Primary Lobe Research Articles

J0011+3217: A peculiar radio galaxy with a one-sided secondary lobe and misaligned giant primary lobes

From the LOFAR Two-metre Sky Survey second data release (LoTSS DR2) at 144 MHz, we identified a peculiar radio galaxy, J0011+3217. It has a large, one-sided diffuse secondary wing that stretches up to 0.85 Mpc (roughly 85% of the size of the primary lobe). The linear size of the primary lobe of the galaxy is 0.99 Mpc. This peculiar source is a giant radio galaxy with a misaligned primary lobe. There is an optical galaxy 16 kpc (7 arcsec) from the host active galactic nucleus of J0011+3217. J0011+3217 has a radio luminosity of 1.65 × 1026 W Hz−1 at 144 MHz with a spectral index of −0.80 between 144 and 607 MHz. J0011+3217 is located 1.2 Mpc from the centre of the Abell 7 cluster. The Abell 7 cluster has a redshift of 0.104 and a mass (M500) of 3.71 × 1014 M⊙. The cluster is associated with strong X-ray emission. We studied the X-ray emission around the cluster and from the region surrounding J0011+3217 using an XMM-Newton image of J0011+3217, and we analysed the velocity structure and spatial distribution of galaxies in the cluster, showing that J0011+3217 inhabits an offset group of galaxies that are moving with respect to Abell 7. The off-axis distortion, or bending, of the primary lobe of J0011+3217 in the outer edges has a strong effect on the relative motion of the surrounding medium; this in turn causes the bending of the jets in the opposite direction of the cluster (like wide-angle tailed sources). We suggest that the morphology of J0011+3217 is influenced by ram pressure created by the Abell 7 cluster, highlighting the complex interactions between the source and the surrounding cluster environment.

Differentiation potential of SOX2-positive stem cells in the bovine pituitary gland

The pituitary gland is the master endocrine gland, harboring stem cells with various genetic characteristics; however, data from non-rodent and non-human sources are scarce. In this study, we isolated putative stem cells from the bovine pituitary gland and investigated their potential for differentiation into hormone-producing cells. Immunohistochemical analysis revealed that in calves and heifers, stem cell marker sex-determining region Y-box 2 (SOX2)-positive cells were widely present in the pituitary gland and partially co-localized with anterior pituitary hormones. Next, a single-cell suspension of primary anterior lobe cells from bovines aged 0 and 12 months was subjected to two-dimensional culture. Consequently, some cells proliferated in the culture dishes. The expression levels of Sox2 and several other stem cell markers were higher in these cells after culture. In addition, almost all proliferating cells were positive for SOX2, whereas all were negative for hormones. In three-dimensional cultures, SOX2-positive cells presented a spheroid-like morphology and differentiated into endocrine cells. These results provide evidence that SOX2-positive cells are pituitary stem cells with the potential to differentiate into hormone-producing cells, regardless of age. Our data lay a theoretical foundation for further studies on controlling fundamental processes, such as body growth, reproduction, and lactation.

Synthesis of Circular Antenna Arrays for Achieving Lower Side Lobe Level and Higher Directivity Using Hybrid Optimization Algorithm

Circular antenna arrays (CAAs) find extensive utility in a range of cutting-edge communication applications such as 5G networks, the Internet of Things (IoT), and advanced beamforming technologies. In the realm of antenna design, the side lobes levels (SLL) in the radiation pattern hold significant importance within communication systems. This is primarily due to its role in mitigating signal interference across the entire radiation pattern’s side lobes. In order to suppress the subsidiary lobe, achieve the required primary lobe orientation, and improve directivity, an optimization problem is used in this work. This paper introduces a method aimed at enhancing the radiation pattern of CAA by minimizing its SLL using a Hybrid Sooty Tern Naked Mole-Rat Algorithm (STNMRA). The simulation results show that the hybrid optimization method significantly reduces side lobes while maintaining reasonable directivity compared to the uniform array and other competitive metaheuristics.

The Role of Lumbar Drains in the Perioperative Management of Primary Spontaneous Temporal Lobe Encephaloceles and Cerebrospinal Fluid Leaks.

