Comparison of calculated dose between planned adaptive software and helical tomotherapy treatment planning programs

Panatda Intanin; Imjai Chitapanarux; Somsak Wanwilairat; Wannapa Nobnop

Authors

Panatda Intanin Department of Radiology, Faculty of Medicine, Chiang Mai University, Thailand
Imjai Chitapanarux Department of Radiology, Faculty of Medicine, Chiang Mai University, Thailand
Somsak Wanwilairat Department of Radiology, Faculty of Medicine, Chiang Mai University, Thailand
Wannapa Nobnop Department of Radiology, Faculty of Medicine, Chiang Mai University, Thailand

Keywords:

helical tomotherapy, planned adaptive, MVCT, dosimetric parameters, เทคนิครังสีตัดขวางแบบเกลียวหมุน, โปรแกรมแพลนอะแดปทีฟ, ปริมาณเชิงรังสีคณิต

Abstract

Purpose To compare between the calculated dose of planned adaptive software on MVCT images and the helical tomotherapy planning dose calculated on kVCT images.

Methods The patients included in this study were 14 head and neck cancer cases treated by helical tomotherapy. All the planning doses were calculated by the planning station on kVCT data sets for PTV70, PTV59.4 and PTV54. The MVCT datasets were acquired by the helical tomotherapy system. The merged image between the kVCT and MVCT images was used for planned adaptive calculation. D95 of all PTVs, D50 of the parotid glands and D2 of the spinal cord were evaluated from a dose-volume histogram (DVH). These dosimetric parameters were compared using Pearson’s correlation.

Results The average D95 (cGy/fraction) of kVCT and MVCT two-dose calculation for PTV70, PTV59.4 and PTV54 was 212.1, 179.9 and 164.9, and 215.8, 183.3 and 162.9, respectively. The average D50 (cGy/fraction) of kVCT and MVCT two-dose calculation for the right and left parotid glands was 89.6 and 91.0, and 85.9 and 87.1 cGy/fraction, respectively. The average D2 (cGy/fraction) of kVCT and MVCT two-dose calculation for the spinal cord was 96.1 and 98.0 cGy/fraction, respectively.

Conclusions The comparison of dosimetric results in this study demonstrated that the MVCT calculated dose by planned adaptive software correlates with the planning dose on kVCT, and they can be substituted by each other.

References

Loo H, Fairfoul J, Chakrabarti A, et al. Tumourshrinkage and contour change during radiotherapyincrease the dose to organs at risk but not thetarget volumes for head and neck cancer patientstreated on the TomoTherapy Hi-ArtTM sys-tem.Clin Oncol 2011; 23:40-7.

Jensen AD, Nill S, Huber PE, Bendl R, DebusJ, Munter MW. A clinical concept for interfractionadaptive radiation therapy in the treatmentof head and neck cancer. Int J Radiat Oncol BiolPhys 2012;82:590-6.

Huang D, Xia P, Akazawa P, et al. Comparison oftreatment plans intensity-modulated radiotherapyand three-dimensional conformal radiotherapy forparanasal sinus carcinoma. Int J Radiat OncolBiol Phys 2003; 56:158-68.

Mackie TR. History of tomotherapy. Phys MedBiol 2006;51:427-53.

Han C, Chen YJ, Liu A, Schultheiss TE, JeffreyYC. Actual dose variation of parotid glands andspinal cord for naso-pharyngeal cancer patientsduring radiotherapy. Int J Radiat Oncol Biol Phys2008;70:1256-62.

Lee C, Langen KM, Lu W, Haimerl J, Schnarr E,Ruchala KJ. Assessment of parotid gland dosechanges during head and neck cancer radiotherapyusing daily megavoltage computed tomographyand deformable image registration. Int J RadiatOncol Biol Phys 2008; 71:1563-71.

Langen KM, Papanikolaou N, Balog J, et al. QAfor helical tomotherapy: report of the AAPM radiationtherapy commit-tee task group 148. Med Phys2010;37: 4817-53.

Crop F, Bernard A, Reynaert N. Improving dosecalculations on TomoTherapy MVCT images. JAppl Clin Med Phys 2012;13:241-53.

Schirm M, Yartsev S, Bauman G, Battista J,Dyk JV. Consistency check of planned adaptiveoption on helical tomo-therapy. Technol Canc ResTreat 2008;6:425-32.

Jacobs S. Adaptive radiotherapy [Internet]. [cited2013 April 8]. Available from https://www.medicaldosimetry.org/pub/39758175-2354-d714-5136-e6e 03944e474