Purpose: Compare the lymphatic flow in the arm after breast cancer surgery and axillary lymph node dissection (ALND) versus sentinel lymph node biopsy (SLNB) using lymphoscintigraphy (LS).
Patients and methods: A cross-sectional study with 39 women >18 years who underwent surgical treatment for unilateral breast cancer and manipulation of the axillary lymph node chain through either ALND or SLNB, with subsequent comparison of the lymphatic flow of the arm by LS. The variables analyzed were the area reached by the lymphatic flow in the upper limb and the sites and number of lymph nodes identified in the ALND or SLNB groups visualized in the three phases of LS acquisition (immediate dynamic and static images, delayed scan images). For all analyses, the level of significance was set at 5%.
Results: There was a significant difference between the ALND and SLNB groups, with predominant visualization of lymphatic flow and/or lymph nodes in the arm and axilla (P=0.01) and extra-axillary lymph nodes (P<0.01) in the ALND group. There was no significant difference in the total number of lymph nodes identified between the two groups. However, there was a significant difference in the distribution of lymph nodes in these groups. The cubital lymph node was more often visualized in the immediate dynamic images in the ALND group (P=0.004), while the axillary lymph nodes were more often identified in the delayed scan images of the SLNB group (P<0.01). The deltopectoral lymph node was only identified in the ALND group, but with no significant difference.
Conclusion: The lymphatic flow from the axilla was redirected to alternative extra-axillary routes in the ALND group.


Keywords: breast neoplasms, lymphadenectomy, radionuclide imaging, lymphatic diseases  


INTRODUCTION

Breast cancer treatment has evolved over recent decades due to advances in techniques for early detection of the disease, with consequent decreases in the mortality rate1,2 and morbidity rate that result from less aggressive surgeries. The status of axillary lymph nodes determines whether the treatment should be more or less invasive, indicating either axillary lymph node dissection (ALND) or sentinel lymph node biopsy (SLNB),3–5 respectively. Surgical injuries resulting from ALND cause obstruction of the primary route of lymphatic drainage of the arm,5,6 leading to postoperative complications, such as hemorrhage, infection, seroma, axillary web syndrome, chronic pain, paraesthesia caused by intercostobrachial nerve damage, reduced range of motion and muscle weakness on the shoulder ipsilateral to the surgery, and, especially, lymphedema.7,8 More conservative intraoperative techniques to approach the axillary chain, such as SLNB have been used in an attempt to prevent lymphedema. Krag et al9 and Giuliano et al10 introduced innovative techniques that represent a new standard of axillary treatment for patients in the early stages of breast cancer, allowing a selective, safe, and less mutilating resection with satisfactory results and a significant reduction of surgical morbidities.11,12 However, this treatment is limited to patients with clinically negative axilla.13,14 The main goal of SLNB is to provide information about the stage and prognosis of the axillary chain to avoid unnecessary axillary lymphadenectomy, consequently decreasing morbidities in the upper limb ipsilateral to the axilla manipulated. Although this surgical technique has been improved, its use reduces but does not eliminate the risk of developing lymphedema,15,16 which has an incidence of 0%–13%.6,17,18 Several factors can lead to this condition, such as the transection of lymphatic vessels of the arm during the SLNB19,20 and obesity.20,21 The increased incidence of lymphedema, especially associated with complementary radiotherapy,22,23impacts the quality of life of these patients.24

Once established, lymphedema is incurable. Studies have demonstrated that both surgical and drug therapies have failed in the cure of the disease.25 However, lymphedema can be avoided, treated, and controlled through daily preventive measures.26 Its diagnosis is difficult, especially in the early stages.23 Without a correct early diagnosis, the treatment begins late and at more advanced stages of the disease. Immediate treatment leads to rapid improvement and prevents disease progression.27The lymphatic system is anatomically complex and difficult to image. For a long time, lymphatic imaging was limited to the use of conventional lymphography, which is an invasive procedure with a high incidence of discomfort and complications.28

Lymphoscintigraphy (LS) has been used since 1950 to study diseases associated with the lymphatic system. Initially, it was used qualitatively to determine the relationship between edema of the extremities and lymphatic system disorders without any association with etiology. In the past three decades, the use of quantitative analysis was implemented.29,30 Numerous studies have demonstrated the reliability of the lymphatic flow studies, regardless of modes of investigation, radiotracers, and interpretation, as described by Akita et al31 using indocyanine green fluorescence imaging for lower leg lymphedema investigation following lymph node dissection for gynecologic cancer.

In mastology, LS is widely used for SLNB. There are no data in the literature on the use of LS to evaluate the lymphatic drainage pathway of the upper limb after SLNB.

In agreement with the new guidelines for the use of more conservative surgical procedures, this study aimed to analyze changes in the lymphatic flow of the arm by LS after ALND versus SLNB performed for postoperative breast cancer.