Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-20T04:05:35.477Z Has data issue: false hasContentIssue false
  • English
  • Français

Does inadequate Point-A dose warrant treatment plan modifications in CT-image-based cervix high dose-rate brachytherapy planning? A dosimetric perspective

Published online by Cambridge University Press:  07 June 2013

R. Yaparpalvi ,
K. J. Mehta ,
S. Mutyala ,
H. C. Kuo ,
L. Hong  and
S. Kalnicki
R. Yaparpalvi*
Affiliation:
Department of Radiation Oncology, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY, USA
K. J. Mehta
Affiliation:
Department of Radiation Oncology, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY, USA
S. Mutyala
Affiliation:
Department of Radiation Oncology, Scott & White Healthcare, Texas A&M Health Science Center, Temple, TX, USA
H. C. Kuo
Affiliation:
Department of Radiation Oncology, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY, USA
L. Hong
Affiliation:
Department of Radiation Oncology, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY, USA
S. Kalnicki
Affiliation:
Department of Radiation Oncology, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY, USA
*
Correspondence to: Ravindra Yaparpalvi, Department of Radiation Oncology, Montefiore Medical Center, 111 East 210th Street, Bronx, New York 10467, USA. Tel: +718-920-7750. Fax: +718-882-6914. E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Background and purpose

To investigate whether inadequate dose to Point-A necessitates treatment plan changes in a time of computed tomography (CT)-image-guided brachytherapy treatment planning for cervix cancer.

Materials and methods

A total of 125 tandem and ovoid insertions from 25 cervix patients treated were reviewed. CT-image-based treatment planning was carried out for each insertion. Point-A is identified and the dose documented; however, dose optimisation in each plan was based on covering target while limiting critical organ doses (PlanTarget). No attempts were made to equate prescription and Point-A dose. For each insertion, a second hypothetical treatment plan was generated by prescribing dose to Point-A (PlanPoint-A). Plans were inter-compared using dose–volume histogram analyses.

Results

A total of 250 treatment plans were analysed. For the study population, the median cumulative dose at Point-A was 80 Gy (range 70–95) for PlanTarget compared with 84·25 Gy for PlanPoint-A. Bladder and rectal doses were higher for PlanPoint-A compared with PlanTarget (p < 0·0001). Target D90 did not correlate with Point-A dose (p = 0·60).

Conclusions

Depending on applicator geometry, tumour size and patient anatomy, Point-A dose may vary in magnitude compared with prescription dose. Treatment plan modifications purely based on inadequate Point-A dose are unnecessary, as these may result in higher organ-at-risk doses and not necessarily improve target coverage.

Keywords

cervixdose prescriptionHDRpointvolume
Type
Original Articles
Information
Journal of Radiotherapy in Practice , Volume 12 , Issue 4 , December 2013 , pp. 318 - 325
Copyright
Copyright © Cambridge University Press 2013 

