The time to relapse correlates with the histopathological growth pattern in nodular lymphocyte predominant Hodgkin lymphoma

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) can present with different histopathological growth patterns. The impact of these histopathological growth patterns on relapse characteristics is unknown. We therefore analyzed paired biopsies obtained at initial diagnosis and relapse from 33 NLPHL patients who had received first-line treatment within German Hodgkin Study Group (GHSG) trial protocols, and from a second cohort of 41 relapsed NLPHL patients who had been treated outside GHSG studies. Among the 33 GHSG patients, 21 patients presented with a typical growth pattern at initial diagnosis, whereas 12 patients had a variant histology. The histopathological growth patterns at initial diagnosis and at relapse were consistent in 67% of cases. A variant histology at initial diagnosis was associated with a shorter median time to lymphoma recurrence (2.8 vs 5.2 years; P = .0219). A similar tendency towards a shorter median time to lymphoma recurrence was observed for patients presenting with a variant histology at relapse, irrespective of the growth pattern at initial diagnosis. Results obtained from the 41 NLPHL patients who had been treated outside GHSG studies were comparable (median time to lymphoma recurrence for variant histology vs typical growth pattern at initial diagnosis: 1.5 vs 7.0 years). In conclusion, the histopathological growth pattern remains consistent at relapse in the majority of NLPHL cases, and has major impact on the time of relapse.     

Appearance of hypoplastic cochleae in CT and MRI: a new subclassification

Introduction  

Hypoplastic cochleae are among the inner ear malformations more frequently encountered by radiologists; little detailed information is available on these, however. We present the first large series of hypoplastic cochleae and document imaging findings to better characterize this anomaly radiologically.     

Biodistribution and radiation dosimetry of the 18?kDa translocator protein (TSPO) radioligand [18F]FEDAA1106: a human whole-body PET study

Purpose

[¹⁸F]FEDAA1106 is a recently developed positron emission tomography (PET) radioligand for in vivo quantification of the 18?kDa translocator protein [TSPO or, as earlier called, the peripheral benzodiazepine receptor (PBR)]. TSPO imaging is expected to be useful for the clinical evaluation of neuroinflammatory diseases. The aim of this study was to provide dosimetry estimates for [¹⁸F]FEDAA1106 based on human whole-body PET measurements.

Methods

PET scans were performed for a total of 6.6?h after the injection of 183.8?±?9.1?MBq of [¹⁸F]FEDAA1106 in six healthy subjects. Regions of interest were drawn on coronal images. Estimates of the absorbed doses of radiation were calculated using the OLINDA software.

Results

Peak uptake was largest in lungs, followed by liver, small intestine, kidney, spleen and other organs. Peak values of the percent injected dose (%ID) at a time after radioligand injection were calculated for the lungs (27.1%ID at 0.2?h), liver (21.1%ID at 0.6?h), small intestine (10.4%ID at 6.3?h), kidney (4.9%ID at 1.8?h) and spleen (4.6%ID at 0.6?h). The largest absorbed dose was found in the spleen (0.12?mSv/MBq), followed by kidneys (0.094?mSv/MBq). The calculated mean effective dose was 0.036?mSv/MBq.

Conclusion

Based on the distribution and dose estimates, the estimated radiation burden of [¹⁸F]FEDAA1106 is moderately higher than that of [¹⁸F]fluorodeoxyglucose (FDG). In clinical studies, the administered activity of this radioligand ought to be adjusted in line with regional regulations. This result would be helpful for further clinical TSPO imaging studies.     

Value of a Dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions

Purpose

In this study, the potential contribution of Dixon-based MR imaging with a rapid low-resolution breath-hold sequence, which is a technique used for MR-based attenuation correction (AC) for MR/positron emission tomography (PET), was evaluated for anatomical correlation of PET-positive lesions on a 3T clinical scanner compared to low-dose CT. This technique is also used in a recently installed fully integrated whole-body MR/PET system.

