Specialists from the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM) agree that technological advances in molecular imaging, along with the joint work of different hospital services, are facilitating an approach to the axilla in breast cancer based on therapeutic de-escalation, with interventions that are more tailored to each patient and less aggressive.
"Technological innovation and multidisciplinary collaboration allow us to move towards more precise, personalized, and less invasive medicine," highlighted Lidia Sancho, a specialist in Nuclear Medicine and a member of SEMNIM, during the 42nd National Congress of SEMNIM.
This topic has been the central focus of the session "Management of the axilla in breast cancer: a multidisciplinary vision," in which breast surgeons, medical oncologists, radiation oncologists, and nuclear medicine experts have reviewed how scientific evidence is modifying clinical practice towards increasingly individualized decisions.
Breast cancer continues to be the most common malignant tumor among women in Spain, with over 37,000 annual diagnoses. Between 20 and 40 percent of patients present with axillary lymph node involvement at some point during the diagnostic process or treatment, making axillary assessment an essential element for prognosis and the choice of therapeutic strategy.
For years, systematic axillary lymphadenectomy (ALx) was considered the standard procedure, despite being associated with complications such as lymphedema, limited shoulder movement, chronic neuropathic pain, and sensory disturbances.
However, as recalled by Macarena Rodríguez-Fraile, president of the SEMNIM Oncology Working Group, various clinical trials have shown that, in certain patient profiles, it is possible to forgo complete ALx without affecting survival, and other studies have demonstrated that some axillary staging procedures can be omitted without worsening oncological outcomes.
"The reality is a progressive de-escalation in axillary management, based on better identifying which patients need treatment and which can benefit from more conservative strategies," explained the breast surgery specialist from the Dr. Peset University Hospital, emphasizing that "this change allows for tissue preservation, reduced morbidity, and maintained oncological safety."
At the congress, it was emphasized that this surgical de-escalation has direct consequences on quality of life: by reducing the aggressiveness of surgery, the rates of lymphedema, which can reach 20-30 percent after a complete lymphadenectomy, as well as postoperative pain and functional sequelae in the arm and shoulder, are reduced.
The key role of nuclear medicine and molecular imaging
In this scenario, nuclear medicine is consolidated as a fundamental tool for both disease evaluation and treatment planning. Positron emission tomography combined with CT allows for non-invasive assessment of tumor burden in the axilla and response to systemic treatment, especially in women treated with neoadjuvant chemotherapy.
Felipe Gómez-Caminero López, a member of the SEMNIM Oncology Working Group, explained that this technique helps to stratify tumor burden, detect clinically relevant regional disease, and support decisions that avoid unnecessary lymphadenectomies.
However, he warned that the sensitivity of this test for identifying microscopic disease remains limited, and therefore it cannot replace sentinel lymph node biopsy, a procedure that allows for the localization and analysis of the first lymph node that receives direct drainage from the primary tumor to determine if regional metastases are present.
Sentinel lymph node biopsy continues to be considered the gold standard in patients with clinically negative axilla, as it allows for the avoidance of unjustified axillary dissections and reduces the morbidity associated with surgery.
In women with initial nodal involvement treated with neoadjuvant chemotherapy, targeted axillary dissection (TAD) has been consolidated as one of the most outstanding advances. This technique combines the localization of the initially metastatic lymph node, marked before systemic treatment using radioactive iodine-125 seeds or other devices, with sentinel lymph node biopsy.
"Pre-systemic treatment nodal marking allows for the application of techniques such as targeted axillary dissection, reducing morbidity without losing relevant clinical information," detailed Sergi Vidal Sicart, from the SEMNIM Radioguided Surgery Working Group.
According to what has been indicated, TAD increases the accuracy of staging after neoadjuvant therapy, decreases the rate of false negatives, and makes it possible to avoid complete lymphadenectomies in a growing number of patients who show a good response to treatment.
Another context analyzed by specialists is that of patients with local recurrence of breast cancer previously subjected to axillary surgery and radiotherapy. In these situations, repeating the sentinel lymph node biopsy poses a technical challenge due to modifications in lymphatic drainage pathways.
Data from the SEMNIM Radioguided Surgery Group indicate that this technique can be performed in more than 80 percent of patients and that up to 20 percent of metastases are located in aberrant or extra-axillary drainage territories, which can be identified through lymphoscintigraphy and molecular imaging.