PMID- 33283982 OWN - NLM STAT- MEDLINE DCOM- 20211028 LR - 20240402 IS - 2051-3909 (Electronic) IS - 2051-3895 (Print) IS - 2051-3895 (Linking) VI - 68 IP - 2 DP - 2021 Jun TI - The effect of imaging modality (magnetic resonance imaging vs. computed tomography) and patient position (supine vs. prone) on target and organ at risk doses in partial breast irradiation. PG - 157-166 LID - 10.1002/jmrs.453 [doi] AB - INTRODUCTION: Conventionally computed tomography (CT) has been used to delineate target volumes in radiotherapy; however, magnetic resonance imaging (MRI) is being continually integrated into clinical practice; therefore, the investigation into targets derived from MRI is warranted. The purpose of this study was to evaluate the impact of imaging modality (MRI vs. CT) and patient positioning (supine vs. prone) on planning target volumes (PTVs) and organs at risk (OARs) for partial breast irradiation (PBI). METHODS: A retrospective data set, of 35 patients, was accessed where each patient had undergone MRI and CT imaging for tangential whole breast radiotherapy in both the supine and prone position. PTVs were defined from seroma cavity (SC) volumes delineated on each respective image, resulting in 4 PTVs per patient. PBI plans were generated with 6MV external beam radiotherapy (EBRT) using the TROG 06.02 protocol guidelines. A prescription of 38.5Gy in 10 fractions was used for all cases. The impact analysis of imaging modality and patient positioning included dose to PTVs, and OARs based on agreed criteria. Statistical analysis was conducted though Mann-Whitey U, Fisher's exact and chi-squared testing (P < 0.005). RESULTS: Twenty-four patients were eligible for imaging analysis. However, positioning analysis could only be investigated on 19 of these data sets. No statistically significant difference was found in OAR doses based on imaging modality. Supine patient position resulted in lower contralateral breast dose (0.10Gy +/- 0.35 vs. 0.33Gy +/- 0.78, p = 0.011). Prone positioning resulted in a lower dose to ipsilateral lung volumes (10.85Gy +/- 11.37 vs. 3.41Gy +/- 3.93, P = <0.001). CONCLUSIONS: PBI plans with PTVs derived from MRI exhibited no clinically significant differences when compared to plans created from CT in relation to plan compliance and OAR dose. Patient position requires careful consideration regardless of imaging modality chosen. Although there was no proven superiority of MRI derived target volumes, it indicates that MRI could be considered for PBI target delineation. CI - (c) 2020 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology. FAU - Brown, Emily AU - Brown E AUID- ORCID: 0000-0003-3139-9547 AD - Medical Radiation Science (MRS), School of Health Sciences, The University of Newcastle, Callaghan, NSW, Australia. AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia. FAU - Dundas, Kylie AU - Dundas K AUID- ORCID: 0000-0002-3203-1157 AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. FAU - Surjan, Yolanda AU - Surjan Y AUID- ORCID: 0000-0001-6460-2594 AD - Medical Radiation Science (MRS), School of Health Sciences, The University of Newcastle, Callaghan, NSW, Australia. FAU - Miller, Daniela AU - Miller D AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. FAU - Lim, Karen AU - Lim K AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. FAU - Boxer, Miriam AU - Boxer M AUID- ORCID: 0000-0003-1102-6081 AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. FAU - Ahern, Verity AU - Ahern V AUID- ORCID: 0000-0001-8911-2727 AD - Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney, NSW, Australia. AD - Westmead Clinical School, University of Sydney, Sydney, NSW, Australia. FAU - Papadatos, George AU - Papadatos G AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. FAU - Batumalai, Vikneswary AU - Batumalai V AUID- ORCID: 0000-0003-2021-2599 AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. FAU - Harvey, Jennifer AU - Harvey J AD - School of Medicine, University of Queensland, Brisbane, QLD, Australia. AD - Princess Alexandra Hospital, Brisbane, QLD, Australia. FAU - Lee, Debra AU - Lee D AD - Medical Radiation Science (MRS), School of Health Sciences, The University of Newcastle, Callaghan, NSW, Australia. FAU - Delaney, Geoff P AU - Delaney GP AUID- ORCID: 0000-0002-1829-396X AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. AD - School of Medicine, University of Western Sydney, Sydney, NSW, Australia. FAU - Holloway, Lois AU - Holloway L AUID- ORCID: 0000-0003-4337-2165 AD - Liverpool and Macarthur Cancer Therapy Centers, Liverpool, NSW, Australia. AD - Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia. AD - South Western Sydney Clinical School, University of New South Wales, Sydney, NSW, Australia. AD - Centre for Medical Radiation Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong, NSW, Australia. LA - eng GR - South Western Sydney Local Health District/ PT - Journal Article DEP - 20201207 PL - United States TA - J Med Radiat Sci JT - Journal of medical radiation sciences JID - 101620352 SB - IM MH - *Breast Neoplasms/diagnostic imaging/radiotherapy MH - Female MH - Humans MH - *Magnetic Resonance Imaging MH - Patient Positioning MH - Prone Position MH - Radiotherapy Dosage MH - Radiotherapy Planning, Computer-Assisted MH - Retrospective Studies MH - Tomography, X-Ray Computed PMC - PMC8168067 OTO - NOTNLM OT - Magnetic resonance imaging OT - X-ray computed tomography OT - organs at risk OT - partial breast irradiation OT - patient positioning COIS- The authors declare no conflict of interest. EDAT- 2020/12/08 06:00 MHDA- 2021/10/29 06:00 PMCR- 2020/12/07 CRDT- 2020/12/07 08:53 PHST- 2020/03/20 00:00 [received] PHST- 2020/11/12 00:00 [accepted] PHST- 2020/12/08 06:00 [pubmed] PHST- 2021/10/29 06:00 [medline] PHST- 2020/12/07 08:53 [entrez] PHST- 2020/12/07 00:00 [pmc-release] AID - JMRS453 [pii] AID - 10.1002/jmrs.453 [doi] PST - ppublish SO - J Med Radiat Sci. 2021 Jun;68(2):157-166. doi: 10.1002/jmrs.453. Epub 2020 Dec 7.