Sergei Zavgorodni

Sergei Zavgorodni
Adjunct Professor
BC Cancer - Victoria
Office: BC Cancer - Victoria


Area of expertise

Monte Carlo modeling, Radiobiological modeling

Overview of research

As a Medical Physicist, I am combining my clinical duties with research, which is mainly concentrated in Monte Carlo calculations for radiotherapy applications and radiobiological modeling.  UVic students at the graduate (PhD and MSc) and undergraduate (co-op and honours) levels make considerable contributions to my research. These contributions are often large enough to result in joint publications in international scientific journals or presentations to national/international conferences. Students, working on these projects, obtain therefore great learning experience by being involved in research from technique development and receiving main results to paper submission, review and publication.

My research in the last few years has mainly focused in two areas; 1) development and applications of Monte Carlo (MC) method to radiotherapy dose calculations; 2) radiobiological modeling with applications to radiotherapy. In these areas I am leading research of our physics group and research performed by university students at graduate (PhD and MSc) and undergraduate (co-op and honours) level.

Monte Carlo radiotherapy dose calculations

Monte Carlo method is well recognised for its superior accuracy in radiotherapy dose calculations. This sets MC as a benchmark for testing any alternative dose calculation algorithms. Implementation of this method to model advanced treatment deliveries has therefore become an essential part of testing alternative dose calculation methods to ensure their accuracy and safety in treatment delivery.  Another attractive aspect of Monte Carlo modeling is that it allows modelling alterations in clinical equipment and treatments that are not yet possible. Such modeling allows investigating potentials of new equipment designs.

Research by our group in Monte Carlo dose calculations area over the last few years evolved from first attempts to utilize NRC-developed BEAM (Rogers et al., 2006) and DOSXYZ (Walters et al., 2006) codes for radiotherapy applications to developing a computer/software infrastructure (named Vancouver Island Monte Carlo (VIMC) system (Zavgorodni et al., 2007, 2008)) capable of automated Monte Carlo dose calculations for most advanced modern radiotherapy patient treatments. This includes intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) with first  commercially available system known as RapidArc treatment.

Our Monte Carlo system for accurate modeling of RapidArc treatment delivery (Bush et al., 2008) is the world's first application of Monte Carlo method to calculate the radiation dose from VMAT treatment. Implementation of RapidArc modeling into our VIMC system allowed our physics group to perform the world's first Monte Carlo evaluation of RapidArc treatment planning algorithm (Gagne et al., 2008).

Our success in Monte Carlo project would not have been possible without efforts and important contributions made by UVic post grad and undergrad students.

Radiobiological modeling with applications to radiotherapy

My research in radiobiological modeling within the last few years has been mostly focused on modeling the impact of potential treatment delivery errors on treatment outcome indices such as biological effective dose (BED), equivalent uniform dose (EUD) and tumour control probability (TCP). New radiobiological concepts of biological effective constant dose (BECD), (Zavgorodni, 2004) and equivalent uniform stochastic dose (EUSD) (Cranmer-Sargison and Zavgorodni, 2005) have been introduced. Application of EUSD to tumour control probability calculations has also been demonstrated (Zavgorodni, 2008).



Graduate students

Elena Timakova - MSc

Selected publications

  • Bush K, Townson R and Zavgorodni S 2008 Monte Carlo simulation of RapidArc radiotherapy delivery Phys. Med. Biol. N359-70
  • Cranmer-Sargison G and Zavgorodni S 2005 EUD-based radiotherapy treatment plan evaluation: incorporating physical and Monte Carlo statistical dose uncertainties Phys. Med. Biol. 50 4097-109
  • Gagne I M, Ansbacher W, Zavgorodni S, Popescu C and Beckham W A 2008 A Monte Carlo evaluation of RapidArc dose calculations for oropharynx radiotherapy Phys. Med. Biol. 7167-85
  • Rogers D W O, Walters B R and Kawrakow I 2006 BEAMnrc Users Manual. In: NRC Report, (Ottawa: National Research Council of Canada)
  • Walters B R B, Kawrakow I and Rogers D W O 2006 DOSXYZnrc Users Manual. In: NRC Report, (Ottawa: National Research Council of Canada)
  • Zavgorodni S 2004 The impact of inter-fraction dose variations on biological equivalent dose (BED): the concept of equivalent constant dose Phys. Med. Biol. 49 5333-45
  • Zavgorodni S 2008 Application of the equivalent uniform stochastic dose (EUSD) to TCP calculations incorporating dose uncertainty and fractionation effects Australasian Physical & Engineering Sciences in Medicine 31 1-9
  • Zavgorodni S, Bush K, Locke C and Beckham W 2007 Vancouver Island Monte Carlo (VIMC) system for radiotherapy treatment planning dosimetry and research Radiotherapy & Oncology 84 Supplement 1, S49
  • Zavgorodni S, Bush K, Locke C and Beckham W 2008 Vancouver Island Monte Carlo (VIMC) system for accurate radiotherapy dose calculations. In: Proceedings of 16th International Conference on Med. Phys., April 13-16, (Dubai, UAE p 78

A full listing of publications can be found on Pub Med.