Segmentation of Head and Neck Lymph Node Regions for Radiotherapy Planning Using Active Contour-Based Atlas Registration

In this paper, we present the segmentation of the headand neck lymph node regions using a new active contourbased atlas registration model. We propose to segment thelymph node regions without directly including them in theatlas registration process; instead, they are segmentedusing the dense deformation field computed from theregistration of the atlas structures with distinctboundaries. This approach results in robust and accuratesegmentation of the lymph node regions even in thepresence of significant anatomical variations between theatlas-image and the patient's image to be segmented. Wealso present a quantitative evaluation of lymph noderegions segmentation using various statistical as well asgeometrical metrics: sensitivity, specificity, dicesimilarity coefficient and Hausdorff distance. Acomparison of the proposed method with two other state ofthe art methods is presented. The robustness of theproposed method to the atlas selection, in segmenting thelymph node regions, is also evaluated.

Docteur, j'ai un ganglion [Doctor, I have a lymph node]

To investigate a recently developed lymphadenopathy can be simple or complex. The medical history, presence or not of symptoms, the general physical examination, and the localization and characteristics of the adenopathy, most often lead to a diagnosis and therapy when indicated. Among young adults, the etiology is either infectious or reactive, rarely tumoral, as opposed to elderly persons. The most important step is to look at signs of severity (or non banality) such as an increased size, hard consistency, supra-clavicular location, an immunocompromised host, a history of Tb exposition. If present, these signs will trigger a biopsy with cyto- or histopathological examination mostly to rule out a malignant tumor. This article reviews the practical steps of an investigation of an isolated adenopathy in an adult patient.

