Lenka Vermeeren

Comparing the Hybrid Fluorescent–Radioactive Tracer Indocyanine Green–99mTc-Nanocolloid with 99mTc-Nanocolloid for Sentinel Node Identification: A Validation Study Using Lymphoscintigraphy and SPECT/CT

The purpose of this study was to compare the lymphoscintigraphic drainage patterns of a hybrid sentinel node tracer consisting of the fluorescent dye indocyanine green (ICG) and 99mTc-nanocolloid with the drainage pattern of 99mTc-nanocolloid alone, the current standard tracer in many European countries. Methods: Twenty-five patients with a melanoma in the head and neck region (n = 10), a melanoma on the trunk (n = 6), or penile carcinoma (n = 9) who were scheduled for sentinel node biopsy were prospectively included. First, the standard 99mTc-nanocolloid procedure was performed. After injection at the lesion site, lymphoscintigraphy was performed with a 10-min dynamic study and static planar images at 10 min and 2 h after injection, followed by SPECT/CT. The same scintigraphic procedure was repeated after injection of hybrid ICG–99mTc-nanocolloid the same afternoon in 10 patients or the next morning in 15 patients. The paired images of both injections were evaluated, and count rates in the sentinel nodes were calculated and compared. Sentinel nodes were surgically localized using blue dye, a γ-ray detection probe, a portable γ-camera, and a fluorescence camera. Results: Lymphatic drainage was visualized in all 25 patients using 99mTc-nanocolloid, leading to the identification of 66 sentinel nodes in total. These same sentinel nodes were also identified during the second scintigraphic procedure with ICG–99mTc-nanocolloid. Moreover, a high correlation between the radioactive counting rates in the sentinel nodes of both scintigraphic studies was observed (mean R2 = 0.83). Intraoperatively (4–23 h after the second injection), all preoperatively identified sentinel nodes could be localized using radio- and fluorescence guidance combined. In total, 95% of the sentinel nodes could be intraoperatively visualized by means of fluorescence imaging, whereas merely 54% stained blue. Ex vivo, all radioactive sentinel nodes were fluorescent and vice versa. No adverse reactions were observed. Conclusion: The lymphatic drainage pattern of ICG–99mTc-nanocolloid is identical to that of 99mTc-nanocolloid. This observation, together with the added value of intraoperative fluorescence guidance, warrants wider evaluation of hybrid ICG–99mTc-nanocolloid as a tracer for sentinel node procedures.

A portable gamma-camera for intraoperative detection of sentinel nodes in the head and neck region

We introduced and evaluated a portable γ-camera for intraoperative visualization of sentinel nodes in the head and neck region. Methods: Planar lymphoscintigraphy and SPECT/CT were performed after peritumoral injection of 99mTc-nanocolloid in 25 patients (head and neck melanoma or oral cavity carcinoma). Sentinel nodes were localized intraoperatively with a portable γ-camera and a hand-held γ-probe. The portable γ-camera was used to determine the distribution of remaining radioactivity after excision of the sentinel nodes. Results: The portable γ-camera visualized all 70 preoperatively identified sentinel nodes. Sentinel nodes at difficult sites could be localized more efficiently, and in 6 patients, 9 additional nodes (1 tumor-positive) were identified with the portable γ-camera after excision. Conclusion: Intraoperative identification of sentinel nodes in the head and neck region with a portable γ-camera is feasible and might lead to detection of more sentinel nodes.

Value of SPECT/CT for Detection and Anatomic Localization of Sentinel Lymph Nodes Before Laparoscopic Sentinel Node Lymphadenectomy in Prostate Carcinoma