To examine the role of lumbar drains (LDs) in the success of spontaneous temporal cerebrospinal fluid (CSF) leak and encephalocele repair. Retrospective cohort study. Tertiary academic health system. Patients undergoing repair of spontaneous temporal lobe encephaloceles or middle fossa CSF leaks during years 2017 to 2023. Transmastoid, middle fossa craniotomy, or combination approaches to CSF leak repair. Failure rate, complication rate, length of stay (LOS), readmission. Sixty-nine patients were included, with a combination approach performed in 78.3%, transmastoid in 17.4%, and isolated middle fossa craniotomy in 4.3%. Mean body mass index was 33.2, mean bony defect size width was 6.51 mm, and defect locations included the epitympanum, antrum, mastoid, and petrous apex. Multilayer closure with three or more layers was performed in 87.0%. LD was used in 73.9% of cases for a mean duration 2.27 days and was associated with longer LOS (3.27 vs. 1.56 d, p = 0.006) but not with failure rate, complications, discharge destination, or readmission. Only one major complication occurred as a result of the drain, but low-pressure headache was anecdotally common. Use of LD in the repair of spontaneous CSF leaks and temporal lobe encephaloceles is associated with longer LOS but not failure rates or other admission-level outcomes.

Shaping Radiation with Line Source Antenna for Ramp Pattern Generation

Array antennas are essential in communication technology because they can produce focused beams of electromagnetic radiation that can be precisely shaped and directed for various applications. These antennas typically generate a radiation pattern with a primary lobe, the main beam, accompanied by smaller minor lobes. The size and distribution of these lobes depend on the array's design and configuration. For large array antennas, the main beam becomes extremely narrow, enabling precise point-to-point communication over long distances. This precision is especially beneficial for applications requiring accurate targeting or transmission to specific locations. However, achieving such optimized performance requires careful design and engineering. This study, builds on Woodward's amplitude control method, initially developed for generating sector beams, to create ramp patterns with unique applications in antenna engineering. By adjusting the amplitudes of the signals fed into each element of the array, the researchers can shape the resulting radiation pattern to meet specific requirements. The paper provides detailed analysis and computational data demonstrating the effectiveness of this approach in achieving the desired beam patterns. These results offer valuable insights into antenna design and optimization, potentially advancements in wireless communication, radar systems, and satellite communication.

End fire linear antenna array synthesis using differential evolution inspired Adaptive Naked Mole Rat Algorithm

Linear antenna arrays (LAAs) play a critical role in smart system communication applications such as the Internet of Things (IoT), mobile communication and beamforming. However, minimizing secondary lobes while maintaining a low beamwidth remains challenging. This study presents an enhanced synthesis methodology for LAAs using the Adaptive Naked Mole Rat Algorithm (ANMRA). ANMRA, inspired by mole-rat mating habits, improves exploration and exploitation capabilities for directive LAA applications. The performance of ANMRA is assessed using the CEC 2019 benchmark test functions, a widely adopted standard for statistical evaluation in optimization algorithms. The proposed methodology results are also benchmarked against state-of-the-art algorithms, including the Salp Swarm Algorithm (SSA), Cuckoo Search (CS), Artificial Hummingbird Algorithm (AHOA), Chimp Optimization Algorithm (ChOA), and Naked Mole Rat Algorithm (NMRA). The results demonstrate that ANMRA achieves superior performance among the benchmarked algorithms by successfully minimizing secondary lobes and obtaining a narrow beamwidth. The ANMRA controlled design achieves the lowest Side Lobe Level (SLL) of − 37.08 dB and the smallest beamwidth of 74.68°. The statistical assessment using the benchmark test functions further confirms the effectiveness of ANMRA. By optimizing antenna element magnitude and placement control, ANMRA enables precise primary lobe placement, grating lobe elimination, and high directivity in LAAs. This research contributes to advancing smart system communication technologies, particularly in the context of IoT and beamforming applications, by providing an enhanced synthesis methodology for LAAs that offers improved performance in terms of secondary lobe reduction and beamwidth optimization.

Primary Endobronchial Conventional Chondrosarcoma Right Lung Upper Lobe: A Case Report and Literature Review

Primary endobronchial chondrosarcoma is extremely rare and hardly reported while reported chondrosarcomas of primary lung origin are rare with most literature coming from a series of case reports and small case series. These tumours can present as centrally located masses and therefore, require extensive workup to exclude alternative aetiology and to confirm diagnosis. Literature review revealed only four reports of primary endobronchial and 29 primary pulmonary chondrosarcoma cases, excluding the current report. We present a rare case of biopsy-proven non-metastatic primary endobronchial conventional chondrosarcoma of the right upper lobar bronchus extending into the right main bronchus managed with technically challenging sleeve bilobectomy of right upper and middle lobes and a viable anastomosis of lower lobe bronchus with the right main bronchus stump and thus, prevented a pneumonectomy. Final histopathology confirmed the diagnosis. Thus, these tumours are difficult to diagnose and challenging to manage and need more data in future to establish protocols.

