Vegetation biomass and topography are associated with seasonal habitat selection and fall translocation behavior in Arctic hares

Habitat selection theory suggests that environmental features selected at coarse scales reveal fundamental factors affecting animal fitness. When these factors vary across seasons, they may lead to large-scale movements, including long-distance seasonal migrations. We analyzed the seasonal habitat selection of 25 satellite-tracked Arctic hares from a population on Ellesmere Island (Nunavut, Canada) that relocated over 100 km in the fall. Since no other lagomorph is known to perform such extensive movements, this population offered an ideal setting to test animal movement and habitat selection theory. On summer grounds hares selected low elevation areas, while on winter grounds they selected high vegetation biomass, high elevation, and steep slopes. During fall relocation, they alternated between stopover and traveling behavioral states (ratio 2:1). Stopover locations were characterized by higher vegetation heterogeneity and lower rugosity than traveling locations, while vegetation biomass and elevation interacted to explain stopover locations in a more complex way. The selected combination of environmental features thus varied across seasons and behavioral states, in a way broadly consistent with predictions based on the changing food and safety needs of hares. Although causality was not demonstrated, our results improve our understanding of long-distance movements and habitat selection in Arctic hares, as well as herbivore ecology in the polar desert. Results also provide strong support to animal movement and habitat selection theory, by showing how some important hypotheses hold when tested in a species phylogenetically distinct from most animal models used in this research field.

The bioequivalence study design recommendations for immediate-release solid oral dosage forms in the international pharmaceutical regulators programme participating regulators and organisations: differences and commonalities

Bioequivalence (BE) studies are considered the standard for demonstrating that the performance of a generic drug product in the human body is sufficiently similar to that of its comparator product. The objective of this article is to describe the recommendations from participating Bioequivalence Working Group for Generics (BEWGG) members of the International Pharmaceutical Regulators Programme (IPRP) regarding the conduct and acceptance criteria for BE studies of immediate release solid oral dosage forms. A survey was conducted among BEWGG members regarding their BE recommendations and requirements related to study subjects, study design, sample size, single or multiple dose administration, study conditions (fasting or fed), analyte to be measured, selection of product strength, drug content, handling of endogenous substances, BE acceptance criteria, and additional design aspects. All members prefer conducting single dose cross-over designed studies in healthy subjects with a minimum of 12 subjects and utilizing the parent drug data to assess BE. However, differences emerged among the members when the drug's pharmacokinetics and pharmacodynamics become more complex, such that the study design (e.g., fasting versus fed conditions) and BE acceptance criteria (e.g., highly variable drugs, narrow therapeutic index drugs) may be affected. The survey results and discussions were shared with the ICH M13 Expert Working Group (EWG) and played an important role in identifying and analyzing gaps during the harmonization process. The draft ICH M13A guideline developed by the M13 EWG was endorsed by ICH on 20 December 2022, under Step 2.

Perception and Utilization of Cannabinoids in Patients Undergoing Radiation Treatment: Our Patients Are Curious

PURPOSE

Limited studies have described the utilization of cannabinoids among patients with cancer. This survey study aimed to characterize utilization patterns and perceptions of cannabinoid use for treatment-related side effects among patients receiving radiation treatment.

METHODS AND MATERIALS

This was an anonymous survey study of patients who were undergoing or recently completed radiation treatment at a comprehensive cancer center. Data on cannabinoid use during cancer treatment, reasons for the use of cannabinoids, perceived effects of cannabinoids, and formulations of usage were collected and summarized using descriptive statistics.

RESULTS

Of the 431 respondents, 111 (25.8%) patients reported cannabinoid use since their cancer diagnosis. Among the cannabinoid users, a majority (73.9%) experienced improvement in symptoms; 38.7% had better relief of cancer-treatment symptoms from cannabinoids in comparison to their prescription medications, and 16.2% lowered the amount of prescription pain medications needed after using cannabinoids. Cannabinoids appeared to be most effective in helping patients manage sleep (76.6%) and anxiety (72.1%). When asked about whether physicians should be discussing cannabinoid use, 45.1% of cannabinoid users wanted to speak with their doctors regarding its utilization. For patients who did not report cannabinoid use, a large majority (83.1%) never had discussions with their doctors regarding its utilization as part of their cancer care, and 34.8% wanted to learn more about cannabinoids from their doctors.

