Dosimetric Impact of Contrast Medium on Different Photon Energies Using Conformal & IMRT Techniques in the Treatment of Carcinoma Cervix and Its Validation with Indigenous Phantom

Document Type : Original Paper

Authors

1 Amity School of Applied Sciences, Amity University (AUUP), NOIDA, India

2 Amity School of Applied Sciences, Amity University (AUUP), NOIDA, India Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India

3 Medical Physics Division, Elekta Medical Systems, India

4 Medical Physics Division & Radiation Oncology Department, Rajiv Gandhi Cancer Institute and Research Center, New Delhi, India

5 Division of Medical Physics & Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India

Abstract

Introduction: Considering the unwanted exposure to organs in the path of the beam, 4-field (4F) and subsequently, Intensity-modulated-radiation-therapy (IMRT), is known as the standard mode of treatment of carcinoma cervix. It is routine practice to inject intravenous contrast during simulation scan which elopes after that from the patient body. Therefore, the impact of contrast media should be investigated for radiation dose calculations.
Material and Methods: An indigenously made phantom, named as ‘original contrast (OC)’, was used with dimensions 15 x 15 x 30 cm3. A sleeve was given to place the ionization chamber at the isocentre of the planning target volume (PTV) inside the cylindrical vial of iodinized contrast. Similarly, a virtual phantom was created with similar dimensions in the presence and absence of contrast media, called as ‘virtual contrast (VC)’ and ‘virtual without contrast (VWC)’ phantom. Plans were generated with photon energies (6MV/10MV/15MV/6FFF/10FFF) using 4F and IMRT technique. Plans were evaluated for PTV (D99%, D10%, Dmean) and Bladder & Rectum (V30Gy, V10Gy). Normal-tissue-integral-dose (NTID) and total-monitor-units (TMU) were also evaluated.
Results: D99% of the PTV was comparable in VC and VWC phantoms but was decreased for OC phantom. Similarly, D10% was reportedly higher as 54.03 Gy (4F, 6 MV), 54.71 Gy (4F, 15 MV), 55.78 Gy (4F, 6 FFF) and 57.64 Gy (4F, 10 FFF) for OC phantom. D30% of the bladder and also the NTID was lesser for IMRT cases in all the selected phantoms. Additionally, 4F has shown lesser spillage with 6MV/15 MV photon beam energies in OC phantom. The ‘total monitor units (TMU)’ required for IMRT plans were significantly higher.
Conclusion: The contrast material under-estimates the planned dose yet has an insignificant influence on the dose calculation. Therefore, unnecessary exposure of dual scans should be avoided the use of 6MV and IMRT technique should be continued in the clinics.

