Comparison of Post-injection Site Pain Between Technetium Sulfur Colloid and Technetium Tilmanocept in Breast Cancer Patients Undergoing Sentinel Lymph Node Biopsy

A Four-Arm Randomized Clinical Trial of Topical Pain Control for Sentinel Node Radiotracer Injections in Patients with Breast Cancer

BACKGROUND

Radioactive tracer injections for breast cancer sentinel lymph node mapping can be painful. In this randomized trial, we compared four approaches to topical pain control for radiotracer injections.

METHODS

Breast cancer patients were randomized (9 April 2021-8 May 2022) to receive the institutional standard of ice prior to injection (n = 44), or one of three treatments: ice plus a vibrating distraction device (Buzzy®; n = 39), 4% lidocaine patch (n = 44), or 4% lidocaine patch plus ice plus Buzzy® (n = 40). Patients completed the Wong-Baker FACES® pain score (primary outcome) and a satisfaction with pain control received scale (secondary). Nuclear medicine technologists (n = 8) rated perceived pain control and ease of administration for each patient. At study conclusion, technologists rank-ordered treatments. Data were analyzed as intention-to-treat. Wilcoxon rank-sum tests were used to compare pain scores of control versus pooled treatment arms (primary) and then control to each treatment arm individually (secondary).

RESULTS

There were no differences in pain scores between the control and treatment groups, both pooled and individually. Eighty-five percent of patients were 'satisfied/very satisfied' with treatment received, with no differences between groups. No differences in providers' perceptions of pain were observed, although providers perceived treatments involving Buzzy© more difficult to administer (p < 0.001). Providers rated lidocaine patch as the easiest, with ice being second.

CONCLUSION

In this randomized trial, no differences in patient-reported pain or satisfaction with treatment was observed between ice and other topical treatments. Providers found treatments using Buzzy® more difficult to administer. Given patient satisfaction and ease of administration, ice is a reasonable standard.

Cost-Effectiveness of [99mTc]Tilmanocept Relative to [99mTc]Sulfur Colloid for Sentinel Lymph Node Biopsy in Early Stage Oral Cavity Cancer

BACKGROUND

Several studies have demonstrated varying rates of efficacy, reliability, and sensitivity of sentinel lymph node biopsy (SLNB) in identifying occult nodal disease for early stage oral cavity squamous cell carcinoma (OCSCC) depending on the radionuclide agent utilized. No head-to-head comparison of cost or clinical outcomes of SLNB when utilizing [99mTc]tilmanocept versus [99mTc]sulfur colloid has been performed. The goal of this study was to develop a decision model to compare the cost-effectiveness of [99mTc]tilmanocept versus [99mTc]sulfur colloid in early stage OCSCC.

PATIENTS AND METHODS

A decision model of disease and treatment as a function of SLNB was created. Patients with a negative SLNB entered a Markov model of the natural history of OCSCC parameterized with published data to simulate five states of health and iterated over a 30-year time horizon. Treatment costs and quality-adjusted life-years (QALYs) for each health state were included. The incremental cost-effectiveness ratio (ICER) was then estimated using $100,000 per additional QALY as the threshold for determining cost-effectiveness.

RESULTS

The base case cost-effectiveness analysis suggested [99mTc]tilmanocept was more effective than [99mTc]sulfur colloid by 0.12 QALYs (7.06 versus 6.94 QALYs). [99mTc]Tilmanocept was more costly, with a lifetime cost of $84,961 in comparison with $84,264 for sulfur colloid, however, the overall base case ICER was $5859 per additional QALY, well under the threshold for cost-effectiveness. Multiple one-way sensitivity analyses were performed, and demonstrated the model was robust to alternative parameter values.

CONCLUSION

Our analysis showed that while [99mTc]tilmanocept is more costly upfront, these costs are worth the additional QALYs gained by the use of [99mTc]tilmanocept.

