Assessment of atherosclerosis in oncologic patients using ¹8F-fluoride PET/CT.

OBJECTIVES: The purpose of this study was to evaluate the prevalence, distribution, and relationship of (18)F-fluoride uptake and arterial calcification in oncologic patients using (18)F-fluoride PET/CT. METHODS: Image data obtained from 29 oncologic patients undergoing whole-body (18)F-fluoride PET/CT were evaluated retrospectively. Arterial wall (18)F-fluoride uptake and calcification were analyzed both quantitatively and semiquantitatively in 8 patients with arterial (18)F-fluoride uptake. RESULTS: Arterial (18)F-fluoride uptake was observed at 35 lesions in 8 (28 %) of the 29 patients, and calcification was observed at 345 lesions in the same patients. Five of the 8 patients had prostate cancer, and the remaining patients had hepatocellular carcinoma or malignant melanoma. In these 8 patients, the prevalence of both (18)F-fluoride uptake and calcification was highest in the abdominal aorta, followed by the descending thoracic aorta and the aortic arch. Colocalization of radiotracer accumulation and calcification could be observed in the 32 lesions (91 %) with arterial (18)F-fluoride uptake, and only the 3 lesions (9 %) with arterial (18)F-fluoride uptake were not colocalized with arterial calcification. The presence of both arterial radiotracer uptake and calcification was significantly associated with advancing age (P < 0.01). CONCLUSION: Our results suggest that (18)F-fluoride PET/CT might be a useful modality for detecting active mineral deposition sites of atherosclerosis in oncologic patients.

Role of 18F-fluoride PET/CT in the assessment of multiple myeloma: initial experience.

PURPOSE: The aim of this study was to report our early experience with (18)F-fluoride PET/CT for detecting lesions and evaluate the usefulness of this modality in the assessment of multiple myeloma (MM). MATERIALS AND METHODS: (18)F-fluoride PET/CT and (99m)Tc-MDP bone scintigraphy (BS) studies from 7 myeloma patients (4 male and 3 female, mean age 55 years) diagnosed according to standard criteria were reviewed retrospectively. Two reviewers visually and quantitatively analyzed the images and recorded their findings after reaching a consensus. Diagnostic certainty regarding the presence or absence of myeloma lesions was evaluated according to the reference standard consisting of whole-body magnetic resonance imaging and whole-body X-ray. RESULTS: A total of 93 affected areas were definite according to the reference standard. Of these, 83 affected areas (89 %) were identified on (18)F-fluoride PET/CT, whereas 54 affected areas (58 %) were found on BS. Mean SUVmax in the affected areas was 9.8 ± 3.2 (standard deviation) ranging from 5.0 to 21.2. A total of s17 lesions with bone fracture were also detected by (18)F-fluoride PET/CT and 2 lesions (12 %) were negative on BS. CONCLUSION: Our result showed that (18)F-fluoride PET was a possible modality to detect areas of lesions in patients with MM.

Assessment of tumor hypoxia by 62Cu-ATSM PET/CT as a predictor of response in head and neck cancer: a pilot study.

OBJECTIVE: In radiotherapy and chemotherapy tumor hypoxia is recognized as a major obstacle to effective treatment. We undertook a pilot study in patients with locally advanced head and neck cancer to determine whether there is a relationship between tumor uptake of (62)Cu-ATSM and response to chemoradiotherapy. METHODS: Seventeen patients were studied using PET/CT with (62)Cu-ATSM and (18)F-FDG prior to the initiation of radiotherapy and chemotherapy. All patients had locally advanced head and neck cancer (stage III or IV). Tumor uptake in all patients was measured by region of interest analysis using the maximal standardized uptake value (SUVmax). A total dose of 50.4-70.2 Gy (median 70.2 Gy) was delivered in 29-39 fractions (median 39 fractions) to tumor. In patients with (non CR) and without (CR) residual/recurrent tumors at 2-year post irradiation, the statistical significance of the differences in tumor (62)Cu-ATSM SUVmax, T/M ratio, (18)F-FDG SUVmax and tumor volume were analyzed using Student's t test and Welch test. The relationship between clinical outcome and (62)Cu-ATSM/(18)F-FDG uptake patterns was analyzed using Kruskal-Wallis test. The correlation between SUVmax of (62)Cu-ATSM and (18)F-FDG was compared by Spearman's rank correlation test. RESULTS: Two of the 17 patients that were enrolled in our study were excluded from the final analysis. Of the 15 remaining patients, 9 patients were free of disease and 6 patients had residual/recurrent tumors. The SUVmax differed significantly (p < 0.05) between patients with or without residual/recurrent tumor on (62)Cu-ATSM PET/CT. Six of the 10 patients with tumors SUVmax >5.00 had residual/recurrent tumor, whereas all of the 5 patients with tumors SUVmax <5.00 were free of disease. There was no significant difference in FDG uptake between patients with and without residual/recurrent tumor. CONCLUSIONS: The results of this pilot study suggested that (62)Cu-ATSM uptake may be a predictive indicator of tumor response to chemoradiotherapy in patients with locally advanced head and neck cancer.

