Solitary Node Research Articles

Resonant Solitary States in Complex Networks

Abstract Partially synchronized solitary states occur frequently when a synchronized system of networked oscillators with inertia is perturbed locally. Several asymptotic states of different frequencies can coexist at the same node.
Here, we reveal the mechanism behind this multistability: additional solitary frequencies arise from the coupling between network modes and the solitary oscillator's frequency, leading to significant energy transfer. This can cause the solitary node's frequency to resonate with a Laplacian eigenvalue. We analyze which network structures enable this resonance and explain longstanding numerical observations.
Another solitary state that is known in the literature is characterized by the effective decoupling of the synchronized network and the solitary node at the natural frequency. Our framework unifies the description of solitary states near and far from resonance, allowing to predict the behavior of complex networks from their topology.

Efficiency of conversion surgery for esophageal squamous cell carcinoma with solitary abdominal para-aortic lymph node metastasis.

Abdominal para-aortic lymph nodes (PANs) are sites of distant metastasis in esophageal squamous cell cancer (ESCC). The prognosis of patients with Stage IVB ESCC and abdominal PAN metastasis is extremely poor. However, chemotherapy for ESCC has recently been developed, and the effectiveness of combined induction therapy and conversion surgery remains unclear. The primary objective of this study was to evaluate the short- and long-term outcomes of conversion surgery for ESCC and solitary abdominal PAN metastases after induction therapy. Thirteen patients who underwent conversion esophagectomy for cStage IVB ESCC with solitary abdominal PAN metastasis after induction therapy between January 2017 and October 2022 at our institution were enrolled. The short- and long-term outcomes of conversion surgery were retrospectively evaluated. Three patients (23.1%) had pathological abdominal PAN metastasis, and six patients (46.2%) without pathological abdominal PAN metastasis showed that chemotherapy eliminated the tumors in the abdominal PAN. Three patients (23.1%) had postoperative complications of Clavien-Dindo grade II or higher. The 3-year overall and recurrence-free survival rates were 83.1% and 51.3%, respectively. Our findings showed that conversion surgery for ESCC and solitary abdominal PAN metastasis led to a good prognosis when induction therapy was successful.

Postoperative Lymph Node Recurrence in Esophageal Cancer After Surgery and Prognosis of Chemoradiotherapy.

This study aimed to evaluate the long-term prognosis of definitive chemoradiotherapy and clinical features of postoperative lymph node (LN) recurrence after curative resection of thoracic esophageal squamous cell cancer (ESCC). A total of 586 patients who underwent radical resection of ESCC at the Hiroshima University Hospital from January 2000 to December 2019 were reviewed retrospectively. This study analyzed the clinical characteristics of 54 patients who developed recurrence in a solitary LN by comparing them to 182 patients who experienced total recurrence. Additionally, we analyzed the prognostic factors of 50 patients who received chemo-radiotherapy (CRT). The results revealed a tendency for a higher incidence of solitary LN recurrence in cases of early esophageal cancer and upper thoracic esophageal cancer among all recurrence cases. The 3-, 5-, and 7-year overall survival (OS) rates were 40.5%, 37.8% and 34.6%, respectively, with a median survival time of 27.9 months. Univariate analysis of OS factors, such as age, depth of the primary tumor at the initial surgery, time to LN recurrence after surgery, site of LN recurrence, and the number of the regional LNs with recurrence showed no significant impact on OS. Approximately 35% of patients with ESCC who experienced LN recurrence after curative resection achieved long-term survival through CRT. Despite the absence of identifiable prognostic factors, CRT proves to be a valuable initial treatment option for LN recurrence.

