EANM practice guidelines for lymphoscintigraphy and sentinel lymph node biopsy in melanoma. Eur J Nucl Med Mol Imaging. 2015;42:1750-1766. [PMID: 26205952 DOI: 10.1007/s00259-015-3135-1]

Surgical radioguidance with beta-emitting radionuclides; challenges and possibilities: A position paper by the EANM

Radioguidance that makes use of β-emitting radionuclides is gaining in popularity and could have potential to strengthen the range of existing radioguidance techniques. While there is a strong tendency to develop new PET radiotracers, due to favorable imaging characteristics and the success of theranostics research, there are practical challenges that need to be overcome when considering use of β-emitters for surgical radioguidance. In this position paper, the EANM identifies the possibilities and challenges that relate to the successful implementation of β-emitters in surgical guidance, covering aspects related to instrumentation, radiation protection, and modes of implementation.

Setting-up a training programme for intraoperative molecular imaging and sentinel node mapping: how to teach? How to learn?

BACKGROUND

The current expansion of image-guided surgery is closely related to the role played by radio-guided surgery in supporting the sentinel node (SN) procedure during more than three decades. The so-called triple approach (lymphoscintigraphy, gamma probe detection and blue dye) was not only essential in the seminal validation of the SN procedure but also a first collective learning effort based on skill transfer and outcome-related evaluation which laid the fundaments to delineate the field of intraoperative molecular imaging (IMI) based on a similar multimodality approach and multidisciplinary practice.

METHODS

These elements are also becoming valid in the current incorporation of SPECT/CT and PET/CT to existing and new protocols of IMI procedures and SN mapping concerning other clinical applications. On the other hand, there is a growing tendency to combine novel modern technologies in an allied role with gamma guidance in the operating room following the development of hybrid tracers and multimodal detection approaches. Against this background, learning initiatives are required for professionals working in this area.

RESULTS

This objective has led to a group of European practitioners with large experience in SN mapping and IMI applications to give shape to a programme made up out of specific learning modules aimed to be used as a conductive thread in peripherical or centralised training instances concerning the topic.

CONCLUSION

The presented work, written as a tutorial review, is placed in an available prior-art context and is primarily aimed at medical and paramedical practitioners as well as at hardware and software developers.

[Nuclear medicine procedure guideline for sentinel lymph node localization]

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma, in breast cancer, in penile and vulva tumors, in head and neck cancer, and in prostate carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node or distant metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. New aspects in this guideline are new radiopharmaceuticals such as tilmanocept and Tc-99m-PSMA and SPECT/CT allowing an easier anatomical orientation. Initial dynamic lymphoscintigraphy in breast cancer is of little significance nowadays. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. A one-day protocol should preferentially be used. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure < 1 mSv/year so that they do not require occupational radiation surveillance. Aspects of quality control were included (scintigraphy, quality control of gamma probe, 6 h SLN course for surgeons, certified breast centers, medical surveillance center).

Sentinel lymph node identification using NIR-II ultrabright Raman nanotags on preclinical models

Surface-enhanced Raman spectroscopy (SERS) nanotags have garnered much attention as promising bioimaging contrast agent with ultrahigh sensitivity, but their clinical translation faces challenges including biological and laser safety. As breast sentinel lymph node (SLN) imaging agents, SERS nanotags used by local injection and only accumulation in SLNs, which were removed during surgery, greatly reduce biological safety concerns. But their clinical translation lacks pilot demonstration on large animals close to humans. The laser safety requires irradiance below the maximum permissible exposure threshold, which is currently not achievable in most SERS applications. Here we report the invention of the core-shell SERS nanotags with ultrahigh brightness (1 pM limit of detection) at the second near-infrared (NIR-II) window for SLN identification on pre-clinical animal models including rabbits and non-human primate. We for the first time realize the intraoperative SERS-guided SLN navigation under a clinically safe laser (1.73 J/cm2) and identify multiple axillary SLNs on a non-human primate. No evidence of biosafety issues was observed in systematic examinations of these nanotags. Our study unveils the potential of NIR-II SERS nanotags as appropriate SLN tracers, making significant advances toward the accurate positioning of lesions using the SERS-based tracer technique.

Staff radiation doses during Sentinel Lymph Node procedure of breast cancer from injection to surgeon

The Sentinel Lymph Node (SLN) or Sentinel Lymph Node Biopsy (SLNB) technique involves various professionals from different departments in clinical settings to manage breast cancer patients properly. Tracing the nodular involvement of breast cancer patients requires radiation source Tc99m labeled with colloidal albumin to be injected at the tumor site. The patient becomes a radiation source for a sufficient time, which concerns the Nuclear Medicine (NM) and surgical staff. The study aims to provide the radiation doses of staff in the NM department during the SLN scintigraphy procedure and obtain an empirical model for calculating the radiation doses to staff in the surgical department from that particular patient. Radiation doses in SLN technique for breast cancer patients are minimal, and a sufficient number of SLN biopsy procedures can be performed by hospital staff within the category of non-radiation workers.

Caring for Pregnant Patients with Cancer: A Framework for Ethical and Patient-Centred Care

(1) Background: Caring for pregnant cancer patients is clinically and ethically complex. There is no structured ethical guidance for healthcare professionals caring for these patients. (2) Objective: This concept paper proposes a theoretically grounded framework to support ethical and patient-centred care of pregnant cancer patients. (3) Methodological approach: The framework development was based on ethical models applicable to cancer care during pregnancy-namely principle-based approaches (biomedical ethics principles developed by Beauchamp and Childress and the European principles in bioethics and biolaw) and relational, patient-focused approaches (relational ethics, ethics of care and medical maternalism)-and informed by a systematic review of clinical practice guidelines. (4) Results: Five foundational discussion themes, summarising the key ethical considerations that should be taken into account by healthcare professionals while discussing treatment and care options with these patients, were identified. This was further developed into a comprehensive ethics checklist that can be used during clinical appointments and highlights the need for a holistic view to patient treatment, care and counselling while providing ethical, patient-centric care. (5) Conclusion: The proposed framework was further operationalised into an ethics checklist for healthcare professionals that aims to help them anticipate and address ethical concerns that may arise when attending to pregnant cancer patients. Further studies exploring clinicians' attitudes towards cancer treatment in the course of pregnancy and patient experiences when diagnosed with cancer while pregnant and wider stakeholder engagement are needed to inform the development of further ethical, patient-centred guidance.

Radio-Guided Occult Lesion Localization With 99m Tc for the Localization of Nonpalpable Melanoma and Soft Tissue Sarcoma Lesions: A Feasibility Study

PURPOSE OF THE REPORT

Localization techniques are needed to facilitate resection of nonpalpable lesions. In this study, the feasibility of radio-guided occult lesion localization (ROLL) with 99m Tc is investigated for the localization of nonpalpable, small, suspicious, or proven melanoma or soft tissue sarcoma lesions at various locations throughout the body.

PATIENTS AND METHODS

Patients with nonpalpable, suspicious, or proven melanoma or soft tissue sarcoma lesions were selected for this study. Within 24 hours before surgery, a median dose of 33.92 MBq 99m Tc-labeled human albumin particles ( 99m Tc-NA or 99m Tc-MAA) was injected in the lesion under ultrasound guidance. A hand-held gamma probe was used to detect the radioactive signal and guidance during surgery.

RESULTS

In this study, 20 patients with a total of 25 lesions were included and analyzed. The median size of the lesions was 1.8 cm (interquartile range [IQR], 1.8-4.0 cm), of which 44% were intramuscular located and 36% were subcutaneous, and 20% consisted of suspicious lymph nodes, mostly in the lower extremity. At median 4 hours (IQR, 3-6 hours) postinjection, 99m Tc ROLL showed a 100% intraoperative identification rate with proper signal identification with the gamma probe in all patients. With a median surgery time of 76 minutes (IQR, 45-157 minutes), all targeted lesions could be resected without 99m Tc-related complications, resulting in 88% microscopically margin-negative resection. No reoperations were needed for the same lesion.

