ESTRO 36 Abstract Book

S622 ESTRO 36 2017 _______________________________________________________________________________________________

Purpose or Objective The majority of breast cancer patients who receive radiation treatment are affected by acute radiation- induced skin changes that are usually assessed by subjective methods, like Radiation Therapy Oncology Group (RTOG) scoring. These methods complicate the comparison between treatments or patient groups and therefore objective and robust methods are needed to assess acute skin reactions. This study investigates the feasibility of new camera-based methods for monitoring skin microcirculation to objectively assess and quantify acute skin reactions during radiation treatment. Material and Methods Fifteen patients undergoing adjuvant radiation therapy for breast cancer were included in the study. The patients received 42.56 Gy in 16 fractions using three dimensional conformal radiotherapy with tangential photon irradiation. Radiation-induced changes in microvascular perfusion and red blood cell (RBC) concentration in the skin of the patients were quantified with laser Doppler flowmetry, laser speckle contrast imaging and polarized light spectroscopy imaging. Measurements were made before treatment, once a week during treatment and directly after the last fraction. Changes in measured values were analysed with two-way analyses of variance with Dunnett’s correction for multiple comparisons. Results Perfusion (Figure 1) and RBC concentration (Figure 2) were increased in the treated breast after 1-5 fractions, with largest effects in the areola and the medial area. No changes in perfusion and RBC concentration were seen in the untreated breast. In contrast, RTOG scores were increased above 0.5 only after two weeks of treatment. Correlations have also been found between perfusion (r=0.52) and RBC concentration (r=0.59) measurements performed during current week and the RTOG score in the following week. Furthermore, a good correlation has been found between perfusion, as measured with LSCI, and relative RBC concentration (r=0.64). Clinically, the results indicate that optical techniques could be used for early assessment of skin changes, with RBC concentration the better predictor.

Figure 2. Variation of red blood cell concentration in irradiated skin of breast cancer patients Conclusion The results showed that radiation-induced microvascular changes in the skin can be objectively measured using novel camera-based techniques before visual changes in the skin are apparent. Also, the proposed methods may be valuable in the comparison of skin reactions between different radiation treatments. EP-1155 Outcomes of breast cancer patients older than 80 years treated with adjuvant radiotherapy R. Barrientos 1 , M. Frelinghuysen 2 , M. Burotto 3 1 Instituto de Radiomedicina IRAM, Radiation Oncology, Concepcion, Chile 2 Hospital Clinico Regional de Concepcion, Radiation Oncology, Concepcion, Chile 3 Clinica Alemana de Santiago, Medical Oncology, Santiago de Chile, Chile Purpose or Objective The main purpose was to estimate surviva l of patients older than 80 years, diagnosed by Stage I-III breast cancer that were treated by surgery and adjuvant radiotherapy with curative intent. Breast cancer specific survival different clinical and pathologic factors that influence survival were estimated. Material and Methods We analyzed 85 breast cancer patients older than 80 years old that received surgery and adjuvant radiotherapy with curative intent. Overall survival was defined as the time from the date histopathological diagnosis until the last date of follow-up (official death certificate). Survival was performed by Kaplan Meier method. A log rank test was used to compare survival of different clinical and pathological factors. Signficance level was determined by (p-value <0.05). Results The median age at the time of diagnosis was 82.7 (range 77 to 88). The median follow up was 42 months. Overall survival was 70% at 5 years. Breast cancer specific survival (BCSS) was 94% a 5 years. Four patients (4.2%) died of cardiovascular disease. Fifty five patients (65%) received partial mastectomy, while 30 patients (35%) received total mastectomy (MT). Fifty four patients (63%) received whole breast or chest wall irradiation, while 31 patients (37%) received locorregional irradiation. Five patients presented cutaneous toxicity grade ≥ 3.In the univariate analysis Clinical preoperative nodes, clinical tumor, locorregional irradiation and pathologic tumor stage were significant for overall survival . No other examined factor was significant.

Figure 1. Variation of capillary perfusion in irradiated skin of breast cancer patients