A case of laparoscopic lymphadenectomy for adenocarcinoma of unknown primary incidentally detected as a solitary enlarged lymph node along the common hepatic artery

BackgroundEven in cancer of unknown primary (CUP), which is rare clinical condition, solitary anterosuperior lymph node (LN) along the common hepatic artery (No.8a LN) enlargement diagnosed as metastatic adenocarcinoma has never been reported.Case presentationA 68-year-old Japanese male, with a history of early gastric cancer that had been completely treated by endoscopic submucosal dissection 26 years ago, was detected a single enlarged nodule along the common hepatic artery, No.8a LN, incidentally by computed tomography performed for monitoring of interstitial pneumonia. Endoscopic ultra-sound-guided fine needle aspiration revealed that this nodule was adenocarcinoma suggestive of metastasis, but other imaging studies, including upper and lower gastrointestinal endoscopy, positron emission tomography, and ultrasonography did not detect any primary cancer. We have finally diagnosed as the LN metastasis of CUP and performed laparoscopic lymphadenectomy for this tumor. The tumor was approximately 5 cm in size, was in close proximity to the pancreas, and involved part of the right gastric artery and vein. LNs in the No.5 and No.8a areas, including this tumor, were dissected laparoscopically, and radical resection was achieved. The patient had no postoperative complication and was discharged on postoperative day 10. Immunohistopathological findings revealed that the tumor was poorly differentiated adenocarcinoma, and different from the histology of gastric cancer resected 26 years ago, although the tumor was suggestive of gastrointestinal origin. Imaging studies performed 2 and 6 months after discharge also did not reveal a primary site.ConclusionWe reported a case of solitary No.8a LN adenocarcinoma of CUP. For diagnostic and therapeutic purposes, radical resection is recommended for single enlarged intra-abdominal LN of CUP.

Clinical features of histiocytic necrotizing lymphadenitis in children.

HNL is often misdiagnosed in older children with persistent fever and lymphadenopathy, leading to unnecessary diagnostic tests and evaluations, inappropriate antibiotic administration, and mismanagement. A multidisciplinary team, including primary care providers, rheumatologists, and pathologists, can improve patient outcomes by increasing their awareness of this rare condition. • Histiocytic necrotizing lymphadenitis (HNL) is characterized by fever, leukopenia, and neck lymphadenopathy with unknown etiology. • The lack of neutrophils or eosinophils in the histology, immunohistochemistry results help distinguish HNL from infectious causes.Although HNL is a self-limiting disease, antibiotics and steroid treatments were used inappropriately. • A fever peak ≥ 40 °C was associated with a longer fever duration in HNL patients.Leukopenia presented more frequently in solitary cervical lymph node (LNs) than in extracervical LNs inpatients with prolonged fever. •Steroids are not recommended as a routine treatment, however, in some severe or relapsing cases withpersistent symptoms, prednisolone (5 mg twice a day for 2 days) or other steroids (an equivalent dose ofprednisolone) responded favorably.

Treatment strategy for lymph node metastasis of hepatocellular carcinoma using an ICG navigation system: a case report

BackgroundSince indocyanine green (ICG) accumulates selectively in hepatocellular carcinoma (HCC) cells, it can be used to detect metastatic lesions. Lymph node metastasis of HCC is rarely observed, both simultaneously and metachronously. Therefore, it is sometimes difficult to identify metachronous lymph nodes during salvage surgery because of prior surgery. Herein, we report a case in which lymph node metastasis of HCC was successfully resected using an ICG navigation system.Case presentationThe patient was a 62-year-old man who had undergone radical liver resection for HCC 8 years ago. During surveillance, contrast-enhanced computed tomography (CT) revealed a mass in the hepatic hilum. Various diagnostic modalities suggested that the patient had a solitary metastatic lymph node of HCC, and extirpation of the tumor was planned. Intraoperative ICG fluorescence imaging allowed surgeons to clearly identify the target lesion. Histopathologically, the tumor was confirmed to be a lymph node metastasis of HCC. The patient’s postoperative course was uneventful, and he remains alive without recurrence 2 years after the second surgery.ConclusionIntraoperative navigation surgery by ICG fluorescence imaging was useful for the safe resection of extrahepatic metastasis of HCC in a complicated situation.

Proton Radiation Therapy for Stage IIA/IIB Testicular Seminoma.

