Erkan Vardareli

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.

Myocardial Tc-99m MDP uptake on a bone scan in senile systemic amyloidosis with cardiac involvement.

A Tc-99m MDP bone scan showed diffuse myocardial uptake in a 61-year-old man who reported progressive glove- and stocking-like parasthesias. Results of complete blood counts, thyroid and liver function tests, tumor markers, electrolytes, and electrocardiography were normal. Electromyelographic findi

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.

TC-99m MIBI spect imaging in patients with lung carcinoma : Is it a functional probe of multidrug resistance genes?

Objective: Multidrug-resistance (MDR) phenotype concerns altered membrane transport that results in lower cell concentrations of cytotoxic drug in many cancer types, including lung cancer, and is related to the overexpression of a variety of proteins that act as adenosine triphosphate-dependent extrusion pumps. Tc-99m Sestamibi (MIBI) is a transport substrate for P-glycoprotein (Pgp) pump. In this study, we assessed the uptake and clearance of technetium-99m-2-hexakis 2-methoxyisobutylisonitrile (Tc-99m MIBI) from the tumor and its correlation with messenger RNA (mRNA) levels of Pgp, MDR-associated protein (MRP1), and lung resistance protein (LRP) in lung carcinoma. Methods: This study was carried out on 19 patients (mean age, 60.1 ± 2.07 years) with advanced-stage lung carcinoma. The tumor samples obtained by bronchoscopy were assessed to estimate the levels of Pgp, MRP1, and LRP expression on mRNA level by quantitative real-time reverse-transcription polymerase chain reaction. Tc-99m MIBI chest imaging was performed 15 and 180 minutes after injection of 740 MBq Tc-99m MIBI. The early (T/Be) and delayed (T/Bd) Tc-99m MIBI uptakes and washout rate (WR) of Tc-99m MIBI from the tumor were measured. Results: No correlation was found between the T/Be Tc-99m MIBI uptake of tumors (T/Be) and the levels of Pgp mRNA, MRP1 mRNA, and LRP mRNA by reverse-transcription polymerase chain reaction. There was a correlation between the mean T/Bd Tc-99m MIBI uptake and Pgp expression of the tumors (P = 0.001, Spearman ρ = − 0.702). There was a correlation between the WR of Tc-99m MIBI from the tumor and Pgp expression of the tumor (P = 0.000, Spearman ρ = 0.875). Washout rate of Tc-99m MIBI was not related to the levels of MRP1 mRNA (P = 0.93, Spearman ρ = 0.02) or LRP mRNA (P = 0.47, Spearman ρ = 0.177). Conclusions: Increased WR of Tc-99m MIBI is related in Pgp over expression of the tumor. Tc-99m MIBI single photon emission computed tomography imaging may be a functional probe of overexpression of Pgp in patients with lung carcinoma. However, Tc-99m MIBI single photon emission computed tomography imaging cannot be used to identify the MDR involved in the MRP1 or LRP in these patients.

Evaluating the Role of Routine Prone Acquisition on Visual Evaluation of SPECT Images

Attenuation artifacts reduce our ability to evaluate perfusion of affected myocardial segments. The aim of this study was to evaluate the impact of routine prone-position image evaluation within a stepwise visual interpretation of myocardial perfusion studies. Methods: We have included 279 consecutive patients who were referred for evaluation of myocardial ischemia. All patients underwent routine electrocardiogram-gated supine SPECT imaging and non–electrocardiogram-gated prone-position SPECT imaging. Three nuclear medicine physicians interpreted the images in the following order: polar maps, supine images, raw images, motion-frozen gated images, and prone images, using a scale of 0–4. Segments with perfusion abnormalities were noted. Results: All physicians reported lower proportions of equivocal evaluations after evaluating prone images (18.3% vs. 4.7%, 19% vs. 11.1%, and 12.2% vs. 6.1%, P < 0.0001, P = 0.0077, and P = 0.0125, respectively). At the prone stage, normalcy rates were 89%, 87%, and 91%. Two physicians had significantly increased normalcy rates at the prone stage (72%–89%, P = 0.039, and 66%–87%, P = 0.006). At the prone stage, a decision reversal to normal or probably normal was observed in 40% (29/72), 33% (17/51), and 43% (21/48). In men, apical, mid, and basal inferior walls and in women apical and mid parts of anterior walls were more likely to be attributed to attenuation. The 2 steps that increased normalcy rates for interpreters were the review of raw images and of prone images. Conclusion: Routine prone imaging increases interpretive certainty and interobserver agreement and changes the final evaluation in a substantial number of patients and significantly decreases the number of equivocal evaluations.

