Diagnostic value of combined CT lymphangiography and 99Tcm-DX lymphoscintigraphy in primary chylopericardium.

OBJECTIVE: To investigate the diagnostic value of combined 99Tcm-DX lymphoscintigraphy and CT lymphangiography (CTL) in primary chylopericardium. METHODS: Fifty-five patients diagnosed with primary chylopericardium clinically were retrospectively analyzed. 99Tcm-DX lymphoscintigraphy and CTL were performed in all patients. Primary chylopericardium was classified into three types, according to the 99Tcm-DX lymphoscintigraphy results. The evaluation indexes of CTL include: (1) abnormal contrast distribution in the neck, (2) abnormal contrast distribution in the chest, (3) dilated thoracic duct was defined as when the widest diameter of thoracic duct was > 3 mm, (4) abnormal contrast distribution in abdominal. CTL characteristics were analyzed between different groups, and P < 0.05 was considered a statistically significant difference. RESULTS: Primary chylopericardium showed 12 patients with type I, 14 patients with type II, and 22 patients with type III. The incidence of abnormal contrast distribution in the posterior mediastinum was greater in type I than type III (P = 0.003). The incidence of abnormal contrast distribution in the pericardial and aortopulmonary windows, type I was greater than type III (P = 0.008). And the incidence of abnormal distribution of contrast agent in the bilateral cervical or subclavian region was greater in type II than type III (P = 0.002). CONCLUSION: The combined application of the 99Tcm-DX lymphoscintigraphy and CTL is of great value for the localized and qualitative diagnosis of primary chylopericardium and explore the pathogenesis of lesions.

Morel-Lavallee associated lymphedema treated with lymphovenous anastomosis: A case report.

Morel-Lavallee Lesions lead to disruption of lymphatic anatomy that require early identification and may necessitate lymphatic reconstruction. We present the case of a 59-year-old male with lower extremity lymphedema resulting after a severe Morel-Lavallee lesion and treated using lymphovenous anastomoses. He was initially managed with multiple aspirations followed by repeat incision and drainage. At 10 months following his injury, he continued to have swelling of his upper thigh and developed a large festoon medially, with lower leg pitting edema. He was diagnosed with lymphedema via lymphoscintigraphy. His superficial lymphatic anatomy was visualized using indocyanine green (ICG) lymphography and showed diffuse dermal backflow across his thigh, with signs of altered lymphatic anatomy distally. We preformed two lymphovenous anastomoses at the level of his mid-thigh to bypass the lymphatic disruption and restore drainage to his lower leg. After rerouting lymphatic flow from the lower extremity, the patient had overall improvement of his symptoms and reduced swelling with continued therapy. At 5 months postoperatively, his volumetric lower extremity measurements showed a decrease by 314 mL and he began walking again in 20-minute intervals. Lymphedema may be an important consideration following severe Morel-Lavallee lesions. Using modern diagnostic and supermicrosurgical techniques, plastic surgeons can help treat this long-term morbidity.

Incidental Breast Cancer Diagnosis From Lymphoscintography Using 99mTc-Labeled Nanocolloid for Cutaneous Melanoma of the Upper Arm.

ABSTRACT: A 51-year-old woman with a 2-mm-Breslow-thickness melanoma on her arm had 99mTc-nanocolloid lymphoscintigraphy to localize the associated sentinel lymph node. A single axillary node was identified, and histology confirmed a micrometastasis of breast tissue origin. Imaging of the patient's breasts and subsequent biopsy confirmed ipsilateral stage III breast cancer, which was treated with lumpectomy and axillary node clearance. This is the first reported case of an incidental solid cancer diagnosis from a sentinel lymph node biopsy undertaken for a different tumor origin. This illustrates the importance of recognizing overlapping lymphatic distribution of sentinel lymph nodes, which can drain multiple organs.

An interactive 3D atlas of sentinel lymph nodes in breast cancer developed using SPECT/CT.