Testicular seminoma affects young men and is associated with very favorable prognosis. The evolution in treatment paradigm has focused on minimizing acute and especially late toxicities. Following orchiectomy, while surveillance is favored in Stage I patients, radiotherapy (RT) is a standard treatment option for de novo or relapsed stage IIA or select non-bulky stage IIB disease. Despite low doses, standard RT fields to paraaortic and pelvic lymphatics using x-rays exposes a large volume of uninvolved normal tissue/viscera to excess dose. This young patient population is especially vulnerable to risks of late RT toxicities including secondary malignancy. Proton beam therapy (PBT) has dosimetric advantage over x-ray-based RT due to lack of exit dose, and comparative dosimetric/modeling studies show significant sparing of uninvolved abdominal/pelvic organs. However, there is scant reported clinical data at this time for PBT. We review our early institutional outcomes with PBT for testicular seminoma. Single institution retrospective review from a tertiary care center of patients treated with PBT from 2013-2022 for testicular seminoma. Recurrence free (RFS) and overall survival (OS) were calculated from the completion of PBT. Toxicities were graded (Gr) using CTCAE v5.0. Four patients underwent PBT, median age 39 (range 36-47). All were Stage I at diagnosis (pT1b n = 3; pT2 n = 1) and were treated for recurrent stage II disease (IIA n = 3; IIB n = 1) at a median of 34 months from orchiectomy (range 3 - 74 months). Nodal extent included 2 with multiple paraaortic nodes, 1 with solitary paraaortic node and 1 with solitary pelvic node. PBT was delivered with pencil-beam scanning, treating paraaortic + ipsilateral pelvic fields (20 Gy in 10 fractions), then sequential boost to involved nodes (10 -16 Gy in 5-8 fractions). Typically, PA or posterior oblique fields were used to minimize dose to out-of-field abdominal/pelvic viscera. Treatment was well tolerated with minimal acute toxicities: fatigue Gr 1 (n = 3), nausea Gr 1 (n = 3). No Gr 2 or higher acute toxicities or significant late toxicities were observed. At median follow up of 30 months (range 3 - 54), no recurrences were observed, and RFS and OS were 100%. Two patients are without evidence of disease > 4 years post-treatment. In this case series, PBT for retroperitoneal and pelvic metastases in Stage IIA/IIB testicular seminoma was associated with oncologic efficacy with minimal toxicity. PBT reduces unnecessary dose to abdominal/pelvic organs compared to x-ray techniques, which is advantageous in young patients who have anticipated long-term survival. This is one of the few series reporting clinical outcomes of PBT in the management of seminoma. Randomized comparisons with x-ray approaches are impractical given the relatively low volume of patients receiving RT in modern seminoma management, so it is essential to report and track longitudinal outcomes across institutions to validate this approach.

Long-Term Outcomes in a Phase II Study of Hypofractionated IGRT 60Gy/ 20F in Patients with Isolated Lymph Node Recurrence after Surgery for Esophageal Carcinoma