CONCLUSIONS

The 99m Tc ROLL procedure is feasible for the localization and excision of small, nonpalpable melanoma and soft tissue sarcoma lesions at various locations in the body.

Performance of a Nonlinear Magnetic Handheld Probe for Intraoperative Sentinel Lymph Node Detection: A Phantom Study

OBJECTIVE

This study investigates the performance of the DiffMag handheld probe (nonlinear magnetometry), to be used for sentinel lymph node detection. Furthermore, the performance of DiffMag is compared with a gamma probe and a first-order magnetometer (Sentimag®, linear magnetometry).

METHODS

The performance of all three probes was evaluated based on longitudinal distance, transverse distance, and resolving power for two tracer volumes. A phantom was developed to investigate the performance of the probes for a clinically relevant situation in the floor of the mouth (FOM).

RESULTS

Considering the longitudinal distance, both DiffMag handheld and Sentimag® probe had comparable performance, while the gamma probe was able to detect at least a factor of 10 deeper. Transverse distances of 13, 11, and 51 mm were measured for the small tracer volume by the DiffMag handheld, Sentimag®, and the gamma probe, respectively. For the large tracer volume this was 21, 18, and 55 mm, respectively. The full width at half maximum, at 7 mm probe height from the phantom surface, was 14, 12, and 18 mm for the small tracer volume and 15, 18, and 25 mm for the large tracer volume with the DiffMag handheld, Sentimag®, and gamma probe, respectively.

CONCLUSIONS

With a high resolving power but limited longitudinal distance, the DiffMag handheld probe seems suitable for detecting SLNs which are in close proximity to the primary tumor. In this study, comparable results were shown using linear magnetometry. The gamma probe reached 10 times deeper, but has a lower resolving power compared with the DiffMag handheld probe.

Virtual reality-based training and pre-operative planning for head and neck sentinel lymph node biopsy

OBJECTIVE

Sentinel lymph node biopsy (SLNB) is crucial for managing head and neck skin cancer. However, variable lymphatic drainage can complicate SLN detection when using Single-Photon Emission Computed Tomography (SPECT) or lymphoscintigraphy. Virtual Reality (VR) can contribute to pre-operative planning by simulating a realistic 3D model, which improves orientation. VR can also facilitate real-patient training outside the operating room. This study explored using a VR platform for pre-operative planning in head and neck skin cancer patients undergoing SLNBs and assessed its value for residential training.

MATERIALS AND METHODS

In this prospective technology pilot study, attending surgeons and residents who performed 21 SLNB operations on patients with head and neck skin cancers (81% males, mean age 69.2 ± 11.3) used a VR simulation model based on each patient's pre-operative SPECT scan to examine patient-specific anatomy. After surgery, they completed a questionnaire on the efficiency of the VR simulation as a pre-operative planning tool and training device for residents.

RESULTS

The attending surgeons rated the VR model's accuracy at 8.3 ± 1.6 out of 10. Three-quarters (76%) of residents reported increased confidence after using VR. The physicians rated the platform's contribution to residents' training at 7.4 ± 2.1 to 8.9 ± 1.3 out of 10.

CONCLUSION

A VR SLNB simulation can accurately portray marked sentinel lymph nodes. It was rated high as a surgical planning and teaching tool among attending surgeons and residents alike and may play a role in pre-operative planning and resident training. Further studies are needed to explore its applications in practice.

Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

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.

Variability of Sentinel Lymph Node Location in Patients with Trunk Melanoma

(1) Background: Melanoma is one of the most aggressive types of neoplasia, and the management of this pathology requires a correct staging, as well as a personalized modern oncological treatment. The main objective of the study is to determine the variability of the lymphatic drainage for patients with melanomas located on the trunk and, secondarily, to determine the features of individuals who underwent sentinel lymph node biopsy (SLNB) depending on the exact location on the trunk. (2) Methods: This retrospective, observational, single-center study included 62 cases of trunk melanoma operated between July 2019 and March 2023, in which SLNB was performed and a total of 84 lymph nodes were excised. (3) Results: Patients had a median age of 54.5 (33-78) years, with 58.1% being male; the melanomas had a median Breslow index of 2.3 (0.5-12.5) mm. Approximately 64.3% of the cohort had melanoma on the upper part of the trunk (54 cases) and 35.7% had it on the lower part (30 cases). The type of anesthesia chosen was general anesthesia in 53 cases and spinal anesthesia in 9 cases (85.5% vs. 14.5%, p < 0.001). The number of sentinel lymph nodes excised was 54 for melanomas located on the upper part of the trunk (8 cervical and 46 axillary) and 30 sentinel lymph nodes for melanomas of the lower part of the trunk (16 at the axillary level and 14 at the inguinal level). Out of the 54 LNs identified in patients with melanoma on the upper part of the trunk, 13 were positive, with a total of 12 positive lymph nodes (LNs) from the axillar basin, and only one from the cervical region. Additionally, the incidence of patients with a minimum of two identified sentinel lymph nodes was 32.2%, with a total of seven having LN involvement in two basins, and only one of these cases showed positivity for malignancy. (4) Conclusions: SLNBs were more frequent in the axillary region overall, and had more positive SLNs. Moreover, melanoma on the upper part of the trunk had a higher rate of positive SLNs compared to the lower part. Tumors located on the lower part of the truck had more positive SLNs in the axillary region than in the inguinal one.

Nonvisualized sentinel node on preoperative lymphoscintigraphy in primary cutaneous melanoma: an 11-year retrospective survey

BACKGROUND

Sentinel lymph node (SLN) biopsy in cutaneous melanoma patients evaluates the regional draining basin for occult micrometastatic disease. Occasionally, nonidentification of SLN impairs the acquisition of this important prognostic factor.

OBJECTIVES

To investigate the outcomes of melanoma patients with negative lymphoscintigraphic findings and patients who underwent SLN biopsy from 2004 to 2015 ( n  = 1200) were retrospectively reviewed for tumor characteristics and clinical outcomes.

METHODS

Patients with nonvisualized lymph nodes (NV group) who underwent only preoperative lymphoscintigraphy were separated and compared with a cohort drawn from all melanoma patients who completed the surgical procedure within the same period (V group).

RESULTS

A negative lymphoscintigraphic scan was observed in 38 cases (3.2% of all patients). The NV group showed a significantly older age (median 66.0 vs. 48.3 years; P  < 0.0001). Head and neck melanomas were more frequent in the NV group compared to the control group (25.1 vs. 7.8%; P  = 0.009). Tumor characteristics such as ulceration and Breslow thickness do not influence the lymphoscintigraphy result. No differences were found in overall survival (OS) and disease-free survival (DFS) between the groups.

CONCLUSIONS

The nonvisualization of regional lymph nodes by lymphoscintigraphy is more frequent in older patients with head and neck melanomas. From the clinical point of view, no specific recommendation emerged for patients' management because the nonvisualization of the SLN did not show a significant influence on DFS and OS rates. However, lack of knowledge of lymph node status suggests performing a tighter follow-up eventually by ultrasound evaluation of all potential lymph node drainage basins.

The impact of sentinel lymph node mapping with hybrid single photon emission computed tomography/computed tomography in patients with melanoma. Comparison to planar radioisotopic lymphoscintigraphy

We studied the diagnostic value of 16 slices of single photon emission computed tomography (SPECT)/computed tomography (CT) in the anatomical localization, image interpretation and extra-sentinel lymph nodes (SLNs) detection compared to dynamic and static planar radioisotopic lymphoscintigraphy (PLS) in patients with melanoma. Eighty-two patients with melanoma underwent dynamic PLS, static PLS and SPECT/CT. Data were obtained using a dual head SPECT/CT 16 slices γ-camera. We evaluated the number and localization of SLNs detected with each imaging method. SPECT/CT demonstrated 48 additional SLNs in comparison with PLS in 29 patients. In five truncal and seven head-neck lesions, dynamic and static PLS failed to detect the SLNs found on SPECT/CT (false negative). In one case of truncal and one case of lower limb melanoma, the foci of increased activity interpreted on PLS as possible SLNs were confirmed to be non-nodal sites of uptake on SPECT/CT (false positive). PLS underestimated the number of SLNs detected, whereas SPECT/CT revealed higher agreement compared to the respective number from histological reports. SPECT/CT showed a better prediction of the number of SLNs and higher diagnostic parameters in comparison to planar imaging. SPECT/CT is an important complementary diagnostic modality to PLS, that improves detection, preoperative evaluation, anatomical landmarks of SLNs and surgical management of patients with melanoma.

