IJMPCERO  Vol.2 No.4 , November 2013
Dosimetric Impact of Inter-Fraction Variation in Interstitial HDR Brachytherapy
ABSTRACT

Background: Patient setup errors in External Beam Radiotherapy (EBRT) are minimized to a great extent, due to recent technological developments but in contrary brachytherapy received least attention in inter-fraction catheter movement and its impact in dose delivery. This article deals with inter-fraction interstitial catheter movement and its impact in dose delivery to the target. An attempt is made to study the dosimetric impact of this variation. Objectives: The objective of the study is to evaluate the inter-fraction variation in the position of implanted interstitial applicators and to assess the dosimetric impact in interstitial High Dose Rate (HDR) brachytherapy. Materials and Methods: 55 patients treated for carcinoma tongue, breast, buccal mucosa, cervix, floor of mouth and soft tissue sarcoma over a period of 2 years (December 2011-May 2013) were considered. All the patients underwent CT scan on the next day of the implant and 3D planning was done either by Eclipse or Oncentra Master plan Treatment Planning System (TPS). Patients were treated by HDR brachytherapy remote after-loading units, either by Gamma Med iX plus or Microselectron. At the end of the last fraction, CT scan was repeated and re-planning done. The variation in position of the implanted applicators/catheters and its impact on dosimetric parameters were evaluated and analyzed. Results: The range of positional displacement of the interstitial catheters ranges from 4.5 mm to 6.8 mm. The maximum variation in prescribed dose to D90 of Clinical Target Volume was 10.88%. Conclusions: If the total duration of interstitial implant of HDR brachytherapy extends for more than a week from the day of imaging, it is recommended to do CT imaging and re-plan again. It is mandatory to suture the buttons of the implant to the skin. Edema and movement of organs (e.g., tongue) are the main cause for the positional variation of the catheters.


Cite this paper
S. Kandasamy, K. Reddy, V. Nagarajan, P. Vedasoundaram and G. Karunanidhi, "Dosimetric Impact of Inter-Fraction Variation in Interstitial HDR Brachytherapy," International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Vol. 2 No. 4, 2013, pp. 111-116. doi: 10.4236/ijmpcero.2013.24015.
References
[1]   R. Ortega, A. Loria and R. Kelly, “A Semiglobally Stable Output Feedback PI2D Regulator for Robot Manipulators,” IEEE Transactions on Automatic Control, Vol. 40, No. 8, 1995, pp. 1432-1436.http://dx.doi.org/10.1109/9.402235

[2]   A. Jemal, T. Murray, A. Samuels, A. Ghafoor, E. Ward and M. J. Thun, “Cancer Statistics 2003,” A Cancer Journal for Clinicians, Vol. 53, No. 1, 2003, pp. 5-26.http://dx.doi.org/10.3322/canjclin.53.1.5

[3]   R. G. Dale and B. Jones, “The Clinical Radiobiology of Brachytherapy,” British Journal of Radiology, Vol. 71, No. 845, 1998, pp. 465-483.

[4]   C. A. Joslin, A. Flynn and E. J. Hall, “Principles and Practice of Brachytherapy Using Afterloading Systems,” Arnold, London, 2001.

[5]   E. K Salminen, K. Kiel, G. S. Ibbott, M. C. Joiner, E. Rosenblatt, E. Zubizarreta, et al., International Conference on Advances in Radiation Oncology (ICARO): Outcomes of an IAEA Meeting, Vienna, 27-29 April 2009.http://dx.doi.org/10.1186/1748-717X-6-11

[6]   R. Nath, L. L. Anderson, G. Luxton, K. A. Weaver, J. F. Williamson and A. S. Meigooni, “Dosimetry of Interstitial Brachytherapy Sources: Recommendations of the AAPM Radiation Therapy Committee Task Group No. 43. American Association of Physicists in Medicine,” Medical Physics, Vol. 22, No. 2, 1995, pp. 209-234.http://dx.doi.org/10.1118/1.597458

[7]   F. Rey, C. Chang, C. Mesina, N. Dixit, B. K. Kevin Teo and L. L. Lin, “Dosimetric Impact of Interfraction Catheter Movement and Organ Motion on MRI/CT Guided HDR Interstitial Brachytheratpy for Gynecologic Cancer,” Radiotherapy & Oncology, Vol. 107, No. 1, 2013, pp. 112-116.http://dx.doi.org/10.1016/j.radonc.2012.12.013

[8]   F. Xu, J. Wang, S. Bai, Q.-F. Xu, Y.-L. Shen and R.-M. Zhong, “Interfractional and Intrafractional Setup Errors in Radiotherapy for Tumors Analyzed by Cone-Beam Computed Tomography,” Chinese Journal of Cancer, Vol. 27, No. 10, 2008, pp. 373-376.

[9]   T. R. Slow, C. L. F. Ngol and W. K. T. Tan, “Inter-Fraction Prostate Motion during Internsity-Modulcated Radiotherapy for Prostate Cancer,” Singapore Medical Journal, Vol. 52, No. 6, 2011, p. 405.

[10]   T. Velmurugan, P. Sukumar, C. Krishnappan and R. Boopathy, “Study of Dosimetric Variation Due to Interfraction Organ Movement in High Dose Rate Interstitial (MUPIT) Brachytherapy for Gynecologic Malignancies,” Polish Journal of Medical Physics and Engineering, Vol. 16, No. 2, 2010, pp. 85-95.

[11]   International Commission on Radiation Units and Measurements (ICRU), “Report 58 on Dose Volume Specification for Reporting Interstitial Therapy,” ICRU, Bethesda, 1997, pp. 1-45.

 
 
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