In oligo metastases in lymph node recurrence after surgery for esophageal cancer, since SBRT (BED>100 Gy10) to mediastinal and abdominal lymph node lesions was not an option due to toxicities in the organs at risk (OAR) such as vessels and gastrointestinal tract, we performed a prospective cohort study of hypofractionated IGRT for isolated lesions. The primary end-points of this study are disease specific survival (DSS) and late treatment toxicities. From 2011 to 2021, 60 Gy/20F/4-4.5wks (78 Gy10) hypofractionated IGRT was performed in a total ITT population of 70 patients after radical surgery (67 cases) and ESD (3 cases), who were diagnosed by CT/PET-CT as having solitary lymph node recurrence (62 cases) or up to 2 adjacent nodes (8 cases). The mean time from surgery to recurrence was 17.9 months (SD 18.1) with a mean age of 67.5 years (SD 9.3), and male to female ratio was 62:8. Pathological results showed that 63 patients (90%) had squamous cell carcinoma. The mean maximum diameter of lesions was 2.5 cm (SD; 1.1 cm). And 51 cases (73%) were treated with CRT concurrently using 5FU plus CDDP (FP), and the rest were treated with RT alone. Lymph node location was lower neck or upper mediastinum in 42 cases, middle and lower mediastinum in 16 cases, and abdomen in 12 cases, respectively. Treatment planning was performed by taking 4DCT fusing PET or MRI images. The Kaplan-Meier method and the Cox proportional hazards regression model were used for overall survival (OS), DSS, and progression free survival (PFS). The mean observation period was 38 months. Primary efficacy was CR in 45 cases (64%), but CR was maintained only in 29 cases (41%). Twenty-two of the 70 patients were relapse-free. OS were 53% and 34% at 2 and 5 years, DSS were 56% and 38% at 2 and 5 years, and PFS were 40% and 39% at 2 and 5 years, respectively. The site of first recurrence was the same or adjacent lymph nodes in 33 cases (47%) and distant metastases in 9 cases (13%). Number of tumors (1 vs. 2), age, and CRT were not significant prognostic factors for OS, DSS, or PFS. In a multivariate analysis, the time from surgery to recurrence ≥12 months was the only significant prognostic factor for PFS (p = 0.018, HR0.50). The same multivariate analysis showed that the only significant prognostic factor for DSS was the location of the recurrent lymph node in the neck and upper mediastinal regions (p = 0.009, HR 0.59). The only late adverse events of Grade 2 or higher were Grade 2 pleural effusion (little and transient) in 6 cases and Grade 2 radiation pneumonitis in 1 case. No acute adverse events were observed other than hematologic toxicity due to FP administration. In locally advanced esophageal cancer, a relatively reliable regional lymph node dissection is often performed, so there is still a chance to aim for cure in cases of solitary recurrence. We found that if the lesion is solitary, localized RT of about 60 Gy/20F/4-4.5 weeks with IGRT can achieve a long-term survival in 40% of patients without any significant adverse events.

Outcome of conventional radiotherapy in small centrally located tumours or lymph nodes: minimal toxicity, remarkable survival but challenging loco-regional control

Background In peripheral lung tumours, stereotactic body radiotherapy (SBRT) is superior to conventional RT. SBRT has also shown high loco-regional control (LC) in centrally located tumours, but there is a high risk of severe toxicity. The STRICTSTARLung trial (NCT05354596) examines if risk-adapted SBRT for central tumours is feasible. In this study, we examined overall survival (OS), Disease-free survival (DSF), LC, and toxicity in patients with central tumours that could have been candidates for SBRT but received conventional RT. Material and methods Retrospectively, we evaluated 49 lung cancer patients that between 2008 and 2021 received RT (60–70Gy in 2 Gy fractions) for a solitary tumour or lymph node with a diameter <5cm located <2cm from the bronchial tree, oesophagus, aorta or heart. All tumours were pathologically verified; 30 were primary lung tumours (T1b-T4) and 19 were solitary lymph nodes (T0N1-N2). Chemotherapy was administered as concomitant (29) or sequential (4). OS and LC were analysed using Kaplan Meier. Cox proportional hazards model for OS and disease-free survival (DFS) was performed including tumour volume, histology, sex, T- vs N-site and chemotherapy. Toxicity was scored. Results In 42 patients, the tumour was located <1 cm to mediastinum. Median follow-up time was 44 months (range: 7–123). The median OS was 51 months. OS at 1-, 3- and 5-year was 88% (SE:5), 59% (SE:7) and 50% (SE:8). Loco-regional recurrences occurred in 16 patients resulting in 1-, and 3-year LC rates of 77% (SE:6) and 64% (SE:8). The majority occurred within 3 years after RT. Only stage showed significant impact on OS and DFS. No patients experienced grade 4–5 toxicity. Seven patients developed grade 3 toxicity (5 oesophageal stenosis, 2 pneumonitis). Conclusion Conventional RT for patients with small central lung tumours or solitary lymph nodes is feasible. Median OS was 51 months, and toxicity was low with no grade 4–5 events.

