Lymphatic Drainage Pathways Research Articles

Incidental dose distribution to contralateral internal mammary nodes in breast cancer patients undergoing adjuvant radiotherapy

Background and purposeIn a relevant number of primary breast cancer patients, lymphatic drainage to the contralateral internal mammary nodes (cIMN) is being observed. Nevertheless, so far lymphatic drainage pathway to the cIMN is largely neglected during adjuvant radiotherapy. Materials and methodsThis study evaluated the incidental dose to the cIMN for 120 volumetric modulated arc therapy (VMAT) treatment plans for node positive breast in dependence of internal mammary node irradiation (IMNI) and deep inspiration breath hold (DIBH). Additionally, incidental dose distribution to the cIMN based on the field design in the MA20, EORTC22922/10925 and AMAROS trials was assessed. ResultsThe incidental dose (Dmean ± SD) to the cIMN-CTV was 13.0 (±4.7) Gy with a maximum dose of < 30 Gy in 113/120 cases. If IMNI was included (n = 80), the Dmean to the cIMN-CTV was significantly higher compared to no IMNI, but still comparably low (n = 40; 14.3 Gy vs. 9.6 Gy; p = 0.0001). Furthermore, the dose in the cIMN during free breathing (n = 80) was higher compared to DIBH (n = 40; 13.9 Gy vs. 11.2 Gy; p = 0.002).Simulated treatment plans based on the randomized RNI trials revealed neglectable dose coverage of the cIMN (Dmean 1.0–1.8 Gy) for all protocols. ConclusionNeither in the randomized RNI trials nor during contemporary treatment techniques clinically relevant dose distribution to the cIMN was observed. Further studies are warranted to assess the potential impact of intended irradiation of cIMN in high-risk patients.

Tumor deposits in thyroid carcinomas.

Tumor deposits (TDs) are defined as discontinuous neoplastic masses within the lymphatic drainage pathway of the primary tumor. The poor prognostic implication of these masses have been demonstrated in various cancers. The aim of this study is to investigate the incidence of TDs in our thyroid carcinoma cases, which has not been studied so far to the best of our knowledge, and to determine the prognostic value of their existence. In this retrospective cohort study, 194 thyroid carcinoma cases with cervical lymph node sampling and/or dissection were reevaluated for TDs. The case series consisted of 176 thyroid papillary carcinoma (TPC) and 18 thyroid medullary carcinoma (TMC) patients. TDs were detected in 54 (27.8%) patients. TMC cases (55.6%) had significantly more TDs compared to TPCs (25.0%; P = .006). TDs were more common in women (P = .045), and in multifocal tumors (P = .017). In addition, cases with TDs had larger tumor size (P = .002), more lymphatic invasion (P = .009), extrathyroidal extension (P < .001), and distant metastasis (P < .001). The mean follow-up period of the patients was 120.1 months (range, 4-341 months). Locoregional recurrence detected in 17 patients (8.8%) was more common in TMC (33.3%) than TPC cases (6.3%; P = .002). Distant metastasis was identified in 27 patients (13.9%). Ten-year recurrence free survival (RFS) and overall survival (OS) for all patients were 89.0% and 92.4%, respectively. Mean estimated OS time for TD negative and TD positive cases were: 281.9 (±17.2), 325.6 (±6.2) and 217.6 (±27.4) months, respectively (P = .002). Sex (P = .001), tumor type (P = .002), pT classification of the tumor (P < .001), perineural invasion (P = .002) and TDs (P = .002) were significantly associated with OS. In TPC cases individually, extrathyroidal extension (P = .001) and TDs (P = .002) were significantly correlated with distant metastasis. In multivariate analysis, only tumor size was detected as an independent prognostic marker in TPC cases (P = .005). Our results demonstrate the existence of TDs in thyroid carcinoma cases, and indicate a more aggressive behavior pattern of TDs in these tumors.

