Many studies have suggested a prognostic value of one or several positron emission tomography (PET) parameters in patients with small cell lung cancer (SCLC). However, studies are often small, and there is a considerable interstudy disagreement about which PET parameters have a prognostic value. The objective of this study was to perform a review and meta-analysis to identify the most promising PET parameter for prognostication. PubMed®, Cochrane, and Embase® were searched for papers addressing the prognostic value of any PET parameter at any treatment phase with any endpoint in patients with SCLC. Pooled hazard ratios (HRs) were calculated by a random effects model for the prognostic value of the baseline maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV). The qualitative analysis included 38 studies, of these, 19 studies were included in the meta-analyses. The pooled results showed that high baseline MTV was prognostic for overall survival (OS) (HR: 2.83 (95% confidence interval [CI]: 2.00-4.01) and progression-free survival (PFS) (HR: 3.11 (95% CI: 1.99-4.90)). The prognostic value of SUVmax was less pronounced (OS: HR: 1.50 (95% CI: 1.17-1.91); PFS: HR: 1.24 (95% CI: 0.94-1.63)). Baseline MTV is a strong prognosticator for OS and PFS in patients with SCLC. MTV has a prognostic value superior to those of other PET parameters, but whether MTV is superior to other prognosticators of tumor burden needs further investigation.

Positron emission tomography (PET) imaging with 2-deoxy-2-[18F]-fluorodeoxyglucose (FDG) was proposed as prognostic marker in radiotherapy. Various uptake metrics and cut points were used, potentially leading to inflated effect estimates. Here, we performed a meta-analysis and systematic review of the prognostic value of pretreatment FDG-PET in head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC), with tests for publication bias. Hazard ratio (HR) for overall survival (OS), disease free survival (DFS), and local control was extracted or derived from the 57 studies included. Test for publication bias was performed, and the number of statistical tests and cut-point optimizations were registered. Eggers regression related to correlation of SUVmax with OS/DFS yielded p = 0.08/p = 0.02 for HNSCC and p < 0.001/p = 0.014 for NSCLC. No outcomes showed significant correlation with SUVmax, when adjusting for publication bias effect, whereas all four showed a correlation in the conventional meta-analysis. The number of statistical tests and cut points were high with no indication of improvement over time. Our analysis showed significant evidence of publication bias leading to inflated estimates of the prognostic value of SUVmax. We suggest that improved management of these complexities, including predefined statistical analysis plans, are critical for a reliable assessment of FDG-PET.

UNASSIGNED: Various inflammatory conditions may present with musculoskeletal symptoms similar to those of polymyalgia rheumatica (PMR). We investigated findings on 18F-fluorodexoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) images that may differentiate PMR from polymyalgia-like illnesses.
UNASSIGNED: We analyzed data from 25 patients with new-onset polymyalgia-like illnesses who fulfilled Bird\'s diagnostic criteria for PMR and had undergone FDG-PET/CT scan. To assess the uptake by major joints and synovial bursae, particularly at PMR-specific sites (shoulder, sternoclavicular, and hip joints, interspinous bursae, ischial tuberosities, and greater trochanters), we used visual scoring system to score FDG uptake: 0, no uptake (same as bone); 1, slight uptake; 2, moderate uptake (same as the liver); 3, greater uptake than the liver; and 4, uptake as strong as in the cerebellum.
UNASSIGNED: The final diagnoses were PMR in 17 patients and non-PMR in eight patients (three malignancies, two infections, one cholesterol crystal embolism, one ANCA-associated vasculitis, and one undefined diagnosis). Although the serum MMP-3 levels were significantly higher in patients with PMR, C-reactive protein and erythrocyte sedimentation rate mean values did not differ between the two groups. In PMR-specific sites, FDG accumulations were observed in all cases of PMR, with a high PET-positive score of 2.00 (range, 0-3), but it was low in non-PMR cases, with a PET-positive score of 1.00 (range, 0-3).
UNASSIGNED: The FDG accumulation patterns in polymyalgia-like illness differ from those in PMR, despite the similar clinical presentations of both conditions. An FDG-PET/CT scan is useful for differentiating PMR from other polymyalgia-like illnesses.

OBJECTIVE: There is no good response evaluation method for skeletal metastasis. We aimed to develop a novel quantitative method to evaluate the response of skeletal metastasis, especially lytic lesions, for treatment.
METHODS: A method to measure active bone metastatic burden quantitatively using F-18 fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) in breast cancer patients, whole skeletal total lesion glycolysis (WS-TLG), a summation of each skeletal lesion\'s TLG, was developed. To identify active bone lesions, a tentative cutoff value was decided using FDG-PET/CT in 85 breast cancer patients without skeletal metastasis and 35 with skeletal metastasis by changing the cutoff value. Then, the WS-TLG method was evaluated by comparing to PET Response Criteria in Solid Tumor (PERCIST) or European Organization for Research and Treatment of Cancer (EORTC) criteria for only bone in 15 breast cancer patients with skeletal metastasis who were treated.
RESULTS: A cutoff value of the standardized uptake value (SUV) = 4.0 gave 91% (77/85) specificity and 97% (34/35) sensitivity. We decided on SUV = 4.0 as a tentative cutoff value. Skeletal metastases of lytic and mixed types showed higher WS-TLG values than those of blastic or intertrabecular types, although statistical significance was not tested. All 15 patients showed agreement with PERCIST or EORTC in the therapeutic bone response.
CONCLUSIONS: This quantitative WS-TLG method appears to be a good biomarker to evaluate skeletal metastasis in breast cancer patients, especially lytic or mixed types. Further clinical studies are warranted to assess the clinical values of this new WS-TLG method.

