RESUMEN
The Papillon experience and the Lyon R96-02 trial have shown that contact X-ray brachytherapy of 50kV is efficient and safe to achieve long term local control and organ preservation for cT1 and early cT2-3 rectal cancers. The OPERA trial, using the Papillon 50™ machine, brings further support to this preservation strategy for selected T2T3ab lesions. Future trials using a contact X-ray boost will try to consolidate and enlarge its place in organ preservation for rectal cancers.
Asunto(s)
Braquiterapia/métodos , Tratamientos Conservadores del Órgano/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto , Neoplasias del Recto/radioterapia , Braquiterapia/instrumentación , Braquiterapia/tendencias , Diseño de Equipo , Predicción , Humanos , Tratamientos Conservadores del Órgano/instrumentación , Tratamientos Conservadores del Órgano/tendencias , Neoplasias del Recto/patología , Factores de Tiempo , Rayos XRESUMEN
Ex vivo heart perfusion (EVHP) may facilitate resuscitation of discarded donor hearts and expand the donor pool; however, a reliable means of demonstrating organ viability prior to transplantation is required. Therefore, we sought to identify metabolic and functional parameters that predict myocardial performance during EVHP. To evaluate the parameters over a broad spectrum of organ function, we obtained hearts from 9 normal pigs and 37 donation after circulatory death pigs and perfused them ex vivo. Functional parameters obtained from a left ventricular conductance catheter, oxygen consumption, coronary vascular resistance, and lactate concentration were measured, and linear regression analyses were performed to identify which parameters best correlated with myocardial performance (cardiac index: mL·min(-1)·g(-1)). Functional parameters exhibited excellent correlation with myocardial performance and demonstrated high sensitivity and specificity for identifying hearts at risk of poor post-transplant function (ejection fraction: R(2) = 0.80, sensitivity = 1.00, specificity = 0.85; stroke work: R(2) = 0.76, sensitivity = 1.00, specificity = 0.77; minimum dP/dt: R(2) = 0.74, sensitivity = 1.00, specificity = 0.54; tau: R(2) = 0.51, sensitivity = 1.00, specificity = 0.92), whereas metabolic parameters were limited in their ability to predict myocardial performance (oxygen consumption: R(2) = 0.28; coronary vascular resistance: R(2) = 0.20; lactate concentration: R(2) = 0.02). We concluded that evaluation of functional parameters provides the best assessment of myocardial performance during EVHP, which highlights the need for an EVHP device capable of assessing the donor heart in a physiologic working mode.