LAUSR

Recently, Novikov et al. [1] has published an interesting article on sentinel node mapping of uterine cervix cancer in the “Annals of Nuclear Medicine”. They reported the results of sentinel node biopsy in IAB and IIA uterine cervix cancer patients. The main focus of their study was the importance of laterality of sentinel node detection on pre-operative SPECT/CT. Patients with bilateral sentinel node detection had 0% false-negative rate despite 100% false-negative rate in patients with unilateral detection. The final conclusion of the study was: “In patients with unilateral SLN localization, SLN biopsy cannot be used for the prediction of regional LN status”. Although the conclusion of the authors is correct, it is not the “whole truth”. Unilateral sentinel node detection in midline tumors does increased the false-negative rate. However, sentinel node algorithm can solve this problem and sentinel node mapping can be performed in unilateral sentinel node detection with high accuracy. What is sentinel node algorithm? In midline tumors, each side of a patient should be considered as a separate unit. In patients with unilateral sentinel node detection, sentinel node status of each side can only predict the status of nonsentinel nodes ipsilaterally. Actually, the reason of sentinel node detection failure in the contralateral side can be due to pathological involvement of the regional lymph nodes and the side with sentinel node detection failure should undergo side specific lymph node dissection. This approach has been successfully applied to all midline tumors including penile, vulvar, endometrial, uterine cervix, bladder, prostate, and anal canal cancers [2–4]. For uterine cervix cancers, sentinel node algorithm increased the sensitivity considerably in couple of previously published studies [5]. Actually, Novikov et al. did not provide side specific results of the positive sentinel and non-sentinel nodes in their study results. However, in the figures of their study, the successful application of sentinel node algorithm can be shown. For example, in Fig. 2 of their study, the patient had unilateral sentinel node visualization in the left obturator and common iliac nodes (both were pathologically negative). Not surprisingly, the involved non-sentinel node was on the right side (right external iliac region). In conclusion, Novikov et al. beautifully showed the importance of pre-operative lymphoscintigraphy and laterality of sentinel node detection in sentinel node biopsy of uterine cervix tumors. However, they only reported “a part of the truth” not the “whole truth”. In my opinion, re-calculation of sensitivity for Novikov et al. study using sentinel node algorithm can show that, even in patients with unilateral sentinel node detection, sentinel node biopsy can be done safely and with high accuracy in uterine cervix tumors.