Correlation of Brown Adipose Tissue with Other Body Fat Compartments and Patient Characteristics

Publication date: Available online 3 November 2017
Source:Academic Radiology
Author(s): Cornelia Brendle, Matthias K. Werner, Maria Schmadl, Christian la Fougère, Konstantin Nikolaou, Norbert Stefan, Christina Pfannenberg
Rationale and ObjectivesThe objective of this study was to assess the relationship of brown adipose tissue (BAT) activity with different fat compartments of the body, body mass index (BMI), outdoor temperature, thyroid-stimulating hormone (TSH) levels, blood glucose, age, and sex in a large patient population using F-18-fluordesoxyglucose positron emission tomography-computer tomography (FDG-PET/CT) scans obtained under thermoneutral conditions.Materials and MethodsFDG-PET/CT scans of 4852 patients were retrospectively analyzed for BAT activity. The volumes of the different fat compartments visceral adipose tissue (VAT), subcutaneous adipose tissue (SCAT), and liver fat, were assessed by computed tomography. Age, sex, TSH levels, blood glucose levels, BMI, primary disease, and the outdoor temperature were determined. Multiple linear regression analyses were performed to identify independent relationships between the parameters.ResultsThe VAT, SCAT, and liver fat content were lower in BAT-positive patients than in BAT-negative patients (each P < 0.0001). BAT-positive patients had a lower BMI (P < 0.0001) and were more often female (P < 0.0001), younger (P < 0.0001), and had higher TSH levels (P = 0.0002), whereas the outdoor temperature and the blood glucose level were not different compared to BAT-negative patients. Age, sex, VAT, and SCAT were independent factors related to BAT.ConclusionsAge, sex, and VAT are the most important determinants of BAT activity under thermoneutral conditions. VAT reflects the association between BAT activity and body fat mass more clearly than BMI. The strength of the association between VAT and BAT decreases during aging in men, but increases in women. This may indicate a different importance of BAT activity for obesity in men and in women.



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Physician Specialty and Radiologist Characteristics Associated with Higher Medicare Patient Complexity

Publication date: Available online 3 November 2017
Source:Academic Radiology
Author(s): Andrew B. Rosenkrantz, Wenyi Wang, Arvind Vijayasarathi, Richard Duszak
Rationale and ObjectivesMeaningfully measuring physician outcomes and resource utilization requires appropriate patient risk adjustment. We aimed to assess Medicare patient complexity by physician specialty and to further identify radiologist characteristics associated with higher patient complexity.Materials and MethodsThe average beneficiary Hierarchical Condition Category (HCC) risk scores (Medicare's preferred measure of clinical complexity) were identified for all physicians using 2014 Medicare claims data. HCC scores were compared among physician specialties and further stratified for radiologists based on a range of characteristics. Univariable and multivariable analyses were performed.ResultsOf 549,194 physicians across 54 specialties, the mean HCC risk score was 1.62 ± 0.75. Of the 54 specialties, interventional radiology ranked 4th (2.60 ± 1.29), nuclear medicine ranked 16th (1.87 ± 0.45), and diagnostic radiology ranked 21st (1.75 ± 0.61). Among 31,175 radiologists, risk scores were higher (P < 0.001) for those with teaching (2.03 ± 0.74) vs nonteaching affiliations (1.72 ± 0.61), practice size ≥100 (1.94 ± 0.70) vs ≤9 (1.59 ± 0.79) members, urban (1.79 ± 0.69) vs rural (1.67 ± 0.59) practices, and subspecialized (1.85 ± 0.81) vs generalized (1.68 ± 0.42) practice patterns. Among noninterventional radiology subspecialties, patient complexity was highest for cardiothoracic (2.09 ± 0.57) and lowest for breast (1.08 ± 0.32) imagers. At multivariable analysis, a teaching affiliation was the strongest independent predictor of patient complexity for both interventional (β = +0.23, P = 0.005) and noninterventional radiologists (β = +0.21, P < 0.001).ConclusionsRadiologists on average serve more clinically complex Medicare patients than most physicians nationally. However, patient complexity varies considerably among radiologists and is particularly high for those with teaching affiliations and interventional radiologists. With patient complexity increasingly recognized as a central predictor of clinical outcomes and resource utilization, ongoing insights into complexity measures may assist radiologists navigating emerging risk-based payment models.



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Integrated 18 F-FDG PET/MRI in breast cancer: early prediction of response to neoadjuvant chemotherapy

Abstract

Purpose

To explore whether integrated ¹⁸F-FDG PET/MRI can be used to predict pathological response to neoadjuvant chemotherapy (NAC) in patients with breast cancer.

