PMID- 35104047 OWN - NLM STAT- MEDLINE DCOM- 20220412 LR - 20220414 IS - 1526-9914 (Electronic) IS - 1526-9914 (Linking) VI - 23 IP - 4 DP - 2022 Apr TI - Development of a quasi-humanoid phantom to perform dosimetric and radiobiological measurements for out-of-field doses from external beam radiation therapy. PG - e13514 LID - 10.1002/acm2.13514 [doi] LID - e13514 AB - Our understanding of low dose, out-of-field radiation and their radiobiological effects are limited, in part due to the rapid technological advances in external beam radiotherapy, especially for non-coplanar and dynamic techniques. Reliable comparisons of out-of-field doses produced by advanced radiotherapy techniques are difficult due to the limitations of commercially available phantoms. There is a clear need for a functional phantom to accurately measure the dosimetric and radiobiological characteristics of out-of-field doses, which would in turn allow clinicians and medical physicists to optimize treatment parameters. We designed, manufactured, and tested the performance of a quasi-humanoid (Q-H) adult phantom. To test the physics parameters, we used computed tomography (CT) scans of assembled Q-H phantom. Static open field and dynamic techniques were measured both in- and out-of-field with ionization chambers and radiochromic films for two configurations (full solid and with water-filled containers). In the areas simulating soft tissues, lung, and bones, median Hounsfield units and densities were, respectively: 129.8, -738.7, 920.8 HU and 1.110, 0.215, 1.669 g/cm(3) . Comparison of the measured to treatment planning systems (TPS) in-field dose values for the sample volumetric arc therapy (VMAT) (6 MV flattening filter-free (FFF)) plan, 96.4% of analyzed points passed the gamma evaluation criteria (L2%/2 mm, threshold (TH) 10%) and less than 1.50% for point dose verification. In the two phantom configurations: full poly(methyl) methacrylate (PMMA) and with water container, the off-axis median doses for open field, relative to the central axis of the beam (CAX) were similar, respectively: 0.900% versus 0.907% (15 cm distance to CAX); 0.096% versus 0.120% (35 cm); 0.018% versus 0.018% (52 cm); 0.009% versus 0.008% (74 cm). For VMAT 6 MV FFF, doses relative the CAX were, respectively: 0.667% (15 cm), 0.062% (35 cm), 0.019% (52 cm), 0.016% (74 cm). The Q-H phantom meets the International Commission on Radiation Units and Measurements (ICRU) and American Association of Physicists in Medicine (AAPM) recommended phantom criteria, providing medical physicists with a reliable, comprehensive system to perform dose calculation and measurements and to assess the impact on radiobiological response and on the risk of secondary tumor induction. CI - (c) 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine. FAU - Kruszyna-Mochalska, Marta AU - Kruszyna-Mochalska M AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Skrobala, Agnieszka AU - Skrobala A AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Romanski, Piotr AU - Romanski P AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Ryczkowski, Adam AU - Ryczkowski A AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Suchorska, Wiktoria AU - Suchorska W AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Radiobiology Laboratories, Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Kulcenty, Katarzyna AU - Kulcenty K AD - Radiobiology Laboratories, Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Piotrowski, Igor AU - Piotrowski I AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Radiobiology Laboratories, Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Borowicz, Dorota AU - Borowicz D AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. FAU - Matuszak, Natalia AU - Matuszak N AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. FAU - Malicki, Julian AU - Malicki J AD - Electroradiology Department, University of Medical Sciences, Poznan, Poland. AD - Medical Physics Department, Greater Poland Cancer Centre, Poznan, Poland. LA - eng GR - 2015/19/B/NZ7/03811/National Science Centre/ PT - Journal Article DEP - 20220201 PL - United States TA - J Appl Clin Med Phys JT - Journal of applied clinical medical physics JID - 101089176 RN - 059QF0KO0R (Water) SB - IM MH - Adult MH - Humans MH - Phantoms, Imaging MH - Radiometry/methods MH - Radiotherapy Dosage MH - Radiotherapy Planning, Computer-Assisted/methods MH - *Radiotherapy, Intensity-Modulated/methods MH - Water PMC - PMC8992956 OTO - NOTNLM OT - humanoid phantoms OT - out-of-field doses OT - radiobiological response OT - risk modeling COIS- The authors declare no conflict of interest. EDAT- 2022/02/02 06:00 MHDA- 2022/04/13 06:00 PMCR- 2022/02/01 CRDT- 2022/02/01 12:16 PHST- 2021/11/28 00:00 [revised] PHST- 2021/09/22 00:00 [received] PHST- 2021/12/08 00:00 [accepted] PHST- 2022/02/02 06:00 [pubmed] PHST- 2022/04/13 06:00 [medline] PHST- 2022/02/01 12:16 [entrez] PHST- 2022/02/01 00:00 [pmc-release] AID - ACM213514 [pii] AID - 10.1002/acm2.13514 [doi] PST - ppublish SO - J Appl Clin Med Phys. 2022 Apr;23(4):e13514. doi: 10.1002/acm2.13514. Epub 2022 Feb 1.