Perimarginal quadrangle dissection: Pushing the boundaries of neck dissection in gingivo-buccal complex cancer

ObjectivesPerimarginal nodes (PMN) lie in close relationship with marginal mandibular nerve (MMN), in the lymphatic drainage pathway of gingivo-buccal cancers (GBC), above the lower border of mandible and remain unaddressed in conventional neck dissection. We have aimed to define the boundaries of perimarginal node dissection, explore incidence of PMN metastasis and its correlation with histopathological characteristics. Materials and methodsA prospective study was conducted on 112 consecutive patients of GB carcinoma. PMN dissection was performed in an anatomically defined quadrangle. Prospective clinical characteristics included subsite, tumor and nodal stage, location of primary and clinical skin involvement. Histopathological characteristics analyzed included grade, size, pathological tumor, nodal stage, skin and/or bone involvement, depth of invasion, Brandwein Gensler histological risk score and lympho-vascular emboli. MMN function was graded at 3 and 6 months post-operatively. ResultsThe PMN were identified histologically in 75.89 % patients. 15.2 % patients harboured metastasis in PMN. 16.7 % patients had clinically occult metastasis with 11.7 % having isolated PMN metastasis. None of the pre-operative clinical factors was found to be significant in predicting incidence of metastasis. Higher nodal burden (p = 0.01) and pathological skin involvement (p = 0.03) were found statistically significant on multivariable analysis. At 6 months follow-up, none of the patients had any MMN functional deformity at rest. ConclusionThere is a high incidence of occult PMN metastasis from gingivo-buccal complex cancer. High nodal stage and pathological skin involvement are independent predictors for PMN metastasis. PMN dissection must be performed in all cases of GB cancer.

Perimarginal lymph node metastasis in gingivo-buccal complex carcinoma: Is it time to push the limits of neck dissection?.

6069 Background: Perimarginal nodes (PMN) are a group of perifacial lymph nodes that lie in close relationship with marginal mandibular nerve (MMN). They lie in the lymphatic drainage pathway of gingivo-buccal cancers (GBC), above the lower border of mandible which forms the superior limit of conventional neck dissection and thus remain unaddressed. With reported incidence of metastasis as high as 20.5%, we aimed to explore incidence of PMN metastasis in GBC, its correlation with histopathological tumor and nodal characteristics. Methods: A prospective study was conducted on 112 consecutive treatment naïve patients of GB squamous cell carcinoma. Patients with unresectable nodal disease, distant metastasis and prior radiotherapy or surgery to neck were excluded. PMN dissection was performed in the quadrangle bounded superiorly by the mandibular alveolar ridge, inferiorly by lower border of mandible, anteriorly by mental foramen and posteriorly by anterior border of masseter. On histopathological analysis, serial step sectioning and cytokeratin immunohistochemistry were performed. Prospective clinical characteristics analyzed were subsite, clinical tumor, nodal stage, location of primary and clinical skin involvement. PMN positivity was correlated with demographic, clinical, nodal status. Histopathological characteristics analyzed included tumor grade, pathological tumor, nodal stage, tumor size, skin and/or bone involvement, depth of invasion, Brandwein Gensler histological risk score and lympho-vascular emboli. MMN functional outcome was graded according to House-Brackman (HB) grading recorded at 3 and 6 months post-operatively. Results: Baseline characteristics are summarized in the table. The PMN were identified histologically in 75.89% (85/112) patients. Metastasis in these nodes were identified in 15.2% (17/112) patients. Our study revealed an occult PMN metastasis of 16.67% (13/78). None of the pre-operative clinical factors was found to be significant in predicting incidence of metastasis. Higher nodal burden (p=0.01) and pathological skin involvement (p=0.03) had statistically significant odds of having PMN metastasis on multivariable analysis. At 6 months follow-up, none of the patients had any MMN functional deformity at rest. Conclusions: There is a high incidence of occult PMN metastasis from gingivo-buccal complex cancer. High nodal stage and pathological skin involvement are independent adverse prognostic factors for PMN metastasis. The limits of conventional neck dissection should be expanded to include clearance of PMN in all cases of gingivo-buccal cancers. [Table: see text]

