Purpose: To study the effect of the Qfix kVue Calypso-compatible couch top on the
dosimetry of Spine Stereotactic Body Radiation Therapy (SBRT). Methods and
Materials: The computed tomography (CT) data set for Qfix kVue
Calypso-compatible couch top with rails were imported into the treatment
planning system (TPS). Nine patients who underwent spine SBRT were selected for
this study. The inclusion criteria included patients who were treated on a
stereotactic linear accelerator with 5 fractions or less from 2016 to 2017
without the couch model. Seven patients were treated with static
intensity-modulated radiation therapy (IMRT) fields and two patients were
treated using volumetric modulated arc therapy (VMAT) technique. The dose was
recalculated for 1) couch top and rails setup (CR) 2) couch-top no rails setup
(CNR), and then compared to 3) no couch no-rails setup (NCNR). Dose to 100% of the target volume (D100%), Dose to cover 99% of
the target volume (D99%), Dose to cover 95% of the target volume (D95%),
Dose to cover 90% of the target volume
(D90%), volume receiving 100% of the prescription dose (V100%),
conformity index (CI), dose gradient index (DGI), and spinal cord threshold and
maximum dose were compared to the plan with NCNR. Results: The average
D100% was 77.89% ± 11.78%, 74.51% ± 12.24%, and 75.83 ± 12.67% for NCNR, CR,
CNR (р = 0.84), respectively. The average D99% was 91.64% ± 9.57%, 89.93% ± 9.48%,
and 91.15% ± 9.55% for NCNR, CR, CNR (р = 0.98), respectively. The average D95%
was 99.14% ± 9.96%, 95.23% ± 9.76, and 96.78% ± 9.84% for NCNR, CR, CNR (р = 0.047),
respectively. The average D90% was 101.3% ± 0.65%, 97.11% ± 2.48%, and 98.75%
± 2.12% for NCNR, CR, CNR (р = 0.0004), respectively. The maximum dose to the
spinal cord was 1750.79 ± 41.84, 1672.90 ± 40.90, and 1709.91 ± 41.35 (cGy) for
NCNR, CR, CNR (р = 0.97), respectively. In all cases, the spinal cord threshold
dose was far below the tolerances and the differences were insignificant.
Average CI was 1.18 ± 0.16, 0.53 ± 0.39, and 0.86 ± 0.24 for NCNR, CR, CNR (р = 0.0002), respectively. Conclusions: The
study investigated the dosimetric impact of Qfix kVue Calypso-compatible
couch top on the quality of the spinal SBRT
treatment using static IMRT or VMAT techniques. IMRT
References
[1]
Seppälä, J.K.H. and Kulmala, J.A.J. (2011) Increased Beam Attenuation and Surface Dose by Different Couch Inserts of Treatment Tables Used in Megavoltage Radiotherapy. Journal of Applied Clinical Medical Physics, 12, 15-23. https://doi.org/10.1120/jacmp.v12i4.3554
[2]
Olch, A.J., Gerig, L., Li, H., Mihaylov, I. and Morgan, A. (2014) Dosimetric Effects Caused by Couch Tops and Immobilization Devices: Report of AAPM Task Group 176. Medical Physics, 41, Article ID: 061501. https://doi.org/10.1118/1.4876299
[3]
De Ost, B., Vanregemorter, J., Schaeken, B. and Van den Weyngaert, D. (1997) The Effect of Carbon Fibre Inserts on the Build-Up and Attenuation of High Energy Photon Beams. Radiotherapy and Oncology, 45, 275-277. https://doi.org/10.1016/S0167-8140(97)00118-7
[4]
Higgins, D.M., Whitehurst, P. and Morgan, A.M. (2001) The Effect of Carbon Fiber Couch Inserts on Surface Dose with Beam Size Variation. Medical Dosimetry, 26, 251-254. https://doi.org/10.1016/S0958-3947(01)00071-1
[5]
Court, L., Urribarri, J. and Makrigiorgos, M. (2010) Carbon Fiber Couches and Skin Sparing. Journal of Applied Clinical Medical Physics, 11, 3241. https://doi.org/10.1120/jacmp.v11i2.3241
[6]