BACKGROUND: The identification and assessment of sentinel lymph nodes (SLNs) in breast cancer is important for optimised patient management. The aim of this study was to develop an interactive 3D breast SLN atlas and to perform statistical analyses of lymphatic drainage patterns and tumour prevalence. METHODS: A total of 861 early-stage breast cancer patients who underwent preoperative lymphoscintigraphy and SPECT/CT were included. Lymphatic drainage and tumour prevalence statistics were computed using Bayesian inference, non-parametric bootstrapping, and regression techniques. Image registration of SPECT/CT to a reference patient CT was carried out on 350 patients, and SLN positions transformed relative to the reference CT. The reference CT was segmented to visualise bones and muscles, and SLN distributions compared with the European Society for Therapeutic Radiology and Oncology (ESTRO) clinical target volumes (CTVs). The SLN atlas and statistical analyses were integrated into a graphical user interface (GUI). RESULTS: Direct lymphatic drainage to the axilla level I (anterior) node field was most common (77.2%), followed by the internal mammary node field (30.4%). Tumour prevalence was highest in the upper outer breast quadrant (22.9%) followed by the retroareolar region (12.8%). The 3D atlas had 765 SLNs from 335 patients, with 33.3-66.7% of axillary SLNs and 25.4% of internal mammary SLNs covered by ESTRO CTVs. CONCLUSION: The interactive 3D atlas effectively displays breast SLN distribution and statistics for a large patient cohort. The atlas is freely available to download and is a valuable educational resource that could be used in future to guide treatment.

LYMPHOSCORE (Lymphoscintigraphy Scoring Reliability) Reliability of a New Qualitative and Semiquantitative Lymphoscintigraphy Scoring System for Primary Lymphedema.

PURPOSE OF THE REPORT: Primary lymphedema (PLE) is a rare chronic disorder. Extremity lymphoscintigraphy offers access for dynamic and functional information on peripheral lymphatics and lymph nodes. We aimed to assess intraobserver and interobserver reliability of a new lymphoscintigraphy quantitative and qualitative scoring system in a homogeneous population of adult patients followed for PLE of the lower limb(s). PATIENTS AND METHODS: This is a monocentric retrospective study. Clinical files of patients who underwent a lymphoscintigraphy were reviewed for inclusion. Lymphoscintigraphies were interpreted twice by 2 observers with a washout period. To assess intraobserver and interobserver reliability for both lower limbs, Cohen κ and Gwet's AC1 reliability coefficients were calculated with 95% confidence interval and P value of the zero-reliability comparison test. To interpret reliability coefficients, we used the orders of magnitude reported by Landis and Koch. RESULTS: One hundred forty-four patients (288 limbs) with PLE were included. For intraobserver reliability, agreement range was 0.87-1 with an almost perfect agreement in all staging items of the score for both limbs with the lower limit of the 95% confidence interval ≥80%. Interobserver reliability was overall strong or almost perfect, ranging from 0.67 to 0.97. CONCLUSIONS: This new scoring system demonstrated excellent intraobserver reliability and a very good interobserver reliability. Lymphoscintigraphy, when performed in a referral center and interpreted by trained nuclear medicine physicians, is a reliable means of investigation in patients with PLE of the lower limbs. This reproducibility advocates for further use of lymphoscintigraphy in multicentric cohorts of PLE patients.

[Nuclear medicine procedure guideline for sentinel lymph node localization]. / DGN-Handlungsempfehlung (S1-Leitlinie) ­ Version 3.

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).

Edema of the upper extremity on the unaffected side in unilateral breast cancer patients.

Breast cancer-related lymphedema (BCRL) occurs usually on the affected side, and its cause and pathophysiology are well known. However, the cause of edema of the upper extremity on the unaffected side is barely known. It is often considered to be chemotherapy-induced general edema, and clinical evaluation is rarely performed in these patients. This study aimed to present the clinical characteristics of unilateral breast cancer patients with edema of upper extremity on the unaffected side, and to emphasize the importance of early diagnosis and medical interventions. This study retrospectively analyzed the medical records of unilateral breast cancer patients complaining edema of upper extremity on the unaffected side, from January 2020 to May 2021. Lymphoscintigraphy was used to assist in confirming the diagnosis of lymphedema, and Doppler ultrasonography or 3D computed tomography angiography were performed to differentiate vascular problems. Fourteen patients were enrolled in the study. Seven, 3, and 4 patients had edema of both upper extremities, edema of the upper extremity on the unaffected side only, and edema of all extremities, respectively. None of the 4 patients with edema of all extremities showed abnormal findings on examination. In patients with edema in the upper extremity on the unaffected side alone, lymphatic flow dysfunction was seen in 2 patients, and deep vein thrombosis (DVT) was diagnosed in 1. In patients with edema of both upper extremities, lymphatic flow dysfunction was seen in 2 patients, and DVT was diagnosed in 3. One patient had DVT and accompanying lymphatic flow dysfunction. Lymphedema and DVT were diagnosed in a number of patients with edema of the upper extremity on the unaffected side, and lymphedema can occur without direct injury to the lymphatic flow system. Therefore, clinicians should not overlook the fact that diseases that require early diagnosis and treatment can occur in patients with edema of the unaffected upper extremity.