CONCLUSIONS

About 1 in 4 patients with cancer reported cannabinoid use to assist in symptom control. A majority had subjective alleviation of treatment-related symptoms from cannabinoid use. Regardless of cannabinoid use, a sizable percentage of patients never had any discussions about cannabinoids with their oncologists, with some expressing interest in learning more. Guidelines are needed to assist radiation oncologists on how cannabinoids may play a role in caring for patients.

Current Status and Future Directions of Image-Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer

PURPOSE

The standard of care for patients with locally advanced cervical cancer is definitive chemoradiation followed by a brachytherapy boost. This review describes the current status and future directions of image-guided adaptive brachytherapy for locally advanced cervical cancer.

METHODS

A systematic search of the PubMed and Clinicaltrials.gov databases was performed, focusing on studies published within the last 10 years. The search queried "cervical cancer [AND] image-guided brachytherapy [OR] magnetic resonance imaging (MRI) [OR] adaptive brachytherapy".

DISCUSSION

The retroEMBRACE and EMBRACE-I trials have established the use of MRI as the standard imaging modality for brachytherapy application and planning. Quantitative imaging and radiomics have the potential to improve outcomes, with three ongoing prospective studies examining the use of radiomics to further risk-stratify patients and personalize brachytherapy. Another active area of investigation includes utilizing the superior soft tissue contrast provided by MRI to increase the dose per fraction and decrease the number of fractions needed for brachytherapy, with several retrospective studies demonstrating the safety and feasibility of three-fraction courses. For developing countries with limited access to MRI, trans-rectal ultrasound (TRUS) appears to be an effective alternative, with several retrospective studies demonstrating improved target delineation with the use of TRUS in conjunction with CT guidance.

CONCLUSIONS

Further investigation is needed to continue improving outcomes for patients with locally advanced cervical cancer treated with image-guided brachytherapy.

Grade 5 Radiation Necrosis After Whole-Brain Radiation Therapy

Whole-brain radiation treatment is often considered for patients with leptomeningeal disease. There are limited reports of the development of radiation necrosis after whole-brain radiation treatment and fewer associating the presence of germline mutations with risk. We present a case report to highlight the need for consideration of radiosensitizing mutations when recommending radiation therapy.

Explainable Artificial Intelligence to Identify Dosimetric Predictors of Toxicity in Patients with Locally Advanced Non-Small Cell Lung Cancer: A Secondary Analysis of RTOG 0617

PURPOSE

Dosimetric predictors of toxicity in patients treated with definitive chemoradiation for locally advanced non-small cell lung cancer are often identified through trial and error. This study used machine learning (ML) and explainable artificial intelligence to empirically characterize dosimetric predictors of toxicity in patients treated as part of a prospective clinical trial.

METHODS AND MATERIALS

A secondary analysis of the Radiation Therapy Oncology Group (RTOG) 0617 trial was performed. Multiple ML models were trained to predict grade ≥3 pulmonary, cardiac, and esophageal toxicities using clinical and dosimetric features. Model performance was evaluated using the area under the curve (AUC). The best performing model for each toxicity was explained using the Shapley Additive Explanation (SHAP) framework; SHAP values were used to identify relevant dosimetric thresholds and were converted to odds ratios (ORs) with confidence intervals (CIs) generated using bootstrapping to obtain quantitative measures of risk. Thresholds were validated using logistic regression.

