECT-based diagnoses, the &kgr; scores for inter-reviewer agreement were 0.889 (P<0.001, 95% confidence interval 0.824–0.954) and 0.504 (P<0.001, 95% confidence interval 0.401–0.607). The diagnostic accuracies of SPECT/spiral CT and SPECT images were 91.1% (82/90) and 58.9% (53/90), respectively (&khgr;2=24.919, P<0.001). ConclusionCompared with SPECT imaging alone, SPECT/spiral CT imaging was more accurate and valuable in the differential diagnosis of solitary spinal lesions in patients with extraskeletal malignancies.

Primary pulmonary osteosarcoma: PET/CT and SPECT/CT findings.

Primary pulmonary osteosarcoma is a rare malignancy with a very poor prognosis. A 58-year-old man with right chest pain had chest radiography, thoracic computed tomography (CT), positron emission tomography/ CT, Tc-99m methylene diphosphonate bone scintigraphy, and single photon emission/CT. CT-guided percutaneous fine-needle aspiration biopsy demonstrated histologic features of osteosarcoma. After 3 courses of chemotherapy, a right middle lobectomy with resection of this lesion was performed confirming the diagnosis of primary pulmonary osteosarcoma.

Role of 18F-FDG PET/CT Imaging in Intrahepatic Cholangiocarcinoma.

Purpose Although intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy after hepatocellular carcinoma, there are limited data available on PET/CT imaging in ICC. This retrospective study analyzed the role of PET/CT imaging in the evaluation of ICC. Methods FDG PET/CT findings were reviewed in 65 patients with histologically confirmed ICC. PET/CT was evaluated based on visual interpretation and the semiquantitative index of SUVmax and tumor-to-normal liver tissue ratio (TNR), which were consequently further analyzed and correlated with tumor localization, differentiation, size, and serum levels of tumor markers. Forty-five cases also underwent abdominal MRI examinations. Results Nineteen patients had hilar ICC, whereas 46 patients had peripheral ICC. Sixty cases of ICC showed elevated FDG uptake with an average SUVmax of 8.3 ± 4.7 and TNR of 3.1 ± 1.7. Five cases located in the hilum were false negative on PET/CT imaging. Compared with hilar ICC, SUVmax and TNR of peripheral ICC were significantly higher (P < 0.05). FDG accumulation correlated with the degree of ICC differentiation. SUVmax and TNR correlated with tumor size, whereas there was no correlation observed with serum levels of carbohydrate antigen 19-9. The sensitivity, specificity, and accuracy of PET/CT and MRI in the diagnosis of regional lymph node metastases were 70.0% versus 50%, 91.7% versus 83.3%, and 81.8% versus 68.2%, respectively. PET/CT upstaged 12.3% and downstaged 3.1% of cases and had no impact on patient management in the remaining 84.6% of cases. Conclusions Combination of FDG PET/CT and abdominal MRI might improve the diagnostic accuracy for ICC.

Diagnostic value of 99mTc-MDP SPECT/spiral CT combined with three-phase bone scintigraphy in assessing suspected bone tumors in patients with no malignant history.

IntroductionThree-phase bone scintigraphy using technetium-99m-methylene diphosphonate is used to diagnose skeletal lesions, whereas single-photon emission computed tomography/computed tomography (SPECT/CT) improves the diagnostic accuracy of bone disease. We investigated the usefulness of SPECT/CT combined with three-phase bone scintigraphy over three-phase bone scintigraphy alone in assessing suspected bone tumors in patients with no malignant history. Materials and methodsForty-eight patients (30 men and 18 women; mean age, 43.3±20.1 years; age range, 11–82 years) with suspected bone tumors who underwent technetium-99m-methylene diphosphonate three-phase bone scintigraphy and SPECT/CT between July 2008 and August 2013 were retrospectively reviewed. The lesion from each patient was resected or biopsied for pathological confirmation of the diagnosis within 3 weeks of the bone scan. All images were interpreted by two experienced nuclear medicine physicians who had not been involved in the selection of data for the present study. The reviewers were aware of the patient’s sex, age, and the lesion’s site but were unaware of the results of other imaging modalities, such as radiography, MRI, and laboratory tests. In cases of discrepancy regarding the interpretations, a consensus was reached after mutual discussion. The diagnostic ability of three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy was compared with pathological results using the &khgr;2-test, with P-values less than 0.05 indicating significant differences. Agreement between three-phase bone scintigraphy alone or SPECT/CT combined with three-phase bone scintigraphy with pathological results was evaluated using &kgr; scores. ResultsPathological results from the 48 lesions of all patients revealed 32 malignant bone tumors and 16 benign lesions. On using three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy for the differential diagnosis of bone lesions, we found sensitivities to be 96.9 and 100%, specificities to be 31.2 and 81.3%, positive predictive values to be 73.8 and 91.4%, and negative predictive values to be 83.3 and 100%, respectively. The diagnostic accuracies of three-phase bone scintigraphy alone and SPECT/CT combined with three-phase bone scintigraphy were 75.0 and 93.8%, respectively (&khgr;2=5.057; P=0.025). &kgr; scores for the agreement of three-phase bone scintigraphy and SPECT/CT combined with three-phase bone scintigraphy with pathological results were 0.333 (P=0.005) and 0.850 (P<0.0001), respectively. ConclusionCompared with three-phase bone scintigraphy, the diagnostic accuracy of SPECT/CT combined with three-phase bone scintigraphy was higher. SPECT/CT combined with three-phase bone scintigraphy is beneficial over three-phase bone scintigraphy for the differential diagnosis of suspected bone tumors in patients with no malignant history.

