SBRT and extreme hypofractionation: A new era in prostate cancer treatments?

AimRadiation therapy (RT) is a standard therapeutic option for prostate cancer (PC). In the last decades, several innovative technology applications have been introduced. 3-Dimensional conformal RT, volumetric/rotational intensity modulated RT associated or not with image-guided RT, are becoming largely diffused in the treatment of PC.BackgroundConsidering that PC could have a low α/β ratio, similar to late-reacting normal tissues, it could also be highly responsive to fraction size. Thus, the reduction of the number of fractions and the increase of the dose/fraction seem to be reasonable choices in the treatment of this cancer. This review reported the technology evolution, the radiobiological and the clinical data about the role of extreme hypofractionated RT in the treatment approach of PC patients.Materials and methodsMedline search and analysis of published studies containing key words: prostate cancer, radiotherapy, stereotactic radiotherapy.ResultsRecent technological developments, combined with an improved knowledge of the radiobiological models in favor of a high sensitivity of PC to larger fraction sizes are opening a new scenario in its treatment, reporting favorable efficacy and acceptable toxicity, despite short follow-up.ConclusionThus, thanks to technological improvement and the recent radiobiological data, “extreme hypofractionated RT” has been strongly introduced in the last years as a potential solid treatment option for PC.     

Past and future climate-driven shifts in the distribution of a warm-adapted bird species,the European Roller Coracias garrulus

ABSTRACT

Capsule: The distribution range of the European Roller Coracias garrulus has undergone large changes over geological times, but although the species is warm-adapted, the human induced climate change is predicted to affect negatively the range of the currently large populations.

Aim: Information on species-specific vulnerability to climate change is crucial not only for designing interventions and setting conservation goals, but also to inform conservation decision-making. Our goal was to map climate suitability for the European Roller in the Western Palaearctic under current climate, and for past (last glacial maximum and mid-Holocene) and future (2050 and 2070) climate scenarios.

Methods: We used MaxEnt for species distribution modelling based on the reconstructed distribution map of the species.

Results: Our results suggest that during glacial periods Rollers persisted in small southern refugia, and then spread and colonized northern latitudes during the mid-Holocene. In the future, our models forecast a shift in climatically suitable range towards northern latitudes and an overall small range contraction (4.5–5.5%). Warmer temperatures will increase climate suitability in northern countries where the species is currently declining or became locally extinct. On the other hand, wide suitable areas under current climatic conditions are predicted to become unsuitable in the future (35–38% by 2050 and 2070, respectively), significantly impacting large populations such as those in Romania, Spain, Bulgaria and Hungary. French and Italian populations are identified to be future key populations for Roller conservation.

Conclusions: Our findings suggest that future climate changes will likely amplify the impacts of existing threats on the majority of large European Roller populations in Europe.     

Radioimmunoassay of prostaglandins A and B in human blood

A highly sensitive radioimmunoassay for the measurement of plasma prostaglandins A and B, expressed in equivalents of PGA₁, is described. This method was used for the measurement of prostaglandins A and B (PGA/B) in 23 healthy volunteers and 25 hypertensive patients.The PGA/B concentration in peripheral venous plasma of 23 healthy normotensive subjects is 115 ± 15 pg/ml. The repeated measurement of the same plasma samples kept frozen for 60 days at ?20°C shows mean 194% increase of PGA/B concentration.The major site of synthesis of PGA/B seems to be the kidney. However in two patients PGA/B concentration in arterial blood was greater than in venous blood suggesting the possibility of cardio-pulmonary synthesis. The major site of inactivation is the hepatic circulation, as PGA/B concentration in hepatal venous blood is by 30% lower than in vena caval blood.The arterial concentration is 3% lower than venous PGA/B demonstrating very low pulmonary inactivation. Therefore the prostaglandins of the A and B series may represent a “circulating hormone”.The plasmatic PGA/B is significantly increased in renovascular and essential hypertension.