RESULTS

The best-performing models for pulmonary, cardiac, and esophageal toxicities, outperforming logistic regression, were extreme gradient boosting (AUC, 0.739), random forest (AUC, 0.706), and naive Bayes (AUC, 0.721), respectively. For pulmonary toxicity, thresholds of a mean dose >18 Gy (OR, 2.467; 95% CI, 1.049-5.800; P = .038) and lung volume receiving ≥20 Gy (V20) > 37% (OR, 2.722; 95% CI, 1.034-7.163; P = .043) were identified. For esophageal toxicity, thresholds of a mean dose >34 Gy (OR, 4.006; 95% CI, 2.183-7.354; P < .001) and V20 > 37% (OR, 3.725; 95% CI, 1.308-10.603; P = .014) were identified. No significant thresholds were identified for cardiac toxicity.

CONCLUSIONS

In this data set, ML approaches validated known dosimetric thresholds and outperformed logistic regression at predicting toxicity. Furthermore, using explainable artificial intelligence, clinically useful dosimetric thresholds might be identified and subsequently externally validated.

Moving the Needle Forward in Genomically-Guided Precision Radiation Treatment

Radiation treatment (RT) is a mainstay treatment for many types of cancer. Recommendations for RT and the radiation plan are individualized to each patient, taking into consideration the patient's tumor pathology, staging, anatomy, and other clinical characteristics. Information on germline mutations and somatic tumor mutations is at present rarely used to guide specific clinical decisions in RT. Many genes, such as ATM, and BRCA1/2, have been identified in the laboratory to confer radiation sensitivity. However, our understanding of the clinical significance of mutations in these genes remains limited and, as individual mutations in such genes can be rare, their impact on tumor response and toxicity remains unclear. Current guidelines, including those from the National Comprehensive Cancer Network (NCCN), provide limited guidance on how genetic results should be integrated into RT recommendations. With an increasing understanding of the molecular underpinning of radiation response, genomically-guided RT can inform decisions surrounding RT dose, volume, concurrent therapies, and even omission to further improve oncologic outcomes and reduce risks of toxicities. Here, we review existing evidence from laboratory, pre-clinical, and clinical studies with regard to how genetic alterations may affect radiosensitivity. We also summarize recent data from clinical trials and explore potential future directions to utilize genetic data to support clinical decision-making in developing a pathway toward personalized RT.

Evaluation of a Deep-Learning Auto-Segmentation Model of Cardiac Substructures

PURPOSE/OBJECTIVE(S)

Increasing evidence has suggested that limiting dose not only to the whole heart but also to cardiac substructures can potentially reduce cardiac toxicities. Manual contouring of cardiac substructure can be challenging and time-consuming. To address this concern, we developed a deep learning (DL) model, trained on convolutional neural network algorithms in large external datasets, for auto-segmentation of cardiac substructures. This study aimed to evaluate the quality of the cardiac substructure contours generated by the DL algorithm.

MATERIALS/METHODS

We identified 28 patients with esophagus or gastroesophageal junction cancer from a single institution who received radiation to the esophagus between January 2017 and December 2022. For each case, the DL-generated cardiac substructures (4 heart chambers - left/right atrium [L/RA] and L/R ventricle [L/RV], 4 coronary arteries - L common [LCA], L anterior descending [LAD], L circumflex [LCx], and R common [RCA], and great vessels - ascending aorta [AA], pulmonary artery [PA], and superior vena cava [SVC]) were modified by two radiation oncologists (RO) using the contouring atlas developed by Duane et al. Spatial overlapping of the contours were then assessed using the Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (HD-95), and normalized surface dice at 2 mm tolerance (NSD-2).

RESULTS

The mean values of DSC, HD-95, and NSD-2 are shown in Table 1. Overall, the mean DSC, HD-95, and NSD-2 for the heart chambers ranged from 0.82 to 0.92, 0.40 cm to 1.52 cm, and 0.68 to 0.85, respectively. Ranges of the mean DSC, HD-95, and NSD-2 for the coronary vessels were 0.41 to 0.74, 0.18 cm to 0.98 cm, and 0.66 to 0.77, respectively. Lastly, comparison of the great vessel contours yielded the following ranges for mean DSC, HD-95, and NSD-2 respectively: 0.72 to 0.92, 0.30 cm to 1.64 cm, and 0.65 to 0.83.

