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At least 91 records · Page 5

HP-LSP: A reference of land surface phenology from fused Harmonized Landsat and Sentinel-2 with PhenoCam data

Abstract Land surface phenology (LSP) products are currently of large uncertainties due to cloud contaminations and other impacts in temporal satellite observations and they have been poorly validated because of the lack of spatially comparable ground measurements. This study provided a reference dataset of gap-free time series and phenological dates by fusing the Harmonized Landsat 8 and Sentinel-2 (HLS) observations with near-surface PhenoCam time series for 78 regions of 10 × 10 km 2 across ecosystems in North America during 2019 and 2020. The HLS-PhenoCam LSP (HP-LSP) reference dataset at 30 m pixels is composed of: (1) 3-day synthetic gap-free EVI2 (two-band Enhanced Vegetation Index) time series that are physically meaningful to monitor the vegetation development across heterogeneous levels, train models (e.g., machine learning) for land surface mapping, and extract phenometrics from various methods; and (2) four key phenological dates (accuracy ≤5 days) that are spatially continuous and scalable, which are applicable to validate various satellite-based phenology products (e.g., global MODIS/VIIRS LSP), develop phenological models, and analyze climate impacts on terrestrial ecosystems.

Science & Technology - Other Topics↗

The first experience of using {sup 99m}Tc-Al{sub 2}O{sub 3}-based radiopharmaceutical for the detection of sentinel lymph nodes in cervical cancer patients

The purpose of the study was to evaluate the feasibility of using {sup 99m}Tc-Al{sub 2}O{sub 3}-based radiopharmaceutical, a novel molecular imaging agent for sentinel lymph node detection in patients with invasive cervical cancer. The study included 23 cervical cancer patients (T1aNxMx-T2bNxMx) treated at the Tomsk Cancer Research Institute. In the 18 hours before surgery, 80 MBq of the {sup 99m}Tc-Al{sub 2}O{sub 3} in peritumoral injected, followed by single-photon emission computed tomography (SPECT) of the pelvis and intraoperative SLN identification. Twenty-seven SLNs were detected by SPECT, and 34 SLNs were identified by intraoperative gamma probe. The total number of identified SLNs per patient ranged from 1 to 3 (the mean number of SLNs was 1.4 per patient). The most common site for SLN detection was the external iliac region (57.2%), followed by the internal iliac (14%), obturator (14%), presacral and retrosacral regions (14%), and the parametrial region (1%). Sensitivity in detecting SLNs was 100% for intraoperative SLN identification and 79% for SPECT image.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Management of Sentinel Lymph Node Metastasis in Merkel Cell Carcinoma: Completion Lymphadenectomy, Radiation, or Both?

Background: Approximately 30% of patients with clinically localized Merkel cell carcinoma (MCC) show nodal involvement on sentinel lymph node biopsy (SLNB). Optimal management of SLNB-positive disease has not been defined. This study compared outcomes after completion lymphadenectomy (CLND), radiation, and combined CLND plus radiation after a positive SLNB. Methods: All patients treated at a single institution for SLNB-positive MCC (1998–2015) were retrospectively evaluated, with examination of patient demographics, clinicopathologic characteristics, outcomes, and regional toxicity. Results: The study identified 71 evaluable patients with SLNB-positive disease. The median age of these patients was 76 years, and 76.1% were men. Of the 71 patients, 11 (15.5%) underwent CLND, 40 (56.3%) received radiation, and 20 (28.2%) underwent CLND plus postoperative radiation. Lymphovascular invasion was significantly more common in the radiation-alone cohort (p = 0.04). For the three cohorts, the median percentages of nodal involvement were respectively 2, 10, and 30% (p = 0.06). After a median follow-up period of 22.3 months, four patients had recurrence in their regional nodal basin (3 radiation-alone patients and 1 CLND + radiation patient). The three cohorts did not differ significantly in the development of distant metastases (p = 0.68) or overall survival (p = 0.72). Six patients experienced surgical-site infections (2 CLND and 4 CLND + radiation patients), and three patients experienced symptomatic lymphedema (1 CLND patient and 2 CLND + radiation patients). Conclusions: Regional failure was infrequent (≤ 10%) regardless of treatment, and morbidity appeared to be low with all approaches. Given that multiple treatment approaches can be successful in treating micrometastatic MCC, future efforts should be directed at refining criteria for allocating patients to a specific method, or possibly no further nodal basin treatment, in an effort to maximize regional control at the lowest cost and morbidity.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Completion Lymph Node Dissection or Radiation Therapy for Sentinel Node Metastasis in Merkel Cell Carcinoma