Methods

Between November 2014 and April 2016, 26 patients with breast cancer who had received NAC and subsequent surgery were prospectively enrolled. Each patient underwent ¹⁸F-FDG PET/MRI examination before and after the first cycle of NAC. Qualitative MRI parameters, including morphological descriptors and the presence of peritumoral oedema were assessed. Quantitatively, PET parameters, including maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis (TLG), and MRI parameters, including washout proportion and signal enhancement ratio (SER), were measured. The performance of the imaging parameters singly and in combination in predicting a pathological incomplete response (non-pCR) was assessed.

Results

Of the 26 patients, 7 (26.9%) exhibited a pathological complete response (pCR), and 19 (73.1%) exhibited a non-pCR. No significant differences were found between the pCR and non-pCR groups in the qualitative MRI parameters. The mean percentage reductions in TLG_30% on PET and SER on MRI were significantly greater in the pCR group than in the non-pCR group (TLG_30% −64.8 ± 15.5% vs. −25.4 ± 48.7%, P = 0.005; SER −34.6 ± 19.7% vs. −8.7 ± 29.0%, P = 0.040). The area under the receiver operating characteristic curve for the percentage change in TLG_30% (0.789, 95% CI 0.614 to 0.965) was similar to that for the percentage change in SER (0.789, 95% CI 0.552 to 1.000; P = 1.000).The specificity of TLG_30% in predicting pCR) was 100% (7/7) and that of SER was 71.4% (5/7). The sensitivity of TLG_30% in predicting non-pCR was 63.2% (12/19) and that of SER was 84.2% (16/19). When the combined TLG_30% and SER criterion was applied, sensitivity was 100% (19/19), and specificity was 71.4% (5/7).

Conclusion

¹⁸F-FDG PET/MRI can be used to predict non-pCR after the first cycle of NAC in patients with breast cancer and has the potential to improve sensitivity by the addition of MRI parameters to the PET parameters.

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EANM Springer Prizes awarded at EANM’ 17 Vienna

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68 Ga-PSMA-11 PET/CT in primary staging of prostate carcinoma: preliminary results on differences between black and white South-Africans

Abstract

Purpose

The incidence of prostate cancer is 60% higher and the mortality rate is two- to three-times greater in black versus white men. We report on differences in ⁶⁸Ga-PSMA-11 PET/CT imaging findings in 77 black South-African (BSAs) and 18 white South-African (WSAs) treatment-naïve primary prostate carcinoma (PPC) patients.

Methods

⁶⁸Ga-PSMA-11 PET/CT imaging findings were compared to histological, biochemical and morphological imaging data. Patients were grouped into three Gleason grade groups (GG), GG 1 (scores 3 + 3 and 3 + 4), GG2 (scores 4 + 3 and 4 + 4) and GG3 (scores 9 and 10), and the PSA difference among the groups was determined. Inter-racial difference in SUVmax of the primary tumor as well as its correlation with serum PSA were also determined.

Results

Ninety-three out of 95 PPC where readily identified on ⁶⁸Ga-PSMA-11 PET/CT imaging. Median PPC SUVmax and serum PSA values proved significantly higher (p = 0.033 and p = 0.003) in GG3 patients (median 16.4 and 180 ng/ml) when compared to GG1 patients (median 9.6 and 25.1 ng/ml) or GG2 patients (median 8.8 and 46.2 ng/ml). SUVmax significantly correlated with serum PSA-values (r = 0.377 (p = 0.0001)). Age, frequency of lymph node involvement and distant metastases, and GGs (p ≥ 0.153) were similar in BSAs and WSAs, both median serum PSA-values as well as SUVmax values proved significantly higher in BSAs when compared to WSAs, respectively, 81.6 ng/ml versus 14.5 ng/ml (p = 0.0001) and 11.9 versus 4.38 (p = 0.004). Moreover, Gleason-score normalized median SUVmax values proved 2.5 times higher in BSAs when compared to WSAs (p = 0.005).

Conclusion

SUVmax values proved significantly related to GG and to be significantly higher in BSAs when compared to WSAs. Also, SUVmax significantly correlated with serum PSA values, which was significantly higher in BSAs when compared with WSAs.

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Impact of dose intensified salvage radiation therapy on urinary continence recovery after radical prostatectomy: Results of the randomized trial SAKK 09/10

Adjuvant radiation therapy (aRT) after radical prostatectomy (RP) is associated with impaired urinary continence recovery as compared to surveillance. Less is known regarding the effect of salvage radiation therapy (sRT) dose intensification on continence outcomes.

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Whole-body total lesion glycolysis is an independent predictor in patients with esophageal cancer treated with definitive chemoradiotherapy

To determine whether pretreatment whole-body total lesion glycolysis (TLGWB) and metabolic tumor volume (MTVWB) are associated with outcomes in patients with esophageal cancer treated with definitive chemoradiotherapy (dCRT).

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