Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis

Giacomo Reggiori, Pietro Mancosu, Simona Castiglioni, Filippo Alongi, Chiara Pellegrini, Francesca Lobefalo, Maddalena Catalano, Antonella Fogliata, Stefano Arcangeli, Piera Navarria, Luca Cozzi, Marta Scorsetti

Research output: Contribution to journalArticle

Abstract

Purpose: To compare volumetric modulated arc therapy with flattening filter free (FFF) and flattening filter (FF) beams in patients with hepatic metastases subject to hypofractionated radiotherapy (RT). Methods: A planning study on 13 virtual lesions of increasing volume was performed. Two single arc plans were optimized with the RapidArc technique using either FFF or FF beams. A second planning study was performed on ten patients treated for liver metastases to validate conclusions. In all cases, a dose of 75 Gy in 3 fractions was prescribed to the planning target volume (PTV) and plans were evaluated in terms of coverage, homogeneity, conformity, mean dose to healthy liver and to healthy tissue. For each parameter, results were expressed in relative terms as the percentage ratio between FFF and FF data. Results: In terms of PTV coverage, conformity index favored FFF for targets of intermediate size while FF resulted more suitable for small (100 cm 3) and large (300 cm 3) targets. Plans optimized with FFF beams resulted in increased sparing of healthy tissue in ≈85 of cases. Despite the qualitative results, no statistically significant differences were found between FFF and FF results. Plans optimized with un-flattened beams resulted in higher average MUGy than plans with FF beams. A remarkable and significant difference was observed in the beam-on time (BOT) needed to deliver plans. The BOT for FF plans was 8.2 1.0 min; for FFF plans BOT was 2.2 0.2 min. Conclusions: RapidArc plans optimized using FFF were dosimetrically equivalent to those optimized using FF beams, showing the feasibility of SBRT treatments with FFF beams. Some improvement in healthy tissue sparing was observed when using the FFF modality due to the different beam's profile. The main advantage was a considerable reduction of beam-on time, relevant for SBRT techniques.

Original languageEnglish
Pages (from-to)1112-1118
Number of pages7
JournalMedical Physics
Volume39
Issue number2
DOIs
Publication statusPublished - Feb 2012

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Intensity-Modulated Radiotherapy
Radiosurgery
Liver
Neoplasm Metastasis
Radiotherapy
Therapeutics

Keywords

  • flattening filter free
  • liver metastases
  • RapidArc

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

Cite this

Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis. / Reggiori, Giacomo; Mancosu, Pietro; Castiglioni, Simona; Alongi, Filippo; Pellegrini, Chiara; Lobefalo, Francesca; Catalano, Maddalena; Fogliata, Antonella; Arcangeli, Stefano; Navarria, Piera; Cozzi, Luca; Scorsetti, Marta.

In: Medical Physics, Vol. 39, No. 2, 02.2012, p. 1112-1118.

Research output: Contribution to journalArticle

Reggiori, Giacomo ; Mancosu, Pietro ; Castiglioni, Simona ; Alongi, Filippo ; Pellegrini, Chiara ; Lobefalo, Francesca ; Catalano, Maddalena ; Fogliata, Antonella ; Arcangeli, Stefano ; Navarria, Piera ; Cozzi, Luca ; Scorsetti, Marta. / Can volumetric modulated arc therapy with flattening filter free beams play a role in stereotactic body radiotherapy for liver lesions? A volume-based analysis. In: Medical Physics. 2012 ; Vol. 39, No. 2. pp. 1112-1118.
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AU - Castiglioni, Simona

AU - Alongi, Filippo

AU - Pellegrini, Chiara

AU - Lobefalo, Francesca

AU - Catalano, Maddalena

AU - Fogliata, Antonella

AU - Arcangeli, Stefano

AU - Navarria, Piera

AU - Cozzi, Luca

AU - Scorsetti, Marta

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