The efficacy of Tilmanocept in sentinel lymph mode mapping and identification in breast cancer patients: a comparative review and meta-analysis of the 99mTc-labeled nanocolloid human serum albumin standard of care
ABSTRACT Sentinel lymph node (SLN) mapping is common, however question remains as to what the ideal imaging agent is and how such an agent might provide reliable and stable localization of SLNs. (99m)Tc-labeled nanocolloid human serum albumin (Nanocoll(®)) is the most commonly used radio-labeled colloid in Europe and remains the standard of care (SOC). It is used in conjunction with vital blue dyes (VBDs) which relies on simple lymphatic drainage for localization. Although the exact mechanism of Nanocoll SLN localization is unknown, there is general agreement that Nanocoll exhibits the optimal size distribution and radiolabeling properties of the commercially available radiolabel colloids. [(99m)Tc]Tilmanocept is a novel radiopharmaceutical designed to address these deficiencies. Our aim was to compare [(99m)Tc]Tilmanocept to Nanocoll for SLN mapping in breast cancer. Data from the Phase III clinical trials of [(99m)Tc]Tilmanocept's concordance with VBD was compared to a meta-analysis of a review of the literature to identify a (99m)Tc albumin colloid SOC. The primary endpoints were SLN localization rate and degree of localization. Six studies were used for a meta-analysis to identify the colloid-based SOC. Five studies (6,134 patients) were used to calculate the SOC localization rate of 95.91 % (CI 0.9428-0.9754) and three studies (1,380 patients) were used for the SOC SLN degree of localization of 1.6683 (CI 1.5136-1.8230). The lower bound of the confidence interval was used for comparison to Tilmanocept. Tilmanocept data included 148 patients, and pooled analysis revealed a 99.99 % (CI 0.9977-1.0000) localization rate and degree of localization of 2.16 (CI 1.964-2.3600). Tilmanocept was superior to the Nanocoll SOC for both endpoints (P < 0.0001).
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ABSTRACT: Two decades ago, lymphatic mapping of sentinel lymph nodes (SLN) was introduced into surgical cancer management and was termed sentinel node navigated surgery. Although this technique is now routinely performed in the management of breast cancer and malignant melanoma, it is still under investigation for use in other cancers. The radioisotope technetium ((99m)Tc) and vital blue dyes are among the most widely used enhancers for SLN mapping, although near-infrared fluorescence imaging of indocyanine green is also becoming more commonly used. (99m)Tc-tilmanocept is a new synthetic radioisotope with a relatively small molecular size that was specifically developed for lymphatic mapping. Because of its small size, (99m)Tc-tilmanocept quickly migrates from its site of injection and rapidly accumulates in the SLN. The mannose moieties of (99m)Tc-tilmanosept facilitate its binding to mannose receptors (CD206) expressed in reticuloendothelial cells of the SLN. This binding prevents transit to second-echelon lymph nodes. In Phase III trials of breast cancer and malignant melanoma, and Phase II trials of other malignancies, (99m)Tc-tilmanocept had superior identification rates and sensitivity compared with blue dye. Trials comparing (99m)Tc-tilmanocept with other (99m)Tc-based agents are required before it can be routinely used in clinical settings.OncoTargets and Therapy 06/2014; 7:1151-8. DOI:10.2147/OTT.S50394 · 2.31 Impact Factor
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ABSTRACT: Background Sentinel lymph node (SLN) surgery is used worldwide for staging breast cancer patients and helps limit axillary lymph node dissection. [99mTc]Tilmanocept is a novel receptor-targeted radiopharmaceutical evaluated in 2 open-label, nonrandomized, within-patient, phase 3 trials designed to assess the lymphatic mapping performance. Methods A total of 13 centers contributed 148 patients with breast cancer. Each patient received [99mTc]tilmanocept and vital blue dye (VBD). Lymph nodes identified intraoperatively as radioactive and/or blue stained were excised and histologically examined. The primary endpoint, concordance (lower boundary set point at 90 %), was the proportion of nodes detected by VBD and [99mTc]tilmanocept. Results A total of 13 centers contributed 148 patients who were injected with both agents. Intraoperatively, 207 of 209 nodes detected by VBD were also detected by [99mTc]tilmanocept for a concordance rate of 99.04 % (p < 0.0001). [99mTc]tilmanocept detected a total of 320 nodes, of which 207 (64.7 %) were detected by VBD. [99mTc]Tilmanocept detected at least 1 SLN in more patients (146) than did VBD (131, p < 0.0001). In 129 of 131 patients with ≥1 blue node, all blue nodes were radioactive. Of 33 pathology-positive nodes (18.2 % patient pathology rate), [99mTc]tilmanocept detected 31 of 33, whereas VBD detected only 25 of 33 (p = 0.0312). No pathology-positive SLNs were detected exclusively by VBD. No serious adverse events were attributed to [99mTc]tilmanocept. Conclusion [99mTc]Tilmanocept demonstrated success in detecting a SLN while meeting the primary endpoint. Interestingly, [99mTc]tilmanocept was additionally noted to identify more SLNs in more patients. This localization represented a higher number of metastatic breast cancer lymph nodes than that of VBD.Annals of Surgical Oncology 03/2013; 20(8). DOI:10.1245/s10434-013-2887-8 · 3.94 Impact Factor
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ABSTRACT: The ability to accurately and easily locate sentinel lymph nodes (LNs) with noninvasive imaging methods would assist in tumor staging and patient management. For this purpose, we developed a lymphatic imaging agent by mixing fluorine-18 aluminum fluoride-labeled NOTA (1,4,7-triazacyclononane-N,N',N''-triacetic acid)-conjugated truncated Evans blue ((18)F-AlF-NEB) and Evans blue (EB) dye. After local injection, both (18)F-AlF-NEB and EB form complexes with endogenous albumin in the interstitial fluid and allow for visualizing the lymphatic system. Positron emission tomography (PET) and/or optical imaging of LNs was performed in three different animal models including a hind limb inflammation model, an orthotropic breast cancer model, and a metastatic breast cancer model. In all three models, the LNs can be distinguished clearly by the apparent blue color and strong fluorescence signal from EB as well as a high-intensity PET signal from (18)F-AlF-NEB. The lymphatic vessels between the LNs can also be optically visualized. The easy preparation, excellent PET and optical imaging quality, and biosafety suggest that this combination of (18)F-AlF-NEB and EB has great potential for clinical application to map sentinel LNs and provide intraoperative guidance.Proceedings of the National Academy of Sciences 01/2015; 112(1):208-213. DOI:10.1073/pnas.1414821112 · 9.81 Impact Factor