99mTc-Tilmanocept performance for sentinel node mapping in breast cancer, melanoma, and head and neck cancer: a systematic review and meta-analysis from a European expert panel

PURPOSE

Although multiple radiopharmaceuticals are currently available for sentinel node (SN) biopsy, 99mTc-tilmanocept is of particular interest due to its low molecular weight and specific binding capability for the mannose receptors of lymphatic reticuloendothelial cells. In the current systematic review and meta-analysis, we aimed to provide an update from a European expert panel on the performance of 99mTc-tilmanocept for SN biopsy.

METHODS

A systematic literature search of the PubMed/Medline and Embase databases was performed to identify studies on the use of 99mTc-tilmanocept for SN identification in oncological patients. The articles' methodological quality was assessed before inclusion. The pooled estimates of the pre-/intraoperative detection rates (DR; proportion of patients with ≥ 1 SN identified) and/or pN + sensitivity (SN + /pN + patients ratio), with 95% confidence intervals (CIs), were calculated for breast cancer, melanoma, and head and neck cancer.

RESULTS

Twenty-four articles were included in the systematic review, and twenty-one provided data for the meta-analysis. According to data availability, the 99mTc-tilmanocept-estimated pooled preoperative and intraoperative DRs were 0.94 (95%CI, 0.88-1.01) and 0.99 (0.98-1.00) for breast cancer, 0.98 (0.96-0.99) and 1.00 (0.99-1.00) for melanoma, and 0.97 (0.93-1.02) and 0.99 (0.96-1.01) for head and neck carcinoma. Finally, the pooled sensitivity for nodal metastasis in melanoma was 0.97 (95% CI, 0.92-1.03).

CONCLUSION

99mTc-tilmanocept is a promising radiotracer for SN mapping in patients with breast cancer, melanoma, or head and neck cancer. We strongly believe that multicenter trials are still needed to assess if 99mTc-tilmanocept is superior to other radiotracers used in clinical routine.

Re-evaluation of Sentinel Lymph Node Biopsy for Melanoma

OPINION STATEMENT

The vast majority of patients newly diagnosed with melanoma present with clinically localized disease, and sentinel lymph node biopsy (SLNB) is a standard of care in the management of these patients, particularly in intermediate thickness cases, in order to provide important prognostic data. However, SLNB also has an important role in the management of patients with other subtypes of melanoma such as thick melanomas, certain thin melanomas, and specific histologic variants of melanoma such as desmoplastic melanoma. Furthermore, there have been technical advances in the SLNB technique, such as the development of newer radiotracers and use of SPECT/CT, and there is some data to suggest performing a SLNB may be therapeutic. Finally, the management of patients with a positive sentinel lymph node (SLN) has undergone dramatic changes over the past several years based on the results of recent important clinical trials. Treatment options for patients with SLN metastases now include surveillance, completion lymph node dissection, and adjuvant therapy with checkpoint inhibitors and targeted therapy. SLNB continues to play a crucial role in the management of patients with melanoma, allowing for risk stratification, potential regional disease control, and further treatment options for patients with a positive SLN.

Sentinel-Lymph-Node Multicenter Trials

Well executed multicenter clinical trials often provide significant evidence and support for, or against, foundational aspects of clinical procedures perceived to improve clinical management of a medical condition. In this review, discussed are reports of multicenter clinical trials designed to investigate sentinel lymph node biopsy procedures in seven types of cancer: breast, melanoma, head and neck, gastric, colon, uterine, and vulvar-with focus on the most recent reports of the hypotheses, objectives, parameters, data, results, implications, and impacts of the included trials. Such trials generally enroll more subjects, in shorter time periods, than do single-center studies. Such studies generally also have greater diversities among investigator practitioners and investigative environments than do single-center studies. The greater number of subjects provides more power to statistical analyses performed in such studies. The more rapid accrual usually results in data being more consistently acquired. The diversities of practitioners and environments may produce results that are more conservative than might be obtained from more "focused" studies; however, diversities in a study often identify implicitly results that are more robust-that is results applicable by more practitioners and applicable in more environments.

