Vertebra Radyoterapisinde Cyberknife ve Imat Tekniklerinin İncelenmesi: Dozimetrik Çalışma

Abstract

Çalışmamızda, TPS (Multiplan ve Eclipse tedavi planlama sistemlerinde) sanal olarak oluşturulan vertebra tümörünün doz dağılımları ile CIRS ATOM fantomda yapılan TLD ölçüm sonuçlarının karşılaştırılması amaçlanmıştır. Ölçümler için, CIRS ATOM fantomun 1 mm kalınlıkta BT görüntüleri alındı. Sağ böbrek, sol böbrek, spinal kord ve kalp organları kritik organ olarak ve hedef hacim olarak CTV tanımlandı. Eclipse (version 8.9.17) ve Multiplan (version 4.5.3) tedavi planlama bilgisayarlarında aynı kriterler kullanılarak planlamalar yapıldı. TLD pozisyonları TPS üzerinde belirlendi ve planlar üzerindeki değerler tespit edildi. Bu değerler TLD değerleriyle karşılaştırıldı. TLD ortalama okuma değeri ile Multiplan TPS de aynı noktadaki doz değeri karşılaştırıldığında minimum ve maksimum fark sırasıyla % 4.4 ve % 8.5 ti. Eclipse TPS de minimum ve maksimum fark sırasıyla % 4.4 ve % 46.5 bulundu. Sonuç olarak, her iki teknikte de kritik organ dozları açısından benzer sonuçlar elde edildi.

Keywords

• Vertebral Işınlama,IMAT,SBRT,TPS Doğrulama,Dozimetri

Investigation of Cyberknife and Imat Techniques in Vertebra Radiotherapy: A Dosimetric Study

Abstract

In our study, it was aimed to compare the dose distributions of the virtual formed vertebra tumor (L1 level) created in TPS (Multiplan and Eclipse treatment planning systems) with the results of TLD dosimetry in CIRS ATOM phantom. For measurements, Computed tomography (CT) images were performed for CIRS ATOM Rando phantom planning. Right kidney, left kidney, spinal cord and heart volumes were formed as critical organs and CTV was created as a target volume. Treatment plans were created using the same criteria in Eclipse (version 8.9.17) and Multiplan (version 4.5.3) TPS. TLD places were identified on the TPS and the values on the plane were read. These values were compared to TLD values. The minimum and maximum differences between the average read value at the TLD measurement point and the dose reading at the same point in the Multiplan TPS were 4.4% to 8.5%, respectively. The minimum and maximum differences between the average read value at the TLD measurement point and the dose reading at the same point in the Eclipse TPS were found as 4.4% and 46.1%, respectively. As conclusion, similar results were obtained in terms of critical organ doses in both techniques. 

Keywords

• Vertebra Irradiation,IMAT,SBRT,TPS Accuracy,Dosimetry

References

1. P.C. Gerszten, C. Ozhasoglu, S.A. Burton, et al. “CyberKnife frameless stereotactic radiosurgery for spinal lesions: clinical experience in 125 cases,” Neurosurgery, vol. 55, no. 1, pp. 89-98, 2004.
2. J.W. Degen, G.J. Gagnon, J.M. Voyadzis, et al. “CyberKnife stereotactic radiosurgical treatment of spinal tumors for pain control and quality of life,” J. Neurosurgery Spine, vol. 2, no.5- 5, pp. 540-549, 2005.
3. A.K. Garg, X.-S. Wang, A. S. Shiu, et al. “Prospective evaluation of spinal reirradiation by using stereotactic body radiation therapy: The University of Texas MD Anderson Cancer Center experience,” Cancer, vol. 117, no. 15, pp. 3509-3516, 2011.
4. M. Foote, D. Letourmeau, D. Hyde, et al., “Technique for stereotactic body radiotherapy for spinal metastases,” J. Clin. Neuro., vol. 18, no. 2, pp. 276-279, 2011.
5. J.R. Adler, R.S. Cox, I. Kaplan and D.P. Martin.,”Stereotactic radiosurgical treatment of brain metastases,” J. Neurosurgery, vol. 76, no. 3, pp. 444-449, 1992.
6. B. L. Guthrie and J. R. Adler., “Computer-assisted preoperative planning, interactive surgery, and frameless stereotaxy,” Clin.Neurosurg, vol. 38, pp. 112-131, 1992.
7. M. J. Murphy and R. S. Cox., “The accuracy of dose localization for an image‐guided frameless radiosurgery system,”Med. Phys., vol. 23, no. 12, pp. 2043-2049, 1996.
8. J. Hrbacek, S. Lang, S. N. Graydon, S. Klock and O. Riesterer,“Dosimetric comparison of flattened and unflattened beams for stereotactic ablative radiotherapy of stage I non‐small cell lung cancer.” Med. Phys. vol. 41, no. 3, pp. 031709-7, 2014.

9. K. Otto. “Volumetric modulated arc therapy: IMRT in a single gantry arc,” Med. Phys. vol. 35, no. 1, pp. 310-317, 2008.
10. R.M. Howell, S.B. Scarboro, S.F. Kry, D.Z. Yaldo. “Accuracy of out-of-field dose calculations by a commercial treatment planning system,” Phys. Med. Biol., vol. 55, no. 23, pp. 6999-7008, 2010.
11. U. Schneider, R.A. Halg, M. Hartmann, et al. “Accuracy of out-of-field dose calculation of Tomotherapy and CyberKnife treatment planning systems: A dosimetric study,” Z. Med. Phy. Vol. 24, no. 3, pp. 211-215, 2014.
12. Y.E. Choi, J. Kwak, S.Y. Song, et al. “Direct plan comparison of RapidArc and CyberKnife for spine stereotactic body radiation therapy,” Journal of the Korean Physical Society, vol. 67, no. 1, pp. 116-122, 2015.