The potential of biology-guided radiation therapy in thoracic cancer: A preliminary treatment planning study.

PurposeWe investigated the feasibility of biology-guided radiotherapy (BgRT), a technique that utilizes real-time positron emission imaging to minimize tumor motion uncertainties, to spare nearby organs at risk.MethodsVolumetric modulated arc therapy (VMAT), intensity-modulated proton (IMPT) therapy, and BgRT plans were created for a paratracheal node recurrence (case 1; 60 Gy in 10 fractions) and a primary peripheral left upper lobe adenocarcinoma (case 2; 50 Gy in four fractions).ResultsFor case 1, BgRT produced lower bronchus V40 values compared to VMAT and IMPT. For case 2, total lung V20 was lower in the BgRT case compared to VMAT and IMPT.ConclusionsBgRT has the potential to reduce the radiation dose to proximal critical structures but requires further detailed investigation.

Multifocal papillary thyroid cancer in children and adults. Lecture

Thyroid cancer is the 9th most common cancer in the world. Thus, in the year 2020, 586.000 cases of thyroid cancer were registered worldwide. The incidence rate among women is 10.1 per 100 thousand population, and among men — 3.1 per 100 thousand population. In Ukraine, in 2019, the standardized rate of incidence of thyroid cancer (world standard) was 6.9 per 100.000 population (2.8 among men, 10.5 among women). In the structure of the incidence of malignant neoplasms of the cervical spine, thyroid cancer ranks first place among women aged 18 — 29 (19.9 %), fourth among both men aged 18 — 29 (8.3 %, and women aged 30 — 54 (8.1 %). Over the past 40 years, increased incidence of thyroid cancer (in particular, papillary thyroid cancer) is observed in most countries, which can be explained by various factors, for example, overdiagnosis, a change in the prevalence of modified risk factors. In Ukraine, in the period from 1989 to 2012, the rate of incidence of papillary thyroid cancer among men increased by 115 %, among women — by 137 %, the annual increase in incidence of papillary thyroid cancer for men and women was 5 and 6 %, respectively. Multifocality in papillary thyroid cancer is a characteristic feature that is much more common in pediatric patients than in adults, but the number of studies in children is limited, which is associated with a lower prevalence of the disease in children. The results of investigations on the multifocality predictors and its role in influencing relapse, persistence, and survival in patients with papillary thyroid cancer are conflicting in both adults and pediatric population. Among the risk factors of multifocality, a smaller number of controversies concerns the links of metastasis in the lymphatic nodes, radiation in the anamnesis, childhood age, and for bilaterality — multifocality of the primary lobe and the presence of contralateral benign nodes (in adults). Other factors as predictors of multifocality have controversial significance and deserve attention in further research. The identification of reliable predictors of multifocality, especially with the help of preoperative data analysis, as well as multifocality risk stratification will facilitate the complex decision‑making process for the correct treatment tactics of children and adults with papillary thyroid cancer.

Radiation Segmentectomy for the Treatment of Primary Hepatic Malignancies of the Caudate Lobe: A Case Series.

Tumors involving the caudate lobe present a unique therapeutic challenge due to their complex anatomy and the safety and efficacy of locoregional therapy can be variable. The purpose of this study is to analyze the outcomes of radiation segmentectomy for primary caudate lobe tumors. Eight patients [5 women and 3 men; median age = 69y (range 50-79)] that underwent transarterial radioembolization (TARE) using yttrium-90 (Y90) glass microspheres for primary caudate lobe tumors (hepatocellular carcinoma = 6, intrahepatic cholangiocarcinoma = 2) from August 2017 to March 2021 were retrospectively analyzed. Descriptive statistics, treatment parameters, tumor response (using modified response evaluation criteria in solid tumors), adverse events [using common terminology criteria for adverse events (CTCAE)], and survival outcomes were evaluated. Eight primary caudate lobe tumors with a median size of 2.2cm [interquartile range (IQR), 1.7-3.3] and Child-Pugh class A liver function underwent TARE of the caudate lobe. The median radiation dose was 596Gy (IQR 356-1585), median total activity was 0.84GBq (IQR 0.56-1.31), median specific activity was 473Bq/sphere (IQR 226-671), and the median number of Y90 microspheres used was 1.4 million (IQR 1.2-3.4). All complications were CTCAE grade 1, and no clinically significant hilar plate complications were observed. In targeted tumors, complete response was seen in all patients. At amedian follow-upperiod of16.6 months (IQR6.6-21.6)75% (6/8) ofpatientswerealive withno in-field progression. Radiation segmentectomy of primary caudate lobe tumors appears effective and is well tolerated in this limited case series within the described treatment parameters. Level 4, Case Series.

