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M
arta
GN
et
al
.
510
R
ev
A
ssoc
M
ed
B
ras
2014; 60(6):508-511
I
s
it
less
toxic
to
use
intensity
-
modulated
radiation
therapy
(IMRT)
compared
to
conventional
or
conformal
radiation
therapy
for
primary
breast
tumors
?
Toxicity related to radiation therapy can be temporally
divided into two sub-categories: acute and delayed.
When comparing IMRT with conventional or confor-
mal radiation therapy of the breast, two studies had acu-
te toxicity as the main outcome.
A phase III multicenter study including 358 patients
showed that the rates of moist desquamation during ra-
diotherapy and up to six weeks after treatment were 31.2%
with IMRT, and 47.8% with conventional or conformal
radiation therapy (p=0.002)(
A
).
16
A recently published English study withmedian follow-
-up of five years and which included 1,145 treated patients
showed that the use of IMRT reduces the rates of telangiec-
tasia (OR 0.58, 95%CI: 0.36 – 0.92, p=0.021)(
A
)
3
(
B
).
17
Regarding delayed toxicity, a minimum of five years
for patient follow-up is required. Some institutional se-
ries reported a low rate of delayed toxicity related to radia-
tion therapy: a study with 7.5 years of median follow-up re-
ports rates of delayed skin toxicity grade II or higher at 39
vs.
52% (p=0.004) with IMRT and conventional radiothe-
rapy, respectively (
D
).
18
Rates of pneumonitis, lymphoe-
dema, and tumor recurrence within the follow-up were
not statistically different between the two groups (
D
).
18
A similar study showed after 4.7 years of median follow-up
that the use of IMRT reduces the rates of acute and delayed
toxicity, with respective rates of delayed breast edema gra-
de II or higher at 6
versus
1% (p=0.009) (
B
).
19
For patients
with larger breasts (volume > 1,600cm
3
), the gains were
more expressive with IMRT: chronic breast edema (3
vs.
30%,
p=0.007) and hyperpigmentation (3
vs.
41%, p=0.001)(
B
).
19
Recommendation
There is less acute toxicity with the use of intensity-modu-
lated radiation therapy (IMRT) compared to conventional
or conformal radiation therapy for primary breast tumors,
especially regarding the rate of moist desquamation du-
ring radiotherapy. Delayed skin toxicity is less prevalent
with IMRT, with a lower incidence of chronic breast ede-
ma, hyperpigmentation, and telangiectasia. These gains
are also seen in larger breasts treated with this technique.
I
s
the
quality
of
life
affected
to
the
point
of
justifying
the
use
of
intensity
-
modulated
radiation
therapy
(IMRT)
over
conformal
or
conventional
radiation
therapy
?
Quality of life is a difficult outcome to be measured, with
many uncertainties, including the difficulty in defining
it and the subjectivity of measurements. For the treat-
ment of breast cancer, quality of life was assessed in stu-
dies using specific tools such as questionnaires or through
cosmetic evaluation of patients, which is intrinsically lin-
ked to quality of life and personal satisfaction.
Cosmesis was evaluated in two randomized studies
as the primary outcome according to the use of IMRT.
306 women underwent cosmetic assessment by se-
rial photographs after 1, 2 and 5 years of follow-up. The
rate of change in the appearance of the breast was 58
vs.
40% (p=0.008) for conventional radiotherapy and IMRT,
respectively (
B
).
4
The findings illustrated a 68% reduction in the risk of
worsening of cosmesis using the RTOG scale after IMRT
(OR=0.68; 95%CI, 0.48 to 0.96; p=0.027) (
B
)
3
(
A
).
17
Direct evaluation of the quality of life through sco-
res or questionnaires was carried out in the study, which
assessed patients based on two questionnaires: EORTC
Quality of Life Questionnaire C-30 general module and
BR-23 module self-assessment. During patient follow-up,
there was a significant correlation between the two sco-
res for quality of life and the presence of breast pain and
radiodermitis (
A
).
16
Recommendation
The use of intensity-modulated radiation therapy (IMRT)
reduces the risk of worsening of cosmesis. There is no evi-
dence for other outcomes related to quality of life.
A
re
there
differences
in
effectiveness
,
local
control
or
overall
survival
among
the
techniques
of
intensity
-
modulated
radiation
therapy
(IMRT),
conformal
RT
and
conventional
RT?
In three phase III randomized trials comparing conven-
tional or conformal RT with IMRT, effectiveness, local
control and overall survival were not the main outcomes
evaluated. The reason for this is that the hypothesis was
not proposed because the prescribed doses and irradia-
ted volumes were equal, regardless of the technique. In
one of these studies, with five years of median follow up,
the rate of local control in the group of women treated
with IMRT and conventional RT in five years was 98.6
and 97.4%, respectively (p=0.36) and the overall survival
in five years was 92.5 and 91.7%, respectively (p=0.88)(
A
).
17
Recommendation
IMRT compared with conventional or conformal radia-
tion therapy techniques for the breast has benefits in
terms of dosage, toxicity and quality of life, while it does
not affect local control and overall survival of patients.