ESTRO 36 Abstract Book

S396 ESTRO 36 _______________________________________________________________________________________________

this linked information to evaluate whether or not trials have been published in a PRJ. Results Of 3479 oncology trials, 2551 (73%) did not deposit a summary result in the registry; only 1096 (32%) had a peer- reviewed publication of their results indexed; only 1596 (46%) had either deposit a summary result in the registry, or published their results in a PRJ, or both. Of 1458 molecular oncology trials, 990 (68%) did not deposit a summary result in the registry; only 514 (35%) had a peer- reviewed publication of their results indexed; only 734 (50%) had either deposit a summary result in the registry, or published their results in a PRJ, or both. Of 483 radiation oncology trials, 414 (85.7%) did not deposit a summary result in the registry; only 154 (32%) had a peer- reviewed publication of their results indexed; only 227 (47%) had either deposit a summary result in the registry, or published their results in a PRJ, or both. Conclusion Our results show that most trials (70%-80%) in oncology did not report the results in the registry, even though they have been required to do so. More than half of these trials might not have been published in the biomedical literature. Molecular oncology and radiation oncology are no exception to the results found in oncology. Our evidence in oncology is therefore distorted in important ways and this might lead, to say the least, to large inefficiencies in our health care system. PO-0751 Uptake of a novel interactive 3D web-based contouring atlas among the radiation oncology community E. Gillespie 1 , N. Panjwani 1 , P. Sanghvi 1 , J. Murphy 1 1 University of California San Diego, Radiation Medicine and Applied Sciences, La Jolla, USA Purpose or Objective In the era of highly conformal treatment techniques, the delivery of safe and effective radiation therapy increasingly relies on accurate target delineation. Current contouring resources are fragmented and cumbersome to use at the point of care. We created a free interactive 3D web-based atlas called eContour (www.eContour.org), which displays best available evidence to guide contour delineation. This study reports on user characteristics, frequency of use, and frequently viewed cases during the first 6 months of dissemination. Material and Methods To track individual user data and collect user feedback, visitors to the eContour website are required to register with their email address, profession and hospital affiliation, while the IP address of the computer from which the website is accessed is used to track the user’s geographic location. Google Analytics and Mixpanel were employed to track the number and duration of each page view, which was linked to the unique registered user. Descriptive statistics were reported, including frequency of repeat use (primary endpoint) defined as the ratio of users that accessed the website on two different days divided by the total number of registered users. Users in the top quintile were further characterized by profession and geographic location. Results eContour has 2,616 registered users, of which most (60%) are radiation oncologists (1,092 practicing physicians and 459 residents). Other users include dosimetrists (16%), physicists (9%), radiation therapists (5%), and medical students (5%). Registered users represent 81 countries, with the majority (56%) of users located in the US (see Figure for map). Overall rate of repeat use was 49%, with residents most likely to return to the site (63%) and physicists least likely (36%). Repeat users visited the site on up to 58 different days during the dissemination period, with residents visiting a mean 6.6 different days and practicing physicians visiting a mean 5.4 different days.

Users in the top quintile were primarily physicians (69%) and from the US (67%). Of 33 posted cases in H&N, GI, GYN, GU and lymphoma, the most frequently viewed disease site was H&N (8,171 case views) followed by GI (4,665 case views) and the most frequently viewed cases were nasopharynx, pre-op rectal, pre-op esophageal, anal, post-op endometrial, and intact prostate cancer, each with over 1,000 page views. Users viewed each case page for an average of 3.7 minutes.

Conclusion eContour has a high rate of repeat use especially among radiation oncologists in the US. Users are most frequently looking for help contouring GI and H&N cancers, and they spend fewer than 4 minutes accessing information within a single case. These preliminary data suggest that eContour is a resource that fills a need among radiation oncology professionals. By providing users with updated contouring guidelines at the point of care, eContour has the potential to improve contour accuracy and ultimately impact quality of radiation delivery. PO-0752 Birth outcomes in female cancer patients received radiotherapy: a nationwide population-based study W.H. Kao 1 , J.H. Hong 1,2 , C.C. Wang 1,2 , Y.J. Chiang 1 , C.F. Kuo 3 1 Chang Gung Memorial Hospital, Department of Radiation Oncology, Taoyuan, Taiwan 2 College of Medicine- Chang Gung University, Department of Medical Imaging and Radiological Sciences, Taoyuan City, Taiwan 3 Chang Gung Memorial Hospital, Department of Rheumatology- Allergy and Immunology-, Taoyuan, Taiwan Purpose or Objective For young female cancer survivors who ever received radiotherapy, adverse pregnant outcomes are serious questions not only for themselves but also for their babies. The purpose of this study was to estimate the risks of adverse foetal-neonatal outcomes in female cancer patients received radiotherapy (RT) compared with women without malignancies. Material and Methods We identified 2,350,335 singleton pregnancies using Taiwan National Health Insurance Database and Taiwan Birth Registry between 2001 and 2012, of which 607 pregnancies were in female cancer patients with RT. Odds ratios (ORs) and 95% confidence intervals (CIs) for foetal- neonatal outcomes were estimated using generalized estimating equation model adjusted by maternal age, income, occupation, Charlson comorbidity index, urbanization, infant sex and birth of year. Results From 2001 to 2012, the mean age at pregnancy of female cancer patients received radiotherapy was 33.5 years old. There were no significant increasing risks with an adjusted OR (95% CIs) of 0.50 (0.21-1.21) for stillbirth, 0.75 (0.55- Poster: Clinical track: Other