Gj. Kutcher et al., TREATMENT PLANNING FOR PRIMARY BREAST-CANCER - A PATTERNS OF CARE STUDY, International journal of radiation oncology, biology, physics, 36(3), 1996, pp. 731-737
Citations number
27
Categorie Soggetti
Oncology,"Radiology,Nuclear Medicine & Medical Imaging
Purpose: The 1989 Patterns of Care Study included treatment planning f
or early breast cancer. A Consensus Committee of radiation physicists
and oncologists determined current guidelines and developed questionna
ires to determine treatment planning and delivery processes used by th
e participating institutions (e.g., use of portal films). This article
presents and analyzes the results of that survey. Methods and Materia
ls: The survey included 449 respondents, distributed as follows: 136 (
30%) from Strata I (academic facilities); 169 (38%) from Strata II (ho
spital based facilities); and 144 (32%) from Strata III (freestanding
facilities). The treatment planning procedures surveyed included: whet
her individualized tissue compensators are used, whether inhomogeneity
corrections are used in dose calculations, the use of computerized to
mography, whether isodose distributions for external beam tangents and
interstitial implants are generated, the use of lymphoscintigraphy, i
mmobilization de,ices, simulations, portal films, etc. Results: The su
rvey results demonstrated that out of 305 patients from Strata I and I
I institutions, 237 (78%) had simulated tangential fields. Consistent
with this finding is that 76 % of patients from Strata I and II instit
utions mere immobilized, while only 51% of Strata III patients were. M
oreover, only 18 out of the 449 (4%) of cases did not have any type of
external beam dose distribution calculated-presumably, in these cases
missing tissue compensation would be unlikely. On the other hand, 41%
of the Strata II, 27% of St ata III, but only 19% of Strata I (p < 0.
0002) cases received CT. Surprisingly, 19% of the Strata I, 35% of the
Strata II, and 35% of the Strata III (p = 0.0011) patients received l
ymphoscintigraphy, perhaps reflecting the use of wide tangents to enco
mpass the internal mammary nodes in these patients. In terms of optimi
zing treatments, 74% of Strata I, 70% of Strata II, and 78% of Strata
III patients had wedges used on both tangential fields, although in 5,
12, and 14%, respectively, no beam modification of any sort was used.
Furthermore, it should be noted that in 7% of the Strata I, 23% of St
rata II, and 37% of Strata III cases there was no attempt to reduce th
e divergence of the tangential fields into the lung. On the other hand
, if one considers the 135 (of 449) patients where matching of the tan
gential and supraclavicular fields was applicable, 41% of Strata I, 22
% of Strata II and 46% of Strata III patients had those fields matched
in a vertical plane, which would involve sophisticated alignment proc
edures. Quality control of treatment delivery was high: 97% of all sur
veyed received portal films at least once. The use of thermoluminescen
t dosimetry (TLD) to measure the dose to the contralateral breast was
of Little interest: only 4 of the 305 Strata I and II patients receive
d in vivo measurements. Conclusions: This national survey has establis
hed the patterns of treatment planning for early breast cancer. It sho
ws a generally consistent approach-although a number of statistically
significant variations have been identified. Copyright (C) 1996 Elsevi
er Science Inc.