OPTimizing Irradiation through Molecular Assessment of Lymph node (OPTIMAL): a randomized open label trial

• Published in: Radiation oncology (London, England) England), 2020-10, Vol.15 (1), p.229-9, Article 229
• Main Authors: Algara López, Manuel, Rodríguez García, Elvira, Beato Tortajada, Inmaculada, Martínez Arcelus, Francisco José, Salinas Ramos, Juan, Rodríguez Garrido, José Reyes, Sanz Latiesas, Xavier, Soler Rodríguez, Ana, Juan Rijo, Germán, Flaquer García, Amanda
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Breast cancer; Breast Neoplasms - pathology; Breast Neoplasms - radiotherapy; Cancer therapies; Care and treatment; Chemotherapy; Chronic toxicity; Clavicle; Complications and side effects; Conserving surgery; Female; Humans; Incidental dose; Irradiation; Lymph nodes; Lymph Nodes - pathology; Lymphatic Metastasis; Lymphatic system; Mammography; Mastectomy; Medical prognosis; Medical treatment; Metastases; Metastasis; Methods; Middle Aged; Mortality; Multicenter Studies as Topic; Nodal irradiation; Nucleic acids; Optimization; Organs at Risk - radiation effects; OSNA; Patient outcomes; Patients; Prevention; Prognosis; Radiation; Radiation therapy; Radiotherapy; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy Planning, Computer-Assisted - standards; Radiotherapy, Intensity-Modulated - methods; Radiotherapy, Intensity-Modulated - standards; Randomized Controlled Trials as Topic; Standardization; Strategy; Study Protocol; Surgery; Thyroid gland; Toxicity; Tumors; Young Adult
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/s13014-020-01672-7

Conservative surgery followed by breast and nodal irradiation is the standard loco-regional early breast cancer (BC) treatment for patients with four or more involved lymph nodes. However, the treatment strategy when fewer nodes are involved remains unclear, especially when lymphadenectomy has not been performed. Sensitive nodal status assessment molecular techniques as the One-Step Nucleic Acid Amplification (OSNA) assay can contribute to the definition and standardization of the treatment strategy. Therefore, the OPTIMAL study aims to demonstrate the feasibility of incidental irradiation of axillary nodes in patients with early-stage BC and limited involvement of the SLN. BC patients who underwent conservative surgery and whose SLN total tumour load assessed with OSNA ranged between 250-15,000 copies/µL will be eligible. Patients will be randomized to receive irradiation on the breast, tumour bed, axillary and supraclavicular lymph node areas (intentional arm) or only on the breast and tumour bed (incidental arm). All areas, including the internal mammary chain, will be contoured. The mean, median, D5% and D95% doses received in all volumes will be calculated. The primary endpoint is the non-inferiority of the incidental irradiation of axillary nodes compared to the intentional irradiation in terms of 5-year disease free survival. Secondary endpoints comprise the comparison of acute and chronic toxicity and loco-regional and distant disease recurrence rates. Standardizing the treatment and diagnosis of BC patients with few nodes affected is crucial due to the lack of consensus. Hence, the quantitative score for the metastatic burden of SLN provided by OSNA can contribute by improving the discrimination of which BC patients with limited nodal involvement can benefit from incidental radiation as an adjuvant treatment strategy. ClinicalTrial.gov, NCT02335957; https://clinicaltrials.gov/ct2/show/NCT02335957.