Lymphoscintigraphy detecting alterations of upper limb lymphatic flow following early sentinel lymph node biopsy in breast cancer

Almir Jose Sarri,1 Eduardo Tinois da Silva,2 Rene Aloisio da Costa Vieira,3 Katia Hiromoto Koga,2 Pedro Henrique Moriguchi Cação,4 Vitor Coca Sarri,5 Sonia Marta Moriguchi2 1Department of Physical Therapy, Barretos Cancer Hospital, Barretos, Sao Paulo, 2Department of Tropical Diseases and Diagnostic Imaging, Botucatu Medical School, Sao Paulo State University – UNESP, Botucatu, 3Department of Mastology and Reconstructive Surgery, Barretos Cancer Hospital, Barretos, 4Department of Radiology – Faculdade de Medicina de São José do Rio Preto (FAMERP), 5Medical School, University of Franca, Sao Paulo, Brazil Purpose: To evaluate early variations in lymphatic circulation of the arm pre- and post-sentinel lymph node biopsy (SLNB) and conservative breast surgery by lymphoscintigraphy (LS).Patients and methods: Between 2005 and 2012, 15 patients underwent LS before and after the SLNB (total=30 studies). The pre-SLNB study was considered the control. Early images within twenty minutes (dynamic and static images) and delayed images within ninety minutes of arms and armpits were acquired using a gamma camera. The LS images before and after the SLNB of each patient were paired and compared to each other, evaluating the site of lymphatic flow (in the early phase) and identifying the number of lymph nodes (in the late phase). These dynamic images were subjected to additional quantitative analysis to assess the lymphatic flow rate using the slope assessed by the angular coefficient of the radioactivity × time curves in areas of interest recorded in the axillary region. The variations of lymphatic flow and the number of lymph nodes in the post-SLNB LS compared to the pre-SLNB LS of each patient were classified as decreased, sustained or increased. The clinical variables analyzed included the period between performing the SLNB and the subsequent LS imaging, age, body mass index, number of removed lymph nodes, type of surgery and whether immediate oncoplastic surgery was performed.Results: The mean age was 54.53±9.03 years (36–73 years), the mean BMI was 27.16±4.16 kg/m2 (19.3–34.42), and the mean number of lymph nodes removed from each patient was 1.6±0.74 (1–3). There was significant difference in the time between surgery and the realization of LS (p=0.002; Mann–Whitney U test), but in an inverse relationship, the higher was the range, the smaller was the lymphatic flow, indicating a gradual reduction of lymphatic flow after surgery (Spearman’s p=0.498, with p=0.013).Conclusion: Upper limb lymphatic flow gradually decreased after the SLNB and conservative breast surgery in this study, but these results are exploratory because of the small sample size. Further studies are needed to confirm and to investigate more in depth these findings. Keywords: lymph node sentinel biopsy, lymphoscintigraphy, nuclear medicine, lymphedema, breast cance