On the analysis of a heterogeneous coupled network of memristive Chialvo neurons

We perform a numerical study on the application of electromagnetic flux on a heterogeneous network of Chialvo neurons represented by a ring-star topology. Heterogeneities are realized by introducing additive noise modulations on both the central–peripheral and the peripheral–peripheral coupling links in the topology not only varying in space but also in time. The variation in time is understood by two coupling probabilities, one for the central–peripheral connections and the other for the peripheral–peripheral connections, respectively, that update the network topology with each iteration in time. We have further reported various rich spatiotemporal patterns like two-cluster states, chimera states, coherent, and asynchronized states that arise throughout the network dynamics. We have also investigated the appearance of a special kind of asynchronization behavior called “solitary nodes” that have a wide range of applications pertaining to real-world nervous systems. In order to characterize the behavior of the nodes under the influence of these heterogeneities, we have studied two different metrics called the “cross-correlation coefficient” and the “synchronization error.” Additionally, to capture the statistical property of the network, for example, how complex the system behaves, we have also studied a measure called “sample entropy.” Various two-dimensional color-coded plots are presented in the study to exhibit how these metrics/measures behave with the variation of parameters.

Diagnostic effectiveness of intraoperative express histological examination as a tool to take decisions on the extent of surgery for papillary thyroid cancer

Background. In case of the screening use of high-resolution ultrasound, the level of detecting thyroid neoplasms is about 25 % in the population. Ultrasound criteria are not enough to detect carcinoma. The following methods are used for the differential diagnosis of malignant thyroid neoplasms: ultrasound scans, computed tomography, fine-needle aspiration (FNA) biopsy, intraoperative express histological and histopathological examination. Some authors consider FNA to be the standard method for primary morphological diagnosis of thyroid nodes. It is not always possible to conduct FNA safely. Also, FNA cannot be a method of 100% morphological identification of a primary tumor. In such cases, the extent of the surgery will depend on the data obtained from the intraoperative express histological examination. Analysis of the diagnostic effectiveness of the express histological examination will help to take a decision on the need for it when choosing the extent of a surgery on the thyroid gland. Aim of the study: to evaluate the diagnostic efficiency of the intraoperative express histological method in the detection of papillary thyroid cancer on solitary nodes (Bethesda IV, V) and metastases of papillary thyroid cancer during surgery. Materials and methods. The results of intraoperative express histological and pathohistological examinations performed at the Ukrainian Scientific and Practical Center for Endocrine Surgery, Transplantation of Endocrine Organs and Tissues from 2018 to 2021 were analyzed. The sample included materials of surgeries on the thyroid gland in case of papillary cancer T1ab-2N0–1 and solitary nodes (Bethesda IV and Bethesda V) according to data obtained using FNA. The sample size in the study of regional metastasis included 220 examinations, 845 examinations in the “gray zone” (Bethesda IV — 465, Bethesda V — 380). Cases of discrepancy between the results of intraoperative express histological and final histopathological examinations were considered. The data was processed using the EZR v. 3.4.1 statistical analysis program. Results. The sensitivity of the express histological examination in case of detecting metastases of thyroid cancer is 72.2 % with the method specificity of 99.9 %. The diagnostic efficiency in detecting metastases of thyroid cancer is 89.1 %. When the express histological examination is used for Bethesda IV nodes, the sensitivity of the method is 8 % with a specificity of almost 100 %. The diagnostic efficiency of the express histological examination is even higher in case of Bethesda V: sensitivity of 47 % with the method specificity of almost 100 %. The values obtained correlate with international data. This testifies to the need for further improvement of the of intraoperative diagnosis method. Conclusions. The diagnostic efficiency of the intraoperative express histological examination for detecting metastases of papillary thyroid cancer in the selected group is 89.1 % with sensitivity of 72.2 % and specificity of 99.9 %. The diagnostic efficiency of intraoperative express histological examination for verification of thyroid cancer in case of Bethesda IV nodes is 63.9 % with sensitivity of 8.2 % and specificity of 99.6 %. The diagnostic efficiency of intraoperative express histological examination for verification of thyroid cancer in Bethesda V nodes is 63.4 % with sensitivity of 47.3 % and specificity of 99.2 %. The intraoperative express histological examination method makes it possible to take decisions on surgical tactics during surgery within the determined limits, so we believe it reasonable to further use and improve it.

Patterns of practice regarding use of radiation therapy following radical prostatectomy: A survey of Radiation Oncologists and Urologists in Australia and New Zealand.

