EP-1140: Dosimetric comparison between Helical Tomotherapy and IMRT for Bilateral Breast Cancer

Abstract Purpose: Dosimetric comparison between volumetric-modulated arc therapy (VMAT) and helical tomotherapy (HT) in the treatment of bilateral breast cancer (BBC). Materials and methods: Ten patients treated on HT were selected retrospectively. Dose prescription was 50 Gy in 25 fractions to breast/chest wall and supraclavicular fossa (SCF) while tumour bed was simultaneously boosted to 61 Gy in 25 fractions. VMAT plans were made with four mono-isocentric partial arcs. The monitoring unit (MU) and treatment time were used to quantify the treatment efficiency. Target volumes were compared for homogeneity index (HI), conformity index (CI) while organs at risk (OARs) were compared for relevant dose volumes and integral doses (IDs). Result: For targets, no significant difference is observed between VMAT and HT in CI but VMAT could give better HI. The mean lung dose, V20 and V5 is 10·6 Gy versus 8·4 Gy (p-value 0·03), 12% versus 11·5% (p-value 0·5) and 78·1% versus 43·4% (p-value 0·005), respectively. The mean heart dose, V30 and V5 is 4·9 Gy versus 4·7 Gy (p-value 0·88), 0·5% versus 1·5% (p-value 0·18) and 26·2% versus 22·8% (p-value 0·4). Integral dose (ID) for the whole body and heart are comparable: 289 Gy kg versus 299 Gy kg (p-value 0·24) and 2·9 Gy kg versus 2·8 Gy kg (p-value 0·80). ID for lungs was significantly higher with VMAT: 7·9 Gy kg versus 6·3 Gy kg (p-value 0·03). There is a 53% reduction in treatment time and 78% in MU with VMAT against HT. Conclusion: VMAT can generate clinically acceptable plans comparable to HT for BBC. HT shows better control over low dose spillage in lungs compared to VMAT thereby increasing ID to lungs. VMAT shows better homogeneity and efficient treatment delivery than HT.

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Dosimetric comparison of helical tomotherapy, volumetric-modulated arc therapy, intensity-modulated radiotherapy, and field-in-field technique for synchronous bilateral breast cancer

Medical Dosimetry ◽

10.1016/j.meddos.2020.01.006 ◽

2020 ◽

Vol 45 (3) ◽

pp. 271-277

Author(s):

Hao-Wen Cheng ◽

Chih-Chieh Chang ◽

An-Cheng Shiau ◽

Ming-Hua Wang ◽

Jo-Ting Tsai

Keyword(s):

Breast Cancer ◽

Helical Tomotherapy ◽

Volumetric Modulated Arc Therapy ◽

Bilateral Breast Cancer ◽

Intensity Modulated Radiotherapy ◽

Field Technique ◽

Dosimetric Comparison ◽

Intensity Modulated ◽

Synchronous Bilateral Breast Cancer ◽

Arc Therapy

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Breast Conserving Treatment for Breast Cancer: Dosimetric Comparison of Sequential versus Simultaneous Integrated Photon Boost

BioMed Research International ◽

10.1155/2014/827475 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 13

Author(s):

Hilde Van Parijs ◽

Truus Reynders ◽

Karina Heuninckx ◽

Dirk Verellen ◽

Guy Storme ◽

...

Keyword(s):

Breast Cancer ◽

Helical Tomotherapy ◽

Organs At Risk ◽

Standard Of Care ◽

Breast Conserving Surgery ◽

Conventional Technique ◽

Breast Conserving Treatment ◽

Safe Alternative ◽

Dosimetric Comparison ◽

Sequential Boost

Background. Breast conserving surgery followed by whole breast irradiation is widely accepted as standard of care for early breast cancer. Addition of a boost dose to the initial tumor area further reduces local recurrences. We investigated the dosimetric benefits of a simultaneously integrated boost (SIB) compared to a sequential boost to hypofractionate the boost volume, while maintaining normofractionation on the breast.Methods. For 10 patients 4 treatment plans were deployed, 1 with a sequential photon boost, and 3 with different SIB techniques: on a conventional linear accelerator, helical TomoTherapy, and static TomoDirect. Dosimetric comparison was performed.Results. PTV-coverage was good in all techniques. Conformity was better with all SIB techniques compared to sequential boost (P= 0.0001). There was less dose spilling to the ipsilateral breast outside the PTVboost (P= 0.04). The dose to the organs at risk (OAR) was not influenced by SIB compared to sequential boost. Helical TomoTherapy showed a higher mean dose to the contralateral breast, but less than 5 Gy for each patient.Conclusions. SIB showed less dose spilling within the breast and equal dose to OAR compared to sequential boost. Both helical TomoTherapy and the conventional technique delivered acceptable dosimetry. SIB seems a safe alternative and can be implemented in clinical routine.

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