Role of lymph node fibroblasts in T cell priming

SummarySecondary lymphoid organs, such as lymph nodes or spleen, are the only places in our body where primary adaptive immune responses are efficiently elicited. These organs have distinct Β and Τ cell rich zones and Τ lymphocytes constantly migrate from the bloodstream into Τ zones to scan dendritic cells (DCs) for antigens they present. Specialized fibroblasts, the Τ zone reticular cells (HR.Cs), span the Τ zone in the form a three-dimensional network. lK.Cs guide incoming Τ cells in their migration, both chemically, by the secretion of the chemokines CCL19 and CCL21, and physically, by construction of a road system to which also DCs adhere. In this way TRCs are thought to facilitate encounters of Τ cells with antigen-bearing DCs and thereby accelerate the selection of rare antigen-specific Τ cells. The resulting Τ cell activation, proliferation and differentiation all take place within the TRC network. However, the influence of TRCs on Τ cell activation has so fer not been elucidated with the possible reasons being that TRCs represent a relative rare cell population and that mice devoid of TRCs have not been described.To circumvent these technical limitations, we established TRC clones and lines to have an abundant source to functionally characterize TRCs. Both the clones and lines show a fibroblastic phenotype, express a surface marker profile comparable to ex vivo TRCs and produce extracellular matrix molecules. However, expression of Ccl19, Ccl21 and ZL-7 is lost and could not be restored by cytokine stimulation. When these TRC clones or lines were cultured in a three-dimensional cell culture system, their morphology changed and resembled that of in vivo TRCs as they formed networks. By adding Τ cells and antigen-loaded DCs to these cultures we successfully reconstructed lymphoid Τ zones that allowed antigen-specific Τ cell activation.To characterize the role of TRCs in Τ cell priming, TRCs were co-cultured with antigen-specific Τ cells in the presence antigen-loaded DCs. Surprisingly, the presence of TRC lines and ex vivo TRCs inhibited rather than enhanced CD8+ Τ cell activation, proliferation and effector cell differentiation. TRCs shared this feature with fibroblasts from non-lymphoid tissues as well as mesenchymal stromal cells. TRCs were identified as a strong source of nitric oxide (NO) thereby directly dampening Τ cell expansion as well as reducing the Τ cell priming capacity of DCs. The expression of inducible NO synthase (iNOS) was up- regulated in a subset of TRCs by both DC-signals as well as interferon-γ produced by primed CD8+ Τ cells. Importantly, iNOS expression was induced during viral infection in vivo in both lymph node TRCs and DCs. Consistent with a role for NO as a negative regulator, the primary Τ cell response was exaggerated in iNOS-/- mice. Our findings highlight that in addition to their established positive roles in Τ cell responses TRCs and DCs cooperate in a negative feedback loop to attenuate Τ cell expansion during acute inflammation.RésuméLes organes lymphoïdes secondaires, comme les ganglions lymphoïdes ou la rate, sont les seuls sites dans notre corps où la réponse primaire des lymphocytes Β et Τ est initiée efficacement. Ces organes ont des zones différentes, riches en cellules Β ou T. Des lymphocytes Τ circulent constamment du sang vers les zones T, où ils échantillonent la surface des cellules dendritiques (DCs) pour identifier les antigènes qu'ils présentent. Des fibroblastes spécialisés - nommés Τ zone reticular cells (TRCs)' forment un réseau tridimensionnel dans la zone T. Les TRCs guident la migration des cellules Τ par deux moyens: chimiquement, par la sécrétion des chimiokines CCL19 et CCL21 et physiquement, par la construction d'un réseau routier en trois dimensions, auquel adhèrent aussi des DCs. Dans ce? cas, on pense que la présence des TRCs facilite les rencontres entre les cellules Τ et les DCs chargées de l'antigène et accélère la sélection des rares cellules Τ spécifiques. Ensuite, l'activation de cellules T, ainsi que la prolifération et la différenciation se produisent toutes à l'intérieur du réseau des TRCs. L'influence des TRCs sur l'activation des cellules T n'est que très peu caractérisée, en partie parce que les TRCs représentent une population rare et que les souris déficientes dans les TRCs n'ont pas encore été découvertes.Pour contourner ces limitations techniques, nous avons établi des clones et des lignées cellulaires de TRC pour obtenir une source indéfinie de ces cellules permettant leur caractérisation fonctionnelle. Les clones et lignées établis ont un phénotype de fibroblaste, ils expriment des molécules de surface similaires aux TRCs ex vivo et produisent de la matrice extracellulaire. Mais l'expression de Ccl19, Ccl21 et 11-7 est perdue et ne peut pas être rétablie par stimulation avec différentes cytokines. Les clones TRC ou les lignées cultivées en un système tridimensionnel de culture cellulaire, montrent une morphologie changée, qui ressemble à celle de TRC ex vivo inclus la construction de réseaux tridimensionnels.Pour caractériser le rôle des TRC dans l'activation des cellules T, nous avons cultivé des TRCs avec des cellules T spécifiques et des DCs chargées avec l'antigène. Etonnamment, la présence des TRC (lignées et ex vivo) inhibait plutôt qu'elle améliorait l'activation, la prolifération et la différenciation des lymphocytes T CDS+. Les TRCs partageaient cette fonction avec des fibr-oblastes des organes non lymphoïdes et des cellules souches du type mésenchymateux. Dans ces conditions, les TRCs sont une source importante d'oxyde nitrique (NO) et par ce fait limitent directement l'expansion des cellules T et réduisent aussi la capacité des DCs à activer les cellules T. L'expression de l'enzyme NO synthase inductible (ïNOS) est régulée à la hausse par des signaux dérivés des DCs et par l'interféron-γ produit par des cellules T de type CD8+ activées. Plus important, l'expression d'iNOS est induite pendant une infection virale in vivo, dans les TRCs et dans les DCs. Par conséquent, la réponse primaire de cellules T est exagérée dans des souris iNOS-/-. Nos résultats mettent en évidence qu'en plus de leur rôle positif bien établi dans la réponse immunitaire, les TRCs et les DCs coopèrent dans une boucle de rétroaction négative pour atténuer l'expansion des cellules T pendant l'inflammation aigiie pour protéger l'intégrité et la fonctionnalité des organes lymphoïdes secondaires.

The role of interval nodes in sentinel lymph node mapping and dissection for melanoma patients.

In sentinel node (SN) biopsy, an interval SN is defined as a lymph node or group of lymph nodes located between the primary melanoma and an anatomically well-defined lymph node group directly draining the skin. As shown in previous reports, these interval SNs seem to be at the same metastatic risk as are SNs in the usual, classic areas. This study aimed to review the incidence, lymphatic anatomy, and metastatic risk of interval SNs. METHODS: SN biopsy was performed at a tertiary center by a single surgical team on a cohort of 402 consecutive patients with primary melanoma. The triple technique of localization was used-that is, lymphoscintigraphy, blue dye, and gamma-probe. Otolaryngologic melanoma and mucosal melanoma were excluded from this analysis. SNs were examined by serial sectioning and immunohistochemistry. All patients with metastatic SNs were recommended to undergo a radical selective lymph node dissection. RESULTS: The primary locations of the melanomas included the trunk (188), an upper limb (67), or a lower limb (147). Overall, 97 (24.1%) of the 402 SNs were metastatic. Interval SNs were observed in 18 patients, in all but 2 of whom classic SNs were also found. The location of the primary was truncal in 11 (61%) of the 18, upper limb in 5, and lower limb in 2. One patient with a dorsal melanoma had drainage exclusively in a cervicoscapular area that was shown on removal to contain not lymph node tissue but only a blue lymph channel without tumor cells. Apart from the interval SN, 13 patients had 1 classic SN area and 3 patients 2 classic SN areas. Of the 18 patients, 2 had at least 1 metastatic interval SN and 2 had a classic SN that was metastatic; overall, 4 (22.2%) of 18 patients were node-positive. CONCLUSION: We found that 2 of 18 interval SNs were metastatic: This study showed that preoperative lymphoscintigraphy must review all known lymphatic areas in order to exclude an interval SN.

