Comparison of Dose Distribution in Clinical Planning and Dose Plan Using the Concept of Definite Target Volume in Stereotactic Radiotherapy Techniques

Document Type : Original Paper

Authors

1 Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia

2 Department of Radiation Oncology, Dr. Cipto Mangunkusumo General Hospital, Jakarta

3 Department of Radiation Oncology, Dr. Cipto Mangunkusumo General Hospital, Jakarta,

Abstract

Introduction: To implement the newly introduced concept volume of Definite Target Volume (DTV) and compare the distribution and dose-escalation in the DTV and clinical plans.
Material and Methods: We used seven samples of hepatocellular carcinoma (HCC) and three cervix tumour plans. DTV is determined through occupancy probability and margin contraction. This margin reduces the Clinical Target Volume (CTV) to obtain the DTV volume. DTV optimisation was achieved by giving the maximum dose to the target volume and limiting the organ at risk (OAR) by constraint.
Results: The DTV volume is obtained with a range of 60.8–913.9 cc for HCC and 2.4–22.9 cc for the cervix tumour. In HCC, the average at DTV volume increased to 124.98 ± 29.02, whereas the average  increased to 105.36% ± 2.66% for the Planning Target Volume-crop (PTV-crop). For cervix tumour cases, the highest dose on DTV volume reached 138.49%, and the average  at DTV volume increased to 116.80% ± 13.19%. In addition, the average  increased to 101.89% ± 5.58% for the PTV-crop. A larger dose delivered at the DTV will be associated with an increase in OAR. The dose increase of OAR-HCC is 106.93% ± 5.57%, and OAR-cervix is 101.18% ± 1.87%.
Conclusion: The larger margins generate smaller DTV volumes or vice versa. The dose to target DTV has increased considerably, but dose increases to PTV-crop and OAR are still within clinically acceptable levels.

Keywords

Main Subjects


  1. Stroom JC, Heijmen BJ. Geometrical uncertainties, radiotherapy planning margins, and the ICRU-62 report. Radiotherapy and oncology. 2002 Jul 1; 64(1):75-83.
  2. The International Commission on Radiation Units and Measurements (ICRU). Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). ICRU Report 83. Oxford University Press, Oxford, UK; 2010; 10(1):1–
  3. Nahum AE, Uzan J. (Radio) biological optimization of external-beam radiotherapy. Computational and Mathematical Methods in Medicine. 2012 Jan 1; 2012.
  4. McKenzie AL, van Herk M, Mijnheer B. The width of margins in radiotherapy treatment plans. Physics in Medicine & Biology. 2000 Nov 1; 45(11):3331.
  5. Segedin B, Petric P. Uncertainties in target volume delineation in radiotherapy–are they relevant and what can we do about them?. Radiology and oncology. 2016 Sep 1; 50(3):254.
  6. Hysing LB, Kvinnsland Y, Lord H, Muren LP. Planning organ at risk volume margins for organ motion of the intestine. Radiotherapy and Oncology. 2006 Sep; 80(3):349–
  7. Guckenberger M, Heilman K, Wulf J, Mueller G, Beckmann G, Flentje M. Pulmonary injury and tumor response after stereotactic body radiotherapy (SBRT): results of a serial follow-up CT study. Radiotherapy and Oncology. 2007 Dec 1; 85(3):435-42.
  8. Andolino DL, Johnson CS, Maluccio M, Kwo P, Tector AJ, Zook J, et al. Stereotactic body radiotherapy for primary hepatocellular carcinoma. International Journal of Radiation Oncology Biology Physics. 2011 Nov 15; 81(4).
  9. Lewis SL, Porceddu S, Nakamura N, Palma DA, Lo SS, Hoskin P, et al. Definitive Stereotactic Body Radiotherapy (SBRT) for Extracranial Oligometastases. American Journal of Clinical Oncology. 2017 Aug 1; 40(4):418-22.
  10. Taniguchi CM, Murphy JD, Eclov N, Atwood TF, Kielar KN, Christman-Skieller C, et al. Dosimetric analysis of organs at risk during expiratory gating in stereotactic body radiation therapy for pancreatic cancer. International Journal of Radiation Oncology Biology Physics. 2013 Mar 15; 85(4):1090-5.
  11. Matsuo Y, Shibuya K, Nakamura M, Narabayashi M, Sakanaka K, Ueki N, et al. Dose-volume metrics associated with radiation pneumonitis after stereotactic body radiation therapy for lung cancer. International Journal of Radiation Oncology Biology Physics. 2012 Jul 15; 83(4).
  12. Watkins WT, Nourzadeh H, Siebers JV. Dose escalation in the definite target volume. Medical Physics. 2020 Jul; 47(7):3174-83.
  13. The Royal College of Radiologist, Society and College of Radiographers, Institute of Physics and Engineering in Medicine Anonimous On Target: ensuring geometric accuracy in radiotherapy. London. The Royal College of Radiologist, 2008
  14. Gong G, Yin Y, Xing L, Guo Y, Chen J, Liu T, et al. Comparison of Internal Target Volumes for Hepatocellular Carcinoma Defined Using 3DCT with Active Breathing Coordinator and 4DCT. Technology in Cancer Research & Treatment. 2011 Dec; 10(6):601-6.
  15. Jensen NB, Assenholt MS, Fokdal LU, Vestergaard A, Schouboe A, Kjaersgaard EB, et al. Cone beam computed tomography-based monitoring and management of target and organ motion during external beam radiotherapy in cervial cancer. Physics and Imaging in Radiation Oncology. 2019 Jan; 9:14-20.
  16. van Herk M, Remeijer P, Lebesque J v. The Probability of Correct Target Dosage: Dose-Population Histograms for Deriving Treatment Margins in Radiotherapy. International Journal of Radiation Oncology Biology Physics. 2000 Jul; 47(4):1121-35.
  17. Sorcini B, Tilikidis A. Clinical application of image-guided radiotherapy, IGRT (on the Varian OBI platform). Cancer/Radiothérapie2006 Sep; 10(5):252-7.