McCormack, S., Diffey, J. and Morgan, A. (2005) The Effect of Gantry Angle on Megavoltage Photon Beam Attenuation by a Carbon Fiber Couch Insert. Medical Physics, 32, 483-487. https://doi.org/10.1118/1.1852792
[7]
Spezi, E. and Ferri, A. (2007) Dosimetric Characteristics of the Siemens IGRT Carbon Fiber Tabletop. Medical Dosimetry, 32, 295-298. https://doi.org/10.1016/j.meddos.2006.11.006
[8]
Berg, M., Bangsgaard, J.P. and Vogelius, I.S. (2009) Absorption Measurements on a New Cone beam CT and IMRT Compatible Tabletop for Use in External Radiotherapy. Physics in Medicine & Biology, 54, N319-N328. https://doi.org/10.1088/0031-9155/54/14/N04
[9]
Butson, M.J., Cheung, T. and Yu, P.K. (2007) Megavoltage X-Ray Skin Dose Variation with an Angle Using Grid Carbon Fibre Couch Tops. Physics in Medicine & Biology, 52, N485-N492. https://doi.org/10.1088/0031-9155/52/20/N03
[10]
ICRU (1991) Recommendations of the International Commission on Radiological Protection. Annals of the ICRP, 21, 1-201. https://doi.org/10.1016/0146-6453(91)90067-Q
[11]
Hoppe, B.S., Laser, B., Kowalski, A.V., et al. (2008) Acute Skin Toxicity Following Stereotactic Body Radiation Therapy for Stage I Nonsmall-Cell Lung Cancer: Who’s at Risk? International Journal of Radiation Oncology, Biology, Physics, 72, 1283-1286. https://doi.org/10.1016/j.ijrobp.2008.08.036
[12]
King, S.C., Acker, J.C., Kussin, P.S., et al. (1996) High-Dose, Hyperfractionated, Accelerated Radiotherapy Using a Concurrent Boost for the Treatment of Nonsmall Cell Lung Cancer: Unusual Toxicity and Promising Early Results. International Journal of Radiation Oncology, Biology, Physics, 36, 593-599. https://doi.org/10.1016/S0360-3016(96)00353-7
[13]
Lee, N., Chuang, C., Quivey, J.M., et al. (2002) Skin Toxicity Due to Intensity-Modulated Radiotherapy for Head-and-Neck Carcinoma. International Journal of Radiation Oncology, Biology, Physics, 53, 630-637. https://doi.org/10.1016/S0360-3016(02)02756-6
[14]
Mihaylov, I.B., Corry, P., Yan, Y., et al. (2008) Modeling of Carbon Fiber Couch Attenuation Properties with a Commercial Treatment Planning System. Medical Physics, 35, 4982-4988. https://doi.org/10.1118/1.2982135
[15]
Pulliam, K.B., Howell, R.M., Followill, D., et al. (2011) The Clinical Impact of the Couch Top and Rails on IMRT and Arc Therapy. Physics in Medicine & Biology, 56, 7435-7447. https://doi.org/10.1088/0031-9155/56/23/007
[16]
Teke, T., Gill, B., Duzenli, C. and Popescu, I.A. (2011) A Monte Carlo Model of the Varian IGRT Couch Top for RapidArc QA. Physics in Medicine & Biology, 56, N295-N305. https://doi.org/10.1088/0031-9155/56/24/N01
[17]
Li, H., Lee, A.K., Johnson, J.L., et al. (2011) Characterization of Dose Impact on IMRT and VMAT from Couch Attenuation for Two Varian Couches. Journal of Applied Clinical Medical Physics, 12, 23-31. https://doi.org/10.1120/jacmp.v12i3.3471
[18]
Van Prooijen, M., Kanesalingam, T., Islam, M.K. and Heaton, R.K. (2010) Assessment and Management of Radiotherapy Beam Intersections with the Treatment Couch. Journal of Applied Clinical Medical Physics, 11, 128-139. https://doi.org/10.1120/jacmp.v11i2.3171
Gardner, S.J., Gulam, M., Song, K., et al. (2015) Generation and Verification of QFix kVue Calypso-Compatible Couch Top Model for a Dedicated Stereotactic Linear Accelerator with FFF Beams. Journal of Applied Clinical Medical Physics, 16, 163-180. https://doi.org/10.1120/jacmp.v16i4.5441
[21]
Benedict, S.H., Yenice, K.M., Followill, D., et al. (2010) Stereotactic Body Radiation Therapy: The Report of AAPM Task Group 101. Medical Physics, 37, 4078-4101. https://doi.org/10.1118/1.3438081