Mainlobe maintenance for FDA-MIMO radar

During radar detection, the adaptive beamforming technique needs to create nulls to resist the interference. When the interference appears within the mainlobe, the main detection beam will become distorted. To solve this problem, a new method for the covariance matrix reconstruction is proposed for the mainlobe maintenance problem, and a worst-case performance optimization (WCPO) algorithm with enhanced waveform robustness is obtained. Its integration is performed over a known region without the target information to obtain the improved covariance matrix, which is then brought into the convex optimization equation to solve for the weight vector. Simulation results show that the output signal-to-noise ratio of this algorithm is higher than that of the conventional WCPO algorithm with a robust beam for the same signal-to-noise ratio. It can also effectively eliminate the primary lobe offset and secondary lobe elevation problems.

One-sized bilobed flap does not fit all standing cones: a mathematical analysis of the standing cone in bilobed flap dynamics.

The bilobed flap (BLF) is a workhorse for nasal repair. Alterations to the length and orientation of the BLF's standing cutaneous deformity (SCD) have been suggested as a means of preventing Z-plasty-induced flap lengthening and consequent ipsilateral alar depression. To investigate the effect of design variations of the SCD on bilobed flap mechanics. Geometric analysis of the BLF was performed using commercially available graphing software. BLFs were designed with a SCD equal to one radius (rBLF) and one diameter (dBLF) of the primary defect as well as with a more superiorly-oriented one diameter SCD (soBLF). Lengths from the pivot point to the distal edges of the primary defect and primary lobe were measured and compared. Elongation or a more superior orientation of the SCD without changes to the rest of the flap design forms a primary lobe along a shorter arc resulting in insufficient flap length to resurface the primary defect. The insufficient length requires secondary motion to complete the repair and possible unintended alar displacement. Modification of the size and orientation of the SCD alters the location of the pivot point, which is a key determinant of BLF mechanics. Therefore, changes to the SCD require alterations to the remainder of the flap design to ensure aesthetic and functional success.

Risk and Lag-time for Development of Lacrimal Gland Carcinoma Expleomorphic Adenoma: Observations and Conjectural Study.

To estimate the proportion of de novo lacrimal gland pleomorphic adenomas (PAs) and carcinomas expleomorphic adenomas (CEPAs), together with age at presentation and first symptom. Conjectural models of tumor growth are considered. Retrospective review of patients with orbital lobe PA or CEPA. The presenting age was examined for conformation to a Gaussian distribution and the cumulative distribution function derived for both tumor types. The risk of CEPA with age was estimated by logistic regression. About one-sixth (27/172; 16%) of these primary orbital lobe tumors were CEPAs, with 145 PAs (76/145 male; 52%) and 27 CEPAs (12/27 male; 44%). The mean presenting age for PAs was 48.3 years (median 47.7; range 11-84 years) and 57.7 years for CEPAs (median 61.2, range 27-91 years) ( p = 0.0062), and the standard deviations for each group are almost identical (16.3 for PAs, 15.9 for CEPAs; p = 0.92). Five (3.4%) PAs and 1 (3.7%) CEPA were asymptomatic: otherwise, the median symptom duration was 24 months for both PAs and CEPAs ( U test: p = 0.65). The odds of CEPA rises significantly with age, increasing 1.04-fold annually ( p = 0.0079). The almost identical measures of dispersion for the presenting ages of PA and CEPA suggests that, once malignant transformation occurs, there might be a relatively constant period before it is evident. CEPAs present about a decade after PAs, this unexpectedly later presentation for the malignancy possibly being explained by a gradual replacement of the PA by the newly arising carcinoma within the preceding benign tumor.

Re: Evaluation of Intraoperative Triamcinolone Injection or Primary Lobe Tacking (Pexing) Sutures for Preventing Pincushioning in Bilobed Transposition Flaps.