Sentinel lymph node detection in oral cancer: a within-patient comparison between [99mTc]Tc-tilmanocept and [99mTc]Tc-nanocolloid

Purpose

Sentinel lymph node (SLN) biopsy has proven to reliably stage the clinically negative neck in early-stage oral squamous cell carcinoma (OSCC). [^99mTc]Tc-tilmanocept may be of benefit in OSCC with complex lymphatic drainage patterns and close spatial relation to SLNs.

Methods

A prospective within-patient evaluation study was designed to compare [^99mTc]Tc-tilmanocept with [^99mTc]Tc-nanocolloid for SLN detection. A total of 20 patients with early-stage OSCC were included, who underwent lymphoscintigraphy with both tracers. Both lymphoscintigraphic images of each patient were evaluated for SLN detection and radiotracer distribution at 2–4 h post-injection.

Results

The injection site’s remaining radioactivity was significantly lower for [^99mTc]Tc-tilmanocept (29.9%), compared with [^99mTc]Tc-nanocolloid (60.9%; p < 0.001). Radioactive uptake in SLNs was significantly lower for [^99mTc]Tc-tilmanocept (1.95%) compared with [^99mTc]Tc-nanocolloid (3.16%; p = 0.010). No significant difference was seen in SLN to injection site ratio in radioactivity between [^99mTc]Tc-tilmanocept (0.066) and [^99mTc]Tc-nanocolloid (0.054; p = 0.232). A median of 3.0 and 2.5 SLNs were identified with [^99mTc]Tc-tilmanocept and [^99mTc]Tc-nanocolloid, respectively (p = 0.297). Radioactive uptake in higher echelon nodes was not significantly different between [^99mTc]Tc-tilmanocept (0.57%) and [^99mTc]Tc-nanocolloid (0.86%) (p = 0.052). A median of 2.0 and 2.5 higher echelon nodes was identified with [^99mTc]Tc-tilmanocept and [^99mTc]Tc-nanocolloid, respectively (p = 0.083).

Conclusion

[^99mTc]Tc-tilmanocept had a higher injection site clearance, but at the same time a lower uptake in the SLN, resulting in an SLN to injection site ratio, which was not significantly different from [^99mTc]Tc-nanocolloid. The relatively low-radioactive uptake in SLNs of [^99mTc]Tc-tilmanocept may limit intraoperative detection of SLNs, but can be overcome by a higher injection dose.

Electronic supplementary material

The online version of this article (10.1007/s00259-020-04984-8) contains supplementary material, which is available to authorized users.

Technological Advances in Lymphatic Surgery: Bringing to Light the Invisible

Lymphatic surgery has become an integral and flourishing component of the field of plastic surgery. The diversity of ongoing technological innovations in perioperative imaging, including intraoperative dyes and cameras, allows plastic surgeons to work at the supermicrosurgical level. This study aims to highlight innovations that have shaped and will continue to revolutionize the perioperative management of the lymphatic surgery patient in the future. As additional advances emerge, we need a systematic and objective way to evaluate the efficacy and clinical integration readiness of such technologies. Undoubtedly, these technologies will help lymphatic surgery trend toward increasing objectivity, which will be critical for continued evolution and advancement.

Next generation of radiotracers for sentinel lymph node biopsy: What is still necessary to establish new imaging paradigms?

Sentinel lymph node (SLN) biopsy is now the standard of care for regional staging in several solid tumors. The interstitial administration of a radiotracer around the primary tumor provide the possibility to sequentially obtain images with a gamma camera and visualize lymphatic mapping and the SLN. There is, however, a large geographical variability in those radiotracers and nanocolloids ranging from 15-100nm which are most widely employed in Europe, while filtered and unfiltered ^99mTc-sulfur colloid (range 20-1000nm) is usually used in the USA with different drawbacks in its use. The new radiotracer ^99mTc-Tilmanocept, designed specifically for the identification of SLNs and recently becoming commercially available in USA and Europe, appears to have the potency to overcome the shortcomings described for the conventional radiotracers used until now for SLN biopsy and at the same time to transform current imaging paradigms. After delineating the challenges for the next generation of radiotracers, this paper discusses the properties of ^99mTc-Tilmanocept, its validation process for SLN biopsy and its emerging clinical applications in various malignancies.

