Within artificial intelligence, machine learning (ML) efforts in radiation oncology have augmented the transition from generalized to personalized treatment delivery. Although their impact on quality and safety of radiation therapy has been limited, they are increasingly being used throughout radiation therapy workflows. Various data-driven approaches have been used for outcome prediction, CT simulation, clinical decision support, knowledge-based planning, adaptive radiation therapy, plan validation, machine quality assurance, and process quality assurance; however, there are many challenges that need to be addressed with the creation and usage of ML algorithms as well as the interpretation and dissemination of findings. In this review, the authors present current applications of ML in radiation oncology quality and safety initiatives, discuss challenges faced by the radiation oncology community, and suggest future directions. 相似文献
In open chest dogs, studies were made of the effects of intravenous trinitroglycerin (10 micrograms/kg per min) on circumflex arterial coronary blood flow, coronary vascular resistance, systemic arterial pressure and myocardial prostaglandin E production before and after indomethacin (n = 9) or indomethacin vehicle (n = 5). During a 30 minute trinitroglycerin infusion, coronary sinus prostaglandin E concentration increased significantly (approximately +41 percent, p less than 0.01) without significant changes in left atrial prostaglandin E concentration. After indomethacin (5 mg/kg), but not indomethacin vehicle alone, a second trinitroglycerin infusion (10 micrograms/kg per min) produced a significantly smaller decrease in coronary vascular resistance (p less than 0.05) and systemic blood pressure (p less than 0.01) and no increase in coronary sinus prostaglandin E (p less than 0.001) by comparison with control values. The heart rate response to trinitroglycerin was significantly greater (p less than 0.05) after than before indomethacin. This study suggests that the mechanism of action of trinitroglycerin may be at least partially mediated through the prostaglandin system. 相似文献
The clinical effectiveness of flecainide acetate was evaluated in 36 patients (29 male and 7 female, average age 56 years) in whom therapy with previous antiarrhythmic agents had failed. All patients had documented ventricular tachycardia on Holter electrocardiographic recording and 31 of 36 (86%) had had syncope or required cardiopulmonary resuscitation, or both. Angiographic findings demonstrated significant coronary artery disease in 22 (61%) and primary left ventricular dysfunction in 14 (39%), with a left ventricular ejection of 0.39 +/- 0.4. Patients were treated with an average flecainide dose of 302 +/- 76 mg/day. The follow-up time was 101 +/- 156 days. Thirty-two of 36 patients (89%) had complete elimination of ventricular tachycardia from Holter monitoring and only 2 patients had flecainide discontinued because of noncardiac side effects (numbness, blurred vision and ataxia). However, the drug was subsequently discontinued in 5 patients because of cardiac side effects (proarrhythmic effect in 2, sinus bradycardia in 1, complete atrioventricular block in 1 and new left bundle branch block in 1) and 10 patients died during flecainide therapy (1 with cerebral stroke, 3 with congestive heart failure and 6 with incessant ventricular tachycardia). A comparison of the general cardiac features of those who died with those who did not revealed a significantly lower ejection fraction (0.24 +/- 0.1 vs 0.45 +/- 0.1, p less than 0.05) and a significantly higher flecainide dose (350 +/- 85 versus 276 +/- 59 mg/day, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Clinical observations suggest that retention of the ileocecal valve is vital for survival in neonates who undergo resection of small bowel to the extent that less than 40 cm remain. Twenty-four puppies underwent 90% resection of small bowel and 12 of these also had a destructive procedure performed on the ileocecal valve. Survival and weight patterns were used to assess results when it was found both parameters supported the clinical observations. The practical application is that all attempts should be made to retain the ileocecal valve in situations in which only short lengths of small bowel remain. 相似文献
The Reid colposcopic index (RCI) helps physicians for interpret the results of colposcopic examination.To compare the accuracy of RCI in colposcopic evaluation between general and oncologic gynecologists, thisprospective trial was conducted by invited women over 20 years of age who were scheduled for a colposcopyat Chiang Mai University Hospital between August, 2008 and May, 2014 to participate. Pregnant patients orthose having a history of hysterectomy or conization were excluded. During the colposcopy, all patients weresimultaneously evaluated by general and oncologic gynecologists utilizing the RCI. Further management witheither a biopsy or LEEP in each patient was dependent on the decision of the attending oncologic gynecologist.The accuracy of the RCI in diagnosing HSIL or more was calculated by the comparison with the final histology.Finally, 135 patients were recruited into this study. The sensitivity, specificity, PPV, NPV, and accuracy of RCIin diagnosing HSIL or more in general gynecologists were 45.2%, 80.7%, 41.1%, 83.2% and 72.6% while in theoncologic gynecologists were 51.6%, 85.6%, 51.6%, 85.6% and 77.8%, respectively. The difference in accuracybetween evaluator groups was not significant (p-value=0.28). Of 3 patients with invasive cervical cancer, all wereundetected by the general gynecologists using RCI while only 1 invasive cervical cancer was missed via RCI bythe oncologic gynecologists. We conclude that RCI could be used by general gynecologists in provincial hospitalswith major concerns about missing invasive cervical cancer. A short training period regarding colposcopy mighthelp to resolve this problem 相似文献
A growth factor is obtained from a human retinoblastoma cell line (Y-79) growing in culture in the absence of any added serum or hormone. The retinoblastoma derived growth factor (RDGF) is still secreted by the Y-79 cells after they have been growing in a serum-free environment for over 5 months. RDGF stimulates both cell division and thymidine uptake of Swiss mouse 3T3 fibroblasts in media containing 0.2% fetal bovine serum. The thymidine uptake occurs maximally 16–42 hr after addition of RDGF.The factor has an apparent molecular weight of 38,000 as determined by Sephadex G-100 chromatography and is heat and trypsin labile. There appears to be additional material of higher MW which also stimulates thymidine uptake by the 3T3 cells. 相似文献
An R-wave synchronous implantable automatic cardioverter-defibrillator (IACD) was evaluated in 12 patients with repeated episodes of cardiac arrest who remained refractory to medical and surgical therapy. Seven men and 5 women, average age 61 years, surgically received a complete IACD system. Coronary artery disease was found in 11 and the prolonged Q-T syndrome in 1. The average ejection fraction was 34%, and 6 patients had severe congestive heart failure (New York Heart Association class III or IV).
The IACD is a completely implantable unit consisting of 2 bipolar lead systems. One system uses a lead in the superior vena cava and on the left ventricular apex through which the cardioverting pulse is delivered. The second system employs a close bipolar lead implanted in the ventricle for sensing rate. After the onset of ventricular tachycardia or fibrillation, the IACD automatically delivers approximately 25 J.
Postoperative electrophysiologic study in 10 and spontaneous ventricular tachycardia in 1 patient demonstrated appropriate IACD function and successful conversion in all with an average of 18 ± 4 seconds. The induced arrhythmias were ventricular tachycardia (160 to 300 beats/min) in 9 and ventricular fibrillation in 1.
These data demonstrate that ventricular tachycardia, not ventricular fibrillation, was the predominant rhythm induced during programmed ventricular stimulation in these survivors of cardiac arrest and that the IACD effectively responded to a wide range of ventricular tachycardia rates as well as ventricular fibrillation. Use of the IACD offers an effective means of therapy for some patients who otherwise may not have survived. 相似文献