Lymphatic spread from left-sided intrahepatic cholangiocarcinoma: reconsiderations based on the lymphatic drainage from the liver

Intrahepatic cholangiocarcinoma (ICC) is known to have a high frequency of lymph node metastasis. Lymph node dissection (LND) is recommended for accurate staging, but the survival benefit of LND remains unclear. Knowledge of the pathways and direction of lymphatic drainage to the regional lymph nodes is essential when considering LND to improve patient survival. The liver has three lymphatic drainage pathways: portal, sublobular, and subcapsular. Of these, the portal lymphatic pathway, which lies along with the portal tracts, is the primary pathway. The efferent portal lymphatic vessels from the left-sided liver, which continue from the portal lymphatic pathway of the liver, communicate with the lymphatic vessels and lymph nodes along the hepatic artery at the hepatoduodenal ligament. In addition, lymphatic flow may also present along the left embryonic (aberrant) hepatic artery in the lesser omentum, based on our experience. This pathway is the previously reported pathway from the left-sided ICC to the lesser curvature of the stomach. However, through this pathway, ICC cells reach lymph nodes along the root of the left gastric artery but not the perigastric lymph nodes along the lesser curvature because of the opposite direction of lymph flow. Although further analyses using a large number of cases are needed to confirm these observations, these two pathways, along the hepatic artery at the hepatoduodenal ligament and the left embryonic (aberrant) hepatic artery in the lesser omentum should be considered when performing LND in the case of ICC in the left-sided liver.

Internal mammary lymphadenopathy in breast cancer: a narrative review and update.

While the axillary nodal basin is the most common lymphatic drainage pathway of the breast, the internal mammary (IM) lymph node chain plays a significant role in breast cancer staging and treatment. It has been identified as sentinel nodal drainage in approximately 13-37% of patients. Despite this, the data is still limited with regard to diagnosis and management when there is suspicion or confirmation of IM lymph node (IMLN) involvement by metastatic breast cancer. The objective of this publication is to provide a comprehensive assessment of the current body of literature surrounding the diagnosis, management and prognostic value of IMLNs in breast cancer treatment. Review of the literature published regarding IMLN diagnosis, significance, and management was completed in PubMed. Additional focus was placed on reviewing articles published within the past 10 years as foundation for an update regarding the current practice and future directions in this space. Improved imaging techniques, with positron emission tomography-computed tomography and magnetic resonance imaging, have led to increase in the identification of IM lymphadenopathy, yielding surgical staging of the IM nodes nearly obsolete. While IM nodal metastases may play a role in overall survival (OS), it has not been demonstrated to be an independent risk factor for increased locoregional recurrence. IM nodal irradiation (IMNI) therapy has been a mainstay in the treatment of IM disease in the context of breast cancer. IMNI has demonstrated improvement in OS and risk of distant recurrence. Wide variations in radiation practices for patients with IM lymphadenopathy exist internationally, highlighting the lack of clear data driven consensus guidelines. Herein, we provide an updated assessment of the current diagnosis, clinical significance, and management of IM lymphadenopathy for breast cancer patients.

Alternative Lymphatic Drainage Pathways in the Trunk Following Oncologic Therapy.