The Characteristics of Sentinel Lymph Node Biopsy in Cutaneous Melanoma and the Particularities for Elderly Patients-Experience of a Single Clinic

BACKGROUND

Melanoma is a malignant tumor that determines approximately 80% of deaths as skin cancer-related. The sentinel lymph node (SLN) represents the first filter of tumor cells toward systemic dissemination. The primary objective was to outline the surgical specifics of the sentinel lymph node biopsy (SLNB) technique, correlate the location of the lymph node with the radiotracer load, and identify the characteristics of older patients.

METHODS

In this prospective study, 122 cases of malignant melanoma needing SLNB technique were included, between June 2019 and November 2022, resulting in 162 lymph nodes removed.

RESULTS

Patients' mean age was 54.3 ± 14.4 years old, the prevalence of 70 years and older being 20.5%. The rate of positive SLN was 24.6%, with a single drainage in 68.9% of cases. The frequency of seroma was 14.8%, while reintervention 1.6%. The inguinal nodes had the highest preoperative radiotracer load (p = 0.015). Patients 70 years old or older had significantly more advanced-stage melanoma (68.0% vs. 45.4%, p = 0.044, OR = 2.56) and a higher rate of positive SLN (40.0% vs. 20.6%, p = 0.045,OR = 2.57). Melanoma of the head and neck was more common among older individuals (32.0% vs. 9.3%, p = 0.007,OR = 4.60).

CONCLUSIONS

The SLNB has a low rate of surgical complications and the positivity of SLN is not related to radiotracer load. Elderly patients are at risk for head and neck melanoma, have more advanced stages, a higher SLN positivity, and a greater rate of surgical complications.

Preclinical feasibility of robot-assisted sentinel lymph node biopsy using multi-modality magnetic and fluorescence guidance in the head and neck

BACKGROUND

Sentinel lymph node biopsy (SLNB) is a staging procedure dependent on accurate mapping of draining lymphatics via tracers. Robot-assisted SLNB enables access to multiple neck levels with a single incision and intraoperative fluorescence guidance to the SLN.

METHODS

Lymphatic mapping in swine was done using a magnetic tracer and fluorescent dye, injected into the tongue. MRI preoperatively mapped lymphatic spread of the magnetic tracer. Dissection was performed using a da Vinci Xi robot guided by fluorescence-imaging of the dye.

RESULTS

Robot-assisted SLNB was successfully performed in all animals (n = 5). A novel MRI protocol differentiated SLNs (n = 6) from lower echelon nodes (n = 11) based on flow progression. Fluorescence imaging provided valuable intraoperative guidance and correlated with magnetic-positive nodes.

CONCLUSIONS

This study demonstrates preclinical feasibility of a robot-assisted approach to SLNB using magnetic and fluorescent tracers in the head and neck, enabling both preoperative mapping and intraoperative guidance.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma, a Clinical Point of View

Sentinel lymph node biopsy (SLNB) is a surgical procedure that has been used in patients with cutaneous melanoma for nearly 30 years. It is used for both staging and regional disease control with minimum morbidity, as proven by numerous worldwide prospective studies. It has been incorporated in the recommendations of national and professional guidelines. In this article, we provide a summary of the general information on SLNB in the clinical guidelines for the management of cutaneous malignant melanoma (American Association of Dermatology, European Society of Medical Oncology, National Comprehensive Cancer Network, and Cancer Council Australia) and review the most relevant literature to provide an update on the existing recommendations for SLNB.

Sentinel Lymph Node Identification in Cutaneous Head & Neck Cancer - Lymphoscintigraphy Late Phase

OBJECTIVE

Sentinel node (SN) biopsy following lymphoscintography is recommended for high-risk cutaneous malignancies. Herein, we investigate different lymphoscintography phases, focusing on the importance of the late static phase and the resultant discovery of distal echelon solitary positive sentinel nodes that would otherwise have been overlooked.

METHODS

In this retrospective cohort study, conducted in a tertiary referral medical center, we assessed SN localization and time from tracer injection to SN identification on lymphoscintigraphy. Findings on scan were compared with SN found in the surgical field, and with the final pathological investigation.

RESULTS

Seventy-three patients, undergoing SN biopsy for head and neck skin malignancies, were investigated. Most patients were male (n = 50). The average age was 65.7 (±15.7) years and the average follow-up time was 29.1 (±22.4) months. Overall, 101 SNs were histologically investigated, demonstrating 7 positive SN. Eleven patients (15%) benefited from the late lymphoscintigraphy phase. In four studies, an SN was identified only in the late static phase, one of which was positive for the disease. In seven patients, SN was identified in the early phase with additional, different, SN on the late phase, one of which was positive for the disease. Comparing the yield (positive SNs) of early versus late phases, demonstrated the same importance (p = 0.275).

CONCLUSIONS

The late lymphoscintigraphy phase has a crucial role in high-risk HN cutaneous cancer.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2164-2168, 2022.

99mTc-labeled colloid SPECT/CT versus planar lymphoscintigraphy for sentinel lymph node detection in patients with breast cancer: a meta-analysis

Background

The aim of this meta-analysis was to compare single-photon emission computed tomography (SPECT/CT) and planar lymphoscintigraphy (PL) in patients with primary breast cancer, undergoing lymphoscintigraphy at initial staging. Specifically, we assessed the detection rate (DR) for sentinel lymph node (SLN), the absolute number of detected SLNs by each technique, and the proportion of patients with additional SLNs detected by one technique compared to the other one. Finally, we aimed to evaluate the impact of SPECT/CT on the surgical approach.

Methods

Original articles, providing a head-to-head comparison between SPECT/CT and PL, including patients with primary breast cancer at first presentation, were searched in PubMed/MEDLINE and Scopus databases through March 31st, 2022. The DR of the imaging techniques was calculated on a per-patient analysis; studies were pooled on their odds ratios (ORs) with a random-effects model to assess the presence of a significant difference between the DRs of SPECT/CT and PL. The number of additional SLNs, calculated as relative risk (RR), and the pooled proportion of patients with additional SLNs using one imaging technique rather than the other one were investigated. The pooled ratio of surgical procedures (SLN harvesting) influenced by the use of SPECT/CT, according to the surgeons, was calculated.

Results

Sixteen studies with 2693 patients were eligible for the calculation of the DR of SPECT/CT and PL. The DR was 92.11% [95% confidence interval (95% CI) 89.32–94.50%] for SPECT/CT, and 85.12% (95% CI 80.58–89.15%) for PL, with an OR of 1.96 (95% CI 1.51–2.55) in favor of SPECT/CT. There was a relative risk of detection of larger number of SLNs (RR: 1.22, 95% CI 1.14–1.32; 12 studies; 979 patients) for SPECT/CT (n = 3983) compared to PL (n = 3321) and a significant proportion of patients with additional SLNs detected by SPECT/CT, which were missed by PL (18.88%, 95% CI: 11.72%-27.27%; 13 studies). Four articles, with a total number of 1427 patients, revealed that 23.98% of the surgical procedures benefited from the use of SPECT/CT.

