Is (99m)Tc-MDP whole body bone scintigraphy adjuvant to (18)F-FDG-PET for the detection of skeletal metastases?

PURPOSE: Due to the fact that fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG-PET/CT) and technetium-99m-methylenediphosphonate ((99m)Tc-MDP) whole body scans identify bone metastases by different mechanisms, i.e. by using glucose metabolism and osteoblastic response in the bone, respectively, it can be expected that there may be some differences between these two methods in the number of lesions identified. The aim of this study was to compare the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) in detecting bone metastases between (18)F-FDG-PET/CT and conventional (99m)Tc-MDP whole body scans. METHODS: Between 2006-2009, 121 patients with malignancies (62 male and 59 female, mean age 59.3±10.8 years, range 37-84) were examined with (18)F-FDG-PET/CT and conventional (99)Tc-MDP whole-body scans for detection of bone metastases. RESULTS: For (18)F-FDG-PET/CT and for (99m)TC-MDP, sensitivity, specificity, accuracy, PPV and NPV for detecting all studied bone metastases were 88.3, 83.6, 86.7, 91.7, 77.8% and 91.7, 71.0, 84.9, 86.6, 80.8%, respectively. For bone metastases of breast and lung cancers, the specificity and accuracy of PET/CT was higher than that of bone scintigraphy. On the other hand, the sensitivity of bone scintigraphy was higher than PET/CT in breast and lung cancers groups and all patients. In the detection of osteolytic and osteosclerotic metastases no difference was found between the two methods, while for osteolytic lesions the mean standardized uptake value (SUV) max was higher than for osteosclerotic lesions. CONCLUSION: For the detection of bone metastases the specificity and accuracy of (18)F-FDG-PET/CT were higher compared to bone scintigraphy, while the sensitivity was lower. It is the opinion of the authors that both studies are complementary to final diagnosis.

Combined transbronchial needle aspiration and PET/CT for mediastinal staging of lung cancer.

In this study, we aimed to evaluate the performance of transbronchial needle aspiration (TBNA) combined with positron emission tomography/computed tomography (PET/CT) for the staging of lung cancer. Twenty-five patients having lymphadenopathies greater than 1 cm on thorax CT and maximum standardized uptake value (SUVmax) ≥ 2.5 on PET/CT were included in this prospective study performed between March 2006 and March 2008. Forty-three lymphnode stations were sampled by using TBNA. Surgical histology, as confirmed by mediastinoscopy, was accepted as the "gold standard". The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of combined TBNA and PET/CT for correct lymph node staging were 67%, 100%, 100%, 76% and 84%; respectively. The initial clinical staging was downstaged after TBNA in 13/19 (69%) patients with adequate TBNA samples, whereas staging was correct in 17/19 (89%) patients assessed by combined TBNA and PET/CT. Staging was completed by TBNA, without mediastinoscopy, in 6/25 (24%) patients. Among the clinical factors that were assessed, only the PET SUVmax was associated with positive TBNA results [odds ratio (OR) 1.27, 95% CI 1.004-1.61, p= 0.046]. A PET SUVmax ≥ 5 was eleven times more likely in patients with positive TBNA results [OR 10.68, 95% CI 1.91-59.62, p< 0.01]. In conclusion, the combination of TBNA with PET/CT increased the sensitivity of TBNA. Combined TBNA and PET/CT may also allow adequate mediastinal staging of lung cancer in most patients with enlarged lymph nodes, and reduce the need for mediastinoscopy. The SUVmax cut off point for a positive TBNA result was ≥ 5.

Coexistence of the monostatic Paget's disease, sensorimotor neuropathy and elderly onset rheumatoid arthritis.

Paget's disease is a chronic focal disease of the skeleton that affects up to 2-3% of the population over the age of 60. Polymyalgia rheumatica (PMR) is an inflammatory condition of unknown etiology characterized by aching and stiffness in the shoulder, pelvic girdle and the neck. There are two incompletely overlapping subsets of RA that have been recognized: one exhibits the classical RA clinical picture, while the other has a PMR-like onset in later ages of life. We reported a rare case of monostatic Paget's disease, sensorimotor neuropathy and elderly onset rheumatoid arthritis in an elderly women.

Primary synovial sarcoma of the kidney: use of PET/CT in diagnosis and follow-up.