Anatomic and functional descriptions of trunk and breast lymphedema following breast cancer treatment are emerging as indicators of lymphatic dysfunction. Indocyanine green-lymphangiography has been instrumental in characterizing this dysfunction in the extremity and can be applied to other regions. Previous work has established a validated Pittsburgh Trunk Lymphedema Staging System to characterize such affected areas. This study aims to identify risk and protective factors for the development of truncal and upper extremity lymphedema using alternative lymphatic drainage, providing implications for medical and surgical treatment. Patients undergoing revisional breast surgery with suspicion of upper extremity lymphedema between 12/2014 and 3/2020 were offered lymphangiography. The breast and lateral/anterior trunks were visualized and blindly evaluated for axillary and inguinal lymphatic flow. A linear-weighted Cohen's kappa statistic was calculated comparing alternative drainage evaluation. Binomial regression was used to compute relative risks (RRs). Significance was assessed at alpha = 0.05. Eighty-six sides (46 patients) were included. Twelve sides underwent no treatment and were considered controls. Eighty-eight percent of the noncontrols had alternative lymphatic flow to the ipsilateral axillae (64%), ipsilateral groins (57%), contralateral axillae (20.3%), and contralateral groins (9.3%). Cohen's kappa for alternative drainage was 0.631 ± 0.043. Ipsilateral axillary and contralateral inguinal drainage were associated with reduced risk of developing truncal lymphedema [RR 0.78, confidence interval (CI) 0.63-0.97, P = 0.04; RR 0.32, CI 0.13-0.79, P = 0.01, respectively]. Radiation therapy increased risk of truncal and upper extremity lymphedema (RR 3.69, CI 0.96-14.15, P = 0.02; RR 1.92, CI 1.09-3.39, P = 0.03, respectively). Contralateral axillary drainage and axillary lymph node dissection were associated with increased risk of upper extremity lymphedema (RR 4.25, CI 1.09-16.61, P = 0.01; RR 2.83, CI 1.23-6.52, P = 0.01, respectively). Building upon previous work, this study shows risk and protective factors for the development of truncal and upper extremity lymphedema. Most prevalent alternative channels drain to the ipsilateral axilla and groin. Ipsilateral axillary and contralateral inguinal drainage were associated with reduced risk of truncal lymphedema. Patients with radiation, axillary dissection, and contralateral axillary drainage were associated with increased risk of upper extremity lymphedema. These findings have important clinical implications for postoperative manual lymphatic drainage and for determining eligibility for lymphovenous bypass surgery.

Lymphatic drainage patterns of malignant skin tumors in the head and neck region: a single-center retrospective study.

This study aimed to clarify the relationship between primary site and lymphatic drainage pattern for malignant skin tumors in the head and neck region. Malignant melanoma and squamous cell carcinoma in the head and neck region are known to have poor prognosis because of lymph node metastasis. Nevertheless, numerous aspects of lymphatic drainage patterns remain elusive. We statistically analyzed data of 47 patients with malignant skin tumors in the head and neck region. Information was collected on the patients' clinical characteristics, primary tumor site, and lymphatic drainage patterns. The parotid lymph nodes drained the greatest amount of lymph from skin tumors of the head and neck. Important lymphatic drainage pathways were the superficial cervical nodes for primary tumors in the buccal/nasal region, level IA and level IB nodes for primary tumors in the lip region, the occipital nodes, posterior auricular nodes, and level VA nodes in the parietal/occipital region, and the preauricular nodes in the auricular region. These findings have considerable significance in terms of understanding lymphatic drainage patterns for malignant skin tumors in the head and neck and may be useful for clinical decision-making and when planning treatment. Further research and clinical applications are expected to contribute to an improved prognosis in patients with cutaneous head and neck malignancies.

Blood pressure lowering enhances cerebrospinal fluid efflux to the systemic circulation primarily via the lymphatic vasculature