CONCLUSION

Our study demonstrates that auto-segmentation of cardiac substructures by DL-powered models can be comparable to manual contours for certain cardiac substructures, namely the four heart chambers and great vessels. Further improvement of the DL on contouring of coronary vessels would be needed prior to the autosegmentation model being widely adopted.

Patient and Caregivers Opinions on Receiving Radiology Results before Oncologist Appointments

PURPOSE/OBJECTIVE(S)

With the passing of the Cures Act, patients now have immediate access to radiology reports and can review the results before discussing the findings with a physician. In Oncology, the results of these imaging reports can be especially sensitive as the results can lead to difficult discussions about patient prognosis, or the need for invasive medical, surgical, or radiation therapies. It is unclear whether immediate access may increase anxiety, stress, and confusion before discussions with an oncologist. In this study, we hypothesized that in the oncology setting, immediate access to imaging reports before meeting with their oncologist would be associated with worsened patient anxiety.

MATERIALS/METHODS

Patients and their caregivers were invited to complete an investigator-developed anonymous multiple-choice survey prior to a scheduled follow-up appointment with their radiation oncologist. Survey questions assessed preferences for reviewing the radiology report prior to their oncology visit, their reported level of anxiety before undergoing diagnostic imaging, after directly receiving their results, and after they have the discussion of their results with the oncologist. Additional metrics collected included patient demographics, the time interval between discussing the results with an oncologist, preference for reviewing the images or just the radiology report, satisfaction with having immediate access to the report, and if they would prefer being blinded from the results until after discussing with their oncologist. Survey items were scored descriptively through summary statistics.

RESULTS

In this interim report of 54 individuals surveyed over a two-week period (89% were patients, 11% were caregivers/family members), a combined 33% reported a high level of anxiety before undergoing their scan. Levels of high anxiety decreased to 20% for those who received their report prior to reviewing with their oncologist and further lowered to 13% after reviewing the report and images with their oncologist. 57% of responders reported discussing the results with an oncologist within 2 days of receiving results. 46% preferred reviewing only radiology reports and not the images, 35% favored reviewing both imaging and the report together and 19% had no preference. Only 18.5% of responders preferred viewing the reports before discussing them with their oncologist and only 20% felt it was beneficial having early access to them.

CONCLUSION

Anxiety associated with oncology-related imaging improved after immediate access to the report and after discussions with oncologists. A small proportion of patients preferred having early access to imaging reports and most patients preferred reviewing only the report, not the images. Strategies including shortened intervals between immediate access and discussions with oncologists may minimize anxiety associated with imaging as most patients preferred first discussing the results with their oncologist.

Incidence of Major Depression, Suicidal Ideation, and Mental Health Treatment Amongst Cancer Survivors

PURPOSE/OBJECTIVE(S)

Receiving a cancer diagnosis and undergoing subsequent treatments can result in a significant psychological burden for cancer patients. However, there is conflicting literature on the incidence of major depression in cancer patients compared to patients without cancer. The purpose of this study was to investigate and further clarify the incidence of major depression, associated treatments, and suicidal ideation in cancer survivors compared to a non-cancer cohort.

MATERIALS/METHODS

This is a retrospective, population-based study using survey responses from the National Survey on Drug Use and Health collected from January 2015 to December 2019. Survey data sets were queried for all respondents aged 18 years or older who provided a cancer history. Patients with a reported history of cancer ("cancer survivors") were further stratified by whether they reported a "recent" cancer diagnosis within the past 12 months. Survey responses were then evaluated for recent diagnoses of and treatments for major depressive disorder and suicidal ideation. Rates were compared between cancer survivors and participants without cancer using the Pearson χ2 test and multivariable logistic regression models, respectively.