Preparation and Evaluation of 99mTc-labeled anti-CD11b Antibody Targeting Inflammatory Microenvironment for Colon Cancer Imaging

CD11b, an active constituent of innate immune response highly expressed in myeloid‐derived suppressor cells (MDSCs), can be used as a marker of inflammatory microenvironment, particularly in tumor tissues. In this research, we aimed to fabricate a 99mTc‐labeled anti‐CD11b antibody as a probe for CD11b+ myeloid cells in colon cancer imaging with single‐photon emission computed tomography (SPECT). In situ murine colon tumor model was established in histidine decarboxylase knockout (Hdc−/−) mice by chemicals induction. 99mTc‐labeled anti‐CD11b was obtained with labeling yields of over 30% and radiochemical purity of over 95%. Micro‐SPECT/CT scans were performed at 6 h post injection to investigate biodistributions and targeting of the probe. In situ colonic neoplasma as small as 3 mm diameters was clearly identified by imaging; after dissection of the animal, anti‐CD11b immunofluorescence staining was performed to identify infiltration of CD11b+ MDSCs in microenvironment of colonic neoplasms. In addition, the images displayed intense signal from bone marrow and spleen, which indicated the origin and migration of CD11b+ MDSCs in vivo, and these results were further proved by flow cytometry analysis. Therefore, 99mTc‐labeled anti‐CD11b SPECT displayed the potential to facilitate the diagnosis of colon tumor in very early stage via detection of inflammatory microenvironment.

SPECT/CT imaging of patella metastasis from a squamous carcinoma of the lung.

A 71-year-old man presented with a progressive right knee pain which persisted for 6 months and was not relieved by pain medications. He had a history of lung squamous carcinoma 1 year ago. X-ray and magnetic resonance imaging (MRI) revealed hyperostosis, degenerative changes, and occupancy lesions of the right patella. The patient underwent Tc methylene diphosphonate (Tc-MDP) bone scan and single photon emission tomography/computed tomography (SPECT/CT), which showed abnormal metabolism of the right patella with bone destruction and soft tissue swelling. Finally, patellectomy was taken and pathology confirmed patella metastasis from lung squamous carcinoma.

Adenosquamous Carcinoma of the Pancreas Demonstrated on 18F-FDG PET/CT Imaging

A 69-year-old woman had gradually worsening abdominal discomfort over a year. A pancreatic mass was revealed by abdominal CT. The patient underwent FDG PET/CT for staging, which demonstrated the hypermetabolic pancreatic mass with multiple liver metastases. The lesion was pathologically confirmed as pancreatic adenosquamous carcinoma after biopsy.

Optimized image acquisition parameters for imaging radioactive iodine-125 seed implantation for cancer treatment.

OBJECTIVE Using nuclear medicine imaging, we explored suitable acquisition window parameters for assessing the distribution of iodine-125 radioactive seed implantation. SUBJECTS AND METHODS We studied 30 patients with various tumors (21 of which were liver cancers) who had received iodine-125 radioactive seed implantation and had undergone whole-body scintigraphy. Scintigraphy images were acquired at a magnification of 1.0 in a 1024×256 matrix and at a scan speed of 25cm/min. Energy peaks were set to 29keV or 35keV, and energy window widths were set to 20%, 50%, 70% and 100%, the image data were divided into eight groups. After image processing under the same conditions, the eight groups of whole-body scintigraphy images were assessed by three experienced nuclear medicine physicians. Two acceptable groups of images were selected from the eight groups of images for each patient. The regions of interest (ROI) of iodine-125, background and whole-body scintigraphy images were outlined to calculate the iodine-125 to background ratio of the radioactive counts and the iodine-125 to whole-body scintigraphy ratio of the radioactive counts. RESULTS Through subjective evaluation by three physicians, the percentages of acceptable images of groups 2, 3 and 7 were more than 50%, with group 2 showing the highest percentage. Furthermore, no statistical significant difference was found in the iodine-125 seed target/background ratio and iodine-125 seed target/whole-body scintigraphy ratio among the three groups (P>0.05). CONCLUSION The parameters to yield high-quality images of iodine-125 radioactive seed were chosen to be an energy peak of 29keV, an energy window width of 50% and a scan speed of 25cm/min.