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.Eifel, P J, Thoms, W W Jr, Smith, T Let al. The relationship between brachytherapy dose and outcome in patients with bulky endocervical tumors treated with radiation alone. Int J Radiat Oncol Biol Phys 1994; 28: 113–118.CrossRefGoogle ScholarPubMed
2.Haie-Meder, C, Potter, R, van Limbergen, Eet al. Recommendations from the gynecological (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 GTV and CTV. Radiother Oncol 2005; 74 (3): 235–245.CrossRefGoogle Scholar
3.Viswanathan, A N, Erickson, B A. Three-dimensional imaging in gynecologic brachytherapy: a survey of the American Brachytherapy Society. Int J Radiat Oncol Biol Phys 2010; 76: 104–109.CrossRefGoogle ScholarPubMed
4.Pearce, A, Craighead, P, Kay, Iet al. Brachytherapy for carcinoma of the cervix: a Canadian survey of practice patterns in a changing era. Radiother Oncol 2009; 81: 194–196.CrossRefGoogle Scholar
5.Saarnak, A E, Boersma, M, van Bunningen, B N F Met al. Inter-observer variation in delineation of bladder and rectum contours for brachytherapy of cervical cancer. Radiother Oncol 2000; 56: 37–42.CrossRefGoogle ScholarPubMed
6.Mai, J, Erickson, B, Rownd, Jet al. Comparison of four different dose specification methods for high-dose-rate intracavitary radiation for treatment of cervical cancer. Int J Radiat Oncol Biol Phys 2001; 51: 1131–1141.CrossRefGoogle Scholar
7.Yoshida, K, Yamazaki, H, Takenaka, Tet al. A dose-volume analysis of magnetic resonance imaging-aided high-dose-rate image-based interstitial brachytherapy for uterine cervical cancer. Int J Radiat Oncol Biol Phys 2010; 77: 765–772.CrossRefGoogle ScholarPubMed
8.Jurgenliemk-Schulz, I M, Lang, S, Tanderup, Ket al. Variation of treatment planning parameters (D90 HR-CTV, D2cc for OAR) for cervical cancer tandem ring brachytherapy in a multicenter setting: comparison of standard planning and 3D image guided optimization based on a joint protocol for dose-volume constraints. Radiother Oncol 2010; 94: 339–345.CrossRefGoogle Scholar
9.Tanderup, K, Nielsen, S K, Nyvang, G Bet al. From point A to the sculpted pear: MR image guidance significantly improves tumour dose and sparing of organs at risk in brachytherapy of cervical cancer. Radiother Oncol 2010; 94: 173–180.CrossRefGoogle Scholar
10.Barillot, I, Horiot, J C, Maingon, Pet al. Maximum and mean bladder dose defined by ultrasonography. Comparison with ICRU reference in gynecological brachytherapy. Radiother Oncol 1994; 30: 231–238.CrossRefGoogle Scholar
11.Ling, C C, Shell, M C, Working, K Ret al. CT-assisted assessment of the bladder rectum dose in gynecological implants. Int J Radiat Onc Biol Phys 1987; 13: 1577–1582.CrossRefGoogle ScholarPubMed
12.Pelloski, C E, Palmer, M, Chronowski, G Met al. 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: 131–137.CrossRefGoogle ScholarPubMed
13.Wachter-Gerstner, N, Wachter, S, Reinstadler, Eet 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: 269–276.CrossRefGoogle ScholarPubMed
14.Yaparpalvi, R, Mutyala, S, Gorla, G Ret al. Point vs. volumetric bladder and rectal doses in combined intracavitary-interstitial high-dose-rate brachytherapy: correlation and comparison with published Vienna applicator data. Brachytherapy 2008; 7: 336–342.CrossRefGoogle ScholarPubMed
15.Koom, W, Sohn, D K, Kim, J-Yet al. Computed tomography-based high-dose rate intracavitary brachytherapy for uterine cervical cancer: preliminary demonstration of correlation between dose-volume parameters and rectal mucosal changes observed by flexible sigmoidoscopy. Int J Radiat Oncol Biol Phys 2007; 68: 1446–1454.CrossRefGoogle ScholarPubMed
16.Huang, E Y, Lin, H, Hsu, H Cet al. High external parametrial dose can increase the probability of radiation proctitis in patients with uterine cervix cancer. Gynecol Oncol 2000; 79: 406–410.CrossRefGoogle ScholarPubMed
17.Fenkell, L, Assenholt, M, Nielsen, S Ket al. Parametrial boost using midline shielding results in an unpredictable dose to tumor and organs at risk in combined external beam radiotherapy and brachytherapy for locally advanced cervical cancer. Int J Radiat Oncol Biol Phys 2011; 79: 1572–1579.CrossRefGoogle Scholar
18.Viswanathan, A N, Dimopoulos, J, Kirisits, Cet al. Computed tomography versus magnetic resonance imaging-based contouring in cervical cancer brachytherapy: results of a prospective trial and preliminary guidelines for standard contours. Int J Radiat Oncol Biol Phys 2007; 68: 491–498.CrossRefGoogle ScholarPubMed
19.Anker, C J, Cachoeira, C V, Boucher, K Met al. Does the entire uterus need to be treated in cancer of the cervix? Role of adaptive brachytherapy. Int J Radiat Oncol Biol Phys 2010; 76: 704–712.CrossRefGoogle ScholarPubMed
20.Dimopoulos, J C A, Lang, S, Kirisits, Cet al. Dose-volume histogram parameters and local tumor control in magnetic resonance image-guided cervical cancer brachytherapy. Int J Radiat Oncol Biol Phys 2009; 75 (1): 56–63.CrossRefGoogle ScholarPubMed
21.Tanderup, K, Georg, D, Potter, Ret al. Adaptive management of cervical cancer radiotherapy. Semin Radiat Oncol 2010; 20 (2): 121–129.CrossRefGoogle ScholarPubMed