RESULTS

Among the 212,411 survey respondents identified, 7,635 (3.6%) reported a cancer history, with 1,486 (0.7%) reporting a recent cancer history. The incidence of major depression was not different between cancer survivors and participants without cancer (9.3% vs. 9.2%; p = 0.762), though the incidence was slightly higher amongst recent cancer survivors (10.0% vs. 9.2%; p = 0.259). Among patients diagnosed with major depression, cancer survivors were significantly more likely to receive treatment for depression (78.6% vs. 60.3%, p<0.001), with 72.6% discussing depressive symptoms with a medical professional and 64.3% receiving prescription medication. Suicidal ideation was significantly lower among cancer survivors (5.1% vs. 6.2%, p<0.001) including recent survivors (5.0% vs. 6.2%, p<0.001). Suicidal ideation was higher in patients with underlying major depression in both cancer survivors and participants without cancer (30.6% vs. 35.6%, p = 0.015). On logistic regression, respondents with underlying depression receiving treatment were more likely to have suicidal ideation (OR: 1.49; p<0.001) while having a cancer diagnosis did not correlate with suicidal ideation (OR: 0.87; p = 0.869).

CONCLUSION

There was no significant overall difference in the incidences of major depression between cancer survivors and patients without cancer. However, one consideration is the under-diagnosis depression among cancer survivors. Symptoms of depression may be overlooked and mistakenly attributed to appropriate grief from a cancer diagnosis. Among patients diagnosed with major depression, cancer survivors were more likely to receive treatment for depression. These results highlight the importance of early depression assessment and treatment for cancer survivors.

Born in the cold: contrasted thermal exchanges and maintenance costs in juvenile and adult snow buntings on their breeding and wintering grounds

Several species of passerines leave their nest with unfinished feather growth, resulting in lower feather insulation and increased thermoregulatory demands compared to adults. However, feather insulation is essential for avian species breeding at northern latitudes, where cold conditions or even snowstorms can occur during the breeding season. In altricial arctic species, increased heat loss caused by poor feather insulation during growth could be counter-adaptative as it creates additional energy demands for thermoregulation. Using flow-through respirometry, we compared resting metabolic rate at thermoneutrality (RMRt), summit metabolic rate (Msum) and heat loss (conductance) in adult and juvenile snow buntings on their summer and winter grounds. In summer, when buntings are in the Arctic, juveniles had a 12% higher RMRt, likely due to unfinished growth, and lost 14% more heat to the environment than adults. This pattern may result from juveniles fledging early to avoid predation at the cost of lower feather insulation. Surprisingly, an opposite pattern was observed at lower latitudes on their wintering grounds. Although they showed no difference in RMRt and Msum, adults were losing 12% more heat than juveniles. We suggest that this difference is due to poorer insulative property of plumage in adults stemming from energetic and time constraints encountered during their post-breeding molt. High plumage insulation in first-winter juvenile buntings could be adaptive to reduce thermoregulatory demands and maximize survival in the first winter of life, while adults could use behavioral strategies to compensate for their greater rate of heat loss.

Dosimetric Evaluation of Cardiac Substructures in Irradiation of Esophagus

PURPOSE/OBJECTIVE(S)

Due to the anatomic proximity of the heart, cardiac toxicity is a major concern in radiation treatment (RT) of esophageal cancer. Historically, the entire heart is considered an organ at risk. However, more recent studies have demonstrated that dose to cardiac substructures may better predict cardiac toxicities. We retrospectively reviewed patients (pts) who had RT to the distal esophagus and evaluated the dose-volume constraints (DVCs) of the cardiac substructures and the whole heart. We hypothesized that the majority of the treatment plans would not meet the DVCs to cardiac substructures noted in the current literature, albeit meeting commonly accepted whole heart DVCs.

