Evaluation and Comparison of Target and At-Risk Organ Dosimetry in Radiation Therapy of Prostate Cancer Patients Using Three-Dimensional Conformal Radiotherapy (3D-CRT) and Intensity-Modulated Radiation Therapy (IMRT)

Document Type : Original Article (s)

Authors

1 MSc in Medical Physics, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 PhD in Medical Physics, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 Radiation Oncologist, Department of Radiation-Oncology, Milad Hospital, Isfahan, Iran

Abstract

Background: The goal of this study was to make a dosimetric comparison between the absorbed dose distribution of the prostate and the organ at risk (OAR) using two different approaches: three-dimensional conformal radiotherapy (3D-CRT) and Intensity-modulated radiotherapy (IMRT), assesed via treatment planning system (TPS) and thermoluminescence dosimetry (TLD).
Methods: In this study, 35 patients with prostate cancer undergoing radiation therapy at Milad Hospital in Isfahan were included. Prostate as target and rectum, bladder and femoral head as healthy organ at risk (OAR) were contoured according to Radiation Therapy Oncology Group (RTOG) criteria. Two separate dosimetry programs IMRT and 3D-CRT have been developed for each patient in order to evaluate the dosimetric status of both methods comparatively. These results were then compared with those of the phantom.
Findings: The doses to the bladder, rectum, and femoral head were 50.3, 58.6, and 16.4 in IMRT and 59.6, 68.8, and 34.8 in 3D-CRT, respectively. The dose measured by TLD in all organs in the phantom was higher than the dose calculated by TPS software in the phantom.
Conclusion: The IMRT method is a better method than 3D-CRT due to better coverage of the target volume and reduction of the cumulative dose of organs at risk (OAR). The dose measured by TLDs was higher than the dose calculated by the treatment planning system, which may be due to the fact that the treatment planning system does not calculate the share of scattered radiation in the absorbed dose of organs.

Keywords


  1. Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer statistics. CA Cancer J Clin 2009; 59(4): 1-25.
  2. Malone S, Croke J, Roustan-Delatour N, Belanger E, Avruch L, Malone C, et al. Postoperative radiotherapy for prostate cancer: A comparison of four consensus guidelines and dosimetric evaluation of 3D-CRT versus tomotherapy IMRT. Int J Radiat Oncol Biol Phys 2012; 84(3): 725-32.
  3. Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2021. CA Cancer J Clin 2021; 71(1): 7-33.
  4. Maier J, Forman J, Tekyi-Mensah S, Bolton S, Patel R, Pontes JE. Salvage radiation for a rising PSA following radical prostatectomy. Urol Oncol 2004; 22(1): 50-6.
  5. Ost P, Fonteyne V, Villeirs G, Lumen N, Oosterlinck W, De Meerleer G. Adjuvant high-dose intensity-modulated radiotherapy after radical prostatectomy for prostate cancer: Clinical results in 104 patients. Eur Urol 2009; 56(4): 669-77.
  6. Jackson A, Marks LB, Bentzen SM, Eisbruch A, Yorke ED, Ten Haken RK, et al. The lessons of QUANTEC: recommendations for reporting and gathering data on dose-volume dependencies of treatment outcome. Int J Radiat Oncol Biol Phys 2010; 76(3 Suppl): S155-60.
  7. Parker C, Sydes MR, Catton C, Kynaston H, Logue J, Murphy C, et al. Radiotherapy and androgen deprivation in combination after local surgery (RADICALS): A new Medical Research Council/National Cancer Institute of Canada phase III trial of adjuvant treatment after radical prostatectomy. BJU Int 2007; 99(6): 1376-9.
  8. Goldin GH, Sheets NC, Meyer AM, Kuo TM, Wu Y, Stürmer T, et al. Comparative effectiveness of intensity-modulated radiotherapy and conventional conformal radiotherapy in the treatment of prostate cancer after radical prostatectomy. JAMA Intern Med
    2013; 173(12): 1136-43.
  9. Uysal B, Beyzadeoǧlu M, Sager O, Dinçoǧlan F, Demiral S, Gamsiz H, et al. Dosimetric evaluation of intensity modulated radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate cancer treatment. Balkan Med J 2013; 30(1): 54-7.
  10. Sheets NC, Goldin GH, Meyer AM, Wu Y, Chang YK, Stürmer T, et al. Intensity-modulated radiation therapy, proton therapy, or conformal radiation therapy and morbidity and disease control in localized prostate cancer. JAMA 2012; 307(15): 1611-20.
  11. Hu JC, Gu X, Lipsitz SR, Barry MJ, D’Amico AV, Weinberg AC, et al. Comparative effectiveness of minimally invasive vs open radical prostatectomy. JAMA 2009; 302(14): 1557-64.
  12. Williams SB, Gu X, Lipsitz SR, Nguyen PL, Choueiri TK, Hu JC. Utilization and expense of adjuvant cancer therapies following radical prostatectomy. Cancer 2011; 117(21): 4846-54.
  13. AlDuhaiby EZ, Breen S, Bissonnette JP, Sharpe M, Mayhew L, Tyldesley S, et al. A national survey of the availability of intensity-modulated radiation therapy and stereotactic radiosurgery in Canada. Radiat Oncol 2012; 7(1): 1-6.
  14. Zelefsky MJ, Fuks Z, Happersett L, Lee HJ, Ling CC, Burman CM, et al. Clinical experience with intensity modulated radiation therapy (IMRT) in prostate cancer. Radiother Oncol 2000; 55(3): 241-9.
  15. Fenoglietto P, Laliberte B, Allaw A, Ailleres N, Idri K, Hay MH, et al. Persistently better treatment planning results of intensity-modulated (IMRT) over conformal radiotherapy (3D-CRT) in prostate cancer patients with significant variation of clinical target volume and/or organs-at-risk. Radiother Oncol 2008; 88(1): 77-87.