BackgroundInside the incompressible cranium, the volume of cerebrospinal fluid is directly linked to blood volume: a change in either will induce a compensatory change in the other. Vasodilatory lowering of blood pressure has been shown to result in an increase of intracranial pressure, which, in normal circumstances should return to equilibrium by increased fluid efflux. In this study, we investigated the effect of blood pressure lowering on fluorescent cerebrospinal fluid tracer absorption into the systemic blood circulation.MethodsBlood pressure lowering was performed by an i.v. administration of nitric oxide donor (sodium nitroprusside, 5 µg kg−1 min−1) or the Ca2+-channel blocker (nicardipine hydrochloride, 0.5 µg kg−1 min−1) for 10, and 15 to 40 min, respectively. The effect of blood pressure lowering on cerebrospinal fluid clearance was investigated by measuring the efflux of fluorescent tracers (40 kDa FITC-dextran, 45 kDa Texas Red-conjugated ovalbumin) into blood and deep cervical lymph nodes. The effect of nicardipine on cerebral hemodynamics was investigated by near-infrared spectroscopy. The distribution of cerebrospinal fluid tracers (40 kDa horse radish peroxidase,160 kDa nanogold-conjugated IgG) in exit pathways was also analyzed at an ultrastructural level using electron microscopy.ResultsNicardipine and sodium nitroprusside reduced blood pressure by 32.0 ± 19.6% and 24.0 ± 13.3%, while temporarily elevating intracranial pressure by 14.0 ± 7.0% and 18.2 ± 15.0%, respectively. Blood pressure lowering significantly increased tracer accumulation into dorsal dura, deep cervical lymph nodes and systemic circulation, but reduced perivascular inflow along penetrating arteries in the brain. The enhanced tracer efflux by blood pressure lowering into the systemic circulation was markedly reduced (− 66.7%) by ligation of lymphatic vessels draining into deep cervical lymph nodes.ConclusionsThis is the first study showing that cerebrospinal fluid clearance can be improved with acute hypotensive treatment and that the effect of the treatment is reduced by ligation of a lymphatic drainage pathway. Enhanced cerebrospinal fluid clearance by blood pressure lowering may have therapeutic potential in diseases with dysregulated cerebrospinal fluid flow.

Fluorescence lymphoscopy with sentinel lymph node biopsy in research of lymphatic flow in early gastric cancer

To analyze the incidence and risk factors of regional lymph node metastatic lesions, as well as patterns of lymphatic drainage in early gastric cancer using indocyanine green (ICG). A prospective single-center non-randomized study included 67 patients with early gastric cancer between 2016 and 2019. All patients underwent endoscopic dissection or surgical resection with sentinel lymph node biopsy. Regional lymph node metastatic lesions were detected in 12 (20.2%) out of 59 patients with examined lymph nodes. Of these, 11 out of 12 patients had sentinel lymph node lesion, and only 1 patient had metastasis outside this lymph node. The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). Risk factors for metastasis of early gastric cancer to regional lymph nodes were high grade adenocarcinoma (p=0.038) and tumor of anterior gastric wall (p=0.013). All patients with tumors of the upper third of the stomach had sentinel lymph node in the left gastric artery basin. Lymph flow was multidirectional in patients with tumors of the middle third of the stomach. In tumors of the lower third of the stomach, sentinel lymph node was located in the right gastroepiploic artery (50%) and left gastric artery basins (36.84%) (p=0.002). Sentinel lymph node was located in the left gastric artery basin in 84% of patients with tumors of the lesser curvature (p<0.001). Lymphatic drainage was multidirectional if tumors were localized on anterior and posterior walls, as well as on the greater curvature. The proposed technique for sentinel lymph node biopsy demonstrated high sensitivity, specificity and accuracy (93.2%, 100% and 98.3%, respectively). ICG is valuable to identify the first lymph node in lymphatic drainage pathway in 83.6% of cases that makes it possible to assess the regional lymphatic collector. In addition, sentinel lymph node biopsy with ICG contributes to analysis of lymphatic drainage in early gastric cancer. The last one has both scientific and practical significance.

Surgical and Perioperative Treatments for Esophagogastric Junction Cancer.

Esophagogastric junction cancer (EGJC) is a rare malignant disease that occurs in the gastroesophageal transition zone. In recent years, its incidence has been rapidly increasing not only in Western countries but also in East Asia, and it has been attracting the attention of both clinicians and researchers. EGJC has a worse prognosis than gastric cancer (GC) and is characterized by complex lymphatic drainage pathways in the mediastinal and abdominal regions. EGJC was previously treated in the same way as GC or esophageal cancer, but, in recent years, it has been treated as an independent malignant disease, and treatment focusing only on EGJC has been developed. A recent multicenter prospective study revealed the frequency of lymph node metastasis by station and established the optimal extent of lymph node dissection. In perioperative treatment, the combination of multi-drug chemotherapy, radiation therapy, molecular targeted therapy, and immunotherapy is expected to improve the prognosis. In this review, we summarize previous clinical trials and their important evidence on surgical and perioperative treatments for EGJC.