MATERIALS/METHODS

We identified 27 pts with esophagus or gastroesophageal junction cancer who received RT to the esophagus between January 2017 and December 2022. For each case, the cardiac substructures (4 heart chambers - left/right atrium [L/RA] and left/right ventricle [L/RV], 4 coronary arteries - left common [LCA], left anterior descending [LAD], left circumflex [LCx], and right common [RCA], and great vessels - ascending and descending aorta [A/DA], pulmonary artery [PA], and superior vena cava [SVC]) were contoured based on the contouring atlas developed by Duane et al. DVCs based on existing literature for the whole heart and each cardiac substructure were reviewed and retrospectively analyzed for each treatment plan (Table 1).

RESULTS

Eighteen (66.7%) pts received 50 Gy/25 fractions, and nine (33.3%) pts received 50.4 Gy/28 fractions. The dose-volume constraints for the whole heart and each cardiac substructure are shown in Table 1. When considering the heart as a whole organ, all the treatment plans met the V45 and V40 objectives, with a mean V45 of 7.1% and V40 of 10.8%. All the cases also met the constraints for RV and PA. However, none of the cases met the DVCs for RA or LV. Only 6 (22.2%) of cases met the constraint for LCx or AA.

CONCLUSION

We found that despite all the treatment plans meeting the whole heart V45 and V40 constraints, none of the cases met the dose constraints to all cardiac substructures. This suggests that dosimetric evaluation of the whole heart alone may not be sufficient in minimizing cardiac toxicities from RT, and thus further supports the importance of defining the cardiac substructures. Future studies will be needed to standardize the dose constraints to these substructures to ensure patient safety.

Synergistic Effect of TVEC and Radiotherapy in the Treatment of Advanced Melanoma

PURPOSE/OBJECTIVE(S)

Talimogene laherparepvec (TVEC) is a genetically modified herpes simplex virus (HSV-1) that has been approved by the US Food and Drug Administration (FDA) for intralesional treatment of melanoma. Recent reports have suggested that radiation treatment (RT) given in conjunction with TVEC, may provide synergistic immune enhancement at the site, and possibly systemically. However, the studies on combining RT with TVEC remain limited. Our study compares melanoma patients (pts) who received TVEC and RT in the same region of the body with pts whose RT field did not include the site of TVEC injection. We hypothesized that RT and TVEC to the same site would induce a more robust local tumor response, and possibly a systemic response, with improvement in clinical outcomes over those pts who had treatments in different regions.

MATERIALS/METHODS

This was a retrospective review of 20 melanoma pts from a single cancer center who were treated with TVEC and RT between January 2015 and September 2022. Overall survival (OS), progression-free survival (PFS), time to distant metastasis (DM), and time to locoregional recurrence (LRR) were compared using Kaplan-Meier analysis and the corresponding log-rank test. Skin toxicity was also tabulated.

RESULTS

Fourteen pts (stage III [71.4%]; stage IV [28.6%]) received TVEC and RT in the same region (left leg [5], right leg [5], back [1], left arm [1], and right arm [1], and scalp [1]), and six (stage III [66.7%]; stage IV [33.3%]) received treatments in separate regions. The overall median follow-up was 10.5 months (mos) (range 1.0 - 58.7 mos). The OS of pts who had TVEC and RT in the same region was 19.0 mos (95% confidence interval [CI], 4.1 - not reached [NR] mos), compared to 18.5 mos for those receiving RT in a different region (95% CI, 1.0 - NR mos) (p = 0.366). PFS with TVEC and RT in the same and different regions were 6.4 mos (95% CI, 2.4 - NR mos) and 2.8 mos (95% CI, 0.7 - 4.4 mos) respectively (p = 0.005). DM was 13.8 mos (95% CI, 4.6 - NR mos) with TVEC and RT in the same field and 2.8 mos (95% CI, 0.7 - 4.4 mos) in different fields (p = 0.001). Lastly, LRR of pts who had TVEC and RT in the same region was 26.0 mos (95% CI, 6.4 - 26.0 mos) compared to 4.4 mos in different regions (95% CI, 0.7 - NR mos) (p = 0.115). No grade 3 or higher skin toxicities were documented among pts who had TVEC and RT in the same region.