Laparoscopic evaluation of sentinel nodes is useful for staging prostate cancer, but preoperative localization of deep abdominal sentinel nodes with planar lymphoscintigraphy is difficult. We evaluated the value of SPECT/CT for detecting and localizing sentinel nodes in prostate cancer. Methods: 99mTc-nanocolloid was injected peri- and intratumorally, guided by transrectal ultrasonography, in 46 patients with prostate cancer of intermediate prognosis. Patients underwent planar imaging after 15 min and 2 h, SPECT/CT after 2 h, and laparoscopic sentinel node lymphadenectomy on the same day. SPECT was fused with CT and analyzed using 2-dimensional orthogonal slicing and 3-dimensional volume rendering. We evaluated the number of extra sentinel nodes found by SPECT/CT, the number of sentinel nodes found by SPECT/CT outside the area of the extended pelvic lymphadenectomy, and the anatomic information provided by SPECT/CT. Furthermore, we classified the value of the additional SPECT/CT images into 3 categories (no advantage, presumable advantage, and definite advantage) according to the extra anatomic information given and whether additional sentinel nodes were found by SPECT/CT. Results: The patients had a mean age of 64 y (range, 53–74 y) and received a mean injected dose of 218 MBq (range, 147–286 MBq). The sentinel node visualization rate was 91% (42 patients) for planar imaging and 98% (45 patients) for SPECT/CT. In 29 of the 46 patients (63%), SPECT/CT revealed additional sentinel nodes (especially lymph nodes near the injection area) not seen on planar imaging. In 7 patients, those additional sentinel nodes were positive for metastasis (being the exclusive metastatic sentinel node in 4 patients). Overall, 15 patients (33%) had positive sentinel nodes. Sentinel nodes outside the area of extended pelvic lymphadenectomy were found in 16 patients (35%), whereas in 56% of these patients those nodes were not seen on planar imaging. Performing SPECT/CT had no advantage in 13% of the patients, a presumable advantage in 24%, and a definite advantage in 63%. Urologic surgeons used the SPECT/CT images to guide their trocar insertion sites and sentinel node finding with the probe. Conclusion: More sentinel nodes can be detected with SPECT/CT than with planar imaging alone. In comparison with planar imaging, SPECT/CT especially reveals extra sentinel nodes near the prostate and outside the area of the extended pelvic lymphadenectomy. Furthermore, the modality provides useful additional information about the anatomic location of sentinel nodes within and outside the pelvic area, leading to improved intraoperative sentinel node identification.

SPECT/CT for preoperative sentinel node localization.

The value of SPECT/CT for detection and localization of sentinel nodes is reviewed. SPECT/CT depicts extra sentinel nodes and identifies non‐nodal tracer accumulation. SPECT/CT is indicated in patients with complex lymphatic drainage as often present in patients with head, neck and scapular melanoma, breast cancer patients with extra‐axillary sentinel nodes and patients with tumors draining to pelvic nodes. SPECT/CT also clarifies the drainage pattern of inconclusive conventional images (non‐visualization or unclear location of the nodes). J. Surg. Oncol. 2010;101:184–190.

SPECT/CT for sentinel lymph node mapping in head and neck melanoma.

The additional value of single photon emission computed tomography with CT (SPECT/CT) for detection and localization of sentinel nodes in patients with a melanoma of the head and neck was determined.

Assessment of lymphatic drainage patterns and implications for the extent of neck dissection in head and neck melanoma patients.

The aim of this study is to evaluate lymphatic drainage with sentinel node location data in patients with head and neck cutaneous melanoma, and to determine the implications for the extent of therapeutic neck dissections.

The Additional Value of Lymphatic Mapping with Routine SPECT/CT in Unselected Patients with Clinically Localized Melanoma

PurposeTo investigate whether single photon emission computed tomography camera with integrated radiographic computed tomography (SPECT/CT) is of additional value compared to conventional lymphoscintigraphy in routine lymphatic mapping in patients with melanoma.MethodsThirty-five unselected patients with a primary melanoma who were scheduled for wide local excision and sentinel node biopsy underwent conventional lymphoscintigraphy and subsequently SPECT/CT. We determined whether SPECT/CT showed additional sentinel nodes, whether it provided better information on the location of the sentinel nodes, and whether this additional anatomic information led to a change in the planned surgical approach.ResultsSPECT/CT depicted the same 69 sentinel nodes as conventional lymphoscintigraphy in all 35 patients plus found eight additional sentinel nodes in seven patients (20%). In two of these patients (5.7%), an additional nodal basin had to be explored to find the extra sentinel nodes. SPECT/CT provided additional anatomic information that was helpful to the surgeon in 11 patients (31%) and led to an adjustment of the surgical approach in 10 patients (29%).ConclusionsSPECT/CT provided relevant additional information in 16 (46%) of the 35 patients. Routine use of SPECT/CT in addition to conventional lymphoscintigraphy is recommended in melanoma patients undergoing lymphatic mapping.

