Standard or hypofractionated radiotherapy in the postoperative treatment of breast cancer: a retrospective analysis of acute skin toxicity and dose inhomogeneities

Abstract

BackgroundTo identify predictive factors of radiation-induced skin toxicity in breast cancer patients by the analysis of dosimetric and clinical factors.Methods339 patients treated between January 2007 and December 2010 are included in the present analysis. Whole breast irradiation was delivered with Conventional Fractionation (CF) (50Gy, 2.0/day, 25 fractions) and moderate Hypofractionated Schedule (HS) (44Gy, 2.75Gy/day, 16 fractions) followed by tumour bed boost. The impact of patient clinical features, systemic treatments and, in particular, dose inhomogeneities on the occurrence of different levels of skin reaction has been retrospectively evaluated.ResultsG2 and G3 acute skin toxicity were 42% and 13% in CF patients and 30% and 7.5% in HS patients respectively. The retrieval and revaluation of 200 treatment plans showed a strong correlation between areas close to the skin surface, with inhomogeneities >107% of the prescribed dose, and the desquamation areas as described in the clinical records.ConclusionsIn our experience dose inhomogeneity underneath G2 – G3 skin reactions seems to be the most important predictor for acute skin damage and in these patients more complex treatment techniques should be considered to avoid skin damage. Genetic polymorphisms too have to be investigated as possible promising candidates for predicting acute skin reactions.

Using a thermoluminescent dosimeter to evaluate the location reliability of the highest–skin dose area detected by treatment planning in radiotherapy for breast cancer

“…Furthermore, uncertainty in TLD devices, which is typically 3% to 5%, may also attribute to this disagreement. The results suggest that the TPS may be a reliable and simple alternative method for estimating the highest skin doses in breast and axillary areas to predict the location of skin reactions, based on the findings of Tortorelli et al 19 Stratified analyses revealed that the consistency between the 2 methods in the axillary and breast areas was limited only in younger patients; older patients may have more creases over their breast and axillary areas, which may increase the uncertainity of dose measurement when the TLD is used. The consistency between the 2 methods in the axillary and breast areas was limited only to the maximum dose near the skin.…”

“…10,16,17 The total radiation dose, dose per fraction, overall treatment time, beam type and energy, and the surface area of the skin that is exposed to radiation contribute to the skin reaction. 18 Tortorelli et al 19 observed a strong correlation between areas close to the skin surface, with inhomogeneities 4107% of the prescribed dose, and desquamation areas. In a previous study, we evaluated the location consistency of moist desquamation and high-skin dose areas in patients with breast cancer.…”

“…This finding corresponds to that of a previous study showing that the maximum dose that is deep seated in the breast parenchyma does not contribute to severe skin damage. 19 The discrepancy in the lesion side and stage between the 2 groups cannot be explained, but the relatively small number of cases in using stratified analyses decreases the statistical power to detect the possible difference. Previous reports have suggested that patients with a larger breast size may have a more severe skin reaction than those with a smaller breast size.…”

“…According to statistics of Department of Health, Executive Yuan, R.O.C., its incidence rate increased by 19.6% from 2008 to 2011. 1 The age-adjusted incidence rate has increased steadily, and in 2011, it reached 74.63 new cases per 100,000 people.…”

Czy radioterapia u chorych na raka piersi po operacji oszczędzającej może być jeszcze krótsza, niż obecnie zalecana?

“…Dane z literatury potwierdzają zależność pomię-dzy nasileniem reakcji ze strony skóry a stopniem niehomogenności dawki w napromienianej piersi, szczególnie jeśli obejmowała tkanki położone tuż pod skórą. Parametr dozymetryczny V > 107% okazał się być niezależnym czynnikiem ryzyka ostrych reakcji popromiennych ze strony skóry [11]. Wiele pytań dotyczących hipofrakcjonowanej radioterapii wymaga odpowiedzi.…”