axis irradiation (CSI) is a method of treating various central nervous system
malignancies. The large target volume typically includes entire spinal cord and
whole brain. Dosimetric comparison was performed between tomotherapy, volumetric modulated arc therapy
(VMAT), and 3D conformal radiation therapy (3D-CRT) for CSI. Methods and Materials: Five (n=5) CSI patients were planned using 3D-CRT, VMAT, and
tomotherapy (normalized such that 95% of PTV received at least 23.4 Gy in 13
fractions). Plans were compared using PTV conformity number (CN) and
homogeneity index (HI), normal tissue (NT) dose statistics, integral dose, and
treatment time. Results: On average,
tomotherapy plans showed higher CN (0.932 vs. 0.860 and 0.672 for SmartArc and
3D-CRT). In terms of HI, VMAT plans consistently showed better dose homogeneity
(1.07 vs. 1.15 and 1.13 for tomotherapy and 3D-CRT). SmartArc delivered lower
maximum dose for majority of NT, but higher mean dose. 3D-CRT plans delivered
higher maximum dose but lower mean dose to NT. Conclusions: SmartArc treatments achieved better PTV homogeneity
and reduced maximum dose to NT. Tomotherapy showed better target conformity,
but 3D-CRT was shown to reduce mean dose to NT. Integral doses were similar
between treatment modalities, but tomotherapy treatment times were much longer.
Cite this paper
P. Myers, S. Stathakis, A. Gutiérrez, C. Esquivel, P. Mavroidis and N. Papanikolaou, "Dosimetric Comparison of Craniospinal Axis Irradiation (CSI) Treatments Using Helical Tomotherapy, SmartarcTM, and 3D Conventional Radiation Therapy," International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Vol. 2 No. 1, 2013, pp. 30-38. doi: 10.4236/ijmpcero.2013.21005.
 E. C. Halperin, C. A. Perez and L. W. Brady, “Perez and Brady’s Principles and Practice of Radiation Oncology,” 5th Edition, Wolters Kluwer Health/Lippincott Williams & Wilkins, Philadelphia, 2008.
 N. Gupta, A. Banerjee and D. Haas-Kogan, “Pediatric CNS tumors. 2nd Editon, Springer, Berlin, 2010.
 R. J. Packer, et al., “Phase III Study of Craniospinal Radiation Therapy Followed by Adjuvant Chemotherapy for Newly Diagnosed Average-Risk Medulloblastoma,” Journal of clinical oncology, Vol. 24, No. 25, 2006, pp. 42024208. doi:10.1200/JCO.2006.06.4980
 J. M. Michalski, E. E. Klein and R. Gerber, “Method to Plan, Administer, and Verify Supine Craniospinal Irradiation,” Journal of applied clinical medical physics, Vol. 3, No. 4, 2002, pp. 310-316. doi:10.1120/1.1508013
 D. S. Sharma, et al., “High-Precision Radiotherapy for Craniospinal Irradiation: Evaluation of Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiation Therapy and Helical TomoTherapy,” The British Journal of Radiology, Vol. 82, No. 984, 2009, pp. 10001009. doi:10.1259/bjr/13776022
 T. F. Lee, et al., “Dosimetric Comparison of Helical Tomotherapy and Dynamic Conformal Arc Therapy in Stereotactic Radiosurgery for Vestibular Schwannomas. Medical Dosimetry, Vol. 36, No. 1, 2011, pp. 62-70.
 C. C. Popescu, et al., “Volumetric Modulated Arc Therapy Improves Dosimetry and Reduces Treatment Time Compared to Conventional Intensity-Modulated Radiotherapy for Locoregional Radiotherapy of Left-Sided Breast Cancer and Internal Mammary Nodes,” International Journal of Radiation Oncology, Biology, Physics, Vol. 76, No. 1, 2010, pp. 287-295.
 A. Fogliata, et al., “Cranio-Spinal Irradiation with Volumetric Modulated Arc Therapy: A Multi-Institutional Treatment Experience,” Radiotherapy and Oncology, Vol. 99, No. 1, 2011, pp. 79-85.
 M. Yoon, et al., “Craniospinal Irradiation Techniques: A Dosimetric Comparison of Proton Beams with Standard and Advanced Photon Radiotherapy,” International Journal of Radiation Oncology, Biology, Physics, Vol. 81, No. 3, 2011, pp. 637-646. doi:10.1016/j.ijrobp.2010.06.039
 M. W. Kissick, et al., “The Helical Tomotherapy Thread Effect,” Medical Physics, Vol. 32, No. 5, 2005, pp. 14141423. doi:10.1118/1.1896453
 F. M. Khan, “Treatment Planning in Radiation Oncology,” 2nd Edition, Lippincott Williams & Wilkins, Philadelphia, 2007.
 A. van’t Riet, et al., “A conformation Number to Quantify the Degree of Conformality in Brachytherapy and External Beam Irradiation: Application to the Prostate,” International Journal of Radiation Oncology, Biology, Physics, Vol. 37, No. 3, 1997, pp. 731-736.
 L. Feuvret, et al., “Conformity Index: A Review,” International Journal of Radiation Oncology, Biology, Physics, Vol. 64, No. 2, 2006, pp. 333-342.
 C. Shi, J. Penagaricano and N. Papanikolaou, “Comparison of IMRT Treatment Plans between Linac and Helical Tomotherapy Based on Integral Dose and Inhomogeneity Index,” Medical Dosimetry, Vol. 33, No. 3, 2008, pp. 215-221. doi:10.1016/j.meddos.2007.11.001
 P. Mavroidis, et al., “Comparison of the Helical Tomotherapy and MLC-based IMRT Radiation Modalities in Treating Brain and Cranio-Spinal Tumors,” Technology in Cancer Research & Treatment, Vol. 8, No. 1, 2009, pp. 3-14.
 J. Y. Hong, et al., “Supine Linac Treatment versus Tomotherapy in Craniospinal Irradiation: Planning Comparison and Dosimetric Evaluation,” Radiation Protection Dosimetry, Vol. 146, No. 1-3, 2011, pp. 364-366.
 Y. K. Lee, et al., “Development and Evaluation of Multiple Isocentric Volumetric Modulated Arc Therapy Technique for Craniospinal Axis Radiotherapy Planning,” International Journal of Radiation Oncology, Biology, Physics, Vol. 82, No. 2, 2010, pp. 1006-1012.
 W. Parker, et al., “Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks,” International Journal of Radiation Oncology, Biology, Physics, Vol. 69, No. 1, 2007, pp. 251-257.
 J. A. Penagaricano, C. Shi and V. Ratanatharathorn, “Evaluation of Integral Dose in Cranio-Spinal Axis (CSA) Irradiation with Conventional and Helical Delivery,” Technology in Cancer Research & Treatment, Vol. 4, No. 6, 2005, pp. 683-689.