Individual Positioning: A Comparative Study of Adjuvant Breast Radiotherapy in the Prone Versus Supine Position

Zoltán Varga, Katalin Hideghéty, Tamás Mezo, Alíz Nikolényi, László Thurzó, Zsuzsanna Kahán

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55 Citations (Scopus)

Abstract

Purpose: To study breast radiotherapy in the prone vs. supine positions through dosimetry and clinical implementation. Methods and Materials: Conformal radiotherapy plans in 61 patients requiring only breast irradiation were developed for both the prone and supine positions. After evaluation of the of the first 20 plan pairs, the patients were irradiated in the prone or supine position in a randomized fashion. These cases were analyzed for repositioning accuracy and skin reactions related to treatment position and patient characteristics. Results: The planning target volume covered with 47.5-53.5 Gy in the prone vs. the supine position was 85.1% ± 4.2% vs. 89.2 ± 2.2%, respectively (p < 0.0001). Radiation exposure of the ipsilateral lung, expressed in terms of the mean lung dose and the V20Gy, was dramatically lower in the prone vs. supine position (p < 0.0001), but the doses to the heart did not differ. There was no difference in the need to correct positioning during radiotherapy, but the extent of displacement was significantly higher in the prone vs. supine position (p = 0.021). The repositioning accuracy in the prone position exhibited an improvement over time and did not depend on any patient-related parameters. Significantly more radiodermatitis of Grade 1-2 developed following prone vs. supine irradiation (p = 0.025). Conclusions: Conformal breast radiotherapy is feasible in the prone position. Its primary advantage is the substantially lower radiation dose to the ipsilateral lung. The higher dose inhomogeneity and increased rate of Grade 1-2 skin toxicity, however, may be of concern.

Original languageEnglish
Pages (from-to)94-100
Number of pages7
JournalInternational Journal of Radiation Oncology Biology Physics
Volume75
Issue number1
DOIs
Publication statusPublished - Sep 1 2009

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Keywords

  • Breast cancer
  • Conformal radiotherapy
  • Prone treatment position
  • Repositioning accuracy
  • Supine treatment position

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

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