Clinical Effectiveness of Fluorescence Lymph Node Mapping Using ICG for Laparoscopic Right Hemicolectomy: A Prospective Case-Control Study.

The distinction between D3 lymph nodes and actual lymphatic pathways in primary tumors can be difficult during surgery, making it challenging to confirm the completeness of D3 lymph node dissection. Fluorescence lymph node mapping (FLNM) is a promising method for lymph node visualization. This study aimed to assess whether FLNM enhances the effectiveness of D3 lymph node dissection in patients with right-sided colon cancer. Endoscopic submucosal indocyanine green injection were performed on the distal margin of the colon cancer. In an FLNM group, the lymphatic drainage pathway and distribution of D3 lymph nodes were explored. Pathological evaluations were conducted for the fluorescent D3 and non-fluorescent D3 lymph nodes. The FLNM group showed a significantly higher number of harvested lymph nodes in the D3 area. In stage III patients, the proportion of D3 lymph node metastasis was significantly higher in the FLNM group. The harvested D3 lymph node count showed a proportional correlation with a metastatic lymph node count of up to 15. FLNM could be considered a promising new strategy to potentially increase harvested D3 lymph node counts in colon cancer surgery.

A novel near-infrared EGFR targeting probe for metastatic lymph node imaging in preclinical mouse models

For the treatment of patients with oral squamous cell carcinoma (OSCC), the imaging of cervical lymph nodes and the evaluation of metastastic progression are of great significance. In recent years, the development of new non-radioactive lymph node tracers has been an area of intense research. Here, we report the synthesis, good biocompatibility, and in vivo evaluation of a new small molecule near-infrared (NIR) fluorescence probe by the conjugation of Lapatinib to S0456 (LP-S). We show that like Lapatinib, LP-S binds to the epidermal growth factor receptor (EGFR) resulting in high quality fluorescence imaging of metastatic lymph nodes in OSCC mouse models. After local injection of LP-S into the tumor, the lymphatic drainage pathway and lymph nodes can be clearly identified by NIR fluorescence imaging. Further, the LP-S probe shows higher contrast and longer retention in metastatic lymph nodes, allowing them to be differentiated from normal lymph nodes, and affording a new choice for fluorescence-guided surgery.Graphical abstractScheme. Chemical synthesis and application of EGFR targeting probe LP-S for imaging of metastatic lymph nodes (mLNs) in OSCC

Qualitative use of ICG angiography and lymphography in periorbital surgery

ABSTRACT Purpose Open imaging fluorescence devices have been utilized in surgical oncology, vascular and plastic surgery; however, the role of indocyanine green (ICG) in periorbital surgery and lymphatics has not been explored. Methods A prospective, single-center diagnostic study was conducted from 2021 to 2022 utilizing ICG to assess both the periorbital vasculature and lymphatics. Fluorescence was captured with open-imaging fluorescent devices. For ICG angiography, a total of 5–10 mg of ICG was given intravenously at various time points to visualize intraoperative blood flow to eyelid flaps, vascular tumors, or extraocular muscles. For ICG lymphography, 0.03–0.06 mg of ICG was injected subcutaneously to visualize the periorbital and facial lymphatic drainage. Results Twenty-two patients underwent ICG angiography. Periorbital vascular supply was seen in eyelid reconstructions (n = 8), anophthalmic reconstructions (n = 2), lacrimal gland tumors (n = 2), orbital venous malformations (n = 2), tumor metastasis (n = 1) and benign tumors (n = 1). The anterior ciliary arteries were visualized to the extraocular muscles in fracture repairs (n = 3) and muscle biopsies (n = 2). Ten patients underwent ICG lymphangiography highlighting the global periorbital lymphatic system. Conclusion ICG allows for visualization of the vasculature of extraocular muscles and tumors, assessing perfusion of flaps during reconstruction and the global periorbital lymphatic drainage pathways.

