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Single Institutional Experience of Electron Conformal Therapy (ECT) and Modulated Electron Therapy (MET) for Post-mastectomy Chest Wall Irradiation

Published online by Cambridge University Press:  01 August 2012

Mutahir Tunio ,
Zaeem Ahmed ,
Asad Zameer ,
Shoukat Ali ,
Kamran A. Awan  and
Basit Khan
Mutahir Tunio*
Affiliation:
King Fahad Medical City, Riyadh-59045, Saudi Arabia
Zaeem Ahmed
Affiliation:
Sindh Institute of Urology and Transplantation, Karachi, Pakistan
Asad Zameer
Affiliation:
Sindh Institute of Urology and Transplantation, Karachi, Pakistan
Shoukat Ali
Affiliation:
Sindh Institute of Urology and Transplantation, Karachi, Pakistan
Kamran A. Awan
Affiliation:
Sindh Institute of Urology and Transplantation, Karachi, Pakistan
Basit Khan
Affiliation:
Sindh Institute of Urology and Transplantation, Karachi, Pakistan
*
Correspondence to: Mutahir Tunio, Assistant Professor, Radiation Oncology, Sindh Institute of Urology & Transplantation, Karachi, Pakistan. Tel: 92 21 99215718, Fax: 92 21 99215469. E-mail: [email protected]
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Abstract

Objective: Two opposed tangential photon beams followed by scar boost with electrons is a common technique for post-mastectomy radiotherapy to the chest wall. However with current advances in x-rays (conformal and intensity modulated radiotherapy), the electrons have gained less attention; and most of the centres are using the conventional electron therapy techniques. Here we share our experience of electron conformal therapy (ECT) and modulated electron therapy (MET) for post-mastectomy scar boost.

Materials and methods: For post-mastectomy chest wall irradiation, 25 patients were treated with ECT and MET in five steps (a) virtual simulation and image acquisition using CT scanner Siemens® followed by (b) data transfer to Coherence Siemens® for contouring of skin, clinical target volume (CTV), planning target volume (PTV) and organs at risk (OARs), followed by (c) forward and reverse planning applying segmented fields using Prowess Panther treatment planning system (TPS) Siemens® and shaping of fields on beam’s eye view (BEV), (d) data transfer to computer assisted fabrication device (Autimo 2D) for lead cut outs and wax blocks and finally (e) quality assurance (QA) and modified treatment delivery.

Results: Apart from energy selection and tumor delineation, the ECT and MET showed maximal sparing of OARs (< 70% of prescribed dose), and improved dose conformity compared to single energy single field plans. Phantom and in vivo dosimetric measurements showed excellent agreement with calculated doses with difference ±2%. Conformity improved little beyond allowing three energies due to energy overlap and field-size constraints and conformity improvement was found at the expanse of dose heterogeneity within the PTV.

Conclusions: ECT and MET is time saving and can be utilised for treating superficial targets to improve the treatment outcome and with better QA; however, efforts are required to design commercially available eMLC (electron multileaf collimators) in modern linear accelerators.

Keywords

Electron conformal therapymodulated electron therapypost-mastectomy chest wall irradiation
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 12 , Issue 2 , June 2013 , pp. 173 - 179
Copyright
Copyright © Cambridge University Press 2012

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References

Dewar, JA. Postmastectomy radiotherapy. Clin Oncol (R Coll Radiol) 2006; 18:185–190.CrossRefGoogle ScholarPubMed
Early Breast Cancer Trialists’ Collaborative Group (EBCTCG): Favourable and unfavourable effects on long-term survival of radiotherapy for early breast cancer: An overview of the randomized trials. Lancet 2000; 355:1757–1770.CrossRefGoogle Scholar
Cuzick, J, Stewart, H, Rutqvist, L, et al. Cause-specific mortality in long-term survivors of breast cancer who participated in trials of radiotherapy. J Clin Oncol 1994; 12:447–453.CrossRefGoogle ScholarPubMed
Perez, CA, Brady, LW, editors. Principles and practice of radiation oncology. 2nd ed. Philadelphia: JB Lippincott; 1992. p. 948–969.Google Scholar
Gaffney, DK, Prows, J, Leavitt, DD, et al. Electron arc irradiation of the postmastectomy chest wall: With CT treatment planning: 20-year experience. Int J Radiat Oncol Biol Phys 2001; 51:994–1001.CrossRefGoogle Scholar
Gez, E, Ashaf, N, Bar-Deroma, R, et al. Postmastectomy electron beam chest wall irradiation in women with breast cancer. Int J Radiat Oncol Biol Phys 2004; 60:1190–4.CrossRefGoogle ScholarPubMed
Perkins, GH, McNeese, MD, Antolak, JA, et al. A custom three dimensional electron bolus technique for optimization of postmastectomy irradiation. Int J Radiat Oncol Biol Phys 2001; 51:1142–51CrossRefGoogle ScholarPubMed
Bauduceau, O, Pons, P, Campana, F, et al. Comparison of classic simulation and virtual simulation in breast irradiation: Prospective study on 14 patients. Cancer Radiother 2005; 9:402–10.CrossRefGoogle ScholarPubMed
Kudchadker, RJ, Antolak, JA, Morrison, WH, et al. Utilization of custom electron bolus in head and neck radiotherapy. J Appl Clin Med Phys 2003; 4:321–333.CrossRefGoogle ScholarPubMed
Kudchadker, RJ, Hogstrom, KR, Garden, AS, et al. Electron conformal radiotherapy using bolus and intensity modulation. Int J Radiat Oncol Biol Phys 2002; 53:1023–1037.CrossRefGoogle ScholarPubMed
Zeidan, OA, Chauhan, BD, Estabrook, WW, et al. Image-guided bolus electron conformal therapy - a case study. J Appl Clin Med Phys 2010; 12:3311.Google ScholarPubMed
Richert, JD, Hogstrom, KR, Fields, RS, et al. Improvement of field matching in segmented-field electron conformal therapy using a variable-SCD applicator. Phys Med Biol. 2007; 52:2459–81.CrossRefGoogle ScholarPubMed
Allozi, R, Li, XA, White, J, Apte, A, et al. Tools for consensus analysis of experts' contours for radiotherapy structure definitions. Radiother Oncol 2010; 97:572–578.CrossRefGoogle ScholarPubMed
Al-Yahya, K, Schwartz, M, Shenouda, G, et al. Energy modulated electron therapy using a few leaf electron collimator in combination with IMRT and 3D-CRT: Monte Carlo-based planning and dosimetric evaluation. Med Phys 2005; 32:2976–2986.CrossRefGoogle ScholarPubMed
Chavaudra, J. Last ICRU recommendations for the prescription, recording and reporting of external bean therapy. Cancer Radiother 1998; 2:607–614.CrossRefGoogle ScholarPubMed
Recht, A, Edge, SB, Solin, LJ, et al. Postmastectomy radiotherapy: Guidelines of the American Society of Clinical Oncology. J Clin Oncol 2001; 19:1539–1569.CrossRefGoogle ScholarPubMed
Gebski, V, Lagleva, M, Keech, A, et al. Survival effects of postmastectomy adjuvant radiation therapy using biologically equivalent doses: A clinical perspective. J Natl Cancer Inst 2006; 98:26–38.CrossRefGoogle ScholarPubMed