Advertisement

Differences Between MRI- and CT-Based Delineation of Target Volume and Organs at Risk in High-Dose-Rate Brachytherapy of Cervix

  • Rangarajan RamyaEmail author
  • S. Saravanan
  • J. Vijayalakshmi
  • K. Kumari
Original Article
  • 10 Downloads

Abstract

Aim

With superior soft tissue imaging characteristics, MRI is better than CT in determining the local disease extent during intracavitary brachytherapy of carcinoma cervix. The aim of the study is to evaluate the differences in dimensions and volumes of the target and organs at risk and the subsequent changes in dosimetry between MRI- and CT-based plans.

Methods and Materials

MRI and CT datasets of 34 locally advanced cervical cancer patients taken up for intracavitary brachytherapy between January and September 2017 were analyzed. The target volumes and organs at risk, namely bladder, rectum and sigmoid, were contoured by the same radiation oncologist on both the MRI and CT images as per the GEC ESTRO guidelines. The dimensions of HRCTV, the dose volume parameters of the target and OAR were recorded for the CT and MRI plans.

Results

CT image significantly overestimated the width (p = 0.000) and thickness (p = 0.009) of HRCTV. The volumes of HRCTV (p = 0.000) and IRCTV (p = 0.041) were larger with CT image compared to MRI. There was no statistically significant difference between rectal (p = 0.107) and sigmoid (p = 0.365) volumes on CT and MRI. There was statistically significant difference (all p < 0.05) between the dose received by 100%, 98%, 90% and 50% (D100, D98, D90 and D50, respectively) of HRCTV and IRCTV on CT and MRI. There was statistically significant difference (all p < 0.05) in the dose delivered to the bladder. However, there was no statistically significant difference (all p > 0.05) in the dose received by rectum and sigmoid on CT and MR plans.

Conclusion

MRI-based brachytherapy planning has shown considerable improvements in tumor control and reductions in normal tissue toxicity. However, the high cost of MRI and non-availability of MRI preclude its use in many centers. CT, on the other hand, is widely available, but it can lead to overestimation of the target, at the time of brachytherapy. Hence, it is important to identify the subset of patients who will benefit from MRI-based planning at the time of brachytherapy.

