Retinoblastoma-comparative analysis of external radiotherapy techniques, including an IMRT technique
- Department of Radiation Oncology, Hospital Universitario Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)
- Department of Radiation Oncology, Instituto Nacional de Cancer, Rio de Janeiro (Brazil)
- Division of Medical Physics, Department of Radiation Oncology, Instituto Nacional de Cancer, Rio de Janeiro (Brazil)
- Department of Radiology, Hospital Universitario Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)
Purpose: To compare the numerous external radiotherapy (RT) techniques for the treatment of retinoblastoma, as well as an intensity-modulated RT (IMRT) technique. The latter was elaborated to evaluate the potential dose reduction in the surrounding tissue, as well as the potential avoidance of subdosage in the ora serrata retinae. Methods and Materials: A 2-year-old patient with unilateral retinoblastoma underwent CT. With the aid of an ophthalmologist, the ocular structures were delimited, and 13 techniques described in published reports were reproduced on three-dimensional planning software and identified according to their authors. A technique with four noncoplanar fields using IMRT was also elaborated. These techniques were compared according to the dose to the ora serrata retinae, lens, orbit (volume that received a dose of {>=}20 Gy), vitreous, optic nerve, lacrimal gland (volume that received a dose of {>=}34 Gy), and cornea and according to their ease of reproducibility. Results: The techniques that attained the therapeutic dose to the ora serrata retinae were the IMRT technique and the techniques of Haye, Cassady, Cormack, and al-Beteri. The Cormack technique had the lowest volume that received a dose of {>=}20 Gy in the orbit, followed by the IMRT technique. The IMRT technique also achieved the lowest volume that received a dose of {>=}34 Gy (14%) in the lacrimal gland. The Abramson/McCormick/Blach, Cassady, Reese, and Schipper techniques were the easiest to reproduce and the Chin the most complex. Conclusion: Retinoblastoma treatment with IMRT has an advantage over the other techniques, because it allows for the greatest reduction of dose to the orbit and lacrimal gland, while maintaining the therapeutic dose to the ora serrata retinae and vitreous.
- OSTI ID:
- 20944748
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 67, Issue 3; Other Information: DOI: 10.1016/j.ijrobp.2006.09.057; PII: S0360-3016(06)03382-7; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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