This study aimed to investigate the patterns of practices of radiation oncologists (ROs) and urologists in Australia and New Zealand with respect to the utilisation of post-prostatectomy radiation therapy (RT) and help guide the development of an update to the existing Faculty of Radiation Oncology Genito-Urinary Group post-prostatectomy guidelines. ROs and urologists with subspecialty practice in prostate cancer from Australia and New Zealand were invited to participate in an online survey comprised of clinical scenarios regarding post-prostatectomy RT. Sixty-five ROs and 28 urologists responded to the survey. In the setting of low-risk biochemical relapse, the threshold for initiating RT was lower for ROs than urologists. ROs were more likely than urologists to recommend adjuvant RT for node-positive disease. When salvage RT was advised for a pT3N0R1 recurrence, there was no consensus amongst ROs on whether to add either ADT or nodal treatment over prostate bed RT alone. For a solitary PSMA-avid pelvic lymph node recurrence, whole pelvis RT with androgen deprivation therapy was the preferred treatment option (72% ROs, 43% urologists). Most ROs (92%) recommended conventionally fractionated RT to 66-70 Gy, with a boost to any PSMA PET avid recurrent disease. This survey highlights the marked discordance in practice for the management of prostate cancer relapse post-prostatectomy. This is seen not only between specialties but also within the radiation oncology community. This emphasises the need for an updated evidence-based guideline to be produced.

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)-A Prospective Multicentric Cohort Study.

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55-1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15-0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19-0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

A case of solitary lymph node recurrence 9years after initial treatment for advanced premenopausal endometrioid endometrial cancer; clinical usefulness of hormonal replacement therapy.

There is no consensus on the use of hormone replacement therapy (HRT) after treatment of advanced corpus cancer. We report a case of advanced corpus cancer at a young age, in which HRT was initiated 7years after surgery, and regional lymph node recurrence was later detected. The patient was 35years old at the time of initial treatment in X year, when she was diagnosed with stageIIIC2 corpus cancer and underwent a hysterectomy with bilateral salpingo-oophorectomy and a retroperitoneal lymphadenectomy. HRT was started at X + 7years, and at X + 9years, a 25 × 12-mm-sized mass was found in the hilum of the right kidney. A laparoscopic resection revealed regional lymph node recurrence of the corpus cancer. A retrospective study further revealed that a tumor measuring 12 × 3mm was found at X + 3years and grew to 18 × 7mm in X + 6years, just before the start of the HRT. We hypothesize that HRT did not induce tumor recurrence; instead, it allowed for long-term follow-up and early diagnosis.

Superficial lymphatic drainage of the vulva and its relation to the regional nodes: an experimental study.

Sentinel node biopsy in vulvar cancer is associated with much less morbidity than inguinofemoral node dissection. Our study focused on describing the morphology of superficial lymphatic drainage of the vulva and its relationship to regional nodes, which may facilitate orientation during surgery. In 24 female cadavers, injections of patent blue (at various localisations medially, unilaterally and bilaterally) were used to visualise the lymphatic drainage of the vulva. After dissection of lymphatic vessels and nodes, their course was documented by photograph and then analysed. Subsequently, a map of vulvar superficial lymphatics was created. The cutaneous and subcutaneous tissue of the vulva primarily drained to superficial inguinal nodes. There was no evidence of a solitary lymph node that drained the unilateral vulva. Each area of the vulva drained to its own lymph node, which was variably localised in the subcutaneous groin around the great saphenous vein. Anastomoses between individual inguinal superficial lymph nodes are likely. Right-left symmetry in the course of lymphatic collectors was not detected. Natural drainage of the medial and paramedial areas to contralateral inguinal nodes was also not detected. The drainage pattern to ipsilateral inguinal nodes was consistent in cadavers without evidence of vulvar disease and may be applicable in the early stages of vulvar cancer. There was no evidence of a solitary node that drained the unilateral vulva. Each part of the vulva may drain to a corresponding lymph node in a different localisation of the groin. The surgeon should take this variability into account.