OBJECTIVE: Cholangiocarcinoma is an infrequent neoplasm barely studied with 18F-FDG-PET/CT. We evaluated the metabolic behavior of cholangiocarcinoma in PET/CT according to its location (intra or extrahepatic) and analyzed the relationship between metabolic parameters of the primary tumor and tumor markers (CA19-9 and CEA), determining their prognostic significance.
METHODS: Retrospective study of PET/CT of 60 patients with untreated cholangiocarcinoma, divided into two groups according to tumor location. FDG uptake was evaluated visually and semiquantitatively [SUVmax and tumor-to-liver ratio (TLR)], and differences between intra and extrahepatic cholangiocarcinomas were tested, both for FDG uptake in the primary tumor and for the presence of regional or distant disease (per-patient), as well as regarding tumor marker levels. A correlation between metabolic parameters and tumor markers was performed, and prognostic value of these factors was determined (univariate and multivariate analyses).
RESULTS: Intrahepatic cholangiocarcinomas were significantly more FDG-avid than extrahepatic ones (p = 0.006 for SUVmax; p = 0.002 for TLR). There were differences neither between both groups considering the capacity of PET/CT to detect regional (p = 0.261) and distant involvement (p = 0.876), nor regarding the levels of tumor markers (p = 0.160 for CA19-9; p = 0.708 for CEA). Metabolic parameters and tumor markers showed a weak positive correlation (R2 0.22-0.27). At the multivariate analysis, advanced stage (p = 0.024), increased CEA (p = 0.022), and higher TLR (p = 0.003) were significantly related with shorter overall survival.
CONCLUSIONS: Intra and extrahepatic cholangiocarcinomas behave differently on PET/CT, though no differences between both groups exist in its capacity to detect regional or distant disease. Metabolic parameters and levels of tumor markers seem to relate with tumor burden, impacting in prognosis.

BACKGROUND: Most peripheral T-cell lymphoma (PTCL) patients have a poor outcome and the identification of prognostic factors at diagnosis is needed.
METHODS: The prognostic impact of total metabolic tumor volume (TMTV0), measured on baseline [(18)F]2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography, was evaluated in a retrospective study including 108 PTCL patients (27 PTCL not otherwise specified, 43 angioimmunoblastic T-cell lymphomas and 38 anaplastic large-cell lymphomas). All received anthracycline-based chemotherapy. TMTV0 was computed with the 41% maximum standardized uptake value threshold method and an optimal cut-off point for binary outcomes was determined and compared with others prognostic factors.
RESULTS: With a median follow-up of 23 months, 2-year progression-free survival (PFS) was 49% and 2-year overall survival (OS) was 67%. High TMTV0 was significantly associated with a worse prognosis. At 2 years, PFS was 26% in patients with a high TMTV0 (>230 cm(3), n = 53) versus 71% for those with a low TMTV0, [P < 0.0001, hazard ratio (HR) = 4], whereas OS was 50% versus 80%, respectively, (P = 0.0005, HR = 3.1). In multivariate analysis, TMTV0 was the only significant independent parameter for both PFS and OS. TMTV0, combined with PIT, discriminated even better than TMTV0 alone, patients with an adverse outcome (TMTV0 >230 cm(3) and PIT >1, n = 33,) from those with good prognosis (TMTV0 ≤230 cm(3) and PIT ≤1, n = 40): 19% versus 73% 2-year PFS (P < 0.0001) and 43% versus 81% 2-year OS, respectively (P = 0.0002). Thirty-one patients (other TMTV0-PIT combinations) had an intermediate outcome, 50% 2-year PFS and 68% 2-year OS.
CONCLUSIONS: TMTV0 appears as an independent predictor of PTCL outcome. Combined with PIT, it could identify different risk categories at diagnosis and warrants further validation as a prognostic marker.

BACKGROUND: Oestrogen is known to play a cardioprotective role in cardiovascular diseases, as demonstrated in a number of animal studies. However, few human studies have investigated sex-based differences with regard to cardiac glucose uptake using (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT).
METHODS: Therefore, we evaluated healthy male and female subjects who underwent FDG-PET/CT examination to determine whether there was a sex-related difference in cardiac glucose uptake with age.
RESULTS: In females, the prevalence of maximal FDG uptake (PET score 2) demonstrated a convex pattern with ageing, and it peaked at age 51-60 years in the females, gradually decreasing to a minimum at age >70 years. In contrast, the prevalence of maximal FDG uptake by age in males was a mirror image of that in females, i.e. it formed a concave pattern with a nadir at 61-70 years, followed by an increase in the prevalence. These findings suggest that female hearts depend more on glucose as an energy substrate as they age, however, efficient glucose uptake is attenuated with increasing age. In contrast, the male heart sustains its glucose uptake capacity at age >70 years.
CONCLUSIONS: This characteristic sex-based difference in cardiac glucose uptake might be related to the female predominance of Takotsubo cardiomyopathy.