Primary renal synovial sarcoma is a rarely seen renal neoplasm. An experienced uropathologist is needed to make the pathological diagnosis. A patient, operated on with a prediagnosis of renal cell carcinoma, the pathology of which was reported as synovial sarcoma, is presented in this article. 18F-fluoro-deoxyglucose positron emission tomography and computed tomography were performed preoperatively and in the postoperative follow-up to detect the primary tumor and lymph node metastases.

FDG uptake in abdominal mesh implant on FDG PET/CT.

A 50-year-old man with peritoneal angiosarcoma underwent total tumor excision along with removal of the total right rectus and medial part of the left rectus muscles 1 year earlier. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) was performed for suspected recurrence. In the anterior abdominal wall extensive subcutaneous FDG uptake showing linear hypermetabolic zone on PET slices was noted. The patient had a history of a dual mesh implant, which consists of polypropylene and polyvinylidene fluoride for the reinforcement of the abdominal wall during the operation. PET/CT fusion image demonstrated that the finding was due to the dual mesh implant in the anterior abdominal wall most likely representing a foreign body reaction.

Early detection of response to imatinib therapy for gastrointestinal stromal tumor by using 18F-FDG-positron emission tomography and computed tomography imaging.

A 41-year old female with metastatic gastrointestinal stromal tumor was referred to 18F-FDG-positron emission tomography and computed tomography (PET/CT) scan before and after one-month treatment with imatinib (Glivec, Gleevec, Novartis, Basel, Switzerland), a tyrosine kinase inhibitor (400 mg/d). Metabolic response was evaluated before and after one month of therapy. The decrease of the maximum standardised uptake value (SUV) was 79% (from 9.8 to 2.1). Positron emission tomography demonstrated complete metabolic response after one-month of imatinib treatment. Additionally, the previous lesion was compared with the coronal computerized tomographic image. There was no difference in the size of the tumor before and after therapy according to CT images. However, metabolic activity was inhibited. 18F-FDG-PET is a valuable method for the detection of response to one-month imatinib treatment in patients with gastrointestinal stromal tumors.

Fluoro-18 fluorodeoxyglucose positron emission tomography/computerized tomography scans in a patient with penile cancer for appropriate therapeutic strategy.

In patients with penile cancer, positron emission tomography (PET) is important for identifying metastatic lesions and for therapeutic strategy planning. By using PET/computerised tomography -CT scanning, more precise localization and attenuation correction is provided by CT as an additional advantage for diagnosis. A 78-year-old man with squamous cell cancer of the glans penis diagnosed after histopathological examination was referred to our Nuclear Medicine Department PET/CT unit by the Urology Department of our Hospital, for investigation of metastases and for therapeutic strategy planning. There was significantly increased focal fluoro-18 fluorodeoxyglucose (18F-FDG) activity (SUV: 18.2) in the glans penile area and slightly increased activity in the right inguinal region which was described as inflammation by the histopathological examination. There was no other increased abnormal 18F-FDG activity. 18F-FDG PET or PET/CT may be used in squamous cell cancer of the penis for the detection of metastases and for therapeutic strategy planning. Finally, invasive procedures such as total bilateral inguinal lymphadenectomy, having a high morbidity, may be avoided.

A false negative by planar scintigraphy liver hemangioma, diagnosed by technetium-99m-red blood cells and technetium-99m-sulfur colloid single photon emission tomography scan.

We present a 42-year-old patient who was examined in the Gastroenterology Department of Gaziantep University for chronic abdominal pain, nausea and vomiting. Ultrasonography showed a 4.7 cm solid hepatic mass on the right lateral side of the right lobe of the liver. The patient was then sent to the Nuclear Medicine Department of Gaziantep University for liver scan. After injecting autologous red blood cells labeled with 740 MBq of technetium-99m ((99m)Tc-RBC), early and delayed anterior planar images of the liver showed no significant findings because of the right kidney shine through the liver. Two days later, after injecting again 740 MBq of (99m)Tc-RBC, we performed a single photon emission tomography (SPET) scan but still this scan was nondiagnostic even in the delayed images of the liver. Three days later, after the iv injection of 185 MBq of technetium-99m-sulphur colloid ((99m)Tc-SC), we observed in the delayed SPET images of the liver, a mismatch defect with decreased focal uptake of (99m)Tc-SC at 60 min while the uptake of (99m)Tc-RBC at the same area was normal or slightly increased. The patient was then operated due to bleeding in the abdominal cavity. A cavernous hemangioma was found, confirmed by histology. The absorbed dose from all three diagnostic scanning procedures was: 4 mSv. In conclusion, the mismatch of the SPET delayed images between the (99m)Tc-RBC and the (99m)Tc-SC scans indicated that this procedure was effective for the diagnosis of liver cavernous hemangioma located in this unusual position.