Methylation signature of lymph node metastases in breast cancer patients.

BACKGROUND: Invasion and metastasis are two important hallmarks of malignant tumors caused by complex genetic and epigenetic alterations. The present study investigated the contribution of aberrant methylation profiles of cancer related genes, APC, BIN1, BMP6, BRCA1, CST6, ESR-b, GSTP1, P14 (ARF), P16 (CDKN2A), P21 (CDKN1A), PTEN, and TIMP3, in the matched axillary lymph node metastasis in comparison to the primary tumor tissue and the adjacent normal tissue from the same breast cancer patients to identify the potential of candidate genes methylation as metastatic markers. METHODS: The quantitative methylation analysis was performed using the SEQUENOM's EpiTYPER? assay which relies on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: The quantitative DNA methylation analysis of the candidate genes showed higher methylation proportion in the primary tumor tissue than that of the matched normal tissue and the differences were significant for the APC, BIN1, BMP6, BRCA1, CST6, ESR-b, P16, PTEN and TIMP3 promoter regions (P<0.05). Among those candidate methylated genes, APC, BMP6, BRCA1 and P16 displayed higher methylation proportion in the matched lymph node metastasis than that found in the normal tissue (P<0.05). The pathway analysis revealed that BMP6, BRCA1 and P16 have a role in prevention of neoplasm metastasis. CONCLUSIONS: The results of the present study showed methylation heterogeneity between primary tumors and metastatic lesion. The contribution of aberrant methylation alterations of BMP6, BRCA1 and P16 genes in lymph node metastasis might provide a further clue to establish useful biomarkers for screening metastasis.

Adjuvant cisplatin-based combined chemotherapy for lymph node (LN)-positive urothelial carcinoma of the bladder (UCB) after radical cystectomy (RC): a retrospective international study of >1500 patients.

OBJECTIVE: To compare outcomes of patients with lymph node (LN)-positive urothelial carcinoma of the bladder (UCB) treated with or without cisplatin-based combined adjuvant chemotherapy (AC) after radical cystectomy (RC). PATIENTS AND METHODS: We retrospectively analysed 1523 patients with LN-positive UCB, who underwent RC with bilateral pelvic LN dissection. All patients had no evidence of disease after RC. AC was administered within 3 months. Competing-risks models were applied to compare UCB-related mortality. RESULTS: Of the 1523 patients, 874 (57.4%) received AC. The cumulative 1-, 2- and 5-year UCB-related mortality rates for all patients were 16%, 36% and 56%, respectively. Administration of AC was associated with an 18% relative reduction in the risk of UCB-related death (subhazard ratio 0.82, P = 0.005). The absolute reduction in mortality was 3.5% at 5 years. The positive effect of AC was detectable in patients aged ≤70 years, in women, in pT3-4 disease, and in those with a higher LN density and lymphovascular invasion. This study is limited by its retrospective and non-randomised design, selection bias, the absence of central pathological review and lack in standardisation of LN dissection and cisplatin-based protocols. CONCLUSION: AC seems to reduce UCB-related mortality in patients with LN-positive UCB after RC. Younger patients, women and those with high-risk features such as pT3-4 disease, a higher LN density and lymphovascular invasion appear to benefit most. Appropriately powered prospective randomised trials are necessary to confirm these findings.

The role of adjuvant chemotherapy for lymph node-positive upper tract urothelial carcinoma following radical nephroureterectomy: a retrospective study.