Conclusions

This meta-analysis favors SPECT/CT over PL for the identification of SLN in patients with primary breast cancer at staging due to higher DR, more SLNs depicted, and a significant proportion of subjects with additional detected SLNs by SPECT/CT compared to PL. Furthermore, SPECT/CT positively influences the surgical procedure. However, PL remains a satisfactory imaging option for imaging departments not equipped with SPECT/CT due to its good patient-based DR.

Transcutaneous sentinel lymph node detection in cutaneous melanoma with indocyanine green and near-infrared fluorescence: A diagnostic sensitivity study

Sentinel lymph node (SLN) biopsy with preoperative radiocolloid-based lymphoscintigraphy and blue dye injection is considered the standard procedure for staging nodal metastases in early-stage cutaneous melanoma patients with clinically uninvolved lymph nodes. While this combination renders good accuracy in SLN detection, radiation exposure and the frequent allergic reactions to the blue dye are considered drawbacks of this technique. Indocyanine green (ICG) is a water-soluble fluorescent dye that can be identified through near-infrared fluorescence imaging (NIRFI). The aim of this prospective diagnostic sensitivity study was to assess the feasibility of ICG and NIRFI to identify SLNs in melanoma transcutaneously ("before skin incision") and to analyze the various factors influencing detection rate, in comparison to lymphoscintigraphy. This study included 93 patients undergoing SLN biopsy for cutaneous melanoma. The region and the number of the SLNs identified with lymphoscintigraphy and with ICG were recorded. Patients' characteristics, as well as tumor details were also recorded preoperatively. One hundred and ninety-four SLNs were identified through lymphoscintigraphy. The sensitivity of ICG for transcutaneous identification of the location of the SLNs was 96.1% overall, while the sensitivity rate for the number of SLNs was 79.4%. Gender and age did not seem to influence detection rate, but a body mass index >30 kg/m2 was associated with a lower identification rate of the number of SLNs (P = .045). Transcutaneous identification of SLNs through ICG and NIRFI technology is a feasible technique that could potentially replace in selected patients the standard SLN detection methodology in cutaneous melanoma.

Guidelines for Cancer Treatment during Pregnancy: Ethics-Related Content Evolution and Implications for Clinicians

Simple Summary

Clinical practice guidelines for cancer treatment during pregnancy have been available for the past 20 years; however, whether they contain bioethical guidance is currently unknown. A systematic medical literature review was performed to identify the presence of biomedical ethics principles present in guidelines published until 2021. Most of the included guidelines (25 out of 32) refer to biomedical ethics principles such as respect for patient’s autonomy, beneficence and justice. Earlier guidelines stress the importance of patient wishes and choices in light of limited evidence and vast unknowns while balancing maternal and fetal wellbeing. More recent guidelines tend to focus on evidence-based data to balance favorable outcomes for pregnant patients and their fetuses with counselling support to help the patients and their support network understand the rationale behind available treatment options. However, ethics-related content in such guidelines is not presented in a structured manner, indicating the need for methodological upgrades. Therefore, a more structured approach is needed when addressing existing and potential ethical issues in clinical practice guidelines for cancer treatment during pregnancy.

Abstract

(1) Background: Current scientific evidence suggests that most cancers, including breast cancer, can be treated during pregnancy without compromising maternal and fetal outcomes. This, however, raises questions regarding the ethical implications of clinical care. (2) Methods: Using a systematic literature search, 32 clinical practice guidelines for cancer treatment during pregnancy published between 2002 and 2021 were selected for analysis and 25 of them mentioned or made references to medical ethics when offering clinical management guidance for clinicians. (3) Results: Four bioethical themes were identified: respect for patient’s autonomy, balanced approach to maternal and fetal beneficence, protection of the vulnerable and justice in resource allocation. Most guidelines recommended informing the pregnant patient about available evidence-based treatment options, offering counselling and support in the process of decision making. The relational aspect of a pregnant patient’s autonomy was also recognized and endorsed in a significant number of available guidelines. (4) Conclusions: Recognition and support of a patient’s autonomy and its relational aspects should remain an integral part of future clinical practice guidelines. Nevertheless, a more structured approach is needed when addressing existing and potential ethical issues in clinical practice guidelines for cancer treatment during pregnancy.

CT Lymphography Using Lipiodol® for Sentinel Lymph Node Biopsy in Early-Stage Oral Cancer

This study evaluated sentinel lymph node (SLN) identification with CT lymphography (CTL) following peritumoral administration of Lipiodol^® relative to conventional ^99mTc-nanocolloid lymphoscintigraphy (including SPECT/CT) in 10 early-stage oral cancer patients undergoing SLN biopsy. Patients first underwent early dynamic and static scintigraphy after peritumoral administration of ^99mTc-nanocolloid. Subsequently, Lipiodol^® was administered at the same injection sites, followed by fluoroscopy and CT acquisition. Finally, late scintigraphy and SPECT/CT were conducted, enabling the fusion of late CTL and SPECT imaging. The next day, designated SLNs were harvested, radiographically examined for Lipiodol^® uptake and histopathologically assessed. Corresponding images of CT, ^99mTc-nanocolloid lymphoscintigraphy and SPECT/late CTL fusion were evaluated. ^99mTc-nanocolloid lymphoscintigraphy identified 21 SLNs, of which 7 were identified with CTL (33%). CTL identified no additional SLNs and failed to identify any SLNs in four patients (40%). Out of six histopathologically positive SLNs, two were identified by CTL (33%). Radiographic examination confirmed Lipiodol^® uptake in seven harvested SLNs (24%), of which five were depicted by CTL. CTL using Lipiodol^® reached a sensitivity of 50% and a negative predictive value (NPV) of 75% (median follow-up: 12.3 months). These results suggest that CTL using Lipiodol^® is not a reliable technique for SLN mapping in early-stage oral cancer.

Sentinel Node Biopsy Imaging in Breast Cancer: Scatter Reduction Using 3-Dimensionally Printed Lead Shields

BACKGROUND

Point of injection scatter (SPI) confounds breast cancer sentinel lymph node detection. Round flat lead shields (FLSs) incompletely reduce SPI, requiring repositioning. We designed lead shields that reduce SPI and acquisition time.

METHODS

Two concave lead shields, a semioval lead shield (OLS) and a semispherical lead alloy shield (SLS), were created with a SICNOVA JCR 1000 3D printer to cover the point of injection (patent no. ES1219895U). Twenty breast cancer patients had anterior and anterior oblique imaging, 5 minutes and 2 hours after a single 111 MBq nanocolloid in 0.2 mL intratumoral or periareolar injection. Each acquisition was 2 minutes. Absolute and normalized background corrected scatter counts (CSCs) and scatter reduction percentage (%SR) related to the FLS were calculated. Repositionings were recorded. Differences between means of %SR (t test) and between means of CSC (analysis of variance) with Holm multiple comparison tests were determined.

RESULTS

Mean %SR was 91.8% with OLS and 92% using SLS in early images (P = 0.91) and 87.2%SR in OLS and 88.5% in late images (P = 0.66). There were significant differences between CSC using FLS and OLS (P < 0.001) and between FLS and SLS (P < 0.001), but not between OLS and SLS (P = 0.17) in early images, with the same results observed in delayed studies (P < 0.001 in relation to FLS and P = 0.1 between both curved lead shields). Repositioning was required 14/20 times with FLS, 4/20 times with OLS, and 2/20 times with SLS.

CONCLUSIONS

We designed 2 concave lead shields that significantly reduce the SPI and repositioning with sentinel lymph node lymphoscintigraphy.

Interventional nuclear medicine's contribution to molecularly targeted precision surgery

The surgical approach to different pathologies, not only oncological, has evolved. As Veronesi's group has coined very graphically, we are moving from "maximum tolerable treatments to minimum effective treatments" and this journey cannot be carried out in any other way than through a multidisciplinary and multimodality approach. Multidisciplinary, because collaboration between surgeons, oncologists, radiologists, nuclear physicians, pathologists, and all those involved in patient follow-up is necessary, and multimodality, because we must move towards precision surgery tailored to each patient in which, on the part of Nuclear Medicine, hybrid imaging (SPECT/CT and PET/CT), bimodal tracers, the use of new allies such as ultrasound or our own adaptation to robotic surgery have a great deal to say. A wide range of possibilities is built on the solid foundation of preoperative scintigraphy, which makes it possible to identify the target tissues and whose knowledge prior to surgery allows the necessary surgical approach to be considered for each patient.