The value of the dermal rim sign on nonenhanced magnetic resonance imaging for predicting dermal backflow in patients with primary lower extremity lymphedema.

PURPOSE: The dermal rim sign (DRS) on nonenhanced magnetic resonance imaging has been shown to predict dermal backflow (DBF) in patients with secondary upper limb lymphedema. However, whether the DRS has the same effects on primary lower extremity lymphedema (PLEL) has not been clearly reported. Therefore, this study aimed to explore whether the DRS can be used to diagnose DBF on lymphoscintigraphy in patients with PLEL. METHODS: A total of 94 patients who were diagnosed with PLEL were recruited for this retrospective study from January 2022 to December 2023. All the patients were divided into two groups according to the lymphoscintigraphy findings: no DBF and DBF. The magnetic resonance imaging data of the two groups were recorded and statistically compared for the following indicators: range of lymphedema involvement (left, right, whole lower limbs, only thigh, only calf and ankle), signs of lymphedema (notable thickening of skin, parallel line sign, grid sign, honeycomb sign, band sign, lymph lake sign, crescent sign, DRS), and lymphedema measurement (skin thickness, band width). The DRS is characterized by notable thickening of the skin plus the grid sign and/or honeycomb sign, plus the band sign. RESULTS: The following statistically significant differences in the following indicators were found between the two groups (P < .05): notable skin thickening, parallel line sign, grid sign, honeycomb sign, band sign, DRS, skin thickness, and band width. The sensitivity, specificity, and accuracy for predicting for DBF with the DRS was 82%, 64%, and 77%, respectively. CONCLUSIONS: This study confirmed good consistency between the DRS and DBF from the perspective of imaging. This tool is suitable for children, adolescents, and patients with contraindications to lymphoscintigraphy. The DRS has important value in assessing the severity of PLEL. The DRS is suggested for the clinical use of combined surgical treatment of PLEL.

Sentinel Node Mapping in Ovarian Tumors: A Study Using Lymphoscintigraphy and SPECT/CT.

Purpose: Ovarian cancer in the early stage requires a complete surgical staging, including radical lymphadenectomy, implying subsequent risk of morbidity and complications. Sentinel lymph node (SLN) mapping is a procedure that attempts to reduce radical lymphadenectomy-related complications and morbidities. Our study evaluates the feasibility of SLN mapping in patients with ovarian tumors by the use of intraoperative Technetium-99m-Phytate (Tc-99m-Phytate) and postoperative lymphoscintigraphy using tomographic (single-photon emission computed tomography/computed tomography (SPECT/CT)) acquisition. Materials and Methods: Thirty-two patients with ovarian mass participated in this study. Intraoperative injection of the radiopharmaceutical was performed just after laparotomy and before the removal of tumor in utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum. Subsequently, pelvic and para-aortic lymphadenectomy was performed for malignant masses, and the presence of tumor in the lymph nodes was assessed through histopathological examination. Conversely, lymphadenectomy was not performed in patients with benign lesions or borderline ovarian tumors. Lymphoscintigraphy was performed within 24 hr using tomographic acquisition (SPECT/CT) of the abdomen and pelvis. Results: Final pathological examination showed 19 patients with benign pathology, 5 with borderline tumors, and 6 with malignant ovarian tumors. SPECT/CT identified SLNs in para-aortic-only areas in 6 (20%), pelvic/para-aortic areas in 14 (47%), and pelvic-only areas in 7 (23%) cases. Notably, additional unusual SLN locations were revealed in perirenal, intergluteal, and posterior to psoas muscle regions in three patients. We were not able to calculate the false negative rate due to the absence of patients with involved lymph nodes. Conclusion: SLN mapping using intraoperative injection of radiotracers is safe and feasible. Larger studies with more malignant cases are needed to better evaluate the sensitivity of this method for lymphatic staging of ovarian malignancies.