OBJECTIVE: To evaluate the effect of adjuvant chemotherapy (AC) on mortality after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC) with positive lymph nodes (LNs) and to identify patient subgroups that are most likely to benefit from AC. PATIENTS AND METHODS: We retrospectively analysed data of 263 patients with LN-positive UTUC, who underwent full surgical resection. In all, 107 patients (41%) received three to six cycles of AC, while 156 (59.3%) were treated with RNU alone. UTUC-related mortality was evaluated using competing-risks regression models. RESULTS: In all patients (Tall N+), administration of AC had no significant impact on UTUC-related mortality on univariable (P = 0.49) and multivariable (P = 0.11) analysis. Further stratified analyses showed that only N+ patients with pT3-4 disease benefited from AC. In this subgroup, AC reduced UTUC-related mortality by 34% (P = 0.019). The absolute difference in mortality was 10% after the first year and increased to 23% after 5 years. On multivariable analysis, administration of AC was associated with significantly reduced UTUC-related mortality (subhazard ratio 0.67, P = 0.022). Limitations of this study are the retrospective non-randomised design, selection bias, absence of a central pathological review and different AC protocols. CONCLUSIONS: AC seems to reduce mortality in patients with pT3-4 LN-positive UTUC after RNU. This subgroup of LN-positive patients could serve as target population for an AC prospective randomised trial.

Local behavior and lymph node metastases of Wilms' tumor: accuracy of computed tomography

Objective To evaluate the accuracy of computed tomography for local and lymph node staging of Wilms' tumor. Materials and Methods Each case of Wilms' tumor was evaluated for the presence of abdominal lymph nodes by a radiologist. Signs of capsule and adjacent organ invasion were analyzed. Surgical and histopathological results were taken as the gold standard. Results Sensitivity was 100% for both mesenteric and retroperitoneal lymph nodes detection, and specificity was, respectively, 12% and 33%, with positive predictive value of 8% and 11% and negative predictive value of 100%. Signs of capsular invasion presented sensitivity of 87%, specificity of 77%, positive predictive value of 63% and negative predictive value of 93%. Signs of adjacent organ invasion presented sensitivity of 100%, specificity of 78%, positive predictive value of 37% and negative predictive value of 100%. Conclusion Computed tomography tumor showed low specificity and low positive predictive value in the detection of lymph node dissemination. The absence of detectable lymph nodes makes their presence unlikely, and likewise regarding the evaluation of local behavior of tumors.

Clinically occult metastases in patients with cutaneous melanoma. Detection with sentinel lymph node biopsy and whole body positron emission tomography

Objective: The aim of this study was to investigate the use of sentinel lymph node biopsy (SLNB) and whole body positron emission tomography (PET), with emphasis on surgical treatment and prognosis, in the detection of clinically occult metastases in patients with clinically localized cutaneous melanoma. Patients and methods: The study population consisted of 1255 patients with clinical stage I–II cutaneous melanoma, operated at Turku University Hospital between 1983 and 2007. 334 patients underwent SLNB and they were compared to 921 retrospective patients. A subgroup of 30 symptom-free patients with high risk melanoma underwent prospectively whole body PET 6–24 months postoperatively. Results: Overall, the disease-specific survival rate was 84.4 % at five years. Sex, Breslow thickness, age and nodal status were independent prognostic factors for survival. SLNB revealed occult nodal metastases in 17 % of the patients. There was no significant difference in disease-specific overall survival between SLNB patients and controls, but the nodal disease-free time was significantly longer suggesting better local control after SLNB and subsequent completion lymph node dissection. The followup time was different between the study cohorts and initial surgery was performed during different time periods. SLNB detected micrometastases in seven of 155 patients (4.5 %) with thin T1 primary melanoma and in four of 25 patients (16 %) with head and neck melanoma. In six of 30 asymptomatic patients with high risk melanoma (20 %), whole body PET detected occult distant metastases. Conclusion: Both SLNB and whole body PET were reliable methods to detect clinically occult metastases in patients with cutaneous melanoma. This upstaging altered the treatment in each case.

Lymph node metastasis in early gastric cancer

OBJECTIVE: to evaluate the incidence of lymph node metastasis in early gastric cancer, identifying risk factors for its development. METHODS: we conducted a prospective study of patients with gastric cancer admitted to the Section of the Esophago-Gastric Surgery of the Surgery of Service HUCFF-UFRJ, from January 2006 to May 2012. RESULTS: the rate of early gastric cancer was 16.3%. The incidence of nodal metastases was 30.8% and occurred more frequently in patients with tumors with involvement of the submucosa (42.9%), in those poorly differentiated (36.4%), in tumors larger than 2 cm (33.3%) and in type III ulcerated lesions (43.8%). CONCLUSION: the incidence of lymph node metastases in patients was very high and suggests that one should keep the radicality of resection in early gastric cancer, particularly in relation to D2 lymphadenectomy, recommended for advanced gastric cancer. Conservative resections, with lymphadenectomies smaller than D2, should be performed only in selected cases, well-studied as for the risk factors of lymph node metastasis. Despite the small number of cases did not permit to relate the rate of lymph node metastasis to the risk factors considered, we noted a strong tendency for the occurrence of these metastases in the poorly differentiated, type III, larger than 2 cm tumors, and in the Lauren diffuse types.

