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.

Ablative radiotherapy in 'early oligometastatic state' is a safe, effective and minimally invasive treatment modality. A good performance status (KPS ≥80) seems to influence the clinical outcome.

Purpose: Prostate motion during the radiotherapy course is an important issue. This study investigated the inter-fraction prostate motion in controlled rectal filling condition. Methods: 10 prostate cancer patients underwent image-guided radiotherapy (IGRT) using a cone-beam computed tomography (CBCT) system, after the insertion of fiducial markers (FMs). The planning CT was the reference CT (CTref) used to estimate the reference intermarker distances, and CBCTs were used for off-line comparison with CTref. We evaluated the influence of rectal and bladder volume on prostate shifts. We calculated the required planning target volume (PTV) margins in this patient population. Results: 120 CBCTs were analyzed. Mean prostate displacements (± SD) along the 3 axes (x, y, z) averaged over the 10 patients, were: 0.90 ± 0.84 mm in x, 0.00 ± 2.07 mm in y, -0.80 ± 1.28 mm in z. There is a statistically significant anti-correlation between prostate displacements and: bladder volume variations (P < 0.001) in the y-axis, and rectal volume variations (P < 0.05) in the z-axis. PTV margins obtained for the directions x, y and z are respectively 2.5, 5.6 and 3.9 mm. Conclusion: IGRT in reproducible empty rectum condition allow a high reduction of daily treatment uncertainties.

In breast cancer, the use of a boost to the tumor bed can improve local control. The aim of this research is to evaluate the safety and efficacy of the boost with intra-operative electron radiotherapy (IOERT) in patients with early-stage breast cancer undergoing conservative surgery and postoperative whole breast irradiation (WBI). The present retrospective multicenter large data were collected between January 2011 and March 2018 in 8 Italian Radiation Oncology Departments. Acute and late toxicity, objective (obj) and subjective (subj) cosmetic outcomes, in-field local control (LC), out-field LC, disease-free survival (DFS) and overall survival (OS) were evaluated. Overall, 797 patients were enrolled. IOERT-boost was performed in all patients during surgery, followed by WBI. Acute toxicity (≥G2) occurred in 179 patients (22.46%); one patient developed surgical wound infection (G3). No patients reported late toxicity ≥ G2. Obj-cosmetic result was excellent in 45%, good in 35%, fair in 20% and poor in 0% of cases. Subj-cosmetic result was excellent in 10%, good in 20%, fair in 69% and poor in 0.3% of cases. Median follow-up was 57 months (range 12–109 months). At 5 years, in-field LC was 99.2% (95% CI: 98–99.7); out-field LC 98.9% (95% CI: 97.4–99.6); DFS 96.2% (95% CI: 94.2–97.6); OS 98.6% (95% CI: 97.2–99.3). In conclusion, IOERT-boost appears to be safe, providing excellent local control for early-stage breast cancer. The safety and long-term efficacy should encourage use of this treatment, with the potential to reduce local recurrence.