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It is an exciting time for big data efforts in radiation oncology. The use of big data to help aid both outcomes and decision‐making research is becoming a reality. However, there are true challenges that exist in the space of gathering and utilizing performance and outcomes data. Here, we summarize the current state of big data in radiation oncology with respect to outcomes and discuss some of the efforts and challenges in radiation oncology big data.

Significant hemostatic abnormalities can occur during orthotopic liver transplantation (OLT). This study addressed three goals: 1)evaluation of the hemostatic mechanism at each stage of the OLT; 2) the relationship of the coagulation process with the thrombelastograph (TEG); and 3) comparison of results in patients requiring retransplantation or who died, with the overall pattern. To evaluate hemostasis during 50 consecutive OLTs, a detailed coagulation and TEG study was done. The surgical procedure was divided into the following stages: Stage I--induction of anesthesia to occlusion of blood flow to the patient’ s diseased liver; Stage II—occlusion of blood flow to the patient’ s diseased liver to reperfusion of the patient’ s new liver; and Stage III—reperfusion of the new liver until skin closure. 28 ml of arterial blood were sampled at the beginning and end of each stage and up to five days posttransplantation for the following: platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, prothrombin, factors V, VII, IX, and X, plasminogen, antiplasmin, antithrombin III (functional and immunologic), fibrinolytic split products, and TEG. The patient’ s core temperature and amount of blood products transfused were obtained intraoperatively during each of the six data times. The ischemia time of the donor liver was recorded. Significant hemostatic abnormalities developed during each of the 50 OLTs, especially during reperfusion of the donor liver. In some instances, this was corrected within one hour, but platelet counts continued to fall, and a number of coagulation factors rebounded only partially. The TEG values correlated with laboratory data and blood loss, but the correlations were not strong. The patient’ s requirement for red cells varied with the operative drop in temperature; however, the donor liver ischemia time and length of Stage II made no significant difference. It is concluded that 1) significant deterioration of coagulation factors occurs during OLT, 2) the TEG is an effective screening test that affords prompt information, 3) aggressive measures should be taken to maintain the patient’ s body temperature at 37°C, 4) patient outcome was not predicted by intraoperative hemostatic evaluation.

Association of heparin non-covalently with bovine factor Xa was analyzed by Superose-12 gel chromatography. In 0.05 M NaCl, 0.02 M Tris, pH 7.5, DEGR-Xa (factor Xa inactivated by dans-Glu-Gly-Arg-CH2Cl) was eluted as a single, sharp peak at Ve/Vt=0-65 (elution volume/internal volume). Mixtures of heparin and DEGR-Xa were eluted as two partially resolved peaks of protein at Ve/Vt=0.59 and 0.65. The fraction of DEGFUXa in the leading peak was directly proportional to [heparin], and at 100 yM heparin the leading peak contained more than half the total protein. When 0.02 M HEPES was substituted for Tris a single, slightly broadened peak at Ve/Vt=0.64 was obtained on chromatography of 100 μM heparin and 10 μM DEGR-Xa. In a buffer system comprising 0.02 M Tris, 0.02 M HEPES, 0.03 M NaCl, pH 7.5, two peaks were eluted at Ve/Vt=0.59 and 0.65. Therefore, Tris increases the affinity of DEGR-Xa for heparin.Solutions buffered with Tris or HEPES were compared for effects on the kinetics of inhibition of factor Xa by antithrombin III-heparin. Reaction mixtures containing 1 nM factor Xa, 30 nM heparin and 600 nM antithrombin III were assayed with S-2222 at intervals of 2-10 sec. Reagent concentrations were chosen (a) to assure pseudo-first-order kinetics, (b) to have [heparin]<< Kq for factor Xa-heparin, and (c) to bind virtually all available heparin to antithrombin III. The same second-order rate constant, Kobs=2.5×107 M−1s−1, was obtained in both buffer systems. We conclude that the association of factor Xa with heparin observed directly by gel chromatography does not contribute to the reaction rate of factor Xa with antithrombin III-heparin.