Document Type : Original Research
Authors
1 MSc, Assistant Professor, Department of Radiotherapy, King George’s Medical University,Lucknow, Uttar Pradesh, India
2 PhD, Professor of Medical Physics, Department of Radiotherapy King George’s Medical University, Lucknow, Uttar Pradesh, India
3 PhD, Senior Scientist, Department of Radiation Oncology Dr. Ram Manohar Lohia Institute of Medical Sciences,Lucknow, Uttar Pradesh India
4 MD, Professor of Radiation Oncology, Department of Radiotherapy King George’s Medical University, Lucknow, Uttar Pradesh, India
5 PhD, Assistant Professor of Medical Physics, Department of Radiotherapy King George’s Medical University, Lucknow, Uttar Pradesh, India
6 MD, Associate Professor of Radiation Oncology, Department of Radiotherapy King George’s Medical University, Lucknow, Uttar Pradesh, India
7 MD, Vice Chancellor, Professor of Radiation Oncology King George’s Medical University, Lucknow, Uttar Pradesh, India
Abstract
Background: Brachytherapy treatment planning in cervix carcinoma patients using two dimensional (2D) orthogonal images provides only point dose estimates while CT-based planning provides volumetric dose assessment helping in understanding the correlation between morbidity and the dose to organs at risk (OARs) and treatment volume.
Objective: Aim of present study is to compare International Commission on Radiation Units and Measurements Report 38 (ICRU 38) reference point doses to OARs with volumetric doses using 2D images and CT images in patients with cervical cancer.
Material and Methods: In this prospective study, 20 patients with cervical cancer stages (IIB-IIIB) were planned for a brachytherapy dose of 7Gy per fraction for three fractions using 2D image-based treatment plan and CT-based plan. ICRU 38 points for bladder and rectum were identified on both 2D image-based plan and CT-based plan and doses (DICRU) at these points were compared to the minimum dose to 2cc volume (D2cc) of bladder and rectum receiving the highest dose.
Results: D2cc bladder dose was 1.60 (±0.67) times more than DICRUb bladder dose whereas D2cc rectum dose was 1.13±0.40 times DICRUr. Significant difference was found between DICRUb and D2cc dose for bladder (p=.0.016) while no significant difference was seen between DICRUr and D2cc dose for rectum (p=0.964).
Conclusion: The study suggests that ICRU 38 point doses are not the true representation of maximum doses to OARs. CT-based treatment planning is more a reliable tool for OAR dose assessment than the conventional 2D radiograph-based plan.
Keywords
- Wachter-Gerstner N, Wachter S, Reinstadler E, Fellner C, Knocke TH, Wambersie A, et al. Bladder and rectum dose defined from MRI based treatment planning for cervix cancer brachytherapy: comparison of dose-volume histograms for organ contours and organ wall, comparison with ICRU rectum and bladder reference point. Radiother Oncol. 2003;68:269-76. PubMed PMID: 13129634.
- Jamema SV, Saju S, Mahantshetty U, Pallad S, Deshpande DD, Shrivastava SK, et al. Dosimetric evaluation of rectum and bladder using image-based CT planning and orthogonal radiographs with ICRU 38 recommendations in intracavitary brachytherapy. J Med Phys. 2008;33:3-8. doi: 10.4103/0971-6203.39417. PubMed PMID: 20041045; PubMed Central PMCID: PMC2786096.
- Madan R, Pathy S, Subramani V, Sharma S, Mohanti BK, Chander S, et al. Comparative evaluation of two-dimensional radiography and three dimensional computed tomography based dose-volume parameters for high-dose-rate intracavitary brachytherapy of cervical cancer: a prospective study. Asian Pac J Cancer Prev. 2014;15:4717-21. PubMed PMID: 24969909.
- Onal C, Arslan G, Topkan E, Pehlivan B, Yavuz M, Oymak E, et al. Comparison of conventional and CT-based planning for intracavitary brachytherapy for cervical cancer: target volume coverage and organs at risk doses. J Exp Clin Cancer Res. 2009;28:95. doi: 10.1186/1756-9966-28-95. PubMed PMID: 19570212; PubMed Central PMCID: PMC2711061.
- Hashim N, Jamalludin Z, Ung NM, Ho GF, Malik RA, Phua V. CT based 3-dimensional treatment planning of intracavitary brachytherapy for cancer of the cervix: comparison between dose-volume histograms and ICRU point doses to the rectum and bladder. Asian Pac J Cancer Prev. 2014;15:5259-64.
- Tan YI, Choo BA, Lee KM. 2D to 3D Evaluation of Organs at Risk Doses in Intracavitary Brachytherapy for Cervical Cancer. J Contemp Brachytherapy. 2010;2:37-43. doi: 10.5114/jcb.2010.13721. PubMed PMID: 28031742; PubMed Central PMCID: PMC5183646.
