DOI: http://dx.doi.org/10.18203/2320-6012.ijrms20180628

Impact of discrete source step size on the 3D dosimetry of interstitial implants with high dose rate brachytherapy

Anil Kumar Maurya, Rajesh Kumar Maurya, Surendrakumar Dayashankar Maurya, Radha Kesarwani, Virendra Singh

Abstract


ABSTRACT

Background: High dose rate remote after loading brachytherapy machines have seen tremendous advancement both technologically and their clinical applications during the last 25 years. With the introduction of computerized remote after loading machines and computerized planning system, stepping source dosimetry system (SSDS) has become the system of choice making almost all traditional dosimetry systems obsolete. In this study we evaluated the impact of source step size on dosimetry of interstitial implant using parameters of ICRU-58 and various quality indices (QI).

Material & Methods: For this study, 10 implant cases which have 3-D CT image based planning were selected. Contouring of clinical target volume and various organs were done following standard guidelines for the same. Plans were optimized to achieve the desired clinical outcome using different source step sizes of 2.5, 5 and 10 mm respectively. Cumulative DVH’s were calculated for the estimation of various ICRU-58 parameters and quality indices.

Results and Conclusion: The mean values of the target volumes, minimum target doses, treated volumes, low dose volumes; high dose volumes, overdose volumes, reference volumes, coverage, external volume, relative dose homogeneity, overdose volume and COIN indices have been presented for the source step sizes of 2.5 mm, 5 mm and 10 mm respectively. Among source step sizes used in this study, most favorable clinically acceptable dose distributions & dose homogeneity occurs around step size of 5 mm as predicted by the various parameters of ICRU-58 and dose quality indices.

 

Keywords: Brachytherapy, interstitial implant, source step-size, remote after loading, optimization, quality indices.


Keywords


Brachytherapy, interstitial implant, source step-size, remote after loading, optimization, quality indices.

Full Text:

PDF

References


Gerbaulet A et al. (2005). "Cervix carcinoma". In Gerbaulet A, Pötter R, Mazeron J, Limbergen EV. The GEC ESTRO handbook of brachytherapy. Belgium: ACCO.

Ash D et al. (2005). "Prostate cancer". In Gerbaulet A, Pötter R, Mazeron J, Limbergen EV. The GEC ESTRO handbook of brachytherapy. Belgium: ACCO.

Van Limbergen E et al. (2005). "Breast cancer". In Gerbaulet A, Pötter R, Mazeron J, Limbergen EV. The GEC ESTRO handbook of brachytherapy. Belgium: ACCO.

Van Limbergen E et al. (2005). "Skin cancer". In Gerbaulet A, Pötter R, Mazeron J, Limbergen EV. The GEC ESTRO handbook of brachytherapy. Belgium: ACCO.

Gerbaulet A et al. (2005). "General aspects". In Gerbaulet A, Pötter R, Mazeron J, Limbergen EV. The GEC ESTRO handbook of brachytherapy. Belgium: ACCO.

Paterson R, Parker HM. A dosage system for interstitial radium therapy. Br J Radiol 1938; 1: 252-340.

Meredith WJ. Radium Dosage: The Manchester System. Edinburgh: Livingston 1967.

Auer T, Hensler E, Eichberger P, et al. 3D navigation for interstitial stereotaxic brachytherapy. Strahlenth Onkol 1998; 174: 82-7.

Mazeron JJ, Gerbaulet A, Simon JM, Hardiman C. How to optimize therapeutic ratio in brachytherapy of head and neck squamous cell carcinoma? Actual Oncol 1998; 37: 583-91.

Thomas I, Chemin A, Lasbareilles O, et al. MRI and CT scan imaging during pulsed dose rate intracavitary brachytherapy in carcinoma of the cervix. Radiother Oncol 1998; 47 (suppl. 1): 8.

Nag S. Principles and practice of brachytherapy 1997. New York: Futura Publishing Company.