FDG PET-CT in cervical cancer: relationship between primary tumor FDG uptake and metastatic potential.

OBJECTIVE: We retrospectively evaluated the relationships between primary tumor F-fluorodeoxyglucose (FDG) uptake measured as the maximum standardized uptake value (SUV(max)) and local extension, and nodal or distant metastasis in patients with cervical cancer on pretreatment FDG positron emission tomography-computed tomography (PET-CT). METHODS: Forty-three patients (mean age, 55.14 years; range, 34-90 years) with cervical cancer who underwent FDG PET-CT scans for staging before the initiation of treatment were included in the study. Primary tumor SUV(max) was calculated; clinical tumor stages, presence of local extension, sites of lymph node and distant organ metastases were recorded. The patients were divided into low and high SUV groups by using the median primary tumor SUV(max). The low SUV group consisted of 21 patients with SUV(max) less than 13.5, the high SUV group consisted of 22 patients with SUV(max) > or = 13.5. Their data were compared statistically. RESULTS: The average SUV(max) was 9.6+/-2.6 and 19.9+/-4.9 in the low and high SUV groups, respectively. In the low SUV group, six patients (29%) had a local extension, eight (38%) had pelvic and/or para-aortic lymph node metastasis, and one had distant organ metastasis (4.7%). In the high SUV group, 10 patients (45%) had a local extension, 16 (73%) had pelvic and/or para-aortic lymph node metastasis, and two (9%) had distant organ metastases. There was a significant difference in the lymph node metastasis rate between the two groups (P<0.05), but differences in local extension and distant organ metastasis were not statistically significant (P>0.05). In addition, there was a moderate correlation between SUV(max) and clinical tumor stages (r=0.40, P=0.0075). CONCLUSION: Higher primary tumor FDG uptake predicts higher nodal metastatic potential in cervical cancer patients. Patients with higher SUV(max) in cervical tumor may need a close follow-up because of their higher metastatic potential.

Reliability of positron emission tomography-computed tomography in identification of mediastinal lymph node status in patients with non-small cell lung cancer.

OBJECTIVE: The involvement of mediastinal lymph nodes is a very important prognostic factor in patients with potentially resectable non-small cell lung cancer. Our aim in this study was to investigate the value of positron emission tomographic-computed tomographic scanning in staging lung cancer, especially for mediastinal lymph node evaluation, and to determine whether this could decrease the need for mediastinoscopy. METHODS: Seventy-eight patients with non-small cell lung cancer who were potential candidates for surgical resection and admitted to the thoracic surgery unit of our hospital from March 2006 to June 2008 joined this prospective study. Positron emission tomographic-computed tomographic scanning was performed as part of the prospective studies used to diagnose or stage the tumors. All 78 patients underwent tissue sampling of mediastinal lymph nodes to compare these with imaging results. The diagnostic efficacy of the computed tomographic and positron emission tomographic-computed tomographic scans compared with histopathologic findings were calculated with sensitivity, specificity, positive and negative predictive values, and accuracy. RESULTS: Final histology was available on 397 lymph node stations (N1, N2, and N3) sampled from 78 patients during mediastinoscopy or surgical intervention. Sensitivity, specificity, and positive and negative predictive values of mediastinal lymph node involvement in patients undergoing thoracic computed tomographic scanning were 45.4%, 80.5%, 27.7%, and 90%, respectively. The accuracy of computed tomographic scanning was 75.6%. The sensitivity, specificity, and positive and negative predictive values of mediastinal lymph node involvement in patients undergoing positron emission tomographic-computed tomographic scanning were 81.8%, 89.5%, 56.2%, and 96.7%, respectively. CONCLUSION: There is a need for mediastinoscopy in positron emission tomographic-computed tomographic scanning-positive mediastinal lymph nodes, but it might not be necessary for positron emission tomographic-computed tomographic scanning-negative lymph nodes.