Accuracy of sentinel node mapping in Marjolin ulcer: Comparison of three different injection techniques.

BACKGROUND: Marjolin ulcer is a specific type of squamous cell cancer that can benefit from the use of lymphoscintigraphy.The purpose of this study was to evaluate 3 different injection techniques for sentinel node biopsy in patients with Marjolin ulcer. METHODS: Forty-eight patients with Marjolin ulcer (27 male and 21 female) ranging in age from 24 to 85 years were included in our study. Intratumoral (IT), peritumoral (PT) and periscar (PS) tissue injections of radiotracer were done in 9, 10, and 29 patients respectively. Injections were done 2-4 h before surgery. Lymphoscintigraphy was done for mapping the lymphatic drainage. During surgery, lymphatic mapping and sentinel node biopsy was performed using a handheld gamma probe. After harvesting sentinel nodes, regional lymph node dissection was done. RESULT: Sentinel node detection rate was higher in the PS group as compared to the IT and PT groups (89.6% vs. 50% and 22.2%) respectively. False negative rate was 0%. Pathologically involved sentinel nodes were detected in 16% of the included patients of our study which led to management change. None of the patients with pathologically non-involved sentinel nodes developed regional lymph node recurrence. CONCLUSION: Lymphatic mapping and sentinel node biopsy is feasible in Marjolin ulcer with high detection rate and low false negative cases which by detection of regional lymph node involvement can potentially change the management of patients. Injection site may be an important factor influencing the success of the procedure and injection of the mapping material in the peri-scar normal skin proximal to the lesion is the best technique.

Identifying Functional Lymph Nodes in Lower Extremity Lymphedema Patients: The Role of High-frequency Ultrasound.

BACKGROUND: Lymph nodes may play a potential role in lymphedema surgery. Radiologic evaluation of nodes may reveal the status of pathologic conditions but with limited accuracy. This study is the first to evaluate the efficacy of ultrasound in detecting functioning nodes in lymphedema patients and presents a criterion for determining the functionality of the lymph nodes. METHODS: This retrospective study reviews 30 lower extremity lymphedema cases which were candidates for lymph node to vein anastomosis. Lymphoscintigraphy and magnetic resonant lymphangiography (MRL) imaging were compared with ultrasound features which were correlated to intraoperative indocyanine green (ICG) nodal uptake as an indication of functionality. RESULTS: Majority were International Society of Lymphology stage 2 late (50.0%) and stage 3 (26.7%). ICG positive uptake (functioning nodes) was noted in 22 (73.3%), while 8 patients (26.6%) had negative uptake (nonfunctioning). Ultrasound had significantly the highest specificity (100%) for identifying functional nodes followed by lymphoscintigraphy (55%) and MRL (36%; p = 0.002, p < 0.001, respectively). This was associated with 100% positive predictive value compared against lymphoscintigraphy (44%) and MRL (36%; p < 0.001 for both). The identified ultrasound imaging criteria for functioning lymph node were oval lymph node shape (Solbiati Index), morphology, vascularity pattern, and vascularity quantification. CONCLUSION: The use of ultrasound in nodal evaluation was proven effective in different pathologic conditions and demonstrated the best prediction for functionality of the lymph node based on the new evaluation criteria.

Efficacy of preoperative lymphoscintigraphy in predicting surgical outcomes of lymphaticovenous anastomosis in lower extremity lymphedema: Clinical correlations in gynecological cancer-related lymphedema.

BACKGROUND: Lymphaticovenous anastomosis (LVA) is a promising microsurgical treatment for lower extremity lymphedema (LEL). Lymphoscintigraphy effectively assesses lower limb lymphatic systems before LVA, but its role in predicting the therapeutic outcomes of LVA is indeterminate. In this study we investigate the efficacy of preoperative lymphoscintigraphy using clinical findings to predict outcomes in gynecological cancer-related LEL patients who underwent LVA. METHODS: A retrospective review was conducted on consecutive gynecological cancer patients with LEL who had undergone LVA between June 2018 and June 2021. The therapeutic efficacy was assessed by measuring the change rate of the lower extremity lymphedema index (LELi) six months after surgery. Clinical data and lymphoscintigraphic findings were analyzed to assess therapeutic efficacy of LVA. RESULTS: Out of the 60 evaluated legs, 83.3% of the legs showed improved results after LVA. Univariable linear regression analysis revealed that higher preoperative LELi, and ovarian cancer were associated with superior LELi change rate (LC rate). Absence of dermal backflow (DBF) on lymphoscintigraphy was associated with inferior LC rate. Multivariable linear regression analysis identified ovarian cancer and higher preoperative LELi were independently correlated with favorable outcomes, while the absence of DBF was independently correlated with inferior outcomes. CONCLUSION: The results of this study emphasizes the effectiveness of preoperative lymphoscintigraphy, preoperative LELi, and primary malignancy as predictors of LVA outcomes in gynecological cancer-related LEL patients.

