Program Information

The Role of Physics in Long Term Epidemiological Studies of Pediatric Radiotherapy Patients

A Berrington deGonzalez

R Howell

C Lee

W Newhauser

A Berrington deGonzalez¹*, R Howell²*, C Lee³*, W Newhauser⁴*, (1) National Cancer Institute, Bethesda, MD, (2) UT MD Anderson Cancer Center, Houston, TX, (3) University of Michigan, Ann Arbor, MI, (4) Louisiana State University, Baton Rouge, LA

Presentations

7:30 AM : What we have learned from epidemiological studies of pediatric radiotherapy patients and remaining questions - A Berrington deGonzalez, Presenting Author
8:00 AM : Experiences at MD Anderson Cancer Center for normal tissue dose reconstructions - R Howell, Presenting Author
8:30 AM : Application of computational human phantoms and Monte Carlo methods in normal tissue dose reconstructions - C Lee, Presenting Author
9:00 AM : Analytical methods for normal tissue dose reconstructions - W Newhauser, Presenting Author

WE-AB-FS1-0 (Wednesday, August 2, 2017) 7:30 AM - 9:30 AM Room: Four Seasons 1

Late effects (>5 years after treatment) are of concern for survivors of childhood cancer because these survivors have high long-term survival rates, many children with cancer require radiation therapy (RT), and children and adolescents are more likely to develop RT-related late effects than adults. Numerous epidemiological studies have demonstrated increased risks of late effects including second cancers, cardiac effects, and many others. Studies that quantify dose response relationships based on dose to individual organs are particularly valuable in driving current clinical practice to develop techniques to minimize and mitigate late effects in future survivors. Valuable information such as temporal trends in late effects with time period can also be gained from such studies. Retrospective dose reconstruction of either organ, body region, or second cancer location is an essential component of such studies. This dosimetry is routinely done using analytical models of the dose and simple phantoms with reference organ locations. The inherent latency in these studies leads to many unique challenges. One of the most substantial challenges is that studies often include patients treated over many decades, and may include patients whose original treatments may have been simple 2D photon, electron or brachytherapy plans, or may have been computed tomography (CT) based for 3D conformal and/or intensity modulated photon therapy, or proton therapy. Regardless, the available data in the treatment record is often insufficient for dose reconstructions. Patient records may be incomplete or include only general descriptions of the treatment. Even with a very complete and modern record, CT scans generally only include anatomy close to the treatment area, and often only hard-copies of plans are available which may include only selected views of the anatomy and making it difficult to assess the field borders and other important plan details. Physicists play a key role in overcoming the challenges of retrospective RT dose reconstruction for late effect studies.

This session will focus on the role of physics in epidemiological late effects studies of pediatric cancer survivors. Specifically the four presentations will provide unique perspectives and focus on (1) what we have learned from epidemiological studies of pediatric RT patients and remaining questions, (2) methods currently in use for large cohort and case-control studies and what level of accuracy is presently achievable and necessary for different types of studies (3) application of computational human phantoms and Monte Carlo radiation transport methods in normal tissue dose reconstructions, and (4) application of analytical methods for normal tissue dose reconstructions.

Learning Objectives:
1. Understand the importance of epidemiological studies in radiotherapy patients
2. Understand key challenges in retrospective dose reconstructions for radiotherapy patients
3. Learn about different methods available for out-of-field organ dosimetry

Handouts

• 127-35249-418554-127413.pdf (A Berrington deGonzalez)

• 127-35250-418554-126414.pdf (R Howell)

• 127-35251-418554-126548.pdf (C Lee)

• 127-35252-418554-127414.pdf (W Newhauser)

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