Consecutive Case Series of Melanoma Sentinel Node Biopsy for Lymphoseek Compared to Sulfur Colloids

BACKGROUND

Sentinel lymph node biopsy (SLNB) is an important adjunct in the staging of patients with melanoma. Preoperative lymphoscintigraphy with radiolabeled isotopes is essential to localize sentinel nodes for removal. Our study compared the effectiveness of Lymphoseek to standard sulfur colloids in patients with melanoma undergoing SLNB.

METHODS

We queried our IRB-approved melanoma database to identify 370 consecutive patients who underwent SLNB from 2012 to 2016 with at least 1 y of follow-up. There were 185 patients in each group. Data points included characteristics of the primary melanoma lymphoscintigraphy and SLNB. Student's t-test and chi-square were used to analyze the data with a P value of <0.05 being considered significant.

RESULTS

Patients were equally matched in regard to age, sex, and primary characteristics of their melanoma. In comparison to sulfur colloid, Lymphoseek required lower radiation dosages (P < 0.001), shorter mapping times (P = 0.008), and decreased number of sentinel nodes removed (P = 0.03). There was no difference in the number of patients with positive nodes (P = 0.5). In addition, there were no statistical differences between the two radioactive tracers in regard to the number of patients with false-negative SLNB.

CONCLUSION

Lymphoseek has the potential to decrease radioactivity and mapping time in patients who need SLNB. With a decrease in the number of nodes removed without loss of sensitivity, there is a potential to avoid unnecessary node removal and thus complications such as lymphedema. Longer follow-up will help to determine if there is any increase in false-negative rates despite fewer nodes removed.

Molecular Imaging of endometrial sentinel lymph nodes utilizing fluorescent-labeled Tilmanocept during robotic-assisted surgery in a porcine model

Molecular imaging with a fluorescent version of Tilmanocept may permit an accurate and facile detection of sentinel nodes of endometrial cancer. Tilmanocept accumulates in sentinel lymph nodes (SLN) by binding to a cell surface receptor unique to macrophages and dendritic cells. Four female Yorkshire pigs underwent cervical stromal injection of IRDye800-Tilmanocept, a molecular imaging agent tagged with near-infrared fluorescent dye and radiolabeled with gallium-68 and technetium-99m. PET/CT scans 1.5 hours post-injection provided pre-operative SLN mapping. Robotic-assisted lymphadenectomy was performed two days after injection, using the FireFly imaging system to identify nodes demonstrating fluorescent signal. After removal of fluorescent nodes, pelvic and periaortic node dissections were performed. Nodes were assayed for technetium-99m activity, and SLNs were established using the “10%-rule”, requiring that the radioactivity of additional SLNs be greater than 10% of the “hottest” SLN. Thirty-four nodal samples were assayed ex vivo for radioactivity. All the SLNs satisfying the “10%-rule” were detected using the FireFly system. Five fluorescent nodes were detected, corresponding with preoperative PET/CT scan. Three pigs had one SLN and one pig had two SLNs, with 100% concordance between fluorescence and radioactivity. Fluorescent-labeled Tilmanocept permits real-time intraoperative detection of SLNs during robotic-assisted lymphadenectomy for endometrial cancer in a porcine model. When radiolabeled with gallium-68, Tilmanocept allows for preoperative localization of SLNs using PET/CT, and shows specificity to SLNs with persistent fluorescent signal, detectable using the FireFly system, for two days post-injection. In conclusion, these findings suggest that a phase I trial in human subjects is warranted, and that a long-term goal of an intra-operative administration of non-radioactive fluorescent-labeled Tilmanocept is possible.