A rare truncal collateral lymph drainage pathway seen on indocyanine green lymphography in patients with secondary lower limb lymphedema

A rare truncal collateral lymph drainage pathway seen on indocyanine green lymphography in patients with secondary lower limb lymphedema

La linfogammagrafía in vivo de los tumores del seno nasal identifica el ganglio retrofaríngeo y el nivel I como ganglios centinela predominantes

ObjectiveTo evaluate by in vivo lymphoscintigraphy and SPECT-CT imaging, the lymphatic drainage patterns of para-nasal sinus (PNS) tumours. To confirm or refute the belief of the retropharyngeal lymph node (RPLN) being the significant draining lymph node for such tumours. MethodsProspective cohort study conducted on previously untreated PNS tumours with no clinico-radiological evidence of lymph node metastasis. Lymphoscintigraphy undertaken by nasal endoscopic assisted peritumoral injection of 99mTc sulphur colloid. Injections were classified as anterior or posterior as per a vertical line along the maxillary sinus ostium. ResultsSeventeen patients were included. Lymphoscintigraphy successfully identified 17 sentinel nodes in 15 patients and was unsuccessful (lymphoscintigraphy failure) in 2 patients. Predominant sites of sentinel lymphatic drainage were noted to be the RPLN (n=8; 47%) and level I (n=7; 42%). Occasional drainage was identified at the peri-parotid node (n=1) and at level II (n=1). Contralateral drainage was noted in 2 patients (level I-1 and RPLN-1).Anterior injections drained predominantly to level I (6/8) and RPLN (2/8), while posterior injections drained predominantly to the RPLN (6/7). The relative risk of RPLN being identified as the sentinel node was significantly higher for posteriorly placed injections than for anteriorly placed injections (RR: 3.43; 95% CI: 1.0-11.8; P=.05). ConclusionThe RPLN is noted as a frequent draining node for sino-nasal tumours and merits routine attention in all sino-nasal tumours. The radio-colloid SPECT-CT technique described here offers an excellent in vivo technique to further explore and validate the lymphatic drainage pathways of these tumours.

Consensus Delineation Guidelines for Pelvic Lymph Node Radiation Therapy of Prostate Cancer: On Behalf of the Francophone Group of Urological Radiation Therapy (GFRU)

Clinical target volume (CTV) delineation for pelvic lymph nodes in prostate cancer is currently based on 3 consensus guidelines with some inherent discrepancies. To improve the reproducibility in nodal delineation, the Francophone Group of Urological Radiotherapy (Groupe Francophone de Radiothérapie Urologique [GFRU]) worked toward proposing an easily applicable, reproducible, and practice-validated contouring guideline for pelvic nodal CTV. The nodal CTV data sets of a high-risk node-negative prostate cancer clinical case contoured by 86 radiation oncologists participating in a GFRU contouring workshop were analyzed. CTV volumes were defined before and after a structured presentation of literature data on lymphatic drainage pathways and patterns of nodal involvement and relapse, illustrated using a reference contour (CRef) defined by 3 GFRU experts. The consistency between the participants' contours and CRef was assessed quantitively by means of the Simultaneous Truth and Performance Level Estimation (STAPLE) method, the Dice coefficient, and the Hausdorff distance and qualitatively using a count map. These results combined with the literature review were thoroughly discussed among GFRU experts to reach a consensus. From the 86 workshop participants, the volume of the STAPLE CTV was 591 cc compared with 502 cc for CRef. The Dice coefficient of the STAPLE CTV compared with the experts' CRef was 0.736 (±0.084) before and 0.823 (±0.070) after the workshop; the standard deviation decreased from 11.5% to 8.5% over the workshop. The Hausdorff distance of the STAPLE CTV compared with the CRef was 34.5 mm (±12.4) before the workshop and 21.8 mm (±9.3) after the workshop. Four areas of significant interobserver variability were identified, and a consensus was reached. Using a robust methodology, our cooperative group proposed an easily applicable, reproducible, and practice-validated guideline for the delineation of the pelvic CTV in prostate cancer, useful for implementation in daily practice and clinical trials.

