Effects of gas-filled temporary breast tissue expanders on radiation dose from modulated rotational photon beams

Gas-filled temporary tissue expanders (TTEs), implanted to assist in post mastectomy breast reconstructions, are expected to produce increased dosimetric uncertainty in breast radiotherapy treatments, due to their containing both a substantial metallic component and a comparatively large volume of gas. This study therefore builds on previous investigations of the dosimetric effects of gas-filled TTEs in static photon and electron beams, by examining the effects of these implants on dose distributions from common modulated rotational treatment techniques; volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT). Radiochromic film measurements were used to evaluate the accuracy of VMAT and HT dose calculations, for a humanoid phantom augmented with a sample Aeroform CO₂-filled TTE (AirXpanders Inc, San Jose, USA) as well as purpose-designed and 3D printed “breast tissue.” Results showed that the TomoTherapy Hi-Art VoLO convolution-superposition algorithm (Accuray Inc, Sunnyvale, USA) produced comparatively accurate calculations of treatment dose within this complex phantom, including immediately anterior and posterior to the TTE. The Varian Eclipse Acuros (AXB) algorithm generally showed better agreement with the film measurement than the Varian Eclipse AAA algorithm (Varian Medical Systems, Palo Alto, USA), although the film measurements showed regions of 5% to 10% disagreement with both AAA and AXB in the dosimetrically-challenging region on the anterior side of the implant. Although the Aeroform CO₂-filled TTE has substantial and obvious effects on the downstream dose from a static photon beam, the results of this study showed how inverse-planning of modulated rotational radiotherapy treatments can produce modulated fluence distributions that compensate for the dramatic density heterogeneities in the implant. Despite some disagreements with the planned dose, all film measurements showed that the use of inverse-planned modulated rotational photon beams resulted in comparatively homogeneous coverage of the radiotherapy target, in the complex patient-like phantom with a gas-filled TTE. Due to the importance of matching each planned fluence distribution to the density distribution within each TTE, careful use of available 3D imaging techniques is advisable, when modulated rotational radiotherapy treatments are delivered to patients with gas-filled TTEs.     

Linear β-amino alcohol catalyst anchored on functionalized magnetite nanoparticles for enantioselective addition of dialkylzinc to aromatic aldehydes

A linear β-amino alcohol ligand, previously found to be a very efficient catalyst for enantioselective addition of dialkylzinc to aromatic aldehydes, has been anchored on differently functionalized superparamagnetic core–shell magnetite–silica nanoparticles (1a and 1b). Its catalytic activity in the addition of dialkylzinc to aldehydes has been evaluated, leading to promising results, especially in the case of 1b for which the recovery by simple magnetic decantation and reuse was successfully verified.

The catalytic activity of a linear β-amino alcohol ligand anchored on functionalized magnetite/silica core–shell nanoparticles has been evaluated in the addition of dialkylzinc to aldehydes leading to promising results.     

A 13-year follow-up of Finnish patients with Salla disease

Background

Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.

Methods

Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16–65 years, 13 years after a similar examination.

Results

The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.

Conclusions

Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development.     

Inferior vena cava collapsibility loses correlation with internal jugular vein collapsibility during increased thoracic or intra-abdominal pressure

Purpose

Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJV) measurements to estimate intravascular volume status. The reliability of the IVC and IJV collapsibility index during increased thoracic or intra-abdominal pressure remains unclear.

Methods

Three phases of sonographic scanning were performed: spontaneous breathing phase, increased thoracic pressure phase via positive pressure ventilation (PPV) phase, and increased intra-abdominal pressure (IAP) phase via laparoscopic insufflation to 15 mmHg. IVC measurements were done at 1–2 cm below the diaphragm and IJV measurements were done at the level of the cricoid cartilage during a complete respiratory cycle. Collapsibility index was calculated by (max diameter − min diameter)/max diameter × 100 %. Chi square, t test, correlation procedure (CORR) and Fisher’s exact analyses were completed.

Results

A total of 144 scans of the IVC and IJV were completed in 16 patients who underwent laparoscopic surgery. Mean age was 46 ± 15 years, with 75 % female and 69 % African-American. IVC and IJV collapsibility correlated in the setting of spontaneous breathing (r² = 0.86, p < 0.01). IVC collapsibility had no correlation with the IJV in the setting of PPV (r² = 0.21, p = 0.52) or IAP (r² = 0.26, p = 0.42). Maximal IVC diameter was significantly smaller during increased IAP (16.5 mm ± 4.9) compared to spontaneous breathing (20.6 mm ± 4.8, p = 0.04) and PPV (21.8 mm ± 5.6, p = 0.01).

Conclusion

IJV and IVC collapsibility correlated during spontaneous breathing but there was no statistically significant correlation during increased thoracic or intra-abdominal pressure. Increased intra-abdominal pressure was associated with a significant smaller maximal IVC diameter and cautions the reliability of IVC diameter in clinical settings that are associated with intra-abdominal hypertension or abdominal compartment syndrome.     

Objectively-measured and self-reported physical activity and fitness in relation to inflammatory markers in European adolescents: the HELENA Study

ObjectiveAtherogenesis involves an inflammatory process that occurs early in life even though clinical symptoms are not observed until adulthood. Two important protective factors for low-grade inflammation may be physical activity (PA) and fitness. We examined the independent associations of objective and subjective measurements of PA and fitness with low-grade inflammation in European adolescents.MethodsA total of 1045 adolescents, aged from 12.5 to 17.5 years old from 10 European cities, were selected from the HELENA-Cross-Sectional Study. Objectively-measured and self-reported PA variables were obtained by accelerometry and the International PA Questionnaire for Adolescents, respectively. Overall, cardiorespiratory, muscular and motor fitness variables were assessed by standardized field-based fitness tests and the International Fitness Scale. C-reactive protein (CRP), complement factors 3 (C3) and 4 (C4), interleukin-6 and TNF-α inflammatory markers were measured.ResultsObjectively-measured vigorous PA was inversely associated with C3 (β = ?0.094, P = 0.021) but it did not remain significant after any objective fitness indicator was included in the model. Other objectively measured or self-reported assessments of PA were not significantly associated with inflammatory markers. All objective measures of fitness were inversely associated with CRP, C3 and C4, whereas only self-reported motor fitness remained significantly associated with C3, C4 and TNF-α. All these observations were independent of age, sex, city and body mass index or waist circumference.ConclusionHigh PA in adolescence may play an indirect role on lessening low-grade inflammation through improvements in fitness.