Effect of Non-Delineated Normal Volumes in IMRT Treatment for Left Breast Cancer: A Treatment Planning Study

Tamer Dawod¹, Sabbah I. Hammoury^2*, Mostafa Elnaggar³, Mustafa Kamal⁴

¹Clinical Oncology and Nuclear Medicine Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
²Medical Physics Department, Alexandria Ayadi Almostakbl Oncology Center (AAAOC), Alexandria, Egypt.
³Department of Cancer Management and Research Medical Research Institute, Alexandria University, Alexandria, Egypt.
⁴Metal Physics Lab, Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt.

DOI: 10.4236/ijmpcero.2015.41003                

Abstract

Introduction: Intensity Modulated Radiation Therapy (IMRT) planning dose calculation process depends on IMRT dose constraints. So, if there was any structure along the treatment beam path not delineated, it would not be taken into account during that calculation process. During IMRT routine practical work, it is noticed that there are some non-delineated normal tissue volumes that received un-aimed dose. Aim: The purpose of this study was to study the effect of unusually delineated normal volumes in IMRT treatment for left sided breast cancer. Method: Ten left sided breast cancer patients were planned with IMRT inverse planning system. The unusually delineated normal volumes were delineated and taken into account in IMRT dose constraints as an Organ at Risk. Doses received by that volume were compared in the two methods quantitatively from Dose Volume Histograms (DVHs) and qualitatively from (axial cuts). Results: The results showed that doses received by the unusually delineated volume when they were delineated and taken into account in IMRT dose constraints were significantly higher than when they were not. Conclusions: The results showed that for IMRT planning technique used for treating left-sided breast cancer, all of the normal tissues/structures that are closed to the treatment targets must be delineated and taken into account in the IMRT planning dose constraints.

