SPECT-CT lymphoscintigraphy: the first experience for evaluation of lymph drainage in the pelvis after hysterectomy

Introduction: It is known that the efficacy level of lymph node dissection (LND) in patients with cervical or endometrial cancer has a direct impact on the postsurgical management and life expectancy. To assess the completeness of the pelvic lymph nodes removal the ultrasonography (USG), X-ray computed tomography (CT) and magnetic resonance (MR) imaging are used. However, these methods do not always allow to judge unambiguously about the absence of metastatic lymph nodes (LN). Lymphoscintigraphy (LSG) is another method that is used to assess the efficacy of lymph node dissection. However, the lack of anatomical landmarks on the obtained images significantly limits the clinical use of this method. Now this limitation is overcome by the use of the hybrid system SPECT-CT. To our knowledge this method had not been used to estimate the efficacy level of the lymph node dissection. The purpose of this study was to show the possibility of application of SPECT-CT in the assessment of pelvic LN and retroperitoneal space after radical surgery. Materials and Methods: The retrospective analysis was performed using the diagnostic results of 25 women (ultrasound, MRI, LSG and SPECT-CT) after surgery performed for cervical or endometrial cancer, with additionally performed pelvic and / or para-aortic LND. Results: We have found that in 78 % of cases the conventional LSG was not able to adequately assess the level of the lymphatic drainage block and the presence of lymph reflux. CT and ultrasound also did not give us the indications of the existence of these pathological conditions of the lymphatic system. Conclusion: The hybrid imaging technology allowed to double the frequency of determination of residual LN in the pelvis in comparison with CT, and in comparison with the conventional LSG. Furthermore, we have shown that the use of the SPECT-CT lymphoscintigraphy could clarify in the assessment of the well-known LN condition, traditionally referred to as lymphadenopathy.