CONCLUSION

Comparing pts who had TVEC and RT to different regions of the body, there was an association with improvements in PFS and DM when both modalities were delivered to the same region of the body. However, we did not find a significant difference in locoregional recurrence or OS. Given some promise with the combined approach and potential immune enhancement from RT, larger trials are needed to better understand the potential positive signal from our study.

The Emerging Role of Radiotherapy in Oligoprogressive Non-Small Cell Lung Cancer

Oligoprogressive disease (OPD) is an emerging concept that describes patients who have progression of disease in a limited number of metastatic sites while on systemic therapy. Growing evidence has suggested the integration of local ablative therapy with systemic agents in patients with OPD further improves survival. In oligoprogressive non-small cell lung cancer, stereotactic body radiotherapy may have an important role in the effective local control of selective progressing metastases, which may translate to better patient outcomes. This review explores the treatment paradigm of this subset of patients and provides an update on the current existing literature on this topic.

Implications of updated staging system for p16+ oropharyngeal squamous cell carcinoma: Is valuable prognostic information being omitted?

BACKGROUND

This study characterized whether the updated AJCC 8th edition nodal staging system for p16+ oropharyngeal squamous cell carcinoma (OPSCC) resulted in the loss of prognostic value.

METHODS

The NCDB was queried for patients with node-positive p16+ OPSCC. The prognostic impact of nodal size, nodal quantity, nodal laterality, and extracapsular extension (ECE) on overall survival (OS) was assessed.

RESULTS

In the clinical cohort, inferior 5-year OS was observed in patients with more than one positive lymph node (p < 0.001; 82% vs. 86%), ECE (p < 0.001; 82% vs. 75%), or nodal size >6 cm (p < 0.001; 66% vs. 82%). In the pathologic cohort, inferior 5-year OS was observed in patients with > four positive lymph nodes (p < 0.001; 76% vs. 90%), ECE (p < 0.001; 83% vs. 92%), or largest nodal size >6 cm (p < 0.001; 81% vs. 89%).

CONCLUSIONS

Simplifications in the current p16+ OPSCC staging system led to loss of prognostic information in nodal staging.

Current landscape of radiation oncology in esophageal cancer: a narrative review

Background and Objective

Esophageal cancer is an aggressive disease that is the sixth leading cause of cancer-related death worldwide. The overall treatment paradigm for esophageal cancer has changed considerably over the past decade. This narrative review aims to summarize the current landscape of radiation oncology for esophageal cancer.

Methods

A systematic search of the MEDLINE/PubMed database and Clinicaltrials.gov was performed, focusing on studies published within the last 10 years. Our search queried "esophageal cancer [AND] neoadjuvant radiation" as well as "locally advanced esophageal cancer [AND] definitive radiation". Our search resulted in 298 total references. These were manually reviewed, and only 58 references were within our scope of interest ranging from 2012-2022.

Key Content and Findings

For resectable esophageal cancer, neoadjuvant chemoradiation followed by surgery has been defined as the standard of care over the past decade. In patients with incomplete response to neoadjuvant chemoradiation, the benefit of immunotherapy in the adjuvant setting has recently been established. Ongoing studies are examining whether perioperative chemotherapy may be equivalent to neoadjuvant chemoradiation in resectable esophageal adenocarcinoma. For locally advanced esophageal cancer, recent studies have failed to show a benefit with radiation dose escalation in an unselected population, although the use of early positron emission tomography (PET) response to guide dose escalation is currently being studied. Other ongoing studies aiming to improve outcomes in locally advanced esophageal cancer involve using proton beam therapy to reduce toxicity and combining immunotherapy or targeted therapies with chemoradiation to amplify response.

Conclusions

Recent advances in radiation oncology may continue to improve outcomes for patients with esophageal cancer.