Solitary states in complex networks: impact of topology

The dynamical behavior of networked systems is expected to reflect the properties of their coupling structure. Yet, symmetry-broken solutions often occur in symmetrically coupled networks. An example are so-called solitary states where the dynamics of one network node is different from the synchronized rest. Here, we investigate the structural constraints of networks for the appearance of solitary states. By performing a large number of numerical simulations, we find that such states occur with high probability in asymmetric networks, among them scale-free ones. We analyze the structural properties of the networks that support solitary states. We demonstrate that the minimum neighbor node degree of a solitary node is crucial for the appearance of solitary states. Finally, we perform bifurcation analysis of dimension-reduced systems, which confirm the importance of the connectivity of the neighboring nodes.

PSAT280 Role of Radiofrequency Ablation Therapy in Recurrent Papillary Thyroid Carcinoma - A Case Study

Abstract Introduction Radiofrequency ablation (RFA) has been studied in solitary and reoccurring/ persistent papillary thyroid cancer (PTC) with favorable results. This case describes a patient with reoccurring PTC who underwent radiofrequency ablation. Clinical Case This is a case of a 68 year old male who was underwent an elective thyroid surgery for compressive multinodular goiter and left inferior parathyroid adenoma. Prior to his surgery he had fine needle aspiration cytologies of multiple nodules that were negative for thyroid cancer. A total thyroidectomy with excision of central cervical lymph nodes, excision of a suspicious right perithyroidal mass and a left inferior parathyroidectomy were performed. The pathology diagnosis was multifocal bilateral papillary thyroid cancer – classical type – with infiltration into perithyroidal adipose tissue and lymph node metastasis (pathological stage: mpT1b pN1a). Serum thyroglobulin was 4.9 ng/mL (reference range 1.6–59.9 ng/mL). Postoperatively, he was given adjuvant radioactive iodine (I-131 120mCi) treatment and suppressive levothyroxine at 250 µg daily, with pretreatment TSH at 14.730 µU/mL and TSH after 4 months of treatment 0.140 µU/mL. Single photon emission computed tomography (SPECT) whole body imaging done seven days post radioactive iodine therapy showed no evidence of distant metastases. Four months after I-131 therapy, a diagnostic ultrasound for a palpable node revealed this to be a right level IIb cystic cervical lymph node (18×16×18 mm) with no overt vascularity. Serum thyroglobulin was &amp;lt;0.2 ng/mL and thyroglobulin antibodies were &amp;lt;14.4 IU/mL. FNA biopsy, with cytology showing papillary thyroid cancer. Needle washout thyroglobulin was elevated (1015.3 ng/mL, reference range &amp;lt; 10ng/mL). This metastatic lymph node was concluded to be recurrent papillary cancer. Surgical dissection and percutaneous alternatives were discussed with the patient. Shared decision making between surgery, intervention radiology and the patient concluded that a less invasive procedure was preferred and the solitary node was a candidate for percutaneous ablation. Post ablation surveillance ultrasonography showed an 80% volume reduction (11×8×12 mm) in node size six weeks post intervention and a 95% volume reduction at six months (8×5×7 mm), with decreased cystic appearance and no vascularity. No complications were reported after the procedure. Conclusion Current guidelines recommend that the mainstay of recurrent thyroid cancer is surgery, followed by radioactive iodine therapy and suppressive thyroid hormone replacement treatment, external beam radiotherapy and/ or chemotherapy. However within recent years, image guided ablation techniques such as radiofrequency ablation has been explored and has become an alternative in selective who wish to avoid extensive lymph node dissection. Multiple studies unanimously report a node volume reduction rate (VRR) of greater than 50%, with some studies reporting almost 99% VRR within 12-24 months; suggesting a role for RFA to replace 'berry picking surgery' in selected patients. Presentation: No date and time listed