Comparison of sentinel lymph node distribution and lymphatic drainage pathway between high- and low-risk endometrial cancers.

This study aimed to compare the distribution and drainage pathway of sentinel lymph nodes between high- and low-risk endometrial cancers. In total, 429 patients with endometrial cancer who underwent sentinel lymph node biopsy in Peking University People's Hospital from July 2015 to April 2022 were retrospectively enrolled. There were 148 patients in the high-risk group and 281 patients in the low-risk group. The unilateral and bilateral detection rates of sentinel lymph nodes were 86.5% and 55.9%, respectively. The highest detection rate was achieved in the subgroup with a combined use of indocyanine green (ICG) and carbon nanoparticles (CNP) (94.4% for unilateral detection and 66.7% for bilateral detection). The upper paracervical pathway (UPP) was detected in 93.3% of cases in the high-risk group and 96.0% of cases in the low-risk group (p = 0.261). The lower paracervical pathway (LPP) was detected in 10.0% of cases in the high-risk group and 17.9% of cases in the low-risk group (p = 0.048). Remarkably increased detection rates of SLN in the common iliac (7.5%) and para-aortic or precaval areas (2.9%) were observed in the high-risk group. In contrast, a markedly decreased detection rate of SLN in the internal iliac area (1.9%) was observed in the high-risk group. The highest detection rate of SLN was observed in the subgroup with a combined use of ICG and CNP. The detection of UPP is important for both high-risk and low-risk cases, while LPP detection plays a more important role in the low-risk group. Lymphadenectomy in the common iliac and para-aortic or precaval areas is essential for patients with high-risk EC. Removal of internal iliac lymph nodes is essential for patients with low-risk EC, in case of ineffective SLN mapping.

Correction: Tracking the Luminal Exposure and Lymphatic Drainage Pathways of Intravaginal and Intrarectal Inocula Used in Nonhuman Primate Models of HIV Transmission

Correction: Tracking the Luminal Exposure and Lymphatic Drainage Pathways of Intravaginal and Intrarectal Inocula Used in Nonhuman Primate Models of HIV Transmission

In-vivo lymphoscintigraphy of sinonasal tumors identifies retropharyngeal node and level I as predominant sentinel nodes

ObjectiveTo evaluate by in- vivo lymphoscintigraphy and SPECT-CT imaging, the lymphatic drainage patterns of para-nasal sinus(PNS) tumors. To confirm or refute the belief of the retropharyngeal lymph node (RPLN) being the significant draining lymph node for such tumors. MethodsProspective cohort study conducted on previously untreated PNS tumors with no clinico-radiological evidence of lymph node metastasis. Lymphoscintigraphy undertaken by nasal endoscopic assisted peritumoral injection of 99mTc Sulfur colloid. Injections were classified as anterior or posterior as per a vertical line along the maxillary sinus ostium. Results17 patients were included. Lymphoscintigraphy successfully identified 17 sentinel nodes in 15 patients and was unsuccessful (lymphoscintigraphy failure) in 2 patients. Predominant sites of sentinel lymphatic drainage were noted to be the RPLN (n = 8; 47%), and Level I (n = 7; 42%). Occasional drainage was identified at the peri-parotid node(n = 1) and at Level II (n = 1). Contralateral drainage was noted in 2 patients (level I-1 and RPLN-1).Anterior injections drained predominantly to Level I (6/8) and RPLN (2/8), while posterior injections drained predominantly to the RPLN ( 6/7). The relative risk of RPLN being identified as the sentinel node was significantly higher for posteriorly placed injections than for anteriorly placed injections (RR- 3.43; 95% CI-1.0-11.8, p = 0.05). ConclusionThe RPLN is noted as a frequent draining node for sino-nasal tumours and merits routine attention in all sino-nasal tumors. The radio-colloid SPECT-CT technique described here offers an excellent in-vivo technique to further explore and validate the lymphatic drainage pathways of these tumours.