Improved Cosmesis in Early Breast Cancer Using
Conformal Radiotherapy
Brian D. Kavanagh and Rachel Rabinovitch, University of Colorado School of Medicine, Aurora, CO
Najeeb Mohideen, Northwest Community Hospital, Arlington Heights, IL
See accompanying article on page 4488
In the article that accompanies this editorial, Mukesh et al
1
from
Cambridge University report a randomized study comparing two
external-beam radiotherapy techniques for early-stage breast cancer.
The central conclusion is that cosmetic outcome is improved by add-
ing a layer of technologic sophistication to the most basic technique
for whole-breast radiotherapy. The authors are to be congratulated for
successfully executing the study; however, like most good research, the
article raises at least as many questions as it answers.
Before we can discuss the clinical results of the study, we first need
to acknowledge that there are differences in the terminology used to
describe the same treatment procedures in different countries. This
nomenclature issue is particularly important in the United States,
where there can be substantial financial implications. Mukesh et al
1
correctly note that the term intensity-modulated radiotherapy
(IMRT) has been applied loosely at times to cover a wide range of
techniques. These range from simple modifications that slant the
cross-sectional profile of the generally flat beam coming out of the
linear accelerator to yield a uniform gradient of internal dose to highly
complex configurations of rotating gantries with shape-shifting mul-
tileaf collimators and variable photon fluence rates that texturize the
beam to paint an undulating internal dose distribution. The latter
complex approach allows coverage, for example, of a base-of-tongue
primary cancer and regional draining lymph nodes with a high dose,
while sparing sensitive normal structures such as the parotid gland and
spinal cord.
In one of its Choosing Wisely campaign recommendations, the
American Society for Radiation Oncology (ASTRO) advises, “Don’t
routinely use intensity modulated radiotherapy (IMRT) to deliver
whole breast radiotherapy as part of breast conservation therapy.”
2
At
first glance this statement seems to conflict with the results of the
Cambridge study, but on closer analysis the disconnect is reconciled
by considering differences in IMRT definitions. What Mukesh et al
1
label as “simple IMRT” is not properly considered IMRT in the United
States, at least not in the sense of being billable according to the
Common Procedural Terminology (CPT) code for IMRT. Instead,
what is described in the article, in CPT-speak, is a method of three-
dimensional (3D) conformal radiation therapy, here accomplished
using an open tangential beam augmented by several additional field-
in-field segments.
That we are here wallowing in the murky morass of CPT billing
semantics is not a criticism of Mukesh et al
1
as much as a concession
that the CPT definition of IMRT is ambiguous and often misunder-
stood. For the record, in other studies in which investigators have
compared so-called IMRT with a simpler technique of breast radio-
therapy, the same terminology confusion has occurred. For example,
Pignol et al
3
similarly referred to a field-in-field 3D conformal RT
technique as IMRT in a study published several years ago in Journal of
Clinical Oncology. The problem with mistakenly referring to a form of
3D conformal RT as IMRT is that some might misinterpret the study
to mean that it is appropriate to bill for IMRT in this setting, which
would substantially escalate costs.
4
Fortunately, parsing help is on the
way through proposed revisions of the definitions of IMRT and cer-
tain other billing codes that should help to avoid this confusion.
5
To nonradiation oncologists, it might be expected that the type of
trial executed by the Cambridge group should be commonplace. How
hard can it be to compare older technology with newer technology? It
is important to realize that it was around 1990 that software capable of
integrating computed tomography scan– based anatomic informa-
tion with the choice of linear accelerator beam direction and aperture
design appeared—in effect, it was the dawn of the era of 3D treatment
planning and delivery. Since that epochal advance, innumerable indi-
vidual software and hardware inventions have expedited stepwise
evolution toward highly refined methods of depositing ionizing radi-
ation therapy inside a patient, all geared toward maximizing the ther-
apeutic ratio, a semiquantitative index conceived as the chance of
providing benefit (eg, tumor control) divided by the chance of causing
harm (ie, adverse effects), although rarely if ever explicitly calculated.
The myriad component contributions that have enabled prog-
ress include the development of multileaf collimators, computerized
dose calculation algorithms accounting for tissue electron density, and
image guidance software and hardware that facilitate target relocaliza-
tion at the time of treatment. And these are just a few of the thousand
small steps in a journey of many miles that cannot all be tested sepa-
rately as to whether they are the best choice in the quest for excellence.
In most cases they have to be accepted at face value as intrinsically
better on a res ipsa loquitur basis, because there are not enough re-
sources available to perform a randomized study at each point along
the way.
Nevertheless, we must periodically pause to gauge where we are
and where we should go, as the Cambridge group has done. At the very
least, it can be reassuring when what is supposed to matter actually
does matter. Here, an adjustment in the treatment plan that avoided
JOURNAL OF CLINICAL ONCOLOGY
E D I T O R I A L
VOLUME 31 NUMBER 36 DECEMBER 20 2013
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