Re: Evaluation of Intraoperative Triamcinolone Injection or Primary Lobe Tacking (Pexing) Sutures for Preventing Pincushioning in Bilobed Transposition Flaps.

Multiple instance learning for lung pathophysiological findings detection using CT scans.

Lung diseases affect the lives of billions of people worldwide, and 4 million people, each year, die prematurely due to this condition. These pathologies are characterized by specific imagiological findings in CT scans. The traditional Computer-Aided Diagnosis (CAD) approaches have been showing promising results to help clinicians; however, CADs normally consider a small part of the medical image for analysis, excluding possible relevant information for clinical evaluation. Multiple Instance Learning (MIL) approach takes into consideration different small pieces that are relevant for the final classification and creates a comprehensive analysis of pathophysiological changes. This study uses MIL-based approaches to identify the presence of lung pathophysiological findings in CT scans for the characterization of lung disease development. This work was focus on the detection of the following: Fibrosis, Emphysema, Satellite Nodules in Primary Lesion Lobe, Nodules in Contralateral Lung and Ground Glass, being Fibrosis and Emphysema the ones with more outstanding results, reaching an Area Under the Curve (AUC) of 0.89 and 0.72, respectively. Additionally, the MIL-based approach was used for EGFR mutation status prediction - the most relevant oncogene on lung cancer, with an AUC of 0.69. The results showed that this comprehensive approach can be a useful tool for lung pathophysiological characterization.

Delphian lymph node metastasis predicts occult contralateral carcinoma for unilateral papillary thyroid carcinoma patients with contralateral benign nodules

BackgroundFor unilateral PTC patients with benign nodules in the contralateral lobe evaluated preoperatively, the necessity of total thyroidectomy remains controversial. This study aimed to investigate the predictive factors for occult contralateral carcinoma and whether DLN metastasis could predict it. MethodsA total of 148 patients with unilateral PTC and contralateral benign nodules who were treated with a near-total thyroidectomy or TT at a single institution between August 2018 and April 2020 were enrolled. Clinicopathological features such as age, sex, TgAb or TPOAb level, primary tumor location, nodule number in contralateral lobe, carcinoma number in primary lobe, tumor size, capsular invasion, central lymph node metastasis, DLN metastasis were analyzed to investigate the rate and predictive factors of occult contralateral carcinoma. Results44.6% patients were diagnosed with occult contralateral thyroid carcinoma. Univariate analysis showed that sex (P = 0.008), mulifocality of primary carcinoma (P < 0.001), tumor size (P = 0.033), capsular invasion (P = 0.042), CLN metastasis (P = 0.004), DLN metastasis (P = 0.001) were associated with occult contralateral carcinoma. Multivariate analysis showed that multifocality of primary carcinoma (p = 0.000, OR = 9.729), DLN metastasis (p = 0.042, OR = 4.701), capsular invasion (p = 0.022, OR = 2.909), and male patients (p = 0.006, OR = 3.926) were all independent predictive factors. ConclusionFor unilateral PTC patients with benign nodules in the contralateral lobe evaluated preoperatively, multifocality of primary carcinoma, DLN metastasis, capsular invasion, and male patients are independent predictors of occult contralateral carcinoma. We suggest separate excision and frozen section of DLN intraoperatively, if DLNs were confirmed metastasized, a TT was highly recommended.

Evaluation of Intraoperative Triamcinolone Injection or Primary Lobe Tacking (Pexing) Sutures for Preventing Pincushioning in Bilobed Transposition Flaps.

Bilobed transposition flaps are prone to pincushioning (trapdooring), whereby contraction of the flap over the wound bed may produce an unsatisfactory functional and aesthetic outcome. There are several proposed methods to prevent this, but there is currently no clear consensus on the ideal technique. To compare primary lobe pexing sutures versus intraoperative triamcinolone (TAC) injection as methods to prevent pincushioning in bilobed transposition flaps. A retrospective chart review of bilobed flap reconstructions identified from the Mohs micrographic surgery database at a single tertiary center in New Zealand. Three hundred forty-two patients met the inclusion criteria: 37 received pexing sutures, 42 intraoperative TAC, and 263 no additional intervention. The most defect common location was the nasal tip (43.6%), followed by the ala (20.8%). Ninety-three participants (27.2%) developed pincushioning at a median 35 days postoperatively. Participants receiving no intervention had a 30.8% pincushioning rate. The TAC group had a 23.8% pincushioning rate (p = .358), and the pexing group had a 5.5% pincushioning rate (p = .001). Participants receiving primary lobe pexing sutures had a statistically significantly lower rate of pincushioning than those receiving no intervention. Intraoperative TAC injections appeared to have little impact on pincushioning.