Keywords

Radiotherapy, IMRT, Linear Accelerator, Treatment Planning System TPS, NTIAV

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Vijayakumar, S. and Chen, G.T. (1995) Implementation of Three Dimensional Conformal Radiation Therapy: Prospects, Opportunities, and Challenges. International Journal of Radiation Oncology Biology Physics, 33, 979-983. http://dx.doi.org/10.1016/0360-3016(95)02060-8
[2]	Prado, K.L., Starkschall, G. and Mohan, R. (2007) Three-Dimensional Conformal Radiation Therapy. In: Khan, F.M., Ed., Treatment Planning in Radiation Oncology, 2nd Edition, Lippincott Williams & Wilkins, Philadelphia, 116-141.
[3]	Tülay, E., Ìefik, ì., Gül, A., et al. (2010) Dosimetric Comparison of Field in Field Intensity-Modulated Radiotherapy Technique with Conformal Radiotherapy Techniques in Breast Cancer. Japanese Journal of Radiology, 28, 283-289. http://dx.doi.org/10.1007/s11604-010-0423-3
[4]	(2014) Intensity-Modulated Radiation Therapy: Medical Policy. Proprietary Information of United Healthcare, Policy Number: 2014T0407M.
[5]	Bucci, M.K., Alison, B. and Mack, R. (2005) Advances in Radiation Therapy: Conventional to 3D, to IMRT, to 4D, and Beyond. CA: A Cancer Journal for Clinicians, 55, 117-134. http://dx.doi.org/10.3322/canjclin.55.2.117
[6]	Khan, F.M. (Ed.) (2010) Physics of Radiation Therapy. 4th Edition, Lippincott Williams & Wilkins, Philadelphia, 431-432.
[7]	Olivier, R., Pauline, R.M., David, A., Norbert, A., Jean-Bernard, D. and Pascal, F. (2013) Simultaneous Integrated Boost Plan Comparison of Volumetric-Modulated Arc Therapy and Sliding Window Intensity-Modulated Radiotherapy for Whole Pelvis Irradiation of Locally Advanced Prostate Cancer. Journal of Applied Clinical Medical Physics, 14, 26-32. http://www.jacmp.org/index.php/jacmp/article/download/4094/2967
[8]	Mercè, B., Mónica, R., Juan, J.R., Santiago, P., Marc, S., Enrique, P., et al. (2012) Dose Variations in Tumor Volumes and Organs at Risk during IMRT for Head-and-Neck Cancer. Journal of Applied Clinical Medical Physics, 13, 1-7. http://dx.doi.org/10.1120/jacmp.v13i6.3723 or http://www.jacmp.org/index.php/jacmp/article/view/3723/2720
[9]	ICRU (1999) International Commission on Radiological Units, Prescribing, Recording and Reporting Photon Beam Therapy. Supplement to ICRU 50, ICRU Report 62, Bethesda.
[10]	Hande, B.A., Metin, G., Cemile, C., Nadir, K. and Kayihan, E. (2011) Comparison of Dose Distributions and Organs at Risk (OAR) Doses in Conventional Tangential Technique (CTT) and IMRT Plans with Different Numbers of Beam in Left-Sided Breast Cancer. Reports of Practical Oncology and Radiotherapy, 16, 95-102. http://dx.doi.org/10.1016/j.rpor.2011.02.001
[11]	Webb, S., Convery, D.J. and Evans, P.M. (1998) Inverse Planning with Constraints to Generate Smoothed Intensity Modulated Beams. Physics in Medicine and Biology, 43, 2785-2794. http://dx.doi.org/10.1088/0031-9155/43/10/008
[12]	Guckenberger, M., Pohl, F., Baier, K., Meyer, J., Vordermark, D. and Flentje, M. (2006) Adverse Effect of a Distended Rectum in Intensity-Modulated Radiotherapy (IMRT) Treatment Planning of Prostate Cancer. Radiotherapy and Oncology, 79, 59-64. http://dx.doi.org/10.1016/j.radonc.2006.03.004
[13]	Sarah, R., Wim, D., Karin, H., et al. (2006) Definition and Delineation of the Clinical Target Volume for Rectal Cancer. International Journal of Radiation Oncology Biology Physics, 65, 1129-1142. http://dx.doi.org/10.1016/j.ijrobp.2006.02.050
[14]	Chui, C.S., Chan, M.F., Yorke, E., Spirou, S. and Ling, C.C. (2001) Delivery of Intensity-Modulated Radiation Therapy with a Conventional Multileaf Collimator: Comparison of Dynamic and Segmental Methods. Medical Physics, 28, 2441-2449. http://dx.doi.org/10.1118/1.1418018
[15]	Jin, G.-H., Chen, L.-X., Deng, X.-W., Liu, X.-W., Huang, Y. and Huang, X.-B. (2013) A Comparative Dosimetric Study for Treating Left-Sided Breast Cancer for Small Breast Size Using Five Different Radiotherapy Techniques: Conventional Tangential Field, Filed-in-Filed, Tangential-IMRT, Multi-Beam IMRT and VMAT. Radiation Oncology, 8, 89. http://dx.doi.org/10.1186/1748-717X-8-89
[16]	Fallon Community Health Plan (2009) Conformal and Intensity Modulated Radiation Therapy (IMRT) of the Breast. Policy number: 200909-0002, 1- 9.
[17]	Alison, L.S., Tomas, K., Alan, H., et al. (2011) Does Inverse-Planned Intensity-Modulated Radiation Therapy Have a Role in the Treatment of Patients with Left-Sided Breast Cancer? Journal of Medical Imaging and Radiation Oncology, 55, 311-319. http://dx.doi.org/10.1111/j.1754-9485.2011.02273.x
[18]	Giorgio, P., Lucag, R., Christian, F., et al. (2011) Geometric and Dosimetric Approach to Determine Probability of Late Cardiac Mortality in Left Tangential Breast Irradiation: Comparison between Wedged Beams and Field-in-Field Technique. International Journal of Radiation Oncology Biology Physics, 81, 894-900. http://dx.doi.org/10.1016/j.ijrobp.2010.12.021
[19]	Rowse, R. (2012) 3D Tangential Wedge Pair Radiotherapy Planning versus 3D Forward Planned IMR T for Breasts in the Reduction of Hot Spots and Cardiac Doses. (A Feasibility Study). Radiography, 18, 68-73. http://dx.doi.org/10.1016/j.radi.2011.12.002