Radiolabeled nanomaterials for biomedical applications: radiopharmacy in the era of nanotechnology

BACKGROUND

Recent advances in nanotechnology have offered new hope for cancer detection, prevention, and treatment. Nanomedicine, a term for the application of nanotechnology in medical and health fields, uses nanoparticles for several applications such as imaging, diagnostic, targeted cancer therapy, drug and gene delivery, tissue engineering, and theranostics.

RESULTS

Here, we overview the current state-of-the-art of radiolabeled nanoparticles for molecular imaging and radionuclide therapy. Nanostructured radiopharmaceuticals of technetium-99m, copper-64, lutetium-177, and radium-223 are discussed within the scope of this review article.

CONCLUSION

Nanoradiopharmaceuticals may lead to better development of theranostics inspired by ingenious delivery and imaging systems. Cancer nano-theranostics have the potential to lead the way to more specific and individualized cancer treatment.

Appraisal of International Guidelines for Cutaneous Melanoma Management using the AGREE II assessment tool

BACKGROUND

The evidence base behind new melanoma treatments is rapidly accumulating. This is not necessarily reflected in current guidance. A recent UK-based expert consensus statement, published in JPRAS, has called for updates to the widely accepted 2015 National Institute for Health and Care Excellence (NICE) guideline for melanoma (NG14). We aimed to compare the quality of NG14 to all other melanoma guidelines published since.

METHODS

We conducted a systematic search of PubMed, Medline, and online clinical practice guideline databases to identify melanoma guidelines published between 29th July 2015 and 23rd August 2021 providing recommendations for adjuvant treatment, radiotherapy, surgical management, or follow-up care. Three authors independently assessed the quality of identified guidelines using the Appraisal of Guidelines for Research & Evaluation Instrument II (AGREE II) assessment tool, which measures six domains of guideline development. Inter-rater reliability was assessed by Kendall's coefficient of concordance (W).

RESULTS

Twenty-nine guidelines were included and appraised with excellent concordance (Kendall's W for overall guideline score 0.88, p<0.001). Overall, melanoma guidelines scored highly in the domains of 'Scope and purpose' and 'Clarity of presentation', but poorly in the 'Applicability' domain. The NICE guideline on melanoma (NG14) achieved the best overall scores.

CONCLUSION

Melanoma treatment has advanced since NG14 was published, however, the NICE melanoma guideline is of higher quality than more recent alternatives. The planned update of NG14 in 2022 is in demand.

The failure of a sentinel node biopsy due to an absence of nodal uptake of nuclear isotope in consecutive melanomas in a single patient – a physiological aberration

Nodal metastasis is an independent prognostic factor in patients with melanoma. Sentinel lymph node biopsy (SNB) is a recommended component of the management of patients with AJCC stage T1b or above. The dermal scar is injected with a Technetium-99 m (^99MTc) Nanocolloid, a radiotracer that drains into sentinel nodes to be identified on a preoperative SPECT/CT scan. Intraoperatively the sentinel nodes are located using a gamma probe and patent blue dye. A 79-year-old male was referred to the Plastics Outpatient Department for management of a biopsy proven pT4b melanoma on the right flank and a suspicious lesion on the right shoulder. He was scheduled for a SNB and wide local excision of the flank melanoma and excisional biopsy of the shoulder lesion. He received injections of ^99MTc Nanocolloid around the flank biopsy scar, however, preoperative, and intraoperative attempts to locate a node using radiological and surgical techniques were unsuccessful. The biopsy of the shoulder lesion sent for histopathology revealed a pT1b melanoma. A subsequent second SNB on the shoulder melanoma was unsuccessful, as ^99MTc Nanocolloid failed to drain into a sentinel node for a second time. The drainage function of lymphatic vessels declines with age however the complete failure of nodal uptake is exceptionally rare. Novel radiotracers such as ^99MTc Tilmanocept have shown superior lymph node tracking in recent tracers.

A Web-Based Prediction Model for Cancer-Specific Survival of Elderly Patients With Hypopharyngeal Squamous Cell Carcinomas: A Population-Based Study

Background: Hypopharyngeal squamous cell carcinomas (HPSCC) is one of the causes of death in elderly patients, an accurate prediction of survival can effectively improve the prognosis of patients. However, there is no accurate assessment of the survival prognosis of elderly patients with HPSCC. The purpose of this study is to establish a nomogram to predict the cancer-specific survival (CSS) of elderly patients with HPSCC.

Methods: The clinicopathological data of all patients from 2004 to 2018 were downloaded from the SEER database. These patients were randomly divided into a training set (70%) and a validation set (30%). The univariate and multivariate Cox regression analysis confirmed independent risk factors for the prognosis of elderly patients with HPSCC. A new nomogram was constructed to predict 1-, 3-, and 5-year CSS in elderly patients with HPSCC. Then used the consistency index (C-index), the calibration curve, and the area under the receiver operating curve (AUC) to evaluate the accuracy and discrimination of the prediction model. Decision curve analysis (DCA) was used to assess the clinical value of the model.

Results: A total of 3,172 patients were included in the study, and they were randomly divided into a training set (N = 2,219) and a validation set (N = 953). Univariate and multivariate analysis suggested that age, T stage, N stage, M stage, tumor size, surgery, radiotherapy, chemotherapy, and marriage were independent risk factors for patient prognosis. These nine variables are included in the nomogram to predict the CSS of patients. The C-index for the training set and validation was 0.713 (95% CI, 0.697–0.729) and 0.703 (95% CI, 0.678–0.729), respectively. The AUC results of the training and validation set indicate that this nomogram has good accuracy. The calibration curve indicates that the observed and predicted values are highly consistent. DCA indicated that the nomogram has a better clinical application value than the traditional TNM staging system.

Conclusion: This study identified risk factors for survival in elderly patients with HPSCC. We found that age, T stage, N stage, M stage, tumor size, surgery, radiotherapy, chemotherapy, and marriage are independent prognostic factors. A new nomogram for predicting the CSS of elderly HPSCC patients was established. This model has good clinical application value and can help patients and doctors make clinical decisions.

Analysis of the Different Lymphatic Drainage Patterns during Sentinel Lymph Node Biopsy for Skin Melanoma

In the last two decades, studies of lymphoscintigraphy imaging in lymphatic mapping reported an extreme heterogeneity of skin lymphatic drainage of some skin area, in contrast with the previous scientific literature. The aim of this study was to investigate the presence of any correlations between the topographical location of cutaneous melanoma and the topographical location of sentinel lymph nodes. Data from 165 patients undergoing sentinel lymph node biopsy between January 2013 and May 2021 were analyzed, demonstrating that melanomas in the Lumbar region presented a significant more heterogeneous drainage by site than those in the Scapular region (p < 0.01) and that melanomas in the Subscapular region were significantly more heterogeneous by laterality (unilateral vs. bilateral) than those in the Scapular region (p < 0.05). Results of this study supported the evidence of multiple lymphatic drainage as regards the sentinel node biopsy performed in skin melanoma located on the dorsal subscapular region and lumbar region. For this reason, the association of preoperative lymphoscintigraphy with another imaging evaluation is needed in these critical cutaneous areas. Recent technical developments enabling fluorescence lymphography together with indocyanine green have significantly improved the visualization of lymphatic drainage patterns at a microscopic level. In the preoperative phase, any doubt can be resolved by associating the SPET-CT scan to lymphoscintigraphy, while during the intraoperative phase, an additional evaluation with indocyanine green can be performed in doubtful cases. The aim of the duplex lymphatic mapping (pre and/or intraoperative) is an accurate search of sentinel nodes, in order to reduce the rate of false negatives.