Evaluating the Surgical Outcome of Lymphovenous Anastomosis in Breast Cancer-Related Lymphedema Using Tc-99m Phytate Lymphoscintigraphy: Preliminary Results.

Background: Breast cancer-related lymphedema (BCRL) remains a significant postcancer treatment challenge with no definitive cure. Recent supermicrosurgical treatments, such as lymphovenous anastomosis (LVA), have shown promise but lack established objective indicators for outcome evaluation. We investigated the utility of Technetium-99m (Tc-99m) lymphoscintigraphy, an imaging technique providing objective information on lymphatic fluid flow, for assessing LVA surgical outcomes. Methods and Results: A retrospective cohort analysis of patients undergoing LVA for BCRL was conducted. Lymphoscintigraphy images pre- and 1-year postsurgery were compared to determine changes in lymphatic fluid flow of 18 patients based on newly defined parameters "uptake ratio" and "washout rates." Statistically significant reduction in the uptake ratio was observed in the forearm at 30 and 60 minutes postinjection phases. In addition, the forearm showed higher washout rate, indicating an improved lymphatic function in the forearm. Conclusion: Tc-99m lymphoscintigraphy can provide valuable objective data for evaluating LVA surgical outcomes in BCRL patients. However, site-specific differences in outcomes highlight the need for individualized surgical planning. Further large-scale studies are necessary to validate these preliminary findings and develop a standardized approach for LVA assessment.

Lymphatic remapping by long-term lymphoscintigraphy follow-up in secondary lymphedema after breast cancer surgery.

The purpose of the study is to investigate long-term changes on lymphoscintigraphy and their association with clinical factors in breast cancer-related lymphedema (BCRL) patients. This single-center cohort study included BCRL patients who underwent baseline and follow-up lymphoscintigraphy. The percentage of excessive circumference (PEC) of the affected upper limb compared with the unaffected side was used as an indicator of the clinical severity of BCRL. Each 99mTc-phytate lymphoscintigraphy image was categorized according to the Taiwan lymphoscintigraphy staging system. Clinical parameters and the lymphoscintigraphy stage at baseline and follow-up were compared and analyzed. Eighty-seven patients were included. Baseline and follow-up lymphoscintigraphies were performed at median 7 (interquartile range [IQR]: 2‒14) and 78 (IQR: 49‒116) months after surgery, respectively. Both lymphoscintigraphy stage and PEC showed variable change with overall increases in their severity. Stepwise multivariable analysis revealed follow-up lymphoscintigraphy stage (P = 0.001) to be independent variables for PEC at follow-up, however, baseline lymphoscintigraphy stage was not. The clinical courses of BCRL and patients' lymphoscintigraphy patterns showed diverse changes over long-term follow-up. In addition to initial lymphoscintigraphy for diagnosis, lymphatic remapping by follow-up lymphoscintigraphy can be useful to visualize functional changes in the lymphatic system that may guide the optimal management in BCRL.

Lymphoscintigraphy and Single-Photon Emission Computed Tomography (SPECT)/CT to Determine Need for Second Sentinel Lymph Node Biopsy for Breast Cancer Recurrence Following Ipsilateral Breast/Axillary Surgery.