Outcomes of "one-day" vs "two-day" injection protocols using Tc-99m tilmanocept for sentinel lymph node biopsy in breast cancer

No prior studies have compared Tc-99m tilmanocept (TcTM) one-day and two-day injection protocols for sentinel lymph node (SLN) biopsy in breast cancer (BC). We retrospectively identified patients with clinically node-negative BC undergoing SLN biopsy at our institution. Patients received a single, intradermal peritumoral injection of TcTM on day of surgery or day prior to surgery in addition to an intraoperative injection of isosulfan blue dye. Univariable and multivariable Poisson regression count models were constructed to assess the effects of injection timing, radiologist, patient and surgeon characteristics on the number of removed SLNs. A total of 617 patients underwent SLN biopsy with TcTM and blue dye. Sixty-seven (10.9%) patients were injected with the two-day protocol. Patients in the one-day protocol had a mean of 3.0 (standard deviation (SD) 1.9) SLNs removed compared with 2.7 (SD 1.4) SLNs in the two-day protocol, P-value = .13. On multivariable analysis, patient age and operating surgeon significantly affected the number of removed SLNs; however, the injection timing and the nuclear radiologist did not influence the number of removed SLNs. The performance of Tc-99m tilmanocept did not differ significantly between one-day and two-day injection protocols. These results are similar to other radiotracers used for SLN biopsy in BC.

Use of 99mTc-Tilmanocept as a Single Agent for Sentinel Lymph Node Identification in Breast Cancer: A Retrospective Pilot Study

^99mTc-tilmanocept received recent Food and Drug Administration approval for lymphatic mapping in 2013. However, to our knowledge, no prior studies have evaluated the use of ^99mTc-tilmanocept as a single agent in sentinel lymph node (SLN) biopsy in breast cancer. Methods: We executed this retrospective pilot study to assess the ability of ^99mTc-tilmanocept to identify sentinel nodes as a single agent in clinically node-negative breast cancer patients. Patients received a single intradermal injection overlying the tumor of either 18.5 MBq (0.5 mCi) of ^99mTc-tilmanocept on the day of surgery or 74.0 MBq (2.0 mCi) on the day before surgery by a radiologist. Immediate 3-view lymphoscintigraphy was performed. Intraoperatively, SLNs were identified with a portable γ-probe. A node was classified as hot if the count (per second) of the node was more than 3 times the background count. Descriptive statistics are reported. Results: Nineteen patients underwent SLN biopsy with single-agent ^99mTc-tilmanocept. Immediate lymphoscintigraphy identified at least 1 sentinel node in 13 of 17 patients (76.5%). Intraoperatively, at least 1 (mean, 1.7 ± 0.8; range, 1-3) hot node was identified in all patients. Three patients (15.8%) had 1 disease-positive SLN. Conclusion: In this small, retrospective pilot study, ^99mTc-tilmanocept performed well as a single agent for intraoperative sentinel node identification in breast cancer. A larger, randomized clinical trial is warranted to compare ^99mTc-tilmanocept as a single agent with other radiopharmaceuticals for sentinel node identification in breast cancer.

Tc-99m tilmanocept versus Tc-99m sulfur colloid in breast cancer sentinel lymph node identification: Results from a randomized, blinded clinical trial

INTRODUCTION

No prior trials have compared sentinel lymph node (SLN) identification outcomes between Tc-99m tilmanocept (TcTM) and Tc-99m sulfur colloid (TcSC) in breast cancer (BC).

METHODS

We report on the secondary outcomes from a randomized, double-blinded, single surgeon clinical trial comparing post-injection site pain between TcTM and TcSC. Patients were randomized to receive a preoperative single, peritumoral intradermal injection of TcTM or TcSC. The number of total, "hot", and blue nodes detected and removed were compared between groups.

RESULTS

Fifty-two (27-TcSC and 25-TcTM) patients were enrolled and underwent definitive surgical treatment. At least one "hot" SLN was detected in all patients. Three (5.8%) patients had a disease positive-SLN. The total number of SLNs removed was 61 (mean 2.26 (standard deviation (SD) 0.90)) in the TcSC group and 54 (mean 2.16 (SD 0.90)) in the TcTM group, P = 0.69. The total number of "hot" nodes in the TcSC group was 1.96 (SD 0.76) compared to 2.04 (SD 0.73) in the TcTM group, P = 0.71.

CONCLUSIONS

The number of identified SLNs did not differ significantly between TcTM and TcSC. Given that no significant technical advantages exist between the two agents, surgeons should choose a radiopharmaceutical based on cost and side effect profile.