Keywords

Main Subjects


  1. Mathur P, Sathishkumar K, Chaturvedi M, Das P, Sudarshan KL, Santhappan S, et al. ICMR-NCDIR-NCRP Investigator Group. Cancer Statistics, 2020: Report From National Cancer Registry Programme, India. JCO Glob Oncol. 2020; 6:1063-75.
  2. Cozzi L, Dinshaw KA, Shrivastava SK, Mahantshetty U, Engineer R, Deshpande DD, et al. A treatment planning study comparing volumetric arc modulation with RapidArc and fixed field IMRT for cervix uteri radiotherapy. Radiother Oncol. 2008; 89(2):180-91.
  3. Hanks GE. Conformal radiotherapy for prostate cancer. Ann Med. 2000; 32(1):57-63.
  4. Michele A, Richard S, Adis T. Side Effects of Radiographic Contrast Media: Pathogenesis, Risk Factors, and Prevention. BioMed Research International. 2014.
  5. Siva P. Raman and Elliot K. Fishman. Bladder malignancies on CT: The under rated role of CT in diagnosis. Am J Roentgenology. 2014; 203(2): 347-54.
  6. Ramm U, Damrau M, Mose S, Manegold KH, Rahl CG, Boettcher HD. Influence of CT contrast agents on dose calculations in a 3D treatment planning system. Phys Med Biol. 2001; 46:2631-5.
  7. Robar JL, Ricco SA, Martin MA. Tumour dose enhancement using modified megavoltage photon beams and contrast media. Phys Med Biol. 2002; 47:2433-49.
  8. Brink JA. Use of high concentration contrast media (HCCM): Principles and Rationale-body CT. Eur J Radiol. 2003; 45:S53-8.
  9. Holloway J, Fuller L, Forstner MD. Effect of intravenous contrast on treatment planning system dose calculations in the lung. Australas Phys Eng Sci Med. 2005; 28:190-5.
  10. Choi Y, Kim JK, Lee HS. Influence of intravenous contrast agent on dose calculations of intensity modulated radiation therapy plans for head and neck cancer. Radiother Oncol. 2006; 81:158-62.
  11. Shi W, Liu C, Lu B, Yeung A, Newlin HE, Amdur RJ, et al. The effect of intravenous contrast on photon radiation therapy dose calculations for lung cancer. Am J Clin Oncol. 2010; 33:153-6.
  12. ac.uk. London: The Royal College of Radiologists, Inc.; c2012. Available from: http://www.rcr.ac.uk/docs/oncology/pdf/BFCO (04) 2_Imaging_Oncology.pdf.
  13. Bhushan M, Yadav G, Tripathi D, Kumar L, Kishore V, Chowdhary RL, et al. Clinical dosimetric impact of AAA and Acuros XB on high-density metallic implants in case of carcinoma cervix. Oncol J India. 2019; 3:28-37.
  14. Bhushan M, Yadav G, Tripathi D, Kumar L, Dewan A, Wahi IK, et al. Effect of Photon Energy on Conventional Intensity- Modulated Radiotherapy and Rapid Arc Radiotherapy Planning for Deep-Seated Targets in Carcinoma Cervix. Asian J Oncol. 2019; 5:24–
  15. Bhushan M, Yadav G, Tripathi D, Kumar L, Kishore V, Dewan A, et al. Dosimetric Analysis of Unflattened (FFFB) and Flattened (FB) Photon Beam Energy for Gastric Cancers Using IMRT and VMAT—a Comparative Study. J Gastrointest Canc. 2019; 50: 408-19.
  16. Lees J, Holloway L, Fuller M, Forstner D. Effect of intravenous contrast on treatment planning system dose calculations in the lung. Australas Phys Eng Sci Med. 2005; 28:190-5.
  17. Shibamoto Y, Naruse A, Pukuma H, Ayakawa S, Sugie C, Tomita N. Influence of contrast materials on dose calculation in radiotherapy planning using computed tomography for tumors at various anatomical regions: A prospective study. Radiother Oncol. 2007; 84:52-5.
  18. Liu AJ, Vora N, Suh S, Liu A, Schultheiss TE, Wong J. Effect of CT contrast on volumetric arc therapy planning (RapidArc and helical tomotherapy) for head and neck cancer. Med Dosim. 2015; 40:32-6.
  19. Heydarheydari S, Farshchian N, Haghparast A. Influence of the contrast agents on treatment planning dose calculations of prostate and rectal cancers. Rep Pract Oncol Radiother. 2016; 21(5):441-6.
  20. Kim HJ, Chang AR, Park YK, Ye SJ. Dosimetric effect of CT contrast agent in Cyberknife treatment plans. Radiat Oncol. 2013, 8:244.
  21. Rankine AW, Lanzon PJ, Spry NA. Effect of contrast media on megavoltage photon beam dosimetry. Med Dosim. 2008; 33:169-74.
  22. Nasrollah J, Mikaeil M, Omid E, Mojtaba SS, Ahad Z. Influence of the intravenous contrast media on treatment planning dose calculations of lower esophageal and rectal cancers. J Can Res Ther. 2014; 10:147-52.
  23. Burridge NA, Rowbottom CG, Burt PA. Effect of contrast enhanced CT scans on heterogeneity corrected dose computations in the lung. J Appl Clin Med Phys. 2006; 7:1-12.
  24. Papanikolaou N, Stathakis S. Dose-calculation algorithms in the context of inhomogeneity corrections for high energy photon beams. Med Phys. 2009 Oct;36(10):4765-75.
  25. Kumar L, Yadav G, Raman K, Bhushan M, Pal M. The dosimetric impact of different photon beam energy on RapidArc radiotherapy planning for cervix carcinoma. J Med Phys. 2015;40(4):207-13.