PET assessment of disease activity in children with juvenile idiopathic arthritis.

BACKGROUND: The degree of 18-fluorodeoxyglucose (FDG) uptake is previously reported to correlate with physical examination and laboratory tests for evaluating disease activity in patients with rheumatoid arthritis. The clinical validity of (18)F-FDG positron emission tomography (PET) has not been evaluated in juvenile idiopathic arthritis (JIA). OBJECTIVE: To assess the relationship between (18)F-FDG PET uptake and disease activity in children with JIA. MATERIALS AND METHODS: A total of 560 joints in 28 children (mean age, 5.4 years; range, 1-16 years) with JIA who had undergone whole-body (18)F-FDG PET before treatment were retrospectively assessed clinically, biochemically and radiographically. PET images were assessed independently by two readers. We investigated the relationships between the degree of synovial (18)F-FDG uptake and radiographic and clinical symptoms and laboratory findings. RESULTS: Joint tenderness and swelling had a positive association with abnormal (18)F-FDG uptake in the joint [odds ratio (OR) 5.37, 7.12, respectively]. The standardized uptake value (SUV) max correlated with the neutrophil count, plasma C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and matrix metalloproteinase (MMP) 3. Joint erosion (OR, 6.17), soft-tissue swelling (OR, 3.77), major joints involvement (OR, 3.50), tenderness (OR, 5.22), and CRP concentration in plasma (OR, 1.81) were positively associated with SUVmax. CONCLUSION: The degree of (18)F-FDG uptake may be associated with the severity of synovitis in children with JIA.

A meta-analysis of (18)F-Fluoride positron emission tomography for assessment of metastatic bone tumor.

PURPOSE: The aim of this study was to assess the diagnostic performance of (18)F-Fluoride positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) compared with bone scintigraphy (BS) planar or BS planar and single photon emission computed tomography (SPECT) in evaluating patients with metastatic bone tumor. MATERIALS AND METHODS: We performed a meta-analysis of all available studies addressing the diagnostic accuracy of (18)F-Fluoride PET, (18)F-Fluoride PET/CT, BS planar, and BS planar and SPECT for detecting the metastatic bone tumor. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios, and drew summary receiver operating characteristic curves using hierarchical regression models. We also compared the effective dose and cost-effectiveness estimated by data from the enrolled studies between (18)F-Fluoride PET or PET/CT and BS planar or BS planar and SPECT. RESULTS: When comparing all studies with data on (18)F-Fluoride PET or PET/CT, sensitivity and specificity were 96.2% [95% confidence interval (CI) 93.5-98.9%] and 98.5% (95% CI 97.0-100%), respectively, on a patient basis and 96.9% (95% CI 95.9-98.0%) and 98.0% (95% CI 97.1-98.9%), respectively, on a lesion basis. The Az values of (18)F-Fluoride PET or PET/CT were 0.986 for the patient basis and 0.905 for the lesion basis, whereas those of BS or BS and SPECT were 0.866 for the patient basis and 0.854 for the lesion basis. However, the estimated effective dose and average cost-effective ratio were poorer for (18)F-Fluoride PET or PET/CT than those of BS planar or BS planar and SPECT. CONCLUSION: (18)F-Fluoride PET or PET/CT has excellent diagnostic performance for the detection of metastatic bone tumor, but the estimated effective dose and average cost-effective ratio are at a disadvantage compared with BS planar or BS planar and SPECT.

The roles of PET and PET/CT in the diagnosis and management of prostate cancer.

2-(18)F-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) imaging in prostate cancer is challenging because glucose utilization in well-differentiated prostate cancer is often lower than in other tumor types. Nonetheless, FDG-PET has a high positive predictive value for untreated metastases in viscera, but not lymph nodes. A positive FDG-PET can provide useful information to aid the clinician's decision on future management in selected patients who have low prostate-specific antigen levels and visceral changes as a result of metastases. On the other hand, FDG-PET is limited in the identification of prostate tumors, as normal urinary excretion of radioisotope can mask pathological uptake. Moreover, there is an overlap in the degree of uptake between prostate cancer, benign prostatic hyperplasia and inflammation. The tracer choice is also important. (11)C-choline has the advantage of reduced urinary excretion, and thus (11)C-choline PET may provide more accurate information on the localization of main primary prostate cancer lesions than MRI or MR spectroscopy. (11)C-choline PET is sensitive and accurate in the preoperative staging of pelvic lymph nodes in prostate cancer. A few studies are available but there were no PET or PET/CT studies with a large number of patients for tissue confirmation of prostate cancer; further investigations are required.