Dose estimates of occupational radiation exposure during radioguided surgery of Tc-99m-PSMA-labeled lymph nodes in recurrent prostate cancer

AIM

 [^99mTc]Tc-PSMA-based radioguided surgery (TPRS) represents a curative approach for localized relapse of prostate cancer. For its simplified regulatory permission, the radiation protection authorities require a ^99mTc- activity below the exemption limit of 10 MBq at the time of surgery. Our aim was to determine the optimal amount of radioactivity (OAR) to comply with that limit and to estimate the maximum number of TPRS procedures per year and surgeon without triggering the full monitoring obligations.

METHODS

 In this retrospective study, a dose rate meter was calibrated using measurements on phantoms and from recently injected (1 min p. i.) patients to determine the activity in the patient from measured dose rates. The effective half-life of ^99mTc-PSMA-I&S in patients was determined from repeated dose rate measurements to estimate dose parameters of relevance for radiation protection. External exposures of the surgeons were measured with personal dosimeters calibrated in H_p(10). The surgeon's finger dose H_p(0.07) is estimated from radioactivity measured in resected lymph nodes. Potenzial incorporations were estimated for an activity of 10 MBq.

RESULTS

 From the first 6 subsequent patients, an effective half-life of 4.15 h was observed. Assuming an operation time 24 h p. i., the OAR was 550 MBq. Operations lasting in average 2 h in a distance of 0.25 m to the patient imply a body dose for surgeons of 4.16 µSv per procedure. Based on these estimates, the surgeon's H_p(10) is less than 1 mSv per year with up to 241 operations per year. H_p(0.07) and potential incorporation of activity do not lead to further limitations.

SUMMARY

 All radiation protection regulations are met with adherence to OAR recommended here without triggering the full monitoring obligations from radiation protection regulations.

Effectiveness of SPECT/CT Imaging for Sentinel Node Biopsy Staging of Primary Cutaneous Melanoma and Patient Outcomes

Purpose

Coregistered SPECT/CT can improve accuracy of sentinel node biopsy (SNB) for staging melanoma. This benefit has implications for pathology services and surgical practice with increased diagnostic and surgical workload. The purpose of this study was to investigate the effectiveness of SPECT/CT imaging.

Methods

SNB data were collected over a 10-year period. Preoperative SLN mapping was performed by using planar lymphoscintigraphy (LSG) for all patients (n = 1522) and after October 2015, patients underwent a second co-registered SPECT/CT scan (n = 559). The patients were stratified according to the imaging protocol. The number of nodes and nodal basins were assessed. The reasons for cancellation also were assessed.

Results

A total of 95% (1446/1522) of patients underwent a successful SNB procedure. Significantly more sentinel nodes were identified by the SPECT/CT protocol (3 vs. 2; p < 0.0001). More patients were cancelled in the SPECT/CT cohort (9.3% vs. 2.5%; p < 0.0001). Head & neck, lower limb, and AJCC IB primaries were significantly less likely to proceed to SNB. SPECT/CT identified significantly more positive SNBs (20.9% vs. 16.5%; p = 0.038). SPECT/CT imaging was associated with improved disease-free (hazard ratio [HR] = 0.74; 95% confidence interval [CI]: 0.54–1.0); p = 0.048) and disease-specific survival (HR = 0.48; 95% CI: 0.3–0.78; p = 0.003). Patients who did not proceed to SNB had a significantly increased nodal relapse rate (23.5% vs. 6.8%; HR = 3.4; 95% CI: 1.9–6.2; p < 0.0001) compared with those who underwent SNB.

Conclusions

This large cohort study confirms the increased accuracy of SPECT/CT for identifying SLN metastases, which would appear to have a significant therapeutic benefit, although an increased risk of cancellation of the SNB procedure on the day of surgery.

Head and neck melanoma: outcome and predictors in a population-based cohort study

Background

To evaluate predictive clinico-pathological characteristics on outcome in head and neck melanoma (HNM) in a population-based study with particular emphasis on the prognostic effect of sentinel lymph node biopsy (SLNB), Charlson comorbidity index (CCI) and distinct tumor localisations.

Methods

Here we primarily describe a retrospective multicenter population-based cohort study with 402 patients having undergone resection with curative intent of HNM between 2010 and 2017. SLNB was used in the diagnosis of 79 HNM patients. Outcome was analyzed, focusing on SLNB, CCI as well as tumor localisation. Overall survival (OAS) und recurrence free survival (RFS) was examined by uni- and multivariate analysis.

Results

Histopathologically verified lymph node metastasis according to SLNB was associated with impaired RFS in HNM patients (p = 0.004). Especially in higher tumor stages, the sole implementation of SLNB improved survival significantly in the present cohort (p = 0.042). With most of the HNM being located in the face, melanoma of the scalp and neck could be linked to deteriorated patient’s outcome in uni- as well as multivariate analysis (p = 0.021, p = 0.004).

Conclusions

SLNB is a useful tool in predicting development of distant metastasis after HNM resection with curative intent. Especially in higher tumor stages, performing a SLNB ameliorated survival of HNM patients. Additionally, CCI as well as a distinct tumor localisations in HNM were identified as important risk factors in our population-based cohort study.

An investigation of aspects of radiochemical purity of 99mTc-labelled human serum albumin nanocolloid

BACKGROUND

Nanocolloidal human serum albumin radiolabelled with 99mTc provides a diagnostic radiopharmaceutical for sentinel node lymphoscintigraphy. NanoHSA (Nanotop), a commercially available kit, enables the simple preparation of this radiopharmaceutical via reconstitution with pertechnetate eluted from a generator. Thin-layer chromatography is widely used for determining radiochemical purity in clinical nuclear medicine. Quality control methods recommended by the manufacturer were sometimes reported to yield variable results. Therefore, we proposed and evaluated three alternative thin-layer chromatography methods for the quality control of [99mTc]Tc-NanoHSA from a commercially available kit.

RESULTS

The radiochemical purity of [99mTc]Tc-NanoHSA determined with all methods was reproducible and met the requirements of the SPC and the European Pharmacopoeia (≥ 95%). Our quality control using iTLC-SG chromatographic paper in methyl ethyl ketone mobile phase identified only free pertechnetate as impurity, resulting in > 99% RCP. The quality control using iTLC-SG in 85% methanol or iTLC-SA in 0.9% NaCl identified an additional small fraction of a hydrophilic impurity, resulting in 95-97% RCP. Glucose was identified as a potential 99mTc-carrying hydrophilic species contributing to hydrophilic impurities.

CONCLUSION

Our quality control of [99mTc]Tc-NanoHSA with non-polar mobile phase tended to underestimate the amount of hydrophilic impurities, although without compromising the final quality of the radiopharmaceutical. Alternative TLC methods using aqueous mobile phases enabled a more accurate determination of hydrophilic impurities.

Non-Sentinel Lymph Node Detection during Sentinel Lymph Node Biopsy in Not-Complete-Lymph-Node-Dissection Era: A New Technique for Better Staging and Treating Melanoma Patients

Sentinel lymph node biopsy has been demonstrated to be an effective staging procedure since its introduction in 1992. The new American Joint Committee on Cancer (AJCC) classification did not consider the lack of information that would result from the less usage of the complete lymph node dissection as for a diagnostic purpose. Thus, this makes it difficult the correct staging and would leave about 20% of the further positive non-sentinel lymph nodes in the lymph node basin. In this paper, we aim to describe a new surgical technique that, combined with single-photon emission computed tomography-computed tomography (SPECT-CT), allows for better staging of melanoma patients. This is a prospective study that includes 104 patients with cutaneous melanoma. Sentinel lymph node biopsy was offered according to the AJCC guideline. Planar lymphoscintigraphy was performed in association with SPECT-CT, identifying and removing all non-biologically “excluded” lymph nodes, guiding the surgeon’s hand in detection and removal of lymph nodes. Even if identification and removal of non-sentinel lymph nodes is unable to increase overall survival, it definitely gives better disease control in the basin. With a “classic” setting, the risk of leaving further lymph nodes out of the sentinel lymph node procedure is around 20%, thus, basically, the surgical sentinel lymph node of first and second lymph nodes would have therapeutic value and complete lymph node dissection classically performed.

