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Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
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Biomedical Science and Engineering

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Photon Dose Calculation Algorithms in the Presence of Low-Density Heterogeneity-a Mini Literature Review

Chang Lau

Department of Clinical Research, Hebeii Hospital, Shijiazhuang, China

Abstract: Dose prediction accuracy in photon dose calculation algorithms is important to ensure accurate delivery of prescribed dose to the tumor during radiation therapy. The main objective of this article is to provide a brief review on most recent dose calculation algorithm called Acuros XB, which is used to calculate the cancer treatment plans in external beam radiation therapy.

Keywords: Acuros XB, dose Calculation, AAA

Received November 10, 2013; Revised January 07, 2014; Accepted January 17, 2014

Citation: Chang Lau, Photon Dose Calculation Algorithms in the Presence of Low-Density Heterogeneity-a Mini Literature Review. Applied Mathematics and Physics, 2 (1). 13-14. January 2014. doi:10.12691/amp-2-1-4

1. Introduction

The primary goal in radiotherapy is to maximize the tumor control while minimizing the dose to the organs at risk (OARs). Dose calculation algorithms employed in treatment planning systems (TPS) play an important role in predicting the radiation dose to the tumor. Hence, inaccurate dose prediction by the dose calculation algorithms may lead to unwanted radiation dose to the normal tissues or reduced dose to the tumor. This will ultimately lead to unfavorable clinical results.

Currently, there are several photon dose calculation algorithms available in the commercial TPS. The most commonly used dose calculation algorithms are collapsed cone convolution superposition (CCCS) and analytical anisotropic algorithm (AAA). Recently, a new dose calculation algorithm called Acuros XB has been implemented in the Eclipse TPS, and several researchers have shown the superiority of Acuros XB over CCCS and AAA, especially when a heterogeneity is involved. The purpose of this study is to review the dosimetric results of dose calculation algorithms in the presence of low-density heterogeneity, with a focus on Acuros XB. Both the AAA and Acuros XB are available in the Eclipse TPS, whereas the CCCS is implemented in the Pinnacle TPS.

2. Methods

A literature search was conducted in Google Scholar using search terms “collapsed cone convolution superposition”, “analytical anisotropic algorithm”, and “Acuros”. Relevant articles were reviewed, and the summary of major findings among selected studies is presented.

3. Results

Several investigators [1-9] have studied the accuracy of Acuros XB, and compared its results with the AAA and CCCS calculations. The research group of Bush et al. [2] showed that Acuros XB was more accurate than the AAA when compared to the Monte Carlo (MC) results, with a difference up to 4.5% for the Acuros XB and up to 17.5% for the AAA. Han et al. [3] showed the larger difference for the AAA (2.5%-6.4%) and smaller difference for the Acuros XB (0.4%-4.4%) when compared to the measurements. Kan et al. [4] showed that the Acuros XB had a smaller deviation (3%) than the AAA (10%) from the measurements.

From the research group of Rana et al. [5,6], the results demonstrated that the Acuros XB was more accurate with a difference up to 3.8%, whereas the AAA showed larger deviation (up to 10.6%) when compared to the measurements. Stathakis et al. [7] showed an agreement between the CCCS and Acuros XB was within 2%, whereas the AAA calculations showed higher deviation (5%). In a recent study involving CCCS, Oyewale [10] showed that the CCCS could have dose prediction errors by up to 6.7% after the photon beam traversing the air gap.

4. Discussion

Although Acuros XB has been found to be more accurate than the AAA and CCCS, the dosimetric differences between the Acuros XB and other dose calculation algorithms may be less distinct for the clinical cases. However, the accuracy of Acuros XB will be important when a tumor site involves a low-density tissue such as the lung. The variation in discrepancies among dose calculation algorithms is mainly due to the difference in beam modeling approach as well as the method used to account the tissue heterogeneity corrections. The involvement of smaller photon fields and low-density medium will typically cause the electronic disequilibrium, and the dose calculation algorithm must be able to account such conditions. Additionally, the inaccurate estimation of primary beam attenuation, beam hardening effect, and lateral scatter will lead to dose prediction errors, especially when photon fields pass through high and low-density heterogeneities such as the bone and lung tissues.

5. Conclusion

The current literature suggests that Acuros XB is more accurate than AAA and CCCS. The improved dose prediction accuracy in Acuros XB may be beneficial in the treatment of lung tumors.

References

[1]   | Vassiliev O, Wareing T, McGhee J, Failla G, Salehpour M, Mourtada F. Validation of a new grid based Blotzmann equation solver for dose calculation in radiotherapy with photon beams. Phys Med Biol 2010; 55: 581-98.
[2]   | Bush K, Gagne IM, Zavgorodni S, Ansbacher W, Beckham W. Dosimetric validation of Acuros XB with Monte Carlo methods for photon dose calculations. Med Phys. 2011 Apr; 38 (4): 2208-21.
[3]   | Han T, Followill D, Mikell J, Repchak R, Molineu A, Howell R, Salehpour M, Mourtada F. Dosimetric impact of Acuros XB deterministic radiation transport algorithm for heterogeneous dose calculation in lung cancer. Med Phys. 2013 May; 40 (5): 051710.
[4]   | Kan MW, Leung LH, So RW, Yu PK. Experimental verification of the Acuros XB and AAA dose calculation adjacent to heterogeneous media for IMRT and RapidArc of nasopharygeal carcinoma. Med Phys. 2013 Mar; 40 (3): 031714.
[5]   | Rana S, Rogers K. Dosimetric evaluation of Acuros XB dose calculation algorithm with measurements in predicting doses beyond different air gap thickness for smaller and larger field sizes. J Med Phys. 2013 Jan; 38 (1): 9-14.
[6]   | Rana S, Rogers K, Lee T, Reed D, Biggs C. Verification and Dosimetric Impact of Acuros XB Algorithm for Stereotactic Body Radiation Therapy (SBRT) and RapidArc Planning for Non-Small-Cell Lung Cancer (NSCLC) Patients. Int Jour of Med Phys Clin Eng Radiat Onc 2013; 2 (1): 6-14.
[7]   | Stathakis S, Esquivel C, Quino L, Myers P, Calvo O, Mavroidis P, Gutiérrez A and Papanikolaou P. Accuracy of the Small Field Dosimetry Using the Acuros XB Dose Calculation Algorithm within and beyond Heterogeneous Media for 6 MV Photon Beams. Int Jour of Med Phys Clin Eng Rad Onc 2012; 1 (3): 78-87.
[8]   | Mißlbeck M, Kneschaurek P. Comparison between Acuros XB and Brainlab Monte Carlo algorithms for photon dose calculation. Strahlenther Onkol. 2012 Jul; 188 (7): 599-605.
[9]   | Fogliata A, Nicolini G, Clivio A, Vanetti E, Cozzi L. Critical appraisal of Acuros XB and Anisotropic Analytic Algorithm dose calculation in advanced non-small-cell lung cancer treatments. Int J Radiat Oncol Biol Phys. 2012; 83 (5): 1587-95.
[10]   | Oyewale S. Dose prediction accuracy of collapsed cone convolution superposition algorithm in a multi-layer inhomogenous phantom. Int J Cancer Ther Oncol 2013; 1 (1): 01016.