There are many situations in radiotherapy where multiple treatment plans need to be compared for selection of an optimal plan. In this study we performed the radiobiological method of plan evaluation to verify the treatment plan comparison procedure of our clinical practice. We estimated and correlated various radiobiological dose indices with physical dose metrics for a total of 30 patients representing typical cases of head and neck, prostate and brain tumors. Three sets of plans along with a clinically approved plan (final plan) treated by either Intensity Modulated Radiation Therapy (IMRT) or Rapid Arc (RA) techniques were considered. The study yielded improved target coverage for final plans, however, no appreciable differences in doses and the complication probabilities of organs at risk were noticed. Even though all four plans showed adequate dose distributions, from dosimetric point of view, the final plan had more acceptable dose distribution. The estimated biological outcome and dose volume histogram data showed least differences between plans for IMRT when compared to RA. Our retrospective study based on 120 plans, validated the radiobiological method of plan evaluation. The tumor cure or normal tissue complication probabilities were found to be correlated with the corresponding physical dose indices.
If the inline PDF is not rendering correctly, you can download the PDF file here.
 Yu CX. Intensity modulated arc therapy: A new method for delivering conformal radiation therapy. The theory & practice of intensity modulated radiation therapy. Madison WI: Advanced Medical Publishing; 1997:107-20.
 Mavroidis P Lind BK Brahme A. Biologically effective uniform dose (D) for specification report and comparison of dose response relations and treatment plans. Phys Med Biol. 2001;46(10):2607-2630.
 Mohan R Wang X Jackson A et al. The potential and limitations of the inverse radiotherapy technique. Radiother Oncol. 1994;32(3):232-348.
 Vineberg KA Eisbruch A Coselmon MM et al. Is uniform target dose possible in IMRT plans in the head and neck? Int J Radiat Oncol Biol Phys. 2002;52(5):1159-1172.
 Miften MM Das SK Su M et al. A dose-volume based tool for evaluating and ranking IMRT treatment plans. J Appl Clin Med Phys. 2004;5(4):1-14.
 Mayo C Yorke E Merchant TE. Radiation associated brainstem injury. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S36-S41.
 Mayo C Martel MK Marks LB et al. Radiation dose–volume effects of optic nerves and chiasm. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S28-S35.
 Kirkpatrick JP van der Kogel AJ Schultheiss TE. Radiation dose-volume effects in the spinal cord. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S42-S49.
 Bhandare N Jackson A Eisbruch A et al. Radiation therapy and hearing loss. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S50-S57.
 Emami B Lyman J Brown A et al. Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys. 1991;21(1):109-122.
 Rubin P. Law and order of radiation sensitivity: absolute versus relative. In: Vaeth JM Meyer JL eds. Frontiers of radiation therapy and oncology. Basel: Karger;1989:7-40.
 Deasy JO Moiseenko V Marks L et al. Radiotherapy dose–volume effects on salivary gland function. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S58-S63.
 Lawton CA Michalski J El-Naqa I et al. RTOG GU Radiation oncology specialists reach consensus on pelvic lymph node volumes for high-risk prostate cancer. Int J Radiat Oncol Biol Phys. 2009;74(2):383-387.
 Viswanathan AN Yorke ED Marks LB et al. Radiation dose–volume effects of the urinary bladder. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S116-S122.
 Michalski JM Gay H Jackson A et al. Radiation dose–volume effects in radiation-induced rectal injury. Int J Radiat Oncol Biol Phys. 2010;76(3Suppl):S123-S129.
 Niemierko A. Reporting and analyzing dose distributions: a concept of equivalent uniform dose. Med Phys. 1997;24(1):103-110.
 Thames HD Zhang M Tucker SL et al. Cluster models of dose–volume effects. Int J Radiat Oncol Biol Phys.. 2004;59(5):1491-1504.
 Lyman JT. Complication probability as assessed from dose-volume histograms. Radiat Res Suppl. 1985;8:S13-S19.
 Niemierko A Goitein M. Modeling of normal tissue response to radiation: the critical volume model. Int J Radiat Oncol Biol Phys. 1993;25(1):135-145.
 Anbumani S Raj NA Prabhakar GS et al. Quantification of uncertainties in conventional plan evaluation methods in Intensity Modulated Radiation Therapy. J BUON. 2014;19(1):297-303.
 Gay HA Niemierko A. A free program for calculating EUD-based NTCP and TCP in external beam radiotherapy. Physica Medica. 2007;23(3):115-125.
 Niemierko A. A generalized concept of equivalent uniform dose (EUD). Med Phys. 1999;26(6):1100.
 Oinam AS Singh L Shukla A et al. Dose volume histogram analysis and comparison of different radiobiological models using in-house developed software. J Med Phys. 2011;36(4):220-229.
 Rana S Cheng C. Radiobiological impact of planning techniques for prostate cancer in terms of tumor control probability and normal tissue complication probability. Ann Med Health Sci Res. 2015;4(2):167-172.
 Jaganathan A Tiwari M Phansekar R et al. Intensity-modulated radiation to spare neural stem cells in brain tumors: a computational platform for evaluation of physical and biological dose metrics. J Cancer Res Ther. 2011;7(1):58-63.
 Kehwar TS. Analytical approach to estimate normal tissue complication probability using best fit of normal tissue tolerance doses into the NTCP equation of the linear quadratic model. J Cancer Res Ther. 2005;1(3):168-179.
 Rana S Rogers K. Radiobiological evaluation of dose calculation algorithms in Rapid Arc planning of esophageal cancer treatment plans. J Solid Tumors. 2013;3(3):44-52.
 Akpati HC Kim C Kim B et al. Unified dosimetry index (UDI): a figure of merit for ranking treatment plans. J Appl Clin Med Phys. 2008;9(3):99-108.