Adopting Advanced Radiotherapy Techniques in the Treatment of Paediatric Extracranial Malignancies: Challenges and Future Directions.

Geometric uncertainties in radiotherapy are conventionally addressed by defining a safety margin around the radiotherapy target. Misappropriation of such margins could result in disease recurrence from geometric miss or unnecessary irradiation of normal tissue. Numerous quantitative organ motion studies in adults have been published, but the first paediatric-specific studies were only published in recent years. In the very near future, intensity-modulated proton beam therapy and magnetic resonance-guided radiotherapy will be clinically implemented in the UK. Such techniques offer the ability to deliver radiotherapy to the pinnacle of precision and accuracy, if geometric uncertainty relating to internal organ motion and deformation can be optimally managed. The optimal margin to account for internal organ motion in children remains largely undefined. Continuing efforts to characterise motion in children and young people is necessary to optimally define safety margins and to realise the full potential of intensity-modulated radiotherapy, magnetic resonance-guided radiotherapy and intensity-modulated proton beam therapy. This overview offers a timely review of published reports on paediatric organ motion, in anticipation of the increasing application of advanced radiotherapy techniques in paediatric radiotherapy.

Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF(©)).

OBJECTIVE: Caffeine has been shown to have effects on certain areas of cognition, but in executive functioning the research is limited and also inconsistent. One reason could be the need for a more sensitive measure to detect the effects of caffeine on executive function. This study used a new non-immersive virtual reality assessment of executive functions known as JEF(©) (the Jansari Assessment of Executive Function) alongside the 'classic' Stroop Colour-Word task to assess the effects of a normal dose of caffeinated coffee on executive function. METHOD: Using a double-blind, counterbalanced within participants procedure 43 participants were administered either a caffeinated or decaffeinated coffee and completed the 'JEF(©)' and Stroop tasks, as well as a subjective mood scale and blood pressure pre- and post condition on two separate occasions a week apart. JEF(©) yields measures for eight separate aspects of executive functions, in addition to a total average score. RESULTS: Findings indicate that performance was significantly improved on the planning, creative thinking, event-, time- and action-based prospective memory, as well as total JEF(©) score following caffeinated coffee relative to the decaffeinated coffee. The caffeinated beverage significantly decreased reaction times on the Stroop task, but there was no effect on Stroop interference. CONCLUSION: The results provide further support for the effects of a caffeinated beverage on cognitive functioning. In particular, it has demonstrated the ability of JEF(©) to detect the effects of caffeine across a number of executive functioning constructs, which weren't shown in the Stroop task, suggesting executive functioning improvements as a result of a 'typical' dose of caffeine may only be detected by the use of more real-world, ecologically valid tasks.