Sentinel Node Detection in Head and Neck Malignancies: Innovations in Radioguided Surgery

Sentinel node mapping is becoming a routine procedure for staging of various malignancies, because it can determine lymph node status more precisely. Due to anatomical problems, localizing sentinel nodes in the head and neck region on the basis of conventional images can be difficult. New diagnostic tools can provide better visualization of sentinel nodes. In an attempt to keep up with possible scientific progress, this article reviews new and innovative tools for sentinel node localization in this specific area. The overview comprises a short introduction of the sentinel node procedure as well as indications in the head and neck region. Then the results of SPECT/CT for sentinel node detection are described. Finally, a portable gamma camera to enable intraoperative real-time imaging with improved sentinel node detection is described.

Paraaortic Sentinel Lymph Nodes: Toward Optimal Detection and Intraoperative Localization Using SPECT/CT and Intraoperative Real-Time Imaging

Paraaortic sentinel node biopsy may be a challenging procedure because the sentinel nodes are located retroperitoneally in close proximity to vital structures. The purpose of this study was to describe and evaluate the value of preoperative SPECT/CT for lymphatic mapping, and a portable γ-camera for intraoperative radioguidance, in patients with paraaortic sentinel nodes. Methods: We evaluated our practice in 18 patients, who were treated at The Netherlands Cancer Institute with sentinel lymphadenectomy for different urologic malignancies and showed paraaortic drainage on preoperative images. After intratumoral injection of 99mTc-nanocolloid, the patients underwent sequential planar lymphoscintigraphy, hybrid SPECT/CT, and sentinel lymphadenectomy. Intraoperative node detection and localization were guided by a laparoscopic γ-probe and a portable γ-camera. This γ-camera was set to display both the 99mTc signal and the 125I-seed signal. This 125I seed was placed on top of the γ-probe, functioning as a pointer on screen, thus enabling real-time sentinel node localization with the γ-camera. Results: In 16 patients with midabdominal drainage on planar images and in 2 patients with nonvisualization on planar images, SPECT/CT showed clear localization of paraaortic sentinel nodes in relation to the abdominal vessels. Five patients underwent open surgery, and 13 patients underwent laparoscopy. The paraaortic sentinel nodes were successfully localized and removed in 15 patients with the help of the portable γ-camera and γ-probe and in 3 patients with the γ-probe only. In 1 patient, the paraaortic sentinel node showed a metastasis. Conclusion: If retroperitoneal drainage is expected, SPECT/CT provides good detection and clear localization of sentinel nodes in relation to anatomic structures. Detection and removal of paraaortic sentinel nodes by means of a laparoscopic γ-probe and real-time imaging with a portable γ-camera is a successful method with high intraoperative detection rates.

SPECT/CT and a portable gamma-camera for image-guided laparoscopic sentinel node biopsy in testicular cancer.

The purpose of this study was to evaluate the utility of SPECT/CT and real-time intraoperative imaging with a portable γ-camera for laparoscopic sentinel node (SN) localization in stage I testicular cancer. Methods: Ten patients with clinical stage I testicular cancer were studied between November 2006 and November 2010. Their mean age was 37 y (range, 25–50 y). The primary tumors were situated on the right side in 5 patients and on the left side in 5. After a funicular block with 2% lidocaine, an average dose of 80 MBq (range, 59–98 MBq) of 99mTc-nanocolloid in a volume of 0.2 mL was injected into the testicular parenchyma. Shortly after injection, a 10-min dynamic study was performed, followed by the acquisition of static planar images at 15 min and 2 h. SPECT/CT was performed at 2 h. After image fusion, SNs were visualized, and their exact anatomic location was determined. The SPECT/CT images were displayed in the operation room to guide SN detection using a laparoscopic γ-ray probe and a portable γ-camera. Results: Lymphatic drainage to the retroperitoneum was seen in all patients. SPECT/CT identified interaortocaval or paracaval SNs in the 5 patients with right-sided tumors, one of whom had an additional SN adjacent to the testicular vessels. In all 5 patients with left-sided tumors, paraaortic SNs were visualized; a node along the testicular vessels was visualized in 2 of these 5. Twenty-six SNs were laparoscopically removed (range, 1–4 per patient). An SN contained metastases in 1 case. No recurrences developed in the 9 patients with a tumor-free SN during a median follow-up of 21 mo (range, 2–50 mo). Conclusion: SPECT/CT enables accurate anatomic localization of retroperitoneal SNs in patients with testicular cancer, facilitating their laparoscopic retrieval. Real-time image guidance by a portable γ-camera improves intraoperative SN detection and appears to identify (20%) additional SNs.