BACKGROUND For patients with cN0 breast cancer, sentinel node biopsy (SNB) is performed to confirm metastasis. When cancer recurs after a breast/axillary surgery, performing a second SNB is debatable in terms of its accuracy and significance. However, SNB is often performed because it is less invasive and can provide significant information. This report describes our experience of performing lymphoscintigraphy and single-photon emission computed tomography (SPECT)/CT to determine whether SNB is informative or not in patients who develop ipsilateral breast tumor recurrence (IBTR) following a breast/axillary surgery. CASE REPORT We included 9 patients with breast cancer and a history of ipsilateral breast/axillary surgery who underwent lymphoscintigraphy and SPECT/CT between April 2020 and July 2023. For lymphoscintigraphy, 20-25 MBq of 99mTc-phytate was injected subcutaneously in the areola, and planar images and SPECT/CT were taken at 15 min and 3 h after the injection. In lymphoscintigraphy, radioisotope accumulation was detected in 2 patients at 15 min and 8 patients at 3 h; it was not detected in 1 patient. The accumulation site was only the axilla in 3 patients; other sites including the axilla in 3, and sites outside the axilla in 2. CONCLUSIONS When a patient who previously underwent breast/axillary surgery develops IBTR, the initial surgery may have altered the lymphatic flow. The lymphatic flow varied between the contralateral or ipsilateral internal mammary lymph nodes, contralateral axilla, multidirectional flow, and the axilla alone. Lymphoscintigraphy and SPECT/CT may be useful for early determination of the need for another SNB.

Lymphoscintigraphy Findings are Associated with Outcome in Children with Chylothorax After Cardiac Surgery.

Postoperative chylothorax in patients with congenital heart diseases (CHD) results in poor outcomes if anatomical and functional abnormalities of the lymphatic system are present. While these abnormalities are typically diagnosed by intranodal lymphangiography and dynamic contrast magnetic resonance lymphangiography, the usefulness of lymphoscintigraphy in these patients has not been evaluated. Between January 2019 and December 2021, 28 lymphoscintigraphies were performed in our institution for investigating prolonged pleural effusion after cardiac surgery. The images were assessed by three board-certified pediatric cardiologists retrospectively to determine the likelihood of a central lymphatic flow disorder. The likelihood was scored (range 1-3) based on structural abnormalities and congestive flow in the lymphatic system. Those scores were summed and the likelihood was categorized as low to intermediate (< 8 points) or high (8 or 9 points). Median age at lymphoscintigraphy was 129 days (IQR, 41-412 days), it was performed at a median of 22 days (IQR, 17-43) after surgery, and median score was 6 points (IQR, 4-7.5). Kendall's coefficient of concordance (0.867; p < 0.05) indicated high inter-rater reliability. Overall survival at 6 months after surgery was 92.5% in the low-to-intermediate group but 68.6% in the high group (p < 0.05), and duration of postoperative thoracic drainage was 27 and 58 days, respectively (p < 0.05). Lymphatic abnormalities detected by lymphoscintigraphy were associated with poorer outcomes. Lymphoscintigraphy was thought to be useful in assessing anatomic and functional lymphatic abnormalities, despite its minimal invasiveness.

Sentinel lymph node detection in thyroid carcinoma using [68Ga]Ga-tilmanocept PET/CT: a proof-of-concept study.

PURPOSE: Sentinel lymph node (SLN) biopsy is rarely used for thyroid carcinoma staging. This is due to challenges associated with conventional Tc-99m-labeled tracers, often producing a large hotspot at the injection site, potentially hiding nearby SLNs (shine-through effect). The aim of this study was to demonstrate the feasibility and effectiveness of SLN visualization using the new PET tracer [68Ga]Ga-tilmanocept. METHODS: Patients with thyroid carcinoma underwent ultrasound-guided peritumoral injection of [68Ga]Ga-tilmanocept and ICG-[99mTc]Tc-nanocolloid. [68Ga]Ga-tilmanocept PET/CT scans were conducted at 15 min and 60 min post-injection to visualize the SLNs. SLN biopsy was performed using ICG-[99mTc]TC-nanocolloid for intraoperative identification. The corresponding lymph node level was resected for reference. RESULTS: Seven differentiated thyroid carcinoma (DTC) and 3 medullary thyroid carcinoma (MTC) patients were included, of which 6 were clinically node-negative. The median number of SLNs detected on [68Ga]Ga-tilmanocept PET/CT and resected was 3 (range 1-4) and 3 (range 1-5), respectively. Eight SLNs were found on PET/CT in the central compartment and 19 in the lateral compartment. The SLN procedure detected (micro)metastases in all patients except one. Seventeen of 27 pathologically assessed SLNs were positive, 8 negative, and 2 did not contain lymph node tissue, which led to upstaging in 5 out of 6 clinically node-negative patients. CONCLUSIONS: [68Ga]Ga-tilmanocept PET/CT identified SLNs in all patients, mainly in the lateral neck. The SLNs were successfully surgically detected and resected using ICG-[99mTc]Tc-nanocolloid. This technique has the potential to improve neck staging, enabling more personalized treatment of thyroid cancer according to the lymph node status. TRIAL REGISTRATION: 2021-002470-42 (EudraCT).