Background: For sentinel lymph node (SLN) metastasis from Merkel cell carcinoma (MCC), the benefit of completion lymph node dissection (CLND) versus radiation therapy (RT) is unclear. This study compares outcomes for patients with SLN metastasis undergoing CLND or RT. We also evaluated positive non-SLNs as a prognostic factor. Methods: Using a prospective database, we identified MCC patients with SLN metastasis who underwent CLND or RT. At our institution, CLND was recommended for patients with acceptable perioperative risk, while therapeutic RT was offered to those with high perioperative risk. Primary outcomes were MCC-specific survival (MCCSS), disease-free survival (DFS), nodal recurrence-free survival (NRFS), and distant recurrence-free survival (DRFS). Results: From 2006 to 2017, 163 patients underwent CLND (n = 137) or RT (n = 26). Median follow-up was 1.9 years. CLND had no significant differences for MCCSS (5-year survival 71% vs. 64%, p = 1.0), DFS (52% vs. 61%, p = 0.8), NRFS (76% vs. 91%, p = 0.3), or DRFS (65% vs. 75%, p = 0.3) compared with RT. Patients with positive non-SLNs (n = 44) had significantly worse MCCSS (5-year survival 39% vs. 87%, p < 0.001), DFS (35% vs. 60%, p = 0.005), and DRFS (54% vs. 71%, p = 0.03) compared with negative non-SLNs (n = 93). Multivariate analysis showed positive non-SLNs were independently associated with MCCSS, DFS, and DRFS. Conclusions: CLND and RT may have similar outcomes for MCC patients with SLN metastasis when treatment aligns with our institutional practices. For patients undergoing CLND, positive non-SLNs is an important prognostic factor associated with poor survival and distant recurrence. This high-risk group should be considered for adjuvant systemic therapy trials.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Long-Term Outcome After Retro-Areolar Versus Peri-Tumoral Injection of Superparamagnetic Iron Oxide Nanoparticles (SPIO) for Sentinel Lymph Node Detection in Breast Cancer Surgery

Background/Objective: SPIO is effective in sentinel node (SN) detection. No nuclear medicine department is needed, and no allergic reactions have occurred. This study aimed to compare retro-areolar and peri-tumoral SPIO injections regarding skin staining, detection rates and number of SNs. Methods: Data on staining size, intensity and cosmetic outcome (0–5; 0 = no problem) were collected by telephone interviews with 258 women undergoing breast conservation. SN detection and the number of SNs were prospectively registered in 332 women. Results: After retro-areolar and peri-tumoral injections, 67.3% and 37.8% (p < 0.001) developed skin staining, with remaining staining in 46.2 vs. 9.4% after 36 months (p < 0.001). Initial mean size was 16.3 vs. 6.8 cm (p < 0.001) and after 36 months, 6.6 vs. 1.8 cm{sup 2} (p < 0.001). At 75.1% of 738 interviews, staining was reported paler. After retro-areolar injections, cosmetic outcome scored worse for 2 years. The mean (median) scores were 1.3(0) vs. 0.5(0) points, and 0.2(0) vs. 0.1(0) points, at 12 and 36 months, respectively. Overall detection rates were 98.3% and 97.4% (p = 0.43) and the number of SNs 1.35 vs. 1.57 (p = 0.02) after retro-areolar and peri-tumoral injections. Injection, regardless of type, 1–27 days before surgery increased detection rates with SPIO, 98.0% vs. 94.2% (p = 0.06) ,and SN numbers, 1.56 vs. 1.27 (p = 0.003). Conclusion: SPIO is effective and facilitates planning for surgery. Peri-tumoral injection reduced staining with a similar detection rate. Staining was not considered a cosmetic problem among most women. Injecting SPIO 1–27 days before surgery increased the detection rate by 3.8% and increased the number of SNs by 0.3.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

The Sentinel Lymph Node Biopsy Using Indocyanine Green Fluorescence Plus Radioisotope Method Compared With the Radioisotope-Only Method for Breast Cancer Patients After Neoadjuvant Chemotherapy: A Prospective, Randomized, Open-Label, Single-Center Phase 2 Trial

