Beschreibung
Metastatic involvement is one of the most important prognostic factors for women diagnosed with cervical cancer. Pelvic lymphadenectomy combined with radical hysterectomy, or trachelectomy in case of fertility-sparing, is the most commonly performed procedure even in early stages. Sentinel lymph node (SLN) mapping and intraoperative examination using the frozen section procedure followed by histopathologic ultrastaging could be an alternative to systematic pelvic lymphadenectomy to precisely diagnose the nodal extension. We evaluated the capability of SLN mapping using indocyanine green (ICG) and blue dye combined and further the diagnostic value of intraoperative SLN examination by frozen section (FS) compared to the final ultrastaging.
We performed a single-center, retrospective study of 103 surgically treated patients with early-stage cervical cancer (FIGO IA1 with lymphovascular space invasion, IA2 and IB1) including tumors up to 4cm of diameter. Location and tracer of all detected SLNs had been documented for a prospective, multi-center trial (SENTIX trial). All SLNs were sent for intraoperative examination by FS and terminal histopathologic ultrastaging with a precise protocol.
Median age was 36.21 and the most common stage was IB1 (62.1%). In average 3.3 ± 1.67 SLNs were detected per patient. Combined bilateral detection rate was 99.0% (102/103), detection of sentinel nodes only failed in one patient. Bilateral detection rate for ICG alone was 93.2% and significantly higher (p=0.004) than for patent blue (77.7%). 97.4% of all SLNs were located below the common iliac vessels (including the external (9.4%), internal (3.8%) and the interiliac (84.1%) regions). No lymph nodes were found in the para-aortic region. 71.8% of all patients had simultaneous bilateral mapping with ICG and blue dye, of whom the SLNs were identical in 91.9%. In 8.1% one additional node was mapped in a further anatomic region. 7 patients (6.9%) had positive lymph nodes. Frozen section failed to detect 1 out of 3 patients with macrometastases and 3 out of 4 with micrometastases. Overall sensitivity of FS was 43% and the negative prediction value 96%.
SLN mapping with ICG is feasible with a very high bilateral detection rate (93.2%). ICG had a significant higher bilateral detection rate compared to patent blue (p=0.004). Combining ICG and patent blue even increased the bilateral detection rate to 99.0% which was also significantly higher compared to ICG alone (p=0.031). Most SLNs were located around the external and internal iliac vessels and no nodes were found in the para-aortic region. Intraoperative examination of SLNs with frozen section seems to have a poor diagnostic value, especially to detect micrometastases.