Resch A, Pötter R, Van Limbergen E, et al. Long Term Results (10 years) of Intensive Breast Conserving Therapy Including a High Dose and Large Volume Interstitial Brachytherapy Boost (LDR/HDR) for T1/T2-Breast Cancer Radiother Oncol. 2002 Apr;63(1):47-58.

Saw CB, Suntharalingam N. Reference dose rate for single- and double-plane Ir-192 implants. Med Phys 1988;15:391–396.

ICRU report 38. Bethesda, MD: International Commission on Radiation Units and Measurements; 1985; 1-20.

ICRU, International Commission on Radiation Units and Measurements, "Dose and volume specification for reporting interstitial therapy". ICRU Report 58 1997; Bethesda, Maryland, USA.

Wambersie A, Battermann JJ. Dose specification and reporting: the ICRU recommendations. Principles and practice of brachytherapy, using afterloading systems 2001; in Joslin CA, Flynn A, Hall EJ. (eds), Arnold, London: 81-102.

Saw CB, Suntharalingam N. Quantitative assessment of interstitial implants. Int J Radiat Oncol Biol Phys 1991;20:135–139.

Wu A, Ulin K, Sternick ES. A dose homogeneity index for evaluating Ir-192 interstitial breast implants. Med Phys 1988;15:104–107

Meertens H, Borger J, Steggerda M, Blom A. Evaluation and optimization on interstitial brachytherapy dose distributions. In: Mould RF, Battermann JJ, Martinez AA, Speiser BL, editors. Brachytherapy from radium to optimization, Veenendaal: Nucletron International B.V, 1994. pp. 300–306.

Mazeron JJ, Gerbaulet A, Simon JM, Hardiman C. How to optimize therapeutic ratio in brachytherapy of head and neck squamous cell carcinoma? Actual Oncol 1998; 37: 583-91.

Baltas D., Kolotas C., Geramani K. et. al, A Confirmality Index (COIN) to evaluate implant quality and dose specification in brachytherapy. Int J Radiat Oncol Biol Phys 1998, 40, 515 – 524.

Loic Feuvret, Georges Noel, Jean-Jacques Mazeron, Pierre Bey; Confirmality Index: A Review; Int J Radiat Oncol Biol Phys 2006, 64(2), 333 – 342.

Ravinder Nath, Lowell L. Anderson, Gary Luxton, Keith A. Weaver, Jeffrey F. Williamson, Ali S. Meigooni; Dosimetry of interstitial brachytherapy sources: Recommendations of the AAPM Radiation Therapy Committee Task Group No. 43; Med. Phys. 22 (2), February 1995, 209-234.

Kestin LL1, Jaffray DA, Edmundson GK, Martinez AA, Wong JW, Kini VR, Chen PY, Vicini FA;

Improving the dosimetric coverage of interstitial high-dose-rate breast implants; Int J Radiat Oncol Biol Phys. 2000 Jan 1;46(1):35-43.

Nag S. (2004). "High dose rate brachytherapy: its clinical applications and treatment guidelines". Technology in Cancer Research and Treatment 3 (3): 269–87. PMID 15161320 (http://www.ncbi.nlm.nih.gov /pubmed/15161320).

Tibor Major, Csaba Polgar, Janos Fodor, Andras Somogyi, Gyorgy Nemeth; Confirmality and homogeneity of dose distributions in interstitial implants at idealized target volumes: a comparison between the Paris and dose-point optimized systems; Radiotherapy and Oncology, 62, 2002, 103-111.

Than S. Kehwar1, Syed F. Akber, Kamlesh Passi; Qualitative Dosimetric and Radiobiological Evaluation of High – Dose –Rate Interstitial brachytherapy Implants; Int. J. Med. Sci. 2008, 5, 41-49.

Sang-June Park, Mitchell Kamrava, Robyn Banerjee, D. Jeffrey Demanes; Effects of Source Step Size on Dose Distribution in High-Dose-Rate Brachytherapy for Esophageal Cancer; Brachytherapy March–April, 2013Volume 12, Supplement 1, Page S60.