Methods

Thirty-five patients routinely scheduled for oncological staging underwent ¹⁸F-fluorodeoxyglucose (FDG) PET/CT and a 2-point Dixon 3-D volumetric interpolated breath-hold examination (VIBE) T1-weighted MR sequence on the same day. Two PET data sets reconstructed using attenuation maps from low-dose CT (PET_{AC_CT}) or simulated MR-based segmentation (PET_{AC_MR}) were evaluated for focal PET-positive lesions. The certainty for the correlation with anatomical structures was judged in the low-dose CT and Dixon-based MRI on a 4-point scale (0?C3). In addition, the standardized uptake values (SUVs) for PET_{AC_CT} and PET_{AC_MR} were compared.

Results

Statistically, no significant difference could be found concerning anatomical localization for all 81 PET-positive lesions in low-dose CT compared to Dixon-based MR (mean 2.51?±?0.85 and 2.37?±?0.87, respectively; p?=?0.1909). CT tended to be superior for small lymph nodes, bone metastases and pulmonary nodules, while Dixon-based MR proved advantageous for soft tissue pathologies like head/neck tumours and liver metastases. For the PET_{AC_CT}- and PET_{AC_MR}-based SUVs (mean 6.36?±?4.47 and 6.31?±?4.52, respectively) a nearly complete concordance with a highly significant correlation was found (r?=?0.9975, p?Conclusion Dixon-based MR imaging for MR AC allows for anatomical allocation of PET-positive lesions similar to low-dose CT in conventional PET/CT. Thus, this approach appears to be useful for future MR/PET for body regions not fully covered by diagnostic MRI due to potential time constraints.     

Which patients with type 2 diabetes mellitus are perceived as ‘difficult’ by general practitioners?

AimsTo find factors that are associated with a general practitioner’s (GP’s) subjective impression of a patient being ‘difficult’ within a sample of patients with type 2 diabetes mellitus (T2DM).MethodsSecondary cross-sectional analysis of a cohort of GP patients with T2DM. GP questionnaire on clinical data and GPs’ subjective ratings of patient attributes (including ‘patient difficulty’). Patient questionnaire on sociodemographics and illness perceptions. Bivariate and multivariate analyses, adjusted for cluster-effect of GP practice.ResultsData from 314 patients from 49 GPs could be analysed. Independent associations with higher GP-rated difficulty were found for (odds ratio; 95% confidence interval): male patients from male GPs (1.27; 1.06–1.53), unmarried men (1.25; 1.04–1.51), men with non-German nationality (1.80; 1.24–2.61), patients perceiving more problems with diabetes (1.17; 1.04–1.30), patients with higher BMI (1.01; 1.00–1.02) and HbA1c values (1.06; 1.02–1.10), patients being perceived by the GP as less adherent (1.34; 1.22–1.46) and less health-literate (1.19; 1.04–1.35).ConclusionsThe impact of patients’ gender and illness perception yield new insights into GP-perceived complexity of care. Culturally and gender-sensitive communication techniques for adapting health care goals to patients’ problems (rather than norm values) may alleviate GPs’ work.     

Optimism bias leads to inconclusive results-an empirical study

Objective

Optimism bias refers to unwarranted belief in the efficacy of new therapies. We assessed the impact of optimism bias on a proportion of trials that did not answer their research question successfully and explored whether poor accrual or optimism bias is responsible for inconclusive results.

Study Design

Systematic review.

Setting

Retrospective analysis of a consecutive-series phase III randomized controlled trials (RCTs) performed under the aegis of National Cancer Institute Cooperative groups.

Results

Three hundred fifty-nine trials (374 comparisons) enrolling 150,232 patients were analyzed. Seventy percent (262 of 374) of the trials generated conclusive results according to the statistical criteria. Investigators made definitive statements related to the treatment preference in 73% (273 of 374) of studies. Investigators’ judgments and statistical inferences were concordant in 75% (279 of 374) of trials. Investigators consistently overestimated their expected treatment effects but to a significantly larger extent for inconclusive trials. The median ratio of expected and observed hazard ratio or odds ratio was 1.34 (range: 0.19-15.40) in conclusive trials compared with 1.86 (range: 1.09-12.00) in inconclusive studies (P < 0.0001). Only 17% of the trials had treatment effects that matched original researchers’ expectations.

Conclusion

Formal statistical inference is sufficient to answer the research question in 75% of RCTs. The answers to the other 25% depend mostly on subjective judgments, which at times are in conflict with statistical inference. Optimism bias significantly contributes to inconclusive results.