Poster presentation | Open | Published:
First clinical results on the potential of intraoperative imaging for sentinel lymph node biopsy in breast cancer
Breast Cancer Researchvolume 9, Article number: SP22 (2007)
The growing interest in the sentinel lymph node (SLN) detection concept has led to the development of several prototypes of hand-held gamma cameras. After the first successful clinical trials with intraoperative imaging probes, the time has come to quantify the clinical benefit of these devices.
To compare the hand-held camera (POCI) with a lymphoscintigraphy in order to precisely localize SLNs in patients with breast cancer requiring SLN biopsy.
The SLN protocol consisted of a peritumoral injection of 160 MBq 99mTc-labeled nano-colloids performed 2 hours before the lymphoscintigraphy, which is realized preoperatively using a conventional single-head gamma camera and then the hand-held POCI camera (field-of-view, 13 cm2) (Figure 1). The day after, in the operating room, the patients undergo one blue-dye subcutaneous tumoral injection. Before incision the surgeon first uses the POCI to perform an intraoperative lymphoscintigraphy and then the counting probe (Europrobe CsI, Eurorad) for transcutaneous SLN prelocalizations. The POCI camera was slowly moved on the skin until SLN identification. The axillary area was scanned with the POCI camera with 10-second acquisition images. SLN detection was defined as positive on the basis of a local radioactivity increase in the intraoperative images of the surveyed region. The SLN excision biopsy was guided, following the established procedure, using the counting probe and blue dye. Finally, a complementary scanning procedure was performed with the POCI directly in the operative wound before skin closure to confirm complete excision or to detect some residuals SLNs. The number and the localization of SLNs obtained by both intraoperative detectors are compared with those obtained the day before with the conventional gamma camera.
To date, 33 patients (mean age: 64 years) have been included in this clinical protocol. A SLN was identified by lymphoscintigraphy in 31/33 patients (94%), versus 30/33 (90.9%) with the POCI (P > 0.3). The mean number of SLNs identified by lymphoscintigraphy was 1.6 (range: 0–4), versus 1.8 (range: 0–4) with the POCI (Table 1). The day of the surgery, at least one SLN (mean: 1.9; range: 0–4) was identified by the POCI in 32/33 patients (97%) (P = 0.13). At least one SLN (mean: 2.3; range: 1–4) was identified in all patients during the surgery. Concerning the duration of these procedures, the mean acquisition time was 15 minutes (range: 10–30) with lymphoscintigraphy, 8.8 minutes (range: 3–18) with the POCI used the day before surgery and 3.35 minutes (range: 2–6.5) with preoperative POCI.
These preliminary clinical results show that the POCI camera is able to predict the number and localization of breast cancer SLNs. The POCI camera appears to be a promising tool to complete or replace the preoperative standard lymphoscintigraphy, especially in surgical centers without an onsite nuclear medicine department.