Keywords

HDR brachytherapy Cervical cancer CT planning MRI planning 

Notes

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

References

  1. 1.
    Eifel PJ, Winter K, Morris M, Levenback C, Grigsby PW, Cooper J, et al. Pelvic irradiation with concurrent chemotherapy versus pelvic and para-aortic irradiation for high-risk cervical cancer: an update of radiation therapy oncology group trial (RTOG) 90–01. J Clin Oncol. 2004;22(5):872–80.CrossRefGoogle Scholar
  2. 2.
    Morris M, Eifel PJ, Lu J, Grigsby PW, Levenback C, Stevens RE, et al. Pelvic radiation with concurrent chemotherapy compared with pelvic and para-aortic radiation for high-risk cervical cancer. N Engl J Med. 1999;340(15):1137–43.CrossRefGoogle Scholar
  3. 3.
    Rose PG, Ali S, Watkins E, Thigpen JT, Deppe G, Clarke-Pearson DL, et al. Long-term follow-up of a randomized trial comparing concurrent single agent cisplatin, cisplatin-based combination chemotherapy, or hydroxyurea during pelvic irradiation for locally advanced cervical cancer: a Gynecologic Oncology Group Study. J Clin Oncol. 2007;25(19):2804–10.CrossRefGoogle Scholar
  4. 4.
    Stehman FB, Ali S, Keys HM, Muderspach LI, Chafe WE, Gallup DG, et al. Radiation therapy with or without weekly cisplatin for bulky stage 1B cervical carcinoma: follow-up of a Gynecologic Oncology Group trial. Am J Obstet Gynecol. 2007;197(5):503e1–6.CrossRefGoogle Scholar
  5. 5.
    Lanciano R, Calkins A, Bundy BN, Parham G, Lucci JA 3rd, Moore DH, et al. Randomized comparison of weekly cisplatin or protracted venous infusion of fluorouracil in combination with pelvic radiation in advanced cervix cancer: a gynecologic oncology group study. J Clin Oncol. 2005;23(33):8289–95.CrossRefGoogle Scholar
  6. 6.
    International Commission on Radiation Units and Measurements. Dose and volume specification for reporting intracavitary therapy in gynecology. Vol 38. Bethesda, MD: International Commission on Radiation Units and Measurements; 1985.Google Scholar
  7. 7.
    Haie-Meder C, Potter R, Van Limbergen E, et al. Recommendations from gynaecological (GYN) GEC-ESTRO Working Group (I): concepts and terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTVand CTV. Radiother Oncol. 2005;74:235–45.CrossRefGoogle Scholar
  8. 8.
    Potter R, Haie-Meder C, Van Limbergen E, et al. Recommendations from gynaecological (GYN) GEC ESTRO working group (II): concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology. Radiother Oncol. 2006;78:67–77.CrossRefGoogle Scholar
  9. 9.
    Hricak H, Gatsonis C, Coakley FV, Snyder B, Reinhold C, Schwartz LH, et al. Early invasive cervical cancer: CT and MR imaging in preoperative evaluation: ACRIN/GOG comparative study of diagnostic performance and interobserver variability. Radiology. 2007;245(2):491–8.CrossRefGoogle Scholar
  10. 10.
    Mitchell DG, Snyder B, Coakley F, Reinhold C, Thomas G, Amendola M, et al. Early invasive cervical cancer: tumor delineation by magnetic resonance imaging, computed tomography, and clinical examination, verified by pathologic results, in the ACRIN 6651/GOG 183 Intergroup Study. J Clin Oncol. 2006;24(36):5687–94.CrossRefGoogle Scholar
  11. 11.
    Potter R, Georg P, Dimopoulos JC, Grimm M, Berger D, Nesvacil N, et al. Clinical outcome of protocol based image (MRI) guided adaptive brachytherapy combined with 3D conformal radiotherapy with or without chemotherapy in patients with locally advanced cervical cancer. Radiother Oncol. 2011;100(1):116–23.CrossRefGoogle Scholar
  12. 12.
    Lindegaard JC, Fokdal LU, Nielsen SK, Juul-Christensen J, Tanderup K. MRI-guided adaptive radiotherapy in locally advanced cervical cancer from a Nordic perspective. Acta Oncol. 2013;52(7):1510–9.CrossRefGoogle Scholar
  13. 13.
    Rijkmans EC, Nout RA, Rutten IH, Ketelaars M, Neelis KJ, Laman MS, et al. Improved survival of patients with cervical cancer treated with image-guided brachytherapy compared with conventional brachytherapy. Gynecol Oncol. 2014;135(2):231–8.CrossRefGoogle Scholar
  14. 14.
    Viswanathan AN, Dimopoulos J, Kirisits C, Berger D, Potter R. Computed tomography versus magnetic resonance imaging-based contouring in cervical cancer brachytherapy: results of a prospective trial and preliminary guidelines for standardized contours. Int J Radiat Oncol Biol Phys. 2007;68:491–8.CrossRefGoogle Scholar
  15. 15.
    Hrycushko B, Pinho DF, Pedrosa I, Medin P, Albuquerque K. MRI versus CT contouring of the high-risk CTV for HDR intracavitary brachytherapy of cervical cancer patients: Love’s labor lost in the dose? Abstr. Brachytherapy. 2014;13:S88.CrossRefGoogle Scholar
  16. 16.
    Eskander RN, Scanderbeg D, Saenz CC, Brown M, Yashar C. Comparison of computed tomography and magnetic resonance imaging in cervical cancer brachytherapy target and normal tissue contouring. Int J Gynecol Cancer. 2010;20:47–53.CrossRefGoogle Scholar
  17. 17.
    Yip WWL, Wong JSY, Lee VWY, Wong FCS, Tung SY. Throwing the dart blind-folded: comparison of computed tomography versus magnetic resonance imaging guided brachytherapy for cervical cancer with regard to dose received by the ‘actual’ targets and organs at risk. J Contemp Brachytherapy. 2017;9(5):446–52.CrossRefGoogle Scholar
  18. 18.
    Krishantry R, Patel FD, Singh P, et al. CT or MRI for Image-based brachytherapy in cervical cancer. Jpn J Clin Oncol. 2012;42:309–13.CrossRefGoogle Scholar
  19. 19.
    Fedrico M, Fotina I, Hegazy N, et al. Analysis of spatial agreement between CT-(+ pre-BT MRI) and MRI-based HRCTV delineation in cevix cancer brachytherapy. Radiother Oncol. 2011;99:S57.CrossRefGoogle Scholar
  20. 20.
    Wang F, Tang Q, Lv G, Zhao F, Jiang X, Zhu X, Li X, Yan S. Comparison of computed tomography and magnetic resonance imaging in cervical cancer brachytherapy: a systematic review. Brachytherapy. 2017;16(2):1.CrossRefGoogle Scholar
  21. 21.
    Swanick CW, Castle KO, Vedam S, Munsell MF, Turner LM, Rauch GM, Jhingran A, Eifel PJ, Klopp AH. Comparison of computed tomography- and magnetic resonance imaging-based clinical target volume contours at brachytherapy for cervical cancer. Int J Radiat Oncol Biol Phys. 2016;96(4):793–800.CrossRefGoogle Scholar
  22. 22.
    Viswanathan AN, Erickson B, Gaffney DK, et al. Comparison and consensus guidelines for delineation of clinical target volume for CT- and MR-based brachytherapy in locally advanced cervical cancer. Int J Radiat Oncol Biol Phys. 2014;90(2):320–8.CrossRefGoogle Scholar

Copyright information

© Association of Gynecologic Oncologists of India 2019

Authors and Affiliations

  1. 1.Department of Radiation OncologyGovernment Royapettah HospitalChennaiIndia

Personalised recommendations