Limited role for surveillance PET-CT scanning in patients with diffuse large B-cell lymphoma in complete metabolic remission following primary therapy

Background:

The usefulness of positron emission tomography with computed tomography (PET–CT) in the surveillance of patients with diffuse large B-cell lymphoma (DLBCL) in complete metabolic remission after primary therapy is not well studied.

Methods:

We performed a retrospective review of our database between 2002 and 2009 for patients with de novo DLBCL who underwent surveillance PET–CT after achieving complete metabolic response (CMR) following primary therapy.

Results:

Four-hundred and fifty scans were performed in 116 patients, with a median follow-up of 53 (range 8–133) months from completion of therapy. Thirteen patients (11%) relapsed: seven were suspected clinically and six were subclinical (all within first 18 months). The positive predictive value in patients with international prognostic index (IPI) <3 was 56% compared with 80% in patients with IPI⩾3. Including indeterminate scans, PET–CT retained high sensitivity 95% and specificity 97% for relapse.

Conclusion:

Positron emission tomography with computed tomography is not useful in patients for the majority of patients with diffuse large B-cell lymphoma in CMR after primary therapy, with the possible exception of patients with baseline IPI ⩾3 in the 18 months following completion of primary therapy. This issue could be addressed by a prospective clinical trial.

A comparison of fat mass and skeletal muscle mass estimation in male ultra-endurance athletes using bioelectrical impedance analysis and different anthropometric methods

Two hundred and fifty seven male Caucasian ultra-endurance athletes were recruited, pre-race, before different swimming, cycling, running and triathlon races. Fat mass and skeletal muscle mass were estimated using bioelectrical impedance analysis (BIA) and anthropometric methods in order to investigate whether the use of BIA or anthropometry would be useful under field conditions. Total body fat estimated using BIA was significantly high (P < 0.001) compared with anthropometry. When the results between BIA and anthropometry were compared, moderate to low levels of agreement were found. These results were in accordance with the differences found in the Bland-Altman analysis, indicating that the anthropometric equation of Ball et al. had the highest level of agreement (Bias = -3.0 ± 5.8 kg) with BIA, using Stewart et al. (Bias = -6.4 ± 6.3 kg), Faulkner (Bias = -4.7 ± 5.8 kg) and Wilmore-Siri (Bias = -4.8 ± 6.2 kg). The estimation of skeletal muscle mass using BIA was significantly (P < 0.001) above compared with anthropometry. The results of the ICC and Bland-Altman method showed that the anthropometric equation from Lee et al. (Bias = -5.4 ± 5.3 kg) produced the highest level of agreement. The combined method of Janssen et al. between anthropometry and BIA showed a lower level of agreement (Bias = -12.5 ± 5.7 kg). There was a statistically significant difference between the results derived from the equation of Lee et al. and Janssen et al. (P < 0.001). To summarise, the determination of body composition in ultra-endurance athletes using BIA reported significantly high values of fat and skeletal muscle mass when compared with anthropometric equations.

Minimising critical organ irradiation in limited stage Hodgkin lymphoma: a dosimetric study of the benefit of involved node radiotherapy

BACKGROUND

Chemotherapy plus radiotherapy is the standard of care for patients with limited stage Hodgkin lymphoma (HL). Radiotherapy is evolving from involved field radiotherapy (IFRT) to involved node radiotherapy (INRT) to decrease radiotherapy-related morbidity. In the absence of long-term toxicity data, dose-volume metrics of organs at risk (OAR) provide a surrogate measure of toxicity risk.

PATIENTS AND METHODS

Ten female patients with stage I-IIA supradiaphragmatic HL were randomly selected. All patients had pre-chemotherapy computerised tomography (CT) and CT-positron emission tomography staging. Using CT planning, three radiotherapy plans were produced per patient: (i) IFRT, (ii) INRT using parallel-opposed beams and (iii) INRT using volumetric modulated arc therapy (VMAT). Radiotherapy dose was 30.6 Gy in 1.8 Gy fractions. OAR evaluated were lungs, breasts, thyroid, heart and coronary arteries.

RESULTS

Compared with IFRT, INRT significantly reduced mean doses to lungs (P < 0.01), breasts (P < 0.01), thyroid (P < 0.01) and heart (P < 0.01), on Wilcoxon testing. Compared with conventional INRT, VMAT improved dose conformality but increased low-dose radiation exposure to lungs and breasts. VMAT reduced the heart volume receiving 30 Gy (V30) by 85%.

CONCLUSIONS

Reduction from IFRT to INRT decreased the volumes of lungs, breasts and thyroid receiving high-dose radiation, suggesting the potential to reduce long-term second malignancy risks. VMAT may be useful for patients with pre-existing heart disease by minimising further cardiac toxicity risks.

[Anti-diabetic drugs. Weight reduction as a favourable side effect]

The increasing prevalence of type 2 diabetes mellitus in the last years is mainly attributable to an increase in life expectancy and the high incidence of obesity. Nearly 90% of all type 2 diabetic patients in Germany are overweight or obese. The attributable risk of obesity in the development of type 2 diabetes mellitus is approximately 70%. Oral anti-diabetic drugs like sulfonylurea, glinides, and glitazones as well as insulin increase body weight within years by up to 8 kg with damaging side effects on cardiovascular organs. Dipeptidylpeptidase 4 (DPP-4) inhibitors do not affect body weight and metformin as well as glucagon like peptid 1 (GLP-1) receptor agonists decrease it. A reduction in body weight by changes in life style is effective but only a few overweight patients achieve the therapeutic goals. By using anti-diabetic drugs as monotherapy or in combination with other anti-diabetic compounds body weight, glycemic control and other cardiovascular risk factors may be influenced favorably.