Interval Sentinel Lymph Nodes With the Use of Routine Lymphoscintigraphy in Extremity Melanoma.

INTRODUCTION: Lymphoscintigraphy (LS) helps identify drainage to interval (epitrochlear or popliteal) lymph node basins for extremity melanomas. This study evaluated how often routine LS evaluation identified an interval sentinel lymph node (SLN) and how often that node was found to have metastasis. METHODS: A single institution, retrospective study identified patients with an extremity melanoma who underwent routine LS and SLN biopsy over a 25-y period. Comparisons of factors associated with the identification of interval node drainage and tumor status were made. RESULTS: In 634 patients reviewed, 5.7% of patients drained to an interval SLN. Of those biopsied, 29.2% were positive for micrometastases. Among patients with biopsies of both the traditional and interval nodal basins, nearly 20% had positive interval nodes with negative SLNs in the traditional basin. Sex, age, thickness, ulceration, and the presence of mitotic figures were not predictive of identifying an interval node on LS, nor for having disease in an interval node. Anatomic location of the primary melanoma was the only identifiable risk factor, as no interval nodes were identified in melanomas of the thigh or upper arm (P ≤ 0.001). CONCLUSIONS: Distal extremity melanomas have a moderate risk of mapping to an interval SLN. Routine LS should be considered in these patients, especially as these may be the only tumor-positive nodes. However, primary extremity melanomas proximal to the epitrochlear or popliteal nodal basins do not map to interval nodes, and improved savings and workflow could be realized by selectively omitting routine LS in such patients.

Lymphoscintigraphy is frequently recommended but seldom used in a "real world setting".

OBJECTIVE: Lymphedema (LED) lacks a standard, simple, guiding noninvasive diagnostic test, unlike the two other circulatory disorders-arterial or venous disease. Lymphoscintigraphy (LSG) has been recommended by several guidelines as the diagnostic test of choice for LED. Several recent expert panels, however, have suggested from anecdotal experience that LSG was used infrequently, and that the diagnosis of LED is usually based on clinical examination. METHODS: To determine the use of LSG in a large real-world LED population, the International Business Machines MarketScan Research Database was examined from April 2012 to March 2020 for patients with a new diagnosis of LED (the index date). Use of LSG (LSG+) was ascertained during the period beginning 12 months prior to the initial coding of a LED diagnosis and ending 12 months after the index date based on the corresponding Current Procedural Terminology code; LSG use for sentinel node mapping at the time of oncologic surgery was excluded. Demographic profiles, comorbidities, and causes of LED among patients with and without evidence of LSG were characterized. RESULTS: We identified 57,674 patients, aged ≥18 years, who had a new diagnosis of LED and health care coverage for ≥12 months before and after this index date. Only a small number (1429; 2.5%) of these patients underwent LSG during the study period. The LSG + cohort was younger (53.7 vs 60.7 years), had a higher proportion of women (91.3% vs 73.4%), but a lower percentage of diabetes (12.8% vs 27.5%), heart failure (2.2% vs 8.7%), hypertension (32.4% vs 51.0%), and obesity (15.1% vs 22.2%) compared with the LED population who did not undergo LSG (all P < .001). Most importantly, the use of LSG for diagnosis varied with the etiology of LED (LSG was most frequently utilized among patients with melanoma-LED (9.5%) and patients with breast cancer-LED (6.7%), in contrast to patients with advanced venous disease-related LED (1.1%; P < .05 for both comparisons). CONCLUSIONS: Despite four guidelines recommending LSG, including the Guidelines of the American Venous Forum (Handbook of Venous and Lymphatic Disease-4th edition), which recommended LSG "for the initial evaluation of patients with LED" with a 1B recommendation, LSG plays a minor role in establishing the diagnosis of LED in the United States. This underlines the need for a better, simple diagnostic test for LED to complement clinical examination.