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.

Colonic Malignant Melanoma: 18 F-FDG PET/CT Findings

Primary malignant melanoma occurs most often in the skin and much less frequently in the choroid layer of the eyes, in the leptomeninges, oral cavity, nasal mucosa, pharynx, esophagus, bronchus, under the nail and vaginal or anorectal mucosa. Primary melanoma of the gastrointestinal tract has been confirmed for lesions occurring in the esophagus, stomach, small bowel, and anorectum through several published reports, as these are the areas where melanocytes normally exist. The occurrence of primary malignant melanoma in the colon is relatively rare, because melanocytes are embryologically absent in the large bowel. Herein we report a patient whose colonic malignant melanoma was diagnosed and disseminated metastatic lesions were revealed with 18F-FDG PET/CT scan. There were multiple nodular lesions showing increased 18F-FDG uptake in both lungs. There was a soft tissue lesion with slightly increased 18F-FDG uptake, which extended to the intraluminal region of the thoracic esophagus. Increased metabolic activity was detected in the asymmetric stomach wall thickening site and in a soft tissue lesion located on the gall bladder wall that was filling the lumen. Multiple hypodense/hyper-metabolic lesions were identified in the liver. Multiple hyper-metabolic polypoid soft tissue lesions were visualized in almost the entire colonic segments. Multiple hyper-metabolic peritoneal implants were noted in all abdominal quadrants. Increased 18F-FDG uptake was detected at the right surrenal gland soft tissue lesion. There was a hyper-metabolic soft tissue lesion on the posterior wall of the rectum. Hyper-metabolic lytic lesions were seen at the thoracal and lumbar vertebrae, left scapula, left iliac bone, sacrum and left femur. There was no evidence of 18F-FDG avid skin lesions in both attenuation corrected and non-corrected images.

SHORT-TERM PROGNOSTIC VALUE OF REST Tc99m-MIBI GATED SPECT AFTER ACUTE NON-Q WAVE MYOCARDIAL INFARCTION

Aim: The purpose of this study is to determine the short–term prognostic value of technetium 99m methoxyisobutylisonitrile gated single photon emission computed tomography (Tc99m–MIBI Gated SPECT) in patients with acute Non–Q wave myocardial infarction (NQMI) in 30 days. Methods: We identified 36 patients who underwent rest Tc99m–MIBI Gated SPECT and who were followed-up 30.65±0.49 days after first a NQMI. 21 patients were males, 15 females, with a mean age of 60.30±10.17 years. Rest Tc99m–MIBI Gated SPECT were performed within 48 (30.7±2.3) hours of admission to the coronary care unit after acute myocardial infarction (MI). The left ventricular ejection fraction (LVEF), end diastolic (EDV) and end systolic volumes (ESV), and summed rest score (SRS) and extent score (ES) were assessed using rest Tc99m–MIBI Gated SPECT. Results: Rest Tc99m–MIBI Gated SPECT parameters and clinical datas were analyzed and divided two group according to prognosis, as new cardiac event (poor prognosis) and stable stuation (good prognosis). During follow-up, 12 patients (33%) had a new clinical event, [4 congestive heart failure (11%), 7 revascularization (19%) and 1 reinfarct (2%)], whereas 24 patients (66%) showed a good outcome. There were significant differences LVEF, EDV, ESV, SRS and ES values between poor and good prognosis group (p=0.011, p=0.016, p=0.017, p 70 ml (RR=5.31, CI 1.17 to 24.14, p=0.027), SRS≥7 (RR=7.00, CI 1.25 to 39.14, p=0.032) and ES≥3 (RR=6.59 CI 0.72 to 60.02, p=0.037). Conclusion: Left ventricular parameters (LVEF, ESV) and perfusion scores (SRS, ES) which obtained by rest Tc99m–MIBI Gated SPECT, provide useful information in the prediction of future cardiac events after NQMI in 30 days.

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.