Magnetic resonance lymphangiography: with or without contrast?

Lymphedema is an important medical issue around the world, caused by an anomalous collection of fluid in soft tissue due to congenital malformations or stenosis or obstruction of lymphatic vessels. Magnetic resonance lymphangiography (MRL) is an emerging technique focused on noninvasive or minimally invasive imaging of lymphatics with the goal to diagnose and treat lymphedema. This review will briefly discuss lymphatic imaging starting with lymphography and radionuclide lymphoscintigraphy up to the newest methods, focusing on MRL, a rising technique, and highlighting the technical aspects fundamental for achieving high-resolution MRL.

Head-to-head comparison of the hybrid tracer indocyanine green-99mTc-nanocolloid with 99mTc-Senti-Scint using sentinel node lymphoscintigraphy and single-photon emission computed tomography combined with computer tomography in melanoma

OBJECTIVE

The hybrid tracer indocyanine green (ICG)-Tc-nanocolloid has been introduced for sentinel node imaging. However, until now, a comparison of this tracer with other radiocolloids with a larger particle size has not been effectuated. Based on a head-to-head evaluation in patients with melanoma, we have compared ICG-Tc-nanocolloid (particle size 5-80 nm) with Tc-Senti-Scint (particle size 100-600 nm) to establish differences in drainage pattern and sentinel node localization using lymphoscintigraphy and single-photon emission computed tomography combined with computer tomography (SPECT-CT) in melanoma patients scheduled for sentinel node biopsy.

METHODS

Twenty-five patients (mean age: 56.9 years, range: 25-79 years) with a melanoma scheduled for SLN biopsy prior to (re)excision of the primary lesion (scar) were prospectively included following a two-day procedure. The first day, after Tc-Senti-Scint injection in four intradermal depots around the primary lesion or scar, early/delayed lymphoscintigraphy and SPECT-CT images were acquired. The injection sites were marked. The second day, after assessing lymph node radioactivity using planar scintigraphy, ICG-Tc-nanocolloid was injected at the previously marked skin points and imaging was performed. The paired planar and SPECT-CT images of both tracers were evaluated with respect to drainage patterns, SLN visualization and non-SLN appearing.

RESULTS

Twenty-four out of 25 patients were evaluable. SLN visualization on a patient basis was 100% for ICG-Tc-nanocolloid and 96% for Tc-Senti-Scint, whereas uptake in non-SLNs was found in, respectively, 71% (17/24) and 61% (14/23). Concordance in drainage to 45 lymph node basins was 91%. Discordant drainage was found for two melanomas in the head-and-neck and one in the clavicular area. Unique lymph node basins were seen in 44/45 (98%) for ICG-Tc-nanocolloid and 42/45 (93%) for Tc-Senti-Scint. Concerning identified SLNs, the number was similar for both tracers (n = 58); however, more non-SLNs (65 vs 50) were visualized with ICG-Tc-nanocolloid than with Tc-Senti-Scint.

CONCLUSION

A slightly higher SLN visualization accompanied by a tendency to depict more non-SLNs was found for ICG-Tc-nanocolloid. Excepting the head and neck area, an overall high concordance in drainage was found for both radiotracers. With an additional value for the hybrid tracer due to the combination of preoperative imaging and the additional visual signal in the operation room, added by the fluorescent component of the hybrid tracer, there was a preference for ICG-Tc-nanocolloid.

PET- and SPECT-based navigation strategies to advance procedural accuracy in interventional radiology and image-guided surgery

INTRODUCTION

Nuclear medicine has a crucial role in interventional strategies where a combination between the increasing use of targeted radiotracers and intraprocedural detection modalities enable novel, but often complex, targeted procedures in both the fields of interventional radiology and surgery. 3D navigation approaches could assist the interventional radiologist or surgeon in such complex procedures.

EVIDENCE ACQUISITION

This review aimed to provide a comprehensive overview of the current application of computer-assisted navigation strategies based on nuclear imaging to assist in interventional radiology and image-guided surgery. This work starts with a brief overview of the typical navigation workflow from a technical perspective, which is followed by the different clinical applications organized based on their anatomical organ of interest.

EVIDENCE SYNTHESIS

Although many studies have proven the feasibility of PET- and SPECT-based navigation strategies for various clinical applications in both interventional radiology and surgery, the strategies are spread widely in both navigation workflows and clinical indications, evaluated in small patient groups. Hence, no golden standard has yet been established.

CONCLUSIONS

Despite that the clinical outcome is yet to be determined in large patient cohorts, navigation seems to be a promising technology to translate nuclear medicine findings, provided by PET- and SPECT-based molecular imaging, to the intervention and operating room. Interventional Nuclear Medicine (iNM) has an exciting future to come using both PET- and SPECT-based navigation.

Regional Lymph Node Metastases in Cutaneous Melanoma: A Single-Center Analysis from Southeast Europe

OBJECTIVE

Sentinel lymph node biopsy is the standard of care for nodal staging in clinically node-negative melanoma patients. Our goal was to present 10-year results of sentinel lymph node biopsy at our institution and to evaluate the clinicopathologic factors as potential predictors of sentinel lymph node and non-sentinel lymph node metastatic involvement in patients with cutaneous melanoma.

METHODS

We have analyzed clinicopathologic and lymphoscintigraphic characteristics in 420 patients with cutaneous melanoma who underwent sentinel lymph node biopsy between 2010 and 2019. In addition, we have examined the results of group of patients with positive sentinel lymph node biopsy undergoing complete lymph node dissection.

RESULTS

The overall detection rate of sentinel lymph node biopsies was 97.1%, of which 18.8% was metastatic. Drainage to one regional basin was seen in 345 patients (83.1%) and to multiple drainage regions in 71 patients (17%). In-transit lymph nodes were detected in 20 patients. On univariate logistic regression analysis, male gender, primary tumor thickness with nodular histology, acral location, presence of ulceration, and the number of nodes harvested were significantly associated with sentinel lymph node biopsy status (p < 0.05). On multivariate analysis, the Breslow thickness was the only independent predictor of sentinel lymph node biopsy status. The metastases in non-sentinel lymph node found in 26 patients with positive sentinel lymph node (35.6%) correlated on univariate, as well as on multivariate logistic regression, with tumor subtype and number of sentinel lymph node harvested.

CONCLUSION

In addition to the well-established primary tumor thickness as a predictor of sentinel lymph node biopsy positivity, we observed acral location and nodular melanoma subtype to significantly enhance the risk of metastases in sentinel lymph node(s). Primary tumor histology and number of nodes harvested were the only statistically significant variables predicting the non-sentinel lymph node status on multivariate analysis. Lymphoscintigraphy imaging characteristics were not significantly associated with sentinel lymph node status.

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.

[Use of radiopharmaceuticals in pediatrics: Specificities and recommandations of SoFRa (Société française de radiopharmacie)]

Radiopharmaceuticals are commonly used in children in nuclear medicine. Because of physiological differences in growing children and their radiosensitivity, precautions must be taken throughout the medication use process. The aim of this work is to propose recommendations, under the aegis of the Société française de radiopharmacie (SoFRa), for each subsystem of the process, in order to ensure the safety of pediatric patients. Furthermore, an analysis of two surveys on diagnostic radiopharmaceuticals dosage used in different nuclear medicine departments in France is detailed. Recommendations for therapeutic radiopharmaceuticals are also provided. Specificities of the preparation for pediatric patients are discussed through the example of the radiopharmaceuticals for lung perfusion scintigraphy. The preparation of individual dose and administration are also described. In nuclear medicine, radiopharmacist's expertise is essential for patient safety. A multidisciplinary approach is necessary to secure pediatric radiopharmaceutical use process.