Background: This study aimed to compare the sentinel lymph node (SLN) identification rates for breast cancer patients after neoadjuvant chemotherapy (NAC) between the dual method (DM) of indocyanine green fluorescence (ICG-F) plus a radioisotope (RI) and RI alone. Methods: This randomized study enrolled 130 patients who received NAC for breast cancer and 122 patients who received SLN biopsy (SLNB) using either DM (n = 58) or RI only (n = 64). The study compared the identification rate, number of SLNs, and detection time of SLNB. Results: Among the 122 patients, 113 (92.6%) were clinically node-positive before NAC. The SLN identification rate was 98.3% in the DM group and 93.8% in the RI group (p = 0.14). The DM group and the RI group were similar in the average number of SLNs (2.2 ± 1.13 vs. 1.9 ± 1.33; p = 0.26) and the time to detection of the first SLN (8.7 ± 4.98 vs. 8.3 ± 4.31 min; p = 0.30). In the DM group, transcutaneous lymphatic drainage was visualized by fluorescence imaging for 65.5% (38 of 58) of the patients. The SLN identification rate was 94.7% using ICG-F and 93% using RI (p = 0.79). During and after the operation, no complications, including allergic reactions or skin necrosis, occurred. Conclusions: This study is the first randomized trial to use ICG-F for SLNB in breast cancer patients after NAC. The DM including ICG-F could be a feasible and safe method for SLNB in initially node-positive breast cancer patients with NAC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Risk of Positive Sentinel Lymph Node After Neoadjuvant Systemic Therapy in Clinically Node-Negative Breast Cancer: Implications for Postmastectomy Radiation Therapy and Immediate Breast Reconstruction

Background: Residual axillary lymph node involvement after neoadjuvant systemic therapy (NST) is the determining factor for postmastectomy radiation therapy (PMRT). Preoperative identification of patients needing PMRT is essential to enable shared decision-making when choosing the optimal timing of breast reconstruction. We determined the risk of positive sentinel lymph node (SLN) after NST in clinically node-negative (cN0) breast cancer. Methods: All cT1-3N0 patients treated with NST followed by mastectomy and SLNB between 2010 and 2016 were identified from the Netherlands Cancer Registry. Rate of positive SLN for different breast cancer subtypes was determined. Logistic regression analysis was performed to determine correlated clinicopathological variables with positive SLN. Results: In total 788 patients were included, of whom 25.0% (197/788) had positive SLN. cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+ , and cT1-2N0 triple-negative patients had the lowest rate of positive SLN: 7.2–11.5%, 0–6.3%, and 2.9–6.2%, respectively. cT1-3N0 ER+HER2− and cT3N0 triple-negative patients had the highest rate of positive SLN: 23.8–41.7% and 30.4%, respectively. Multivariable regression analysis showed that cT2 (odds ratio [OR] 1.93; 95% confidence interval [CI] 1.01–3.96), cT3 (OR 2.56; 95% CI 1.30–5.38), grade 3 (OR 0.44; 95% CI 0.21–0.91), and ER+HER2− subtype (OR 3.94; 95% CI 1.77–8.74) were correlated with positive SLN. Conclusions: In cT1-3N0 ER+HER2+, cT1-3N0 ER−HER2+, and cT1-2N0 triple-negative patients treated with NST, immediate reconstruction can be considered an acceptable option due to low risk of positive SLN. In cT1-3N0 ER+HER2− and cT3N0 triple-negative patients treated with NST, risks and benefits of immediate reconstruction should be discussed with patients due to the relatively high risk of positive SLN.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Novel use of flu surveillance data: Evaluating potential of sentinel populations for early detection of influenza outbreaks

Influenza causes significant morbidity and mortality each year, with 2–8% of weekly outpatient visits around the United States for influenza-like-illness (ILI) during the peak of the season. Effective use of existing flu surveillance data allows officials to understand and predict current flu outbreaks and can contribute to reductions in influenza morbidity and mortality. Previous work used the 2009–2010 influenza season to investigate the possibility of using existing military and civilian surveillance systems to improve early detection of flu outbreaks. Results suggested that civilian surveillance could help predict outbreak trajectory in local military installations. To further test that hypothesis, we compare pairs of civilian and military outbreaks in seven locations between 2000 and 2013. We find no predictive relationship between outbreak peaks or time series of paired outbreaks. This larger study does not find evidence to support the hypothesis that civilian data can be used as sentinel surveillance for military installations. We additionally investigate the effect of modifying the ILI case definition between the standard Department of Defense definition, a more specific definition proposed in literature, and confirmed Influenza A. We find that case definition heavily impacts results. In conclusion, this study thus highlights the importance of careful selection of case definition, and appropriate consideration of case definition in the interpretation of results.

