Evaluation of dynamic lymphoscintigraphy and sentinel lymph-node biopsy for detecting occult metastases in patients with penile squamous cell carcinoma

To evaluate the introduction of dynamic lymphoscintigraphy and sentinel lymph-node (SLN) biopsy (used to detect occult lymph node metastases in patients with penile cancer and clinically impalpable inguinal lymph nodes at presentation) at a UK tertiary referral centre for penile cancer. In all, 75 patients with penile squamous cell carcinoma of stage T1, grade >= 2, and unilateral or bilateral impalpable groin nodes, were prospectively enrolled over a 2-year period. Patients underwent lymphoscintigraphy with (99m)technetium-labelled nanocolloid which was injected intradermally around the tumour or into the distal penile shaft skin. Four hours later, the SLN(s) were identified during surgery using a hand-held gamma-probe and intradermal injections with blue dye. Completion lymph node dissection was subsequently used in patients with tumour-positive SLNs. In all, 255 SLNs were removed from 143 groins; all excised nodes had taken up the radioactive marker, and the blue dye was evident in 87%. Eighteen of 75 (24%) patients and 21 of 143 groins (15%) had a tumour-positive SLN. All but one patient went on to completion lymph node dissection. Three of these 18 (17%) had further disease in other than SLNs. Six of 143 (4%) groins developed minor complications. One false-negative result was reported at a median (range) follow-up of 11 (2-24) months. This technique is feasible for managing penile cancer in a UK tertiary referral centre. The initial results suggest that it can accurately identify the SLN(s), which can then be removed for pathological review with minimal morbidity.