The role of computational methods for automating and improving clinical target volume definition

Treatment planning in radiotherapy distinguishes three target volume concepts: the gross tumor volume (GTV), the clinical target volume (CTV), and the planning target volume (PTV). Over time, GTV definition and PTV margins have improved through the development of novel imaging techniques and better image guidance, respectively. CTV definition is sometimes considered the weakest element in the planning process. CTV definition is particularly complex since the extension of microscopic disease cannot be seen using currently available in-vivo imaging techniques. Instead, CTV definition has to incorporate knowledge of the patterns of tumor progression. While CTV delineation has largely been considered the domain of radiation oncologists, this paper, arising from a 2019 ESTRO Physics research workshop, discusses the contributions that medical physics and computer science can make by developing computational methods to support CTV definition. First, we overview the role of image segmentation algorithms, which may in part automate CTV delineation through segmentation of lymph node stations or normal tissues representing anatomical boundaries of microscopic tumor progression. The recent success of deep convolutional neural networks has also enabled learning entire CTV delineations from examples. Second, we discuss the use of mathematical models of tumor progression for CTV definition, using as example the application of glioma growth models to facilitate GTV-to-CTV expansion for glioblastoma that is consistent with neuroanatomy. We further consider statistical machine learning models to quantify lymphatic metastatic progression of tumors, which may eventually improve elective CTV definition. Lastly, we discuss approaches to incorporate uncertainty in CTV definition into treatment plan optimization as well as general limitations of the CTV concept in the case of infiltrating tumors without natural boundaries.

Contrast-enhanced ultrasound for sentinel lymph node mapping in the routine staging of canine mast cell tumours: A feasibility study

Canine mast cell tumours (MCTs) typically spread to lymph nodes (LNs) before reaching distant sites, and LN assessment is an important part of MCT staging. Sentinel LN (SLN) mapping techniques to identify draining LNs are being developed and could improve the accuracy of MCT staging. The primary objective of this feasibility study was to determine the safety and effectiveness of contrast-enhanced ultrasound (CEUS) to identify SLNs. Secondary objectives were to determine if the SLNs identified by CEUS coincided with the regional LN predicted by the anatomical lymphosomes, if previous MCT excision altered CEUS SLN findings, and if CEUS could identify MCT nodal metastases. Between June 2017 and March 2019, 59 dogs with 62 MCTs were enrolled. No adverse events related to CEUS were reported. CEUS detected at least 1 SLN in 59/62 MCTs (95.2%, 95% CI: 86.5-99.0%). In only 32/59 (54.2%) MCTs, clinicians would have correctly predicted the SLN(s) identified by CEUS. Among the 35 MCTs that had histological examination of the SLN(s), the prevalence of metastasis was 60% (95% CI: 42.1-76.1%). Additional staging procedures did not reveal any metastases in dogs with histologically non-metastatic SLNs. Integration of CEUS SLN mapping into the routine staging of MCTs is promising, but future studies are required to refine this procedure and to investigate if it would translate into a clinical benefit.

Lymphoscintigraphy for Sentinel Node Mapping in Head and Neck Cancer

The aim of this comprehensive review is to describe and analyze the role of the sentinel node mapping in head and neck cancers. For this purpose, head and neck neoplasms have been categorized in cutaneous malignancies and neoplasms of the upper aerodigestive tract. A concise description of lymphatic drainage will be the "prelude" for each section, as well as the description of the injection techniques, when specific. Concisely, the attention has been focused on detection rate of the sentinel node by lymphoscintigraphy for each cancer, and for those patients in which the sentinel lymph node has been identified, true-positives rates, false-negative rates, and overall accuracy has been pointed out. Overall, in cutaneous neoplasms of the head and neck, the detection rate is higher than 90%, however the false-negative rate is still an issue, in particular in melanoma, inducing the need for newer developments. In fact, new tracers and techniques are already available, while prospective multicenter trials exploring the outcome impact are needed in the near future. For the upper aerodigestive tract and in particular oral cavity and oropharynx, sentinel lymph node identification by lymphoscintigraphy allows avoiding unnecessary neck dissection and/or node irradiation. Even in this case, the main limit remains the risk of false-negative rates. While, for patients affected by laryngeal and hypopharyngeal cancers the data seem very limited and, although the feasibility has been demonstrated, performances of this lymphoscintigraphy still need to be confirmed by multicenter studies.

Comparison of 99mTc-Labeled Colloid SPECT/CT and Planar Lymphoscintigraphy in Sentinel Lymph Node Detection in Patients with Melanoma: A Meta-Analysis

We compared the detection rate (DR) for sentinel lymph nodes (SLN), the number of SLNs and the subjects with additional SLNs of single-photon emission computed tomography (SPECT/CT) and planar lymphoscintigraphy (PL) in patients with melanoma. Furthermore, we evaluated the impact of SPECT/CT on surgical plans. Articles containing head-to-head comparisons between SPECT/CT and PL were searched in Pubmed/MEDLINE and Scopus. The literature search was updated until December 31st, 2019. DR was calculated on a per patient-based analysis; the studies were pooled by their odds ratios (ORs) with a random effects model to assess the significance of difference (p < 0.05). The number of additional SLNs (calculated as the relative risk) and pooled proportion of patients with additional SLNs were investigated. The pooled ratio of surgical procedures influenced by the SPECT/CT findings was calculated. Seventeen studies with 1438 patients were eligible for the calculation of DR of SPECT/CT and PL. The average DR was 98.28% (95% confidence interval (95% CI): 97.94-99.19%) for the SPECT/CT and 95.53% (95% CI: 92.55-97.77%) for the PL; OR of 2.31 (95% CI: 1.66-4.18, p < 0.001) in favor of the SPECT/CT. There was a relative risk of a higher number of SLNs (1.13) for the SPECT/CT and 17.87% of patients with additional SLNs were detected by SPECT/CT. The average impact of SPECT/CT on surgery resulted in 37.43% of cases. This meta-analysis favored SPECT/CT over PL for the identification of SLNs in patients with melanoma due to a higher DR, reproducibility, number of SLNs depicted, proportion of patients with additional SLNs and the impact on the surgical plan. However, PL remains a good option due to the high values of the DR for SLNs.

Effect of delay between nuclear medicine scanning and sentinel node biopsy on outcome in patients with cutaneous melanoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is an important staging tool for the management of melanoma. A multicentre study was done to validate previous findings that the timing of lymphoscintigraphy influences the accuracy of SLNB and patient outcomes, particularly survival.

METHODS

Data were reviewed on patients undergoing SLNB for melanoma at three centres in the UK and Sweden, examining the effect of timing of SLNB after nuclear medicine scanning. Kaplan-Meier survival analysis was used to assess overall (OS), disease-specific (DSS) and progression-free (PFS) survival, stratified by timing of lymphoscintigraphy. Independent risk factors for survival were identified by Cox multivariable regression analysis.

RESULTS

A total of 2270 patients were identified. Median follow-up was 56 months. Univariable analysis showed a 4·2 per cent absolute and 35·5 per cent relative benefit in DSS (hazard ratio 1·36, 95 per cent c.i. 1·05 to 1·74; P = 0·018) for 863 patients whose SLNB was performed up to 12 h after lymphoscintigraphy compared with 1407 patients who had surgery after more than 12 h. There were similar OS and PFS benefits (P = 0·036 and P = 0·022 respectively). Multivariable analysis identified timing of lymphoscintigraphy as an independent predictor of OS (P = 0·017) and DSS (P = 0·030). There was an excess of nodal recurrences as first site of recurrence in the group with delayed surgery (4·5 versus 2·5 per cent; P = 0·008).

CONCLUSION

Delaying SLNB beyond 12 h after lymphoscintigraphy with ⁹⁹ Tc-labelled nanocolloid has a significant negative survival impact in patients with melanoma.