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01-01-2018 | Original Article

Air–electron stream interactions during magnetic resonance IGRT

Skin irradiation outside the treatment field during accelerated partial breast irradiation

Authors: Jong Min Park, Kyung Hwan Shin, Jung-in Kim, So-Yeon Park, Seung Hyuck Jeon, Noorie Choi, Jin Ho Kim, Hong-Gyun Wu

Published in: Strahlentherapie und Onkologie | Issue 1/2018

Abstract

Purpose

To investigate and to prevent irradiation outside the treatment field caused by an electron stream in the air generated by the magnetic field during magnetic resonance image-guided accelerated partial breast irradiation (APBI).

Materials and methods

In all, 20 patients who received APBI with a magnetic resonance image-guided radiation therapy (MR-IGRT) system were prospectively studied. The prescription dose was 38.5 Gy in 10 fractions of 3.85 Gy and delivered with a tri-cobalt system (the ViewRay system). For each patient, primary plans were delivered for the first five fractions and modified plans with different gantry angles from those of the primary plan (in-treatment plans) were delivered for the remaining five fractions to reduce the skin dose. A 1 cm thick bolus was placed in front of the patient’s jaw, ipsilateral shoulder, and arm to shield them from the electron stream. Radiochromic EBT3 films were attached to the front (towards the breast) and back (towards the head) of the bolus during treatment. Correlations between the measured values and the tumor locations, treatment times, and tumor sizes were investigated.

Results

For a single fraction delivery, the average areas of the measured isodoses of 14% (0.54 Gy), 12% (0.46 Gy), and 10% (0.39 Gy) at the front of the boluses were as large as 3, 10.4, and 21.4 cm², respectively, whereas no significant dose could be measured at the back of the boluses. Statistically significant but weak correlations were observed between the measured values and the treatment times.

Conclusion

During radiotherapy for breast cancer with an MR-IGRT system, the patient must be shielded from electron streams in the air generated by the interaction of the magnetic field with the beams of the three-cobalt treatment unit to avoid unwanted irradiation of the skin outside the treatment field.

Correa C, Harris EE, Leonardi MC et al (2017) Accelerated Partial Breast Irradiation: Executive summary for the update of an ASTRO Evidence-Based Consensus Statement. Pract Radiat Oncol 7:73–79CrossRefPubMed

Smith BD, Arthur DW, Buchholz TA et al (2009) Accelerated partial breast irradiation consensus statement from the American Society for Radiation Oncology (ASTRO). Int J Radiat Oncol Biol Phys 74:987–1001CrossRefPubMed

Polgar C, Van Limbergen E, Potter R et al (2009) Patient selection for accelerated partial-breast irradiation (APBI) after breast-conserving surgery: recommendations of the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) breast cancer working group based on clinical evidence. Radiother Oncol 94:264–273CrossRef

Chang JH, Lee NK, Kim JY et al (2013) Phase II trial of proton beam accelerated partial breast irradiation in breast cancer. Radiother Oncol 108:209–214CrossRefPubMed

Sayan M, Wilson K, Nelson C, Gagne H (2017) Rubin D Heimann R. A novel schedule of accelerated partial breast radiation using intensity-modulated radiation therapy in elderly patients: survival and toxicity analysis of a prospective clinical trial. Radiat Oncol J 35:32–38CrossRefPubMedPubMedCentral

Sung K, Lee KC, Lee SH (2014) Ahn SH Choi J. Cardiac dose reduction with breathing adapted radiotherapy using self respiration monitoring system for left-sided breast cancer. Radiat Oncol J 32:84–94CrossRefPubMedPubMedCentral

Vicini FA, Chen P, Wallace M et al (2007) Interim cosmetic results and toxicity using 3D conformal external beam radiotherapy to deliver accelerated partial breast irradiation in patients with early-stage breast cancer treated with breast-conserving therapy. Int J Radiat Oncol Biol Phys 69:1124–1130CrossRefPubMed

Rusthoven KE, Carter DL, Howell K et al (2008) Accelerated partial-breast intensity-modulated radiotherapy results in improved dose distribution when compared with three-dimensional treatment-planning techniques. Int J Radiat Oncol Biol Phys 70:296–302CrossRefPubMed

Oliver M, Chen J, Wong E, Van Dyk J, Perera F (2007) A treatment planning study comparing whole breast radiation therapy against conformal, IMRT and tomotherapy for accelerated partial breast irradiation. Radiother Oncol 82:317–323CrossRefPubMed

10.

