Introduction: Breast cancer is the most common tumor in women and represents the leading cause of cancer death. Radiation therapy plays a key-role in the treatment of all breast cancer stages. Therefore, the adoption of evidence-based treatments is warranted, to ensure equity of access and standardization of care in clinical practice. Method: This national document on the highest evidence-based available data was developed and endorsed by the Italian Association of Radiation and Clinical Oncology (AIRO) Breast Cancer Group. We analyzed literature data regarding breast radiation therapy, using the SIGN (Scottish Intercollegiate Guidelines Network) methodology ( www.sign.ac.uk ). Updated findings from the literature were examined, including the highest levels of evidence (meta-analyses, randomized trials, and international guidelines) with a significant impact on clinical practice. The document deals with the role of radiation therapy in the treatment of primary breast cancer, local relapse, and metastatic disease, with focus on diagnosis, staging, local and systemic therapies, and follow up. Information is given on indications, techniques, total doses, and fractionations. Results: An extensive literature review from 2013 to 2021 was performed. The work was organized according to a general index of different topics and most chapters included individual questions and, when possible, synoptic and summary tables. Indications for radiation therapy in breast cancer were examined and integrated with other oncological treatments. A total of 50 questions were analyzed and answered. Four large areas of interest were investigated: (1) general strategy (multidisciplinary approach, contraindications, preliminary assessments, staging and management of patients with electronic devices); (2) systemic therapy (primary, adjuvant, in metastatic setting); (3) clinical aspects (invasive, non-invasive and micro-invasive carcinoma; particular situations such as young and elderly patients, breast cancer in males and cancer during pregnancy; follow up with possible acute and late toxicities; loco-regional relapse and metastatic disease); (4) technical aspects (radiation after conservative surgery or mastectomy, indications for boost, lymph node radiotherapy and partial breast irradiation). Appendixes about tumor bed boost and breast and lymph nodes contouring were implemented, including a dedicated web application. The scientific work was reviewed and validated by an expert group of breast cancer key-opinion leaders. Conclusions: Optimal breast cancer management requires a multidisciplinary approach sharing therapeutic strategies with the other involved specialists and the patient, within a coordinated and dedicated clinical path. In recent years, the high-level quality radiation therapy has shown a significant impact on local control and survival of breast cancer patients. Therefore, it is necessary to offer and guarantee accurate treatments according to the best standards of evidence-based medicine.

Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, occurring in 1–2% of the general population. Patients affected by AF have an increased risk of stroke and heart failure and European guidelines recommend catheter ablation of AF in symptomatic patients refractory to antiarrhythmic therapy. In elderly patients, the AF ablation procedure is associated with a higher rate of overall complications. Recently, stereotactic arrhythmia radioablation (STAR) with precise high-dose of radiation was used to treat ventricular arrhythmias. Purpose No data were reported in literature about the use of Linac-based STAR, so a prospective phase-II trial was designed to evaluate safety of Linac-based STAR in elderly patients with paroxysmal AF. Methods Fourteen patients (mean age 78±6 years; 57% male) were enrolled in the study. All patients had symptomatic paroxysmal AF refractory to antiarrhythmic drugs. All patients performed 1-week ECG-Holter monitoring (ECG-HM) and transthoracic echocardiogram before and after STAR. Primary end-point was defined as all the adverse events of special interest related to STAR treatment; secondary end-point was defined as AF recurrence after the treatment. The study was approved by the local Ethics Committee and all patients signed informed consent. Results All patients performed STAR with a mean overall treatment time of 3 minutes. No serious adverse events were documented acutely and after 6 months of follow up. Transthoracic echocardiogram did not show cardiac damage after STAR. The 1-week ECG-HM performed before STAR documented symptomatic AF episodes in all patients. The 1-week ECG-HM performed 1-month after procedure documented frequent symptomatic atrial ectopy and atrial tachycardias without AF recurrences. The 1-week ECG-HM performed 3 and 6 months after procedure did not revealed AF recurrences. Two patients had a single episode of sustained atrial tachycardia 6 months after STAR. Both patients performed a left atrial mapping using CARTO system and Pentaray mapping catheter documenting PV isolation without vein stenosis (figure); no phrenic nerve damage was documented in both patients. All patients had an improvement in quality of life. Conclusion Our preliminary data reported for the first time that the LINAC-based STAR approach could represent a valid alternative to perform PVI in elderly patients with paroxysmal AF. Funding Acknowledgement Type of funding sources: None.

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