59 BASIC BIOLOGICAL SCIENCES↗

WFIP3 Sentinel Buoy 3 / Raw Data

This dataset contains raw data collected by sentinel buoy 3 during the WFIP3 project period at the WFIP3 location. It was deployed from 3/14/2024 19:10Z to the present day, but stopped telemetering data on 4/17/2024 13:00Z.

17 WIND ENERGY↗

WFIP3 Sentinel Buoy 2 / Raw Data

This dataset contains raw data collected by sentinel buoy 2 during the WFIP3 project period at the WFIP3 location. It was deployed on 3/14/2024 15:35Z and is still currently deployed.

17 WIND ENERGY↗

WFIP3 Sentinel Buoy 4 / Raw Data

This dataset contains raw data collected by sentinel buoy 4 during the WFIP3 project period at the WFIP3 location. It was deployed on 3/14/2024 12:00Z and is still currently deployed.

17 WIND ENERGY↗

WFIP3 Sentinel Buoy 1 / Raw Data

This dataset contains processed data collected by sentinel buoy 1 during the WFIP3 project period at the WFIP3 location. It was deployed on 6/4/2024 16:35Z and is still currently deployed.

17 WIND ENERGY↗

WFIP3 Sentinel Buoy 1 / Raw Data

This dataset contains processed data collected by sentinel buoy 1 during the WFIP3 project period at the WFIP3 location. It was deployed on 6/4/2024 16:35Z and is still currently deployed.

17 WIND ENERGY↗

WFIP3 Sentinel Buoy 5 / Raw Data

This dataset contains raw data collected by sentinel buoy 5 during the WFIP3 project period at the WFIP3 location. It was deployed on 7/9/2024 12:15Z and is still currently deployed.

17 WIND ENERGY↗

Domestic Dogs as Sentinels for West Nile Virus but not Aedes -borne Flaviviruses, Mexico

We tested 294 domestic pet dogs in Mexico for neutralizing antibodies for mosquito-borne flaviviruses. We found high (42.6%) exposure to West Nile virus in Reynosa (northern Mexico) and low (1.2%) exposure in Tuxtla Gutierrez (southern Mexico) but very limited exposure to Aedes-borne flaviviruses. In conclusion, domestic dogs may be useful sentinels for West Nile virus.

59 BASIC BIOLOGICAL SCIENCES↗

Sentinel protist taxa of the McMurdo Dry Valley lakes, Antarctica: a review

High-latitude meromictic lakes such as those in the Antarctic McMurdo Dry Valleys (MDV) harbor aquatic ecosystems dominated by the microbial loop. Within this habitat, which is limited year-round by light and nutrients, protists, or single celled eukaryotes, play outsized roles in the food web as the dominant primary producers and the apex predators. Thus, the MDV lake ecosystem represents an ideal system to study the role of sentinel protist taxa in carbon and nutrient cycling. The perennially ice-covered lakes are part of the McMurdo Long Term Ecological Research (McM LTER; mcmlter.org) established in 1993. In this review we will highlight the diversity and trophic roles of the MDV lake protist community and compare environmental factors driving spatiotemporal patterns in key protist taxa in two lakes within the McM LTER, Lakes Bonney and Fryxell. We will then discuss lessons learned from manipulated experiments on the impact of current and future climate-driven environmental change on sensitive protist taxa. Last, we will integrate knowledge gained from 25 years of lab-controlled experiments on key photosynthetic protists to extend our understanding of the function of these extremophiles within the MDV aquatic food webs. Our research group has studied the distribution and function of the MDV microbial community for nearly two decades, training the next generation of scientists to tackle future problems of these globally significant microbes. This review article will also highlight early career scientists who have contributed to this body of work and represent the future of scientific understanding in the Anthropocene.

54 ENVIRONMENTAL SCIENCES↗