Localization of metastasis within the sentinel lymph node biopsies: a predictor of additional axillary spread of breast cancer?

PURPOSE: To explore the relationship between morphological characteristics and histologic localization of metastasis within sentinel lymph nodes (SLN) and axillary spread in women with breast cancer. METHODS: We selected 119 patients with positive SLN submitted to complete axillary lymph node dissection from July 2002 to March 2007. We retrieved the age of patients and the primary tumor size. In the primary tumor, we evaluated histologic and nuclear grade, and peritumoral vascular invasion (PVI). In SLNs we evaluated the size of metastasis, their localization in the lymph node, number of foci, number of involved lymph nodes, and extranodal extension. RESULTS: Fifty-one (42.8%) patients had confirmed additional metastasis in non-sentinel lymph nodes (NLSN). High histologic grade, PVI, intraparenchymatous metastasis, extranodal neoplastic extension and size of metastasis were associated with positive NLSN. SLN metastasis affecting the capsule were associated to low risk incidence of additional metastasis. After multivariate analysis, PVI and metastasis size in the SLN remained as the most important risk factors for additional metastasis. CONCLUSIONS:The risk of additional involvement of NSLN is higher in patients with PVI and it increases progressively according the histologic localization in the lymph node, from capsule, where the afferent lymphatic channel arrives, to the opposite side of capsule promoting the extranodal extension. Size of metastasis greater than 6.0 mm presents higher risk of additional lymph node metastasis.

Uterine lymphangiography: comparison of two methods for locating the medial iliac lymph node

Different methods for lymphatic mapping in dogs, such as infusing tissues with vital dyes or radioactive substances, have been studied, aiming at the early detection of lymph node metastasis. Thus, one could anticipate therapeutic measures and, consequently, prolong the survival and improve the quality of life of the patients. The objectives of this experiment were to locate the nodes responsible for draining the uterine body and horns and to try to establish the relationship between the uterus and the medial iliac lymph nodes to contribute to the early diagnosis and prognosis of uterine disorders. We studied 15 female dogs divided into two groups (5 dead and 10 intraoperative ovariohysterectomy bitches). The dye used was patent blue V (Patent Bleu V®). It was observed that the iliac lymph node chain receives much of the uterine (horns) drainage. This method should be considered for safer studies of uterine sanity. This information suggests that evaluating these lymph nodes will allow correlating changes in their physiological status with uterine pathologies.

Lymph node transfer in the treatment of postmastectomy lymphedema

Background: Lymphedema is a debilitating disorder with few treatment options. Clinical studies have shown that microvascular lymph node transfer may improve the lymphatic function of the affected limb. This study provides information about the clinical efficacy and safety of this procedure. Further, the biological background of this technique is clarified with an analysis of postoperative production of lymphatic growth factors and cytokines related to lymphangiogenesis. Patients and Methods: The effect of lymph node transfer to recipient and donor sites was analyzed with lymphoscintigraphy, limb circumference measurements, and appearance of clinical symptoms. Axillary seroma samples were analyzed from four patient groups: Axillary lymph node removal (ALND), Microvascular breast reconstruction (BR), lymph node transfer (LN) and combined lymph node transfer and breast reconstruction (LN-BR). Results: The postoperative lymphatic transport index was improved in 7/19 patients. Ten patients were able to reduce or discontinue compression therapy 6 - 24 months postoperatively. The donor lower limb lymphatic flow was slightly impaired (Ti >10) in 2 patients. No donor site lymphedema symptoms appeared during the 8 – 56-month follow-up. A high concentration of the VEGF-C protein was detected in the seroma fluid of all flap transfer groups. The concentration of the anti-inflammatory and anti-fibrotic cytokine IL-10 was increased in the LN-BR group samples when compared to the ALND or BR group. Conclusions: According to this preliminary study, the lymph node transfer seems to be beneficial for the lymphedema patients. However, a randomized study comparing the effect of BR and LN-BR is needed to evaluate the clinical efficacy of lymph node transfer. In addition, the effect of this surgery on the donor site needs to be studied further. The clinical effects of the lymph node transfer might be partly mediated by increased production of the lymphangiogenic growth factor (VEGF-C) as well as the anti-fibrotic cytokine (IL-10).