S232
Clinical - Breast
ESTRO 2026
2,563 patients including 1,198 consecutive women treated with exclusive IORT following breast- conserving surgery, between 2006 and 2025. Criteria for PBI were: age older tan 50 years, unifocal tumors up to 30 mm, grade I or II, mínimum negative margins of 2 mm, positive hormonal receptors and negative lymph nodes. Clinical, pathological, and treatment- related variables were recorded. Patients were stratified according to compliance with consensus recommendations for PBI eligibility. Local control , disease free survival and overal survival were analyzed using Kaplan-Meier estimates and comparison of cohorts that met or not PBI crtieria was made. Results: Patients included have a mean age of 65 years and were postmenopausal in 96% of cases. The median diameter was 12,3 mm and the hystologic grade was I or II in 51,6% and 46,7 % respectively. The majority of patients were treated with low kilovoltage units 96,8% and the rest with electron mobile accelerators. At last follow up, 98 % were alive but 20 patients (1,8%) died by other conditions different than cancer. After a median follow-up of 36 months, 23 local recurrences (2 %) were observed in the overall cohort. Patients fulfilling international selection criteria for PBI showed a significantly lower rate of local recurrence compared with those who did not met the criteria (1,3% vs. 7,1%; p < 0.001). No significant differences were found in regional or distant control. Acute and late toxicity were mild and cosmetic outcomes were rated as good or excellent in most patients.
from 1.77 Gy to 1.16 Gy, and the anterior interventricular artery (IVA) from 4.42 Gy to 2.9 Gy (p < 0.004). Target volume coverage remained excellent, with 95% of the volume receiving ≥ 95% of the prescribed dose (Dbreast95%: 39 Gy with VMAT vs. 38.4 Gy with RAD technique). Conclusion: RAD irradiation preserves target coverage while improving sparing of OARs. This approach appears particularly promising for locoregional irradiation in younger women and warrants further clinical evaluation. Keywords: Hybrid; RapidArc dynamic; locally advanced Intraoperative radiotherapy as partial breast irradiation in early breast cancer: Results of the national registry of Spain (RIOMA trial) Javier Sanz 1 , Reyes Ibáñez 2 , Amalia Palacios 3 , Germán Juan 4 , Evelyn Martinez 5 , Arantxa Eraso 6 , Enrique Cardenas 7 , Raul Hernanz 8 , Rosa Cañon 9 , Beatriz Pinar 10 , Manuel Algara 1 1 Radiation Oncology, Hospital del Mar, Barcelona, Spain. 2 Radiation Oncology, Hospital Miguel Servet, Zaragoza, Spain. 3 Radiation Oncology, Hospital Reina Sofia, Córdoba, Spain. 4 Radiation Oncology, Hospital Mini-Oral 1118 Universitario Central de Asturias, Oviedo, Spain. 5 Radiation Oncology, Institut Català d'Oncologia, Hospitalet de LLobregat, Spain. 6 Radiation Oncology, Institut Català d'Oncologia, Hospitalet de Llobregat, Spain. 7 Radiation Oncology, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain. 8 Radiation Oncology, Hospital Ramon y Cajal, Madrid, Spain. 9 Radiation Oncology, Hospital Quiron, Torrevieja, Spain. 10 Radiation Oncology, Hospital Uiversitario Dr Negrinde Gran Canaria, Las Palmas de Gran CanariA, Spain Purpose/Objective: Partial breast irradiation (PBI) has become an accepted alternative to whole-breast irradiation in selected patients with early-stage breast cancer. Nevertheless, proper patient selection remains crucial to achieve optimal local control. Intraoperative irradiation (IORT) has been questioned as an option to perform PBI at ASTRO guidelines[i]. We report the results from the Spanish National Registry of Intraoperative Radiotherapy (RIOMA trial; NCT07030231) utilizing four different treatment units in 10 centers. The analysis focus on local recurrence rates and the impact of compliance with international selection criteria for exclusive PBI. Material/Methods: An analysis was performed from registry of a total
Conclusion: The results of our national registry confirms that exclusive intraoperative PBI provides excellent local control and tolerance in patients with early-stage breast cancer and favorable prognostic features. However, patients not meeting consensus recommendation criteria experienced a substantially higher risk of local relapse. A strict selection of candidates is therefore recommended to ensure optimal oncological outcomes. References: [i] Partial Breast Irradiation for Patients With Early- Stage Invasive Breast Cancer or Ductal Carcinoma In
Made with FlippingBook - Share PDF online