Park CK, Pritz J, Zhang GG, Forster KM, Harris EE (2012) Validating fiducial markers for image-guided radiation therapy for accelerated partial breast irradiation in early-stage breast cancer. Int J Radiat Oncol Biol Phys 82:e425–e431CrossRefPubMed

11.

Wooten HO, Green O, Yang M et al (2015) Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (6)(0)Co Magnetic Resonance Image Guidance Radiation Therapy System. Int J Radiat Oncol Biol Phys 92:771–778CrossRefPubMed

12.

Wooten HO, Rodriguez V, Green O et al (2015) Benchmark IMRT evaluation of a Co-60 MRI-guided radiation therapy system. Radiother Oncol 114:402–405CrossRefPubMed

13.

Park JM, Park S, Wu H, Kim J (2015) Commissioning experience of tri-cobalt-60 MRI-guided radiation therapy system. Prog Med Phys 26:193–200CrossRef

14.

Mutic S, Dempsey JF (2014) The ViewRay system: magnetic resonance-guided and controlled radiotherapy. Semin Radiat Oncol 24:196–199CrossRefPubMed

15.

Kim J, Park S, Lee YH, Shin KH, Wu H, Park JM (2015) Effect of low magnetic field on dose distribution in the partial-breast irradiation. Prog Med Phys 26:208–214CrossRef

16.

Vicini F, White J, Arthur D, et al (2011) NSABP B‑39/RTOG 0413: A randomized phase III study of conventional whole breast irradiation versus partial breast irradiation for women with stage 0, I, or II breast cancer. Available at: http://www.rtog.org/members/protocols/0413/0413.pdf. Accessed 6 February 2016

17.

Kim JI, Park SY, Kim HJ, Kim JH, Ye SJ, Park JM (2014) The sensitivity of gamma-index method to the positioning errors of high-definition MLC in patient-specific VMAT QA for SBRT. Radiat Oncol 9:167CrossRefPubMedPubMedCentral

18.

Reyhan ML, Chen T, Zhang M (2015) Characterization of the effect of MRI on Gafchromic film dosimetry. J Appl Clin Med Phys 16:5743CrossRef

19.

Micke A, Lewis DF, Yu X (2011) Multichannel film dosimetry with nonuniformity correction. Med Phys 38:2523–2534CrossRefPubMed

20.

Ferreira BC, Lopes MC, Capela M (2009) Evaluation of an Epson flatbed scanner to read Gafchromic EBT films for radiation dosimetry. Phys Med Biol 54:1073–1085CrossRefPubMed

21.

Lewis D, Chan MF (2015) Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry. Med Phys 42:416–429CrossRefPubMed

22.

ICRP (2007) The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann. ICRP 37(2–4)

Title: Air–electron stream interactions during magnetic resonance IGRT
Skin irradiation outside the treatment field during accelerated partial breast irradiation
Authors: Jong Min Park
Kyung Hwan Shin
Jung-in Kim
So-Yeon Park
Seung Hyuck Jeon
Noorie Choi
Jin Ho Kim
Hong-Gyun Wu
Publication date: 01-01-2018
Publisher: Springer Berlin Heidelberg
Published in: Strahlentherapie und Onkologie / Issue 1/2018
Print ISSN: 0179-7158
Electronic ISSN: 1439-099X
DOI: https://doi.org/10.1007/s00066-017-1212-z

At a glance: The ONWARDS insulin icodec trials

Springer Medicine

Air–electron stream interactions during magnetic resonance IGRT

Skin irradiation outside the treatment field during accelerated partial breast irradiation

Abstract

Purpose

Materials and methods

Results

Conclusion

At a glance: The ONWARDS insulin icodec trials

Springer Medicine

Abstract

Purpose

Materials and methods

Results

Conclusion

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