PATIENTS AND METHODS
This prospective cross-sectional study selected 39 women >18 years who underwent surgical treatment for unilateral breast cancer and either ALND or SLNB as the axillary lymph node chain approach between 2005 and 2012. The lymphatic flow of the arm in the postoperative period was compared between the two lymphatic manipulation techniques. LS was performed up to 60 days after the surgery. An arm range of motion corresponding to >120° of shoulder flexion was also required for women who underwent ALND. The exclusion criteria were as follows: patients who underwent chemotherapy or radiotherapy before surgery, patients with knowledge of the lymphatic pathology before ALND and SLNB, and presence of inflammatory or infectious processes associated with arms. The Research Ethics Committee of Barretos Cancer Hospital approved this study, and all patients signed an informed consent form.
All lymphoscintigraphies were performed with a standardized acquisition technique according to the protocol developed by Sarri et al29 using a dual-head gamma camera (GE Medical Systems Israel Ltd, Millennium VG Hawkeye, Tirat Hacarmel, Israel) equipped with a low-energy high-resolution collimator with a 20% window centered around the 140 keV photopeak and matrices of 128×128 for dynamic images, 256×256 for static images, and 256×1,024 for the whole-body scan (WBS), with no magnification. With patients in the supine position and arms raised above the head, 37 MBq of 99m Tc-phytate (Nuclear and Energetic Research Institute – IPEN, FITA-TEC fitato de sódio [99m Tc], São Paulo, Brazil) by volume of 0.5 mL was administered subcutaneously (fan technique) into the second interdigital space29 of the manipulated limb using an insulin syringe. Dynamic images were obtained immediately after injection at a rate of 1 minute per image for 20 minutes for a field of view including the area from the hands to the axillae (Dynamic). Two static images with time of 500 seconds were acquired immediately after the end of the Dynamic: one was acquired in the same field of view as the Dynamic projection (Static 1), and the other was acquired in the anterior thoracic region and axillae projection (Static 2). With the patient in the same position, a WBS at a bed speed of 7 cm/minute started 90 minutes after injection of the radiotracer and included anterior and posterior projections. The patients attended the LS procedures wearing appropriate clothing that would not restrict the superficial lymphatic flow.
The lymphoscintigraphies from the two groups were analyzed based on the area reached by the radiotracer in the lymphatic ducts of the upper limb and on the sites and number of lymph nodes visualized in the three phases of LS acquisition. A sequential ordinal classification was used for the area reached by the lymphatic fluid, from the injection site to the most distant point reached, using a 0–14 scale, respectively, with the number of lymph nodes visualized, as proposed by Sarri et al29 and is shown in Figure 1.
For statistical analysis, the points reached by the lymphatic fluid were grouped into the forearm (points 0–3), arm and axilla (points 4–9), and extra-axillary lymph nodes in the thoracic region (points 10–12). The images acquired in the three phases of the LS of women who underwent ALND and SLNB were paired and compared. Frequencies, percentages, and measures of central tendency and dispersion were used to characterize the sample. The Mann–Whitney U test was used to compare the number of lymph nodes visualized, age, and body mass index (BMI) between the ALND and SLNB groups (Table 1) and descriptive analysis in Table 2. Fisher’s exact test was used to compare the qualitative variables (Table 3). For all analyses, the level of significance was set at 5%.