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Discordant findings in patients with non-small-cell lung cancer: absolutely normal bone scans versus disseminated bone metastases on positron-emission tomography/computed tomography

OBJECTIVE At present, metastatic bone involvement is usually assessed using bone scintigraphy, which has a high sensitivity but a poor specificity. The objective of our study was to compare the sensibility of the 2-deoxy-2-[18F] fluoro-d-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) for the detection of bone metastasis in patients with non-small-cell lung cancer (NSCLC) whose technetium 99m methylenediphosphonate (Tc-99m MDP) bone scans were absolutely normal. MATERIAL AND METHODS This study based on the retrospective analysis of 95 consecutive patients with histologically proven NSCLC who underwent F-18 FDG PET/CT and Tc-99m MDP bone scan at the Eskişehir Osmangazi University School of Medicine, Department of Nuclear Medicine between November 2006 and October 2008. Nineteen patients (19 of 95, 20%) with absolutely normal Tc-99m bone scan versus multiple high-grade F-18 FDG avid bony metastases on F-18 FDG PET/CT were selected for the review. Their ages ranged from 46 to 73 years (15 males and four females; mean: 57.2 years). RESULTS Nine patients had squamous cell carcinoma, six had adenocarcinoma, three had large cell carcinoma and one had adenosquamous cell carcinoma. Tc-99m MDP bone scan that did not reveal bony abnormalities or radiotracer uptake was characteristic of benign disease (defined as absolutely normal) in these patients. Whereas, F-18 FDG PET/CT not only showed extremely disseminated heterogeneous nest-like high-grade FDG avid metastatic foci within the marrow cavity of the upper and lower thoracic spine, lumbar spine, pelvis, rib cages and bilateral proximal long bones, but also showed disseminated osteolytic bony metastases in these areas. CONCLUSION Discordant findings of skeletal metastasis between Tc-99m MDP bone scans and F-18 FDG PET/CT imaging may be seen in 20% of the patients with NSCLC. F-18 FDG PET/CT could detect metastatic bone involvement more accurately than bone scintigraphy. Bone scans are insensitive to early bone marrow neoplastic infiltration. Assessment of glucose metabolism with FDG PET/CT can represent a more powerful tool to detect early bone metastases in lung cancer than with traditional bone scans.

Tc-99m methoxyisobutylisonitrile bone marrow imaging for predicting the levels of myeloma cells in bone marrow in multiple myeloma: correlation with CD38/CD138 expressing myeloma cells

The percentage of myeloma cells in bone marrow is subsequently an important index of disease in patients with multiple myeloma (MM). Bone marrow myeloma cells can be detected by strong CD38/CD138 positivity and light scatter characteristics using flow cytometry. The aim of the study was to evaluate the relationship between the degree of Tc-99m methoxyisobutylisonitrile (MIBI) uptake and the percentage of CD38/CD138 expressing myeloma cells in the bone marrow of patients with MM. A total of 15 patients with MM (mean age: 61.7±2.4 years; 7 F and 8 M) were included in the study. Tc-99m MIBI imaging was obtained 20 min after injection of 740 MBq Tc-99m MIBI. Planar spot images of the pelvis and thorax were acquired. The uptake of Tc-99m MIBI in the bone marrow was evaluated using a qualitative and also a semiquantitative scoring system for the bone marrow in areas that included the proximal femurs, anterior iliac crest, and sternum. In all patients, flow cytometry was performed for assessing the percentage of CD38/CD138 expressing myeloma cells in the bone marrow samples. There was a statistically significant positive correlation between the percentage of CD38/CD138 expressing plasma cells in bone marrow and both mean qualitative (r=0.689, p=0.005) and semiquantitative (r=0.669, p=0.006) results of Tc-99m MIBI uptake. In conclusion, our results indicate that increased Tc-99m MIBI uptake of bone marrow is related to the percentage of plasma cell infiltration of bone marrow. Tc-99m MIBI bone marrow imaging may be a useful tool for predicting the levels of myeloma cells in bone marrow of patients with MM.

Cerebral Hemodynamic Patterns With Technetium Tc 99m Exametazime Single Photon Emission Computed Tomography and Transcranial Doppler Sonography A Validation Study Using Visual Stimulation