- Fellner C, Potter R, Knocke TH, Wambersie A. Comparison of radiography- and computed tomography-based treatment planning in cervix cancer in brachytherapy with specific attention to some quality assurance aspects. Radiother Oncol. 2001;58:53-62. PubMed PMID: 11165682.
- Vinod SK, Caldwell K, Lau A, Fowler AR. A comparison of ICRU point doses and volumetric doses of organs at risk (OARs) in brachytherapy for cervical cancer. J Med Imaging Radiat Oncol. 2011;55:304-10. doi: 10.1111/j.1754-9485.2011.02272.x. PubMed PMID: 21696566.
- Pelloski CE, Palmer M, Chronowski GM, Jhingran A, Horton J, Eifel PJ. Comparison between CT-based volumetric calculations and ICRU reference-point estimates of radiation doses delivered to bladder and rectum during intracavitary radiotherapy for cervical cancer. Int J Radiat Oncol Biol Phys. 2005;62:131-7. doi: 10.1016/j.ijrobp.2004.09.059. PubMed PMID: 15850913.
- Barillot I, Horiot JC, Maingon P, Bone-Lepinoy MC, Vaillant D, Feutray S. Maximum and mean bladder dose defined from ultrasonography. Comparison with the ICRU reference in gynaecological brachytherapy. Radiother Oncol. 1994;30:231-8. PubMed PMID: 8209007.
- Kim RY, Pareek P. Radiography-based treatment planning compared with computed tomography (CT)-based treatment planning for intracavitary brachytherapy in cancer of the cervix: analysis of dose-volume histograms. Brachytherapy. 2003;2:200-6. doi: 10.1016/j.brachy.2003.06.001. PubMed PMID: 15062127.
- Ling CC, Schell MC, Working KR, Jentzsch K, Harisiadis L, Carabell S, et al. CT-assisted assessment of bladder and rectum dose in gynecological implants. Int J Radiat Oncol Biol Phys. 1987;13:1577-82. PubMed PMID: 3624031.
- Schoeppel SL, LaVigne ML, Martel MK, McShan DL, Fraass BA, Roberts JA. Three-dimensional treatment planning of intracavitary gynecologic implants: analysis of ten cases and implications for dose specification. Int J Radiat Oncol Biol Phys. 1994;28:277-83. PubMed PMID: 8270452.
- Van Den Bergh F, Meertens H, Moonen L, Van Bunningen B, Blom A. The use of a transverse CT image for the estimation of the dose given to the rectum in intracavitary brachytherapy for carcinoma of the cervix. Radiother Oncol. 1998;47:85-90. PubMed PMID: 9632298.
- Deshpande DD, Shrivastav SK, Pradhan AS, Viswanathan PS, Dinshaw KA. Dosimetry of intracavitary applications in carcinoma of the cervix: rectal dose analysis. Radiother Oncol. 1997;42:163-6. PubMed PMID: 9106925.
- Mahantshetty U, Tiwana MS, Jamema S, Mishra S, Engineer R, Deshpande D, et al. Additional rectal and sigmoid mucosal points and doses in high dose rate intracavitary brachytherapy for carcinoma cervix: a dosimetric study. J Cancer Res Ther. 2011;7:298-303. doi: 10.4103/0973-1482.87027. PubMed PMID: 22044811.
- Cheng JC, Peng LC, Chen YH, Huang DY, Wu JK, Jian JJ. Unique role of proximal rectal dose in late rectal complications for patients with cervical cancer undergoing high-dose-rate intracavitary brachytherapy. Int J Radiat Oncol Biol Phys. 2003;57:1010-8. PubMed PMID: 14575832.
- Krishnatry R, Patel FD, Singh P, Sharma SC, Oinam AS, Shukla AK. CT or MRI for image-based brachytherapy in cervical cancer. Jpn J Clin Oncol. 2012;42:309-13. doi: 10.1093/jjco/hys010. PubMed PMID: 22348889.
- 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. doi: 10.1016/j.ijrobp.2006.12.021. PubMed PMID: 17331668.
- Esche BA, Crook JM, Isturiz J, Horiot J-C. Reference volume, milligram-hours and external irradiation for the Fletcher applicator. Radiother Oncol. 1987;9:255-61.
- Shin KH, Kim TH, Cho JK, Kim JY, Park SY, et al. CT-guided intracavitary radiotherapy for cervical cancer: Comparison of conventional point A plan with clinical target volume-based three-dimensional plan using dose-volume parameters. Int J Radiat Oncol Biol Phys. 2006;64:197-204. doi: 10.1016/j.ijrobp.2005.06.015. PubMed PMID: 16169676.
)