Outflows in the radio-intermediate quasar III Zw 2: a polarization study with the EVLA and uGMRT

ABSTRACT We present results from a polarization study of the radio-intermediate quasar, III Zw 2, at a redshift of 0.089, with the upgraded Giant Metrewave Radio Telescope (uGMRT) at 685 MHz and the Karl G. Jansky Very Large Array (VLA) at 5 and 34 GHz. We detect a kpc-scale outflow, exhibiting transverse magnetic (B-) fields. The curved jet terminates in a bow-shock-like radio structure with inferred B-fields aligned with the lobe edges. We suggest that the radio outflow in III Zw 2 is a combination of a collimated jet along with a wind-like component. This ‘wind’ component could be a magnetized accretion disc wind or the outer layers of a broadened jet or a combination of both. The current data cannot differentiate between these possibilities. We also detect kpc-scale lobe emission that is misaligned with the primary lobes in the uGMRT images. The spectral indices and the electron lifetimes in the misaligned lobe are similar to the primary lobe, suggesting that the misaligned lobe is not a relic. We propose that changing spectral states of the accretion disc, and the subsequent intermittent behaviour of the outflow, along with the close interplay between the jet and ‘wind’ could explain the radio-intermediate nature of III Zw 2. Our study shows that radio-intermediate quasars are promising sources for understanding the role of jets and winds in galaxy evolution and demonstrates the power of radio polarization studies towards achieving this.

Ubx-Collier signaling cascade maintains blood progenitors in the posterior lobes of the Drosophila larval lymph gland.

Drosophila larval hematopoiesis occurs in a specialized multi-lobed organ called the lymph gland. Extensive characterization of the organ has provided mechanistic insights into events related to developmental hematopoiesis. Spanning from the thoracic to the abdominal segment of the larvae, this organ comprises a pair of primary, secondary, and tertiary lobes. Much of our understanding arises from the studies on the primary lobe, while the secondary and tertiary lobes have remained mostly unexplored. Previous studies have inferred that these lobes are composed of progenitors that differentiate during pupation; however, the mechanistic basis of this extended progenitor state remains unclear. This study shows that posterior lobe progenitors are maintained by a local signaling center defined by Ubx and Collier in the tertiary lobe. This Ubx zone in the tertiary lobe shares several markers with the niche of the primary lobe. Ubx domain regulates the homeostasis of the posterior lobe progenitors in normal development and an immune-challenged scenario. Our study establishes the lymph gland as a model to tease out how the progenitors interface with the dual niches within an organ during development and disorders.

Unnecessity of Routine Dissection of Right Central Lymph Nodes in cN0 Papillary Thyroid Carcinoma Located at the Left Thyroid Lobe.

ObjectiveThe lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) is an important part of the central lymph nodes (LNs). We aimed to explore the rate and predictors of LN-prRLN metastasis in cN0 papillary thyroid carcinoma (PTC) located at the left thyroid lobe.MethodsPatients with surgically treated primary left lobe PTC were retrospectively enrolled. The metastatic distribution of LN-prRLN and postoperative complications were assessed. The association between LN-prRLN metastasis and clinicopathological variables was evaluated by univariate and multivariate analyses.ResultsA total of 857 patients were included for the analysis. Central LN metastasis was noted in 310 (35.3%) cases. The most (27.6%) and least (1.7%) commonly involved LNs were the left paratracheal LN and the LN-prRLN. In the univariate analysis, the tumor size, multifocality, the extent of extrathyroidal extension (none vs. macroscopic vs. macroscopic maximal), and perineural invasion were associated with positive LN-prRLN. In the multivariate analysis, tumor size of >40.0 mm and macroscopic maximal invasion were found as the only two independent predictors. Transient and permanent hypoparathyroidism were noted in 90 (10.2%) and 13 (1.5%) patients, respectively. Voice change was noted in 40 (4.6%) patients, and 20 patients recovered.ConclusionsIn cN0 PTC located at the left lobe, LN-prRLN metastasis was very uncommon. We found that LN-prRLN dissection is not required routinely, but should be performed if the tumor size is >40.0 mm and macroscopic maximal extrathyroidal extension is present.