Treatment planning comparison of flattening filter and flattening filter-free for left-sided breast with deep inspiration breath hold using ECOMP and VMAT


  • Piyathida Buaprom Department of Radiology, Faculty of Science, Ramkhamhaeng university
  • Tanik Hongcharoen Department of Radiology, Faculty of Science, Ramkhamhaeng university
  • Rawinawan Adisaksodsai Department of Radiology, Faculty of Science, Ramkhamhaeng university
  • Paowarin Khayaiwong Department of Radiology, Faculty of Science, Ramkhamhaeng university
  • Puntiwa Oonsiri Division of Radiation Oncology, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society


flattening filter free, volumetric modulated arc therapy, deep inspiration breath hold, left-sided breast


Background: The radiotherapy treatment planning with flattening filter-free (FFF) may reduce the treatment time because the dose rate is increased.

Objective: To compare the treatment planning between flattening filter (FF) and FFF for left-sided breast with deep inspiration breath hold (DIBH) using electronic tissue compensation (ECOMP) and volumetric modulated arc therapy (VMAT) techniques.

Materials and Methods: The treatment planning for left-sided breast with DIBH of FF-ECOMP, FFF-ECOMP, FF-VMAT, and FFF-VMAT were generated. The maximum dose rate was set at 600 and 1400 MU/min for 6 MV and 6 MV-FFF, respectively. The average dose in organs at risk (OARs) such as heart, ipsilateral lung, contralateral lung, left anterior descending artery, and contralateral breast was evaluated. The patient-specific QA was also checked by using the portal dosimetry. The total monitor unit (MU) and beam on time were observed.

Results: Most of the OARs showed higher doses in FFF-ECOMP. The doses in PTV and OARs were not significantly different between the FF-VMAT and FFF-VMAT. The total MU of the FF mode was significantly lower than the FFF mode. The delivery time of FF-ECOMP was longer than FFF-ECOMP by approximately 1.4 times. The %gamma passing rate of portal dosimetry for all techniques was higher than 95%.

Conclusion: The FFF mode was suitable for left-sided breast with DIBH treatment planning. The shortest to the longest delivery time following each technique were FFF-ECOMP, FF-ECOMP, FF-VMAT, and FFF-VMAT, respectively. The FFF-ECOMP showed a higher dose than FF-ECOMP in the organs at risk due to higher MU, but no difference in the VMAT for both FF and FFF modes.



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How to Cite

Buaprom P, Hongcharoen T, Adisaksodsai R, Khayaiwong P, Oonsiri P. Treatment planning comparison of flattening filter and flattening filter-free for left-sided breast with deep inspiration breath hold using ECOMP and VMAT. J Thai Assn of Radiat Oncol [Internet]. 2023 Aug. 10 [cited 2023 Dec. 12];29(2):R1-R13. Available from:



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