Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-28T02:52:49.076Z Has data issue: false hasContentIssue false

The effect of leg position on the dose distribution of intracavitary brachytherapy for cervical cancer: 3D computerised tomography plan evaluation and in vivo dosimetric study

Published online by Cambridge University Press:  20 May 2016

Mustafa Cengiz*
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Fatma Colak
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Demet Yildiz
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Ali Dogan
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Gokhan Ozyigit
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Ferah Yildiz
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
Murat Gurkaynak
Affiliation:
Department of Radiation Oncology, Hacettepe University, Ankara, Turkey
*
Correspondence to: Mustafa Cengiz, Faculty of Medicine, Department of Radiation Oncology, Hacettepe University, 06100 Sihhiye, Ankara, Turkey. E-mail: [email protected]

Abstract

Purpose

To evaluate the impact of leg position on the dose distribution during intracavitary brachytherapy for cervical cancer.

Patients and methods

This prospective study was performed on 11 women with cervical cancer who underwent intracavitary brachytherapy. After insertion of the brachytherapy applicator, two sets of computed tomography slices were taken including pelvis, one with straight leg and one with leg flexion position with knee support. The dose (7 Gy) was prescribed to point A. The radiotherapy plan was run on the Plato Planning Software System V14·1 to get the dose distributions. Also, rectum and bladder doses were measured for both leg positions during the treatment. The doses and volumes of organs were compared via the Wilcoxon signed-rank test by using Statistical Package for the Social Sciences 11·5 statistical software.

Results

No significant difference regarding the dose distributions and volumes of target, sigmoid and bladder due to leg position was observed, either on 3D planning or on in vivo dose measurements. However, there were significant differences for 25 and 50% isodose coverage of rectum in favour of straight leg position (p=0·026). There were no significant differences regarding maximum doses in any critical organ.

Conclusion

Difference in leg position caused only a small change in rectum dose distribution and did not cause any other change in either dose distributions or in vivo measured doses of both target and critical organs during cervical brachytherapy. Straight leg position appears better with regard to rectum dose.

Type
Original Articles
Copyright
© Cambridge University Press 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Atahan, IL, Yildiz, F, Ozyar, E et al. Radiotherapy in the adjuvant setting of cervical carcinoma: treatment, results, and prognostic factors. Int J Gynecol Cancer 2007; 17: 813820.Google Scholar
2. Okkan, S, Atkovar, G, Sahinler, I et al. Results and complications of high dose rate and low dose rate brachytherapy in carcinoma of the cervix: cerrahpasa experience. Radiother Oncol 2003; 67: 97105.Google Scholar
3. Weeks, KJ, Montana, GS. Three-dimensional applicator system for carcinoma of the uterine cervix. Int J Radiat Oncol Biol Phys 1997; 37: 455463.Google Scholar
4. Cengiz, M, Gurdalli, S, Selek, U et al. Effect of bladder distension on dose distribution of intracavitary brachytherapy for cervical cancer: three-dimensional computed tomography plan evaluation. Int J Radiat Oncol Biol Phys 2008; 70: 464468.Google Scholar
5. Schoeppeel, SL, La Vigne, ML, Martel, MK et al. Three-dimensional treatment planning of intracavitary gynecologic implants: analysis of ten cases and implications for dose specification. Int J Radiat Oncol Biol Phys 1993; 28: 277283.Google Scholar
6. Cengiz, M, Selek, U, Genc, M et al. Comment on ‘Correlation between the treated volume, the GTV and the CTV at the time of brachytherapy and histopathologic findings in 33 patients with operable cervix carcinoma’. Radiother Oncol 2005; 75: 367368.Google Scholar
7. Pelloski, CE, Palmer, M, Chronowski, GM et al. Comparison between CT-based volumetric calculations and ICRU reference-point estimates of radiation dose delivered to bladder and rectum during intracavitary radiotherapy for cervical cancer. Int J Radiat Oncol Biol Phys 2005; 62: 131137.Google Scholar
8. Nag, S, Gardenes, H, Chang, S et al. Proposed guidelines for image-based intracavitary brachytherapy for cervical carcinoma: report from image-guided bracyhtherapy working group. Int J Radiat Oncol Biol Phys 2004; 60: 11601172.Google Scholar
9. Pötter, R, Haie-Meder, C, Limbergen, E et al. Recommendations from gynecological (GYN) GEC ESTRO working group (II): concepts and terms in 3D image-based treatment planning in cervix cancer bracyhterapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology. Radiother Oncol 2006; 78: 6777.Google Scholar
10. Steenbakkers, RJ, Duppen, JC, Betgen, A et al. Impact of knee support and shape of table top on rectum and prostate position. Int J Radiat Oncol Biol Phys 2004; 60: 13641372.Google Scholar
11. Nag, S, Erickson, B, Thomadsen, B et al. The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix. Int J Radiat Oncol Biol Phys 2000; 48: 201211.Google Scholar
12. Chao, KS, Cengiz, M, Herzog, T. Gynocologic tumors. In Gregoire V, Scalliet P, Ang KK (eds) Clinical Target Volumes Conformal and Intensity Modulated Radiation Therapy. Berlin: Springer, 2004; pp. 171186.Google Scholar
13. Schoeppel, SL, LaVigne, ML, Martel, MK et al. 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: 277283.Google Scholar
14. Thomadsen, BR, Shahabi, S, Stitt, JA et al. High dose rate brachytherapy for carcinoma of the cervix: the Madison system-II – procedural and physical considerations. Int J Radiat Oncol Biol Phys 1992; 24: 349357.CrossRefGoogle ScholarPubMed
15. Pham, HT, Chen, Y, Rouby, E et al. Changes in high dose rate tandem and ovoid applicator positions during treatment in an unfixed brachytherapy system. Radiology 1998; 206: 525531.Google Scholar
16. Cheng, JC, Peng, LC, Chen, YH et al. 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: 10101018.Google Scholar
17. Wang, X, Liu, R, Yank, K et al. High dose rate versus low dose rate intracavity brachytherapy for locally advanced uterine cervix cancer. Cochrane Database Syst Rev 2010; 7: CD 007563.Google Scholar
18. Usla, CW, Wabersieb, A, Potter, R, Georg, D. In-vivo dosimetry for gynaecological brachytherapy: physical and clinical considerations. Radiother Oncol 2005; 77: 310317.Google Scholar