The HyTEC Project

The 1991 “Emami paper”1 summarized dose/volume/outcome estimates for normal tissues as part of a full issue the International Journal Radiation Oncology, Biology, Physics (IJROBP) dedicated to report an NCI-funded Collaborative Working Group on Evaluation High Energy Photon External Beam Treatment Planning. It guided and informed many providers helped countless patients in early years 3D planning. Quantitative Analyses Normal Tissue Effects Clinic (QUANTEC) project aimed update Emami based reported tissue outcomes during following decades clinical implementation planning.2 QUANTEC received financial assistance from American Association Physicists Medicine (AAPM) Society Oncology (ASTRO) but worked independently either organization’s structure. was published supplementary IJROBP 2010.2 Given explosive growth stereotactic body radiation therapy (SBRT, also known ablative radiotherapy or SABR), it is timely have similar literature-based dose/volume both tumors treated with SBRT. AAPM led this effort through Biological Hypofractionated Radiotherapy/SBRT (WGSBRT) under Subcommittee (BESC). WG, which has chosen acronym HyTEC (“Hy”-dose per fraction, Clinic), consists physicists guest members who are physicians, physicists, radiobiologists, biostatisticians, biomathematicians. While made significant contributions effort, oversaw much more closely, scientific review process conducted committee highly nature reviews, articles will be IJROBP, having free access via “Publications” section website. A special May 1, 2021. covers main anatomic sites SBRT—cranial, head neck, thoracic, abdominal, pelvic spinal—including nine disease multiple associated tissues. There several introductory “vision” papers that address topics related underlying radiobiology, immunologic, mathematical outcome modeling. basic strategy Emami1 its companion modeling paper3 QUANTEC2 continued by HyTEC: provide risk organ tolerances treatment planning, dose-outcome data statistical dose-response As QUANTEC, article features table summarizing major findings each site-specific report.4 Similar guidance SBRT planning been previously provided AAPM’s Task 101 other works.5-7 Although growing availability prompted these remain suboptimal. Problems sparsity quality were QUANTEC8, 9 unfortunately persist era SBRT, similarly limited them. last paper includes reporting standards wishlist improve future publications. Physicists, particular, strongly encouraged ensure when they author concerning outcomes, sufficient detail included (in material if necessary) facilitate analyses. Ideally, all outcome-related reports would clearly define prescription dose fractionation, along doses critical anatomical structures. lessons8 pooling articles,9 introduction standards, useful suggestions promote comprehensive reporting. Clinical adoption outpaced analyses, especially considering strong impact fraction size late effects. We hope provides analysis summary practice. Useful Links: WGSBRT members: https://www.aapm.org/org/structure/?committee_code=WGSBRT papers: https://www.aapm.org/pubs/QUANTEC.asp https://www.aapm.org/pubs/HyTEC/