Solitary pulmonary nodules: etiology, sizes and topographical features

Objective — determination of the size and localization of solitary pulmonary nodules (SPN) of various etiology and their qualitative-quantitative characteristics when separated into malignant and benign formations.&#x0D; Materials and methods. The randomized retrospective study involved 422 patients who were hospitalized in the National Institute of phthisiology and pulmonology named after F.G. Yanovsky from 2017 to 2021. Criteria for inclusion in the study group are focal lesions of the lungs of unclear etiology, the size of which did not exceed 3,0 cm, and the presence of no more than 3 foci in both lungs of one patient according to X-ray examination. The number, size and location of the SPN were determined according to X-ray examination or computed tomography of the chest organs.. A total of 473 nodules were found. The etiology of SPN was determined according to the results of histological and cytological examination of biopsy or operative material and/or microbiolo­gical data. All nodules were divided into three groups, depending on their size.&#x0D; Results and discussion. The etiological spectrum of all revealed SPN in the five-year period is determined. It was established that among all SPN malignant tumors (39.1 %) are dominated the average size of which was (2.14 ± 0.1) cm, on the second place in the number of observations were nodules of infectious origin (31.0 %), the average size — (1.97 ± 0.1) cm, and on the third — benign tumors (18.7 %). the average size — (1.57 ± 0.1) cm. The average size of malignant tumors and SPN of infectious origin was significantly larger than the size of benign tumors and vascular formations. It was shown that in a group with SPN sizes 0.3—1.0 cm malignant tumors amounted to 22.9 %. and in a group with a size from 2.1 to 3.0 cm — 51.5 %, respectively 55.3 % of all SPNs were found in the right lung, 44.7 % in the left. In the upper lobe of the right lung. 52.3 % of nodules were found. which is significantly more than in middle. 16.0 % of SPN (p &lt; 0.001), and the lower lobe — 31.7 % (p &lt; 0.001). In the upper lobe of the left lung. 59.4 % of SPN were diagnosed, and in its lower lobe — 40.6 % (p &lt; 0.001).&#x0D; Conclusions. Among all solitary pulmonary nodules of various etiology. the largest specific gravity have malignant nodes — 39.1 % and nodules of infectious genesis — 31.0 %. and the average size of these SPN is essentially larger than the size of benign tumors and vascular formations. The percentage of malignancies increases from 22.9 to 51.4 % with an increase sizes of SPN from 1.0 to 3.0 cm. Significant predominance by the number of nodules in size from 1.1 cm to 3 cm is evidence of improper level of detection SPN in Ukraine. Solitary pulmonary nodes are significantly more often found in the right lung. Moreover, lesions of the upper lobes of the right and left lungs are observed more often than the lower lobes of the lungs.

A rare case of a retrocrural lymph node metastasis from a chromophobe renal cell cancer: complete thoracoscopic resection with a new multi-joint articulating surgical instrument

We report a rare case of a 69-year-old man with a solitary retrocrural lymph node metastasis in the posterior mediastinum of an oligo-metastatic chromophobe renal cell cancer that was radically resected in a curative intent using new articulating Artisential® instruments.

Oncological Safety of Skin-Sparing Mastectomy and Immediate Breast Reconstruction in Extensive Ductal Carcinoma In Situ

IntroductionSkin-sparing mastectomy (SSM) with immediate breast reconstruction is the ideal treatment for interested and suitable patients with extensive ductal carcinoma in situ (DCIS). There is no guideline to indicate on how large DCIS the procedure can be performed safely. The primary target of this study was to define the oncological safety of SSM in extensive pure DCIS. The secondary target was to find predictive factors for DCIS upstaging to invasive disease. Materials and methodsA total of 71 consecutive patients with extensive pure DCIS and undergoing SSM with immediate latissimus dorsi (LD) breast reconstruction were retrospectively evaluated. ResultsThe median size of DCIS lesion in preoperative imaging was 60 mm, the median weight of mastectomy specimen was 350 g, and the median resection margin (RM) was 2.0 mm. A total of 20 patients (28%) had an RM less than 0.5 mm and nine patients (13%) had ink positive margins. Six patients having positive RM underwent reoperation. A total of 29 patients (41%) presented invasive cancer foci in final histopathological assessment and nine patients (13%) had an axillary metastasis. Adjuvant therapy was given to 23 patients presenting invasive cancer. There were no local recurrences or distant metastases (0%, 95% confidence interval 0-0.051) during the mean follow-up of 71 mo. None of the factors evaluated predicted upstaging to invasive disease. ConclusionsSSM with immediate breast reconstruction in patients with extensive DCIS is oncologically safe even when the margins are close or positive. Additional invasive foci and solitary axillary lymph node metastases are frequent but do not worsen the outcome.