Applied Radiobiology and Bioeffect Planning

Author:  David Wigg
ISBN:  9781930524057      ISBN10:  1930524056
Published:  2001 | 486 | Hardcover



Clinical Oncology  |  (2002) 14: 515-518

"Dr. Wigg explains that the main purpose of his book is to recommend the development of bioeffet planning as an experimental tool to compare with standard isodose plans. During the evolution of his theme he has achieved a most impressive monograph of the kind that many of us will find invaluable in taking our understanding and competence in radiobiological modelling a significant way forward. Most of all we can be grateful to Dr. Wigg for providing a host of powerful models that we can try ourselves (most can be achieved dynamically with 'live graphs' just by using a spreadsheet) and for the invaluable collation of radiobiological parameter values into a set of tables in Chapter 8. We can also thank him for his intelligent discussion of the applicability of the models analysed, the uncertainties involved, how sensitive the various models actually are to the values and spread of radiobiological parameters, and his addressing of the legitimate concerns frequently expressed about radiobiological modelling. I was also pleased to see his most sophisticated models tested against clinical results.

"This book is rich fare indeed for those wanting to model radiobiological response. Nearly 500 large pages are packed with equations and three major mathematical 'engines' required for modelling an impressive variety of vexing radiobiological problems. We are taken from the usual fare of comparing different fractionation regimes, through the advantages of low dose rate brachytherapy and on to more difficult areas such as volume effect, combining chemotherapy and radiotherapy, and even predictions of patient numbers required for satisfactory statistical outcomes in clinical trials.

"Before enthusing too much it should be noted that this is not a book for the novice, but then neither does one really need to be an expert to find it useful. If the reader is already familiar with manipulating LQ equations and is moderately versed in the use of TCPs, NTCPs, survival curves etc., then this is a book that will repay serious study. Indeed, apart from possibly the use of the aforementioned Chapter 8 (worth having the book in your library for that chapter alone), careful study is the only option to get the rich rewards from this book. By contrast, the casual reader looking for a quick answer is likely to find it a rather daunting read. The density of new concepts can be quite high within a single paragraph, sometimes with scanty background explanation, and some of the equations require significant unpacking and referral back to earlier chapters. Hence the book would not work as a radiobiological primer. Even those reasonably familiar with the mathematics of radiobiology may still find some of the equation formats and symbolisms unfamiliar. Nevertheless, the meanings of the terms are all mentioned (albeit rather briefly) in the text, which is one reason why the text does have to be studied as the glossary is very thin for the quantity of mathematical terms introduced.

"Wigg gives explicit analytical solutions for all the variables of interest within a model. This makes for some cumbersome expressions at first glance, although to be fair the equations are just long, rather than using advanced mathematics. However, I found it ironic that 'r' was substituted for the familiar / (and inconsistently only sometimes so), whereas substitutions for longer expressions could have helped to ease the unwieldy look of the equations. Maybe the recasting of equations within the text could have been left as an exercise for the reader, especially as the explicit equations are given anyway on the axes of the many graphical illustrations. Unfortunately using so many long equations appears to have challenged the proofreader as I counted 19 typographical errors, mostly in the equations. The corresponding equations in the figures all appear correct but there were also some other unfortunate slips in the figures, such as in Chapter 4 where the hyperfractionation intervals are all given as 6 h in a set of graphs designed to show the effect of changing interfraction interval. Nevertheless, I think that all the typographical errors are easy to spot, although I am concerned that if the proof-reading is not good then confidence in the tabulated parameter values should also be questioned as slips there will be less apparent without careful checking of the referenced literature.

"Whilst 'ready reckoner' graphs and tables are already a part of bioeffect planning, the final chapter takes the reader through examples of full bioeffect plans. Unfortunately this is a frustrating chapter because it describes a planning system developed by the author which the reader will not have! I assume expert readers are to be inspired to write their own. For the rest of us it is an intriguing read but we could have done with some help, such as a piece of software or a link to an Internet resource if the author would like to promote isoeffect distributions into wider use. Also the diagrams in this chapter are far too small and the term 'TCP' is confusingly used to refer both to 'Tissue Complication Probability' and 'Tumour Control Probability' in a rapid flow of similar tiny diagrams. The font sizes for some of the 'mathematical engines' of the penultimate chapter are also on the verge of readability.

"There were a few items I was surprised to see missed out. For instance, Biologically Effective Dose and Equivalent Dose in 2 Gy fractions were mentioned briefly a few times, but I missed the familiar acronyms! I was also curious as to why General Equivalence was not discussed, when Dr. Wigg seemed on the verge of mentioning it a number of times in the chapter on fractionated and continuous irradiation.

"All told any criticisms are minor compared to what the book gives us, as Dr. Wigg details some powerful and well-analyzed tools and shows us how to investigate the behaviour of models for the knotty problems we are really interested in. Many times my reviewing process was slowed down due to being struck by an intriguing model and an hour or two subsequently spent reproducing graphs and tweaking variables! Dr. Wigg also keeps more than a weather eye on addressing the well-placed fears of the radiotherapist against employing radiobiological models which may not be fully mature. However, he concludes this as a dilemma, as to merely use dose planning is also misleading in terms of patient outcome. Relying on mere isodose plans is tantamount to assuming that isoeffect equal isodose, which is itself a 'wrong but useful' radiobiological model (to borrow a phrase from Dr. Wigg's historical review). Meanwhile Dr. Wigg constantly examines the applicability of the models he presents throughout the book.

"In summary, I would like to say thank you to Dr. Wigg for all his work. This is a well-placed 'book of our time' that is sure to progress bioeffect planning and general radiobiological understanding. I can heartily recommend this book and believe the contents will richly reward serious study."

S. Locks

Clinical Oncology (2002) 14:515-518