Experimental and finite element analysis of the mouse caudal vertebrae loading model: prediction of cortical and trabecular bone adaptation

In this study, we attempt to predict cortical and trabecular bone adaptation in the mouse caudal vertebrae loading model using knowledge of bone's local mechanical environment at the onset of loading. In a previous study, we demonstrated appreciable 25.9 and 11% increases in both trabecular and cortical bone volume density, respectively, when subjecting the fifth caudal vertebrae (C5) of C57BL/6 (B6) mice to an acute loading regime (amplitude of 8N, 3000 cycles, 10 Hz, 3 times a week for 4 weeks). We have also established a validated finite element (FE) model of the C5 vertebra using micro-computed tomography (micro-CT), which characterizes, in 3D, the micro-mechanical strains present in both cortical and trabecular compartments due to the applied loads. To investigate the relationship between load-induced bone adaptation and mechanical strains in-vivo and in-silico data sets were compared. Using data from the previous cross-sectional study, we divided cortical and trabecular compartments into 15 subregions and determined, for each region, a bone formation parameter ΔBV/BS (a cross-sectional measure of the bone volume added to cortical and trabecular surfaces following the described loading regime). Linear regression was then used to correlate mean regional values of ΔBV/BS with mean values of mechanical strains derived from the FE models which were similarly regionalized. The mechanical parameters investigated were strain energy density (SED), the orthogonal strains (e (x), e (y), e (z)) and the three shear strains (e (xy), e (yz), e (zx)). For cortical regions, regression analysis showed SED to correlate extremely well with ΔBV/BS (R (2) = 0.82) and e (z) (R (2) = 0.89). Furthermore, SED was found to predict expansion of the cortical shell correlating significantly with the regional percentage increases in cortical tissue volume (R (2) = 0.92), cortical marrow volume (R (2) = 0.91) and cortical thickness (R (2) = 0.56). For trabecular regions, FE parameters were found not to correlate with load-induced trabecular bone morphology. These results indicate that load-induced cortical morphology can be predicted from population data, whereas the prediction of trabecular morphology requires subject-specific micro- architecture.

Comparable short-term prognosis in diabetic and non-diabetic patients with acute coronary syndrome after cardiac rehabilitation

BACKGROUND

Patients with pathological glucometabolism are at increased risk of recurrent cardiovascular events after acute coronary syndrome (ACS). The goal of this study was to investigate the association of glucometabolism and the one-year outcome of cardiac rehabilitation patients.

DESIGN

Prospective multicentre registry from four German rehabilitation clinics.

METHODS

During 2005-2006, 1614 consecutive patients (85.9% male, mean age 55 ± 10.3 years) were included after the first ACS (mean 18.9 days) and classified into group 1 (apparent diabetes mellitus, n = 268), group 2 (no diabetes, impaired oral glucose tolerance [OGT], n = 185), and group 3 (normal fasting glucose and normal OGT, n = 1161). The mean follow-up was 13.4 months and the follow-up events were analysed by multivariate logistic regression models with backward elimination.

RESULTS

The overall mortality was 1.3% (group 1: 1.2%; group 2: 1.8%; group 3: 1.5%; p(Trend) = NS). The target blood pressure values at discharge (<140/90 mmHg) were achieved by 88.7%, 89.1% and 90.8% of patients in groups 1, 2 and 3, respectively (p(Trend) = NS). The target value for LDL cholesterol (<100 mg/dl) was attained by 87.0%, 80.8% and 81.5% of the patients in groups 1, 2 and 3, respectively (p(Trend) = NS). There was a trend of a lower proportion of patients reaching the target values for HDL-C of 46.1%, 51.4% and 60.8% (p(Trend) < 0.001) and triglycerides of 65.1%, 79.9% and 74.6% (p(Trend) = 0.004) for groups 1, 2 and 3, respectively. The strongest multivariate predictors for overall mortality were patients experiencing a previous stroke (OR, 6.29 [95% CI: 1.06-37.19]; p = 0.042) and, with a trend, peripheral arterial disease (OR, 3.60 [95% CI: 0.95-13.68]; p = 0.061). In the multivariate analysis, the diabetic state had no association with poor outcomes (i.e. death or rehospitalization).

CONCLUSION

The short-term prognosis for both diabetic and non-diabetic patients was good and was determined by end organ damage rather than by glucometabolic status. Diabetic patients received comparable (and not more aggressive) pharmacotherapy and therefore achieved target values for cardiovascular risk factors to a lesser extent than the non-diabetic and pre-diabetic patients.

Attosecond control of electron dynamics in carbon monoxide

Laser pulses with stable electric field waveforms establish the opportunity to achieve coherent control on attosecond time scales. We present experimental and theoretical results on the steering of electronic motion in a multielectron system. A very high degree of light-waveform control over the directional emission of C(+) and O(+) fragments from the dissociative ionization of CO was observed. Ab initio based model calculations reveal contributions to the control related to the ionization and laser-induced population transfer between excited electronic states of CO(+) during dissociation.