Objective. To assess whether a correlation between perfusion changes to visual stimulus on the bilateral occipital areas and blood flow velocity changes to visual stimulus in both posterior cerebral arteries is present. Methods. Nine right‐handed healthy subjects (4 women and 5 men; mean ± SD age, 58.0 ± 5.6 years) were included in the study. Visual stimulation was performed in room light with the subjects eyes open and looking around versus eyes closed as the stimulus‐off condition. The blood flow velocities were recorded using transcranial Doppler sonography, and the regional cerebral blood flow measurements were recorded with the use of technetium Tc 99m exametazime and a single photon emission computed tomographic gamma camera system. Individual reactivity was defined as a relative increase of blood flow velocity and perfusion, which were calculated as percentage changes of baseline values. Results. Visual stimuli produced a marked increase of blood flow velocity in both posterior cerebral arteries (35.2 ± 2.3 cm/s; P < .001) without a significant side‐to‐side difference in all subjects as well as a marked increase of perfusion on both occipital areas (24.9 ± 4.8 cm/s; P < .01). Moreover, there was a positive correlation between blood flow velocity changes and perfusion changes on both sides (r = 0.833; P < .01). Conclusions. The use of bilateral simultaneous Doppler recordings by means of a flow velocity averaging algorithm to a specific stimulus allows quantitative assessment of blood flow responses, and simple visual stimuli can be applied for different disorders to assess the vasomotor regulation that may result in measurable abnormal cerebral flow regulation even when clinically stabilized.

Atrial angiosarcoma imaged by F-18 FDG PET/CT

Sarcomas arising primarily in the heart are rare. Angiosarcoma is an extremely rare, most common primary cardiac malignant tumour. We report the F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) / computed tomography (CT) images of a patient with an invasive angiosarcoma arising from the right atrium. A 55-year-old woman with primary high-grade cardiac angiosarcoma underwent tumour resection at another centre was referred to our institution for postoperative F-18 FDG PET/ CT scans to assess the residual/metastatic disease. Preoperative magnetic resonance imaging revealed a 6.5x3.5-cm mass extending along the lateral wall of the right atrium surrounding the inferior vena cava and atria ventricular junction, extending to aortic root as well as into the right pericardium. Concomitant pericardial effusion was noticed. The debulking surgery was performed to remove the mass. Four weeks after surgery, the patient underwent the F-18 FDG PET/CT scans (1hour after the administration of 465 MBq F-18 FDG with the subject fasted for 6 h beforehand). Three-plane images (PET, contrast-enhanced CT and fused PET/CT in axial, sagittal and coronal projections) revealed a residual mass with significantly increased uptake of F-18 FDG (SUVmax of 16.4) in the right atrium measuring 5.0x4.5 cm in size (Fig. 1, Video 1, 2. See corresponding video/movie images at www.anakarder.com ). There was no evidence of distant metastatic disease. The patient subsequently underwent chemotherapy regimen. Still, primary cardiac sarcoma is a rare clinical entity, with an incidence of 0.0001% in collected autopsy series. The majority of patients with cardiac sarcomas presents with unresectable tumours and have a poor prognosis. Prognosis of primary cardiac angiosarcoma is generally poor with usually a short and fatal course: the mean survival for patients with primary cardiac angiosarcoma is 9-12 months following diagnosis. Treatment options for these sarcomas include surgery, chemotherapy, and radiation therapy, alone or in combination. Complete resection of cardiac sarcoma is difficult, in view of the location and extent of involvement. PET with F-18 FDG, an analogue of glucose, provides valuable functional information based on the increased glucose uptake and glycolysis of cancer cells and depicts metabolic abnormalities. F-18 FDG PET/CT acquires PET and CT data in the same imaging session and allows accurate anatomical localization of the lesions detected on the PET/CT scan.

An unusual localization of extramedullary hematopoiesis

A 37-year-old man with a history of thalassemia intermedia diagnosed 20 years earlier had fatigue, weakness, and a yellowish discoloration of the skin and sclera. On physical examination he was noted to have only mild hepatomegaly. Cirrhosis and hemosiderosis were diagnosed by liver biopsy. Tc-99m SC bone marrow scintigraphy and SPECT imaging demonstrated an unusual accumulation of tracer in the pelvis mimicking the bladder. Two months later, In-111 demonstrated an extramedullary bone marrow site at the same location. Diagnosis was confirmed by CT scan and CT guided needle biopsy.

Bowel visualization as a sign of cerebrospinal fluid leakage on radionuclide cisternography.

We report a case of massive cerebrospinal fluid (CSF) leakage imaged by radionuclide cisternography. A 27-year-old man was admitted to the hospital with a 3-month history of clear fluid drainage from his right nostril. There was no history of previous trauma or surgery to the head. Radionuclide cisternography with Tc-99m DTPA was performed to assess the CSF leakage. In addition to the activity in the right nasal cavity, posterior imaging of the abdomen showed sequestered activity along the spinal cord and throughout the colon at 6 hours. The well-delineated colonic activity from swallowing the labeled CSF because of the presence of rhinorrhea was prominent at 24 hours.

Prominent imaging of the liver on bone densitometry: metastasis of papillary thyroid carcinoma.

A 71-year-old woman had a bone densitometry examination because of weakness and bone pain lasting 3 months. The liver was coincidentally imaged in the right upper quadrant in this examination. Widespread calcifications were evident in the liver. Later, an abdominal ultrasound showed massive, irregular calcifications in the liver. Papillary thyroid carcinoma metastases were proved by the psammoma bodies, papillary arrangement, and calcifications seen on the liver biopsy.