A Survey of the Criteria Used for the Selection of Alternative Comparator Products by Participating Regulators and Organizations of the International Pharmaceutical Regulators Programme

The safety and efficacy of a generic product are partly based on demonstrating bioequivalence to the innovator product; however, when the innovator product is no longer available as a comparator product, a survey conducted within the Bioequivalence Working Group for Generics (BEWGG) of the International Pharmaceutical Regulators Programme (IPRP) indicated that the criteria for selecting an alternative comparator product varies. For most members of the BEWGG, an existing marketed generic that was approved based on a comparison with the locally registered innovator product can be used, contingent on criteria that ranges from allowing any generic to be used, to allowing only specific criteria-defined generics to be used. Notwithstanding the acceptability of a generic as an alternative comparator, it is not always the preferred comparator for several jurisdictions. Some jurisdictions require the use of a locally sourced alternative innovator comparator (e.g., the same medicinal ingredient manufactured by a different company) or a foreign innovator comparator. Unlike the other members of the BEWGG, the European Union (EU) has no such options available, rather mechanisms are in place to allow manufacturers to develop a new comparator. The criteria described herein regarding the use of an alternative comparator product can also be applied to scenarios where a specific strength of a series of strengths or an innovative fixed dose combination are discontinued. The results of the survey demonstrate that while criteria for selecting alternative comparator products are not harmonized among the BEWGG participants, the common concern for all jurisdictions is to select a comparator product that meets the safety and efficacy standards of the original innovator product.

Utilization of model-agnostic explainable artificial intelligence frameworks in oncology: a narrative review

Background and Objective

Machine learning (ML) models are increasingly being utilized in oncology research for use in the clinic. However, while more complicated models may provide improvements in predictive or prognostic power, a hurdle to their adoption are limits of model interpretability, wherein the inner workings can be perceived as a "black box". Explainable artificial intelligence (XAI) frameworks including Local Interpretable Model-agnostic Explanations (LIME) and SHapley Additive exPlanations (SHAP) are novel, model-agnostic approaches that aim to provide insight into the inner workings of the "black box" by producing quantitative visualizations of how model predictions are calculated. In doing so, XAI can transform complicated ML models into easily understandable charts and interpretable sets of rules, which can give providers with an intuitive understanding of the knowledge generated, thus facilitating the deployment of such models in routine clinical workflows.

Methods

We performed a comprehensive, non-systematic review of the latest literature to define use cases of model-agnostic XAI frameworks in oncologic research. The examined database was PubMed/MEDLINE. The last search was run on May 1, 2022.

Key Content and Findings

In this review, we identified several fields in oncology research where ML models and XAI were utilized to improve interpretability, including prognostication, diagnosis, radiomics, pathology, treatment selection, radiation treatment workflows, and epidemiology. Within these fields, XAI facilitates determination of feature importance in the overall model, visualization of relationships and/or interactions, evaluation of how individual predictions are produced, feature selection, identification of prognostic and/or predictive thresholds, and overall confidence in the models, among other benefits. These examples provide a basis for future work to expand on, which can facilitate adoption in the clinic when the complexity of such modeling would otherwise be prohibitive.

Conclusions

Model-agnostic XAI frameworks offer an intuitive and effective means of describing oncology ML models, with applications including prognostication and determination of optimal treatment regimens. Using such frameworks presents an opportunity to improve understanding of ML models, which is a critical step to their adoption in the clinic.

Warming in the land of the midnight sun: breeding birds may suffer greater heat stress at high- versus low-Arctic sites

Rising global temperatures are expected to increase reproductive costs for wildlife as greater thermoregulatory demands interfere with reproductive activities. However, predicting the temperatures at which reproductive performance is negatively impacted remains a significant hurdle. Using a thermoregulatory polygon approach, we derived a reproductive threshold temperature for an Arctic songbird-the snow bunting (Plectrophenax nivalis). We defined this threshold as the temperature at which individuals must reduce activity to suboptimal levels (i.e. less than four-time basal metabolic rate) to sustain nestling provisioning and avoid overheating. We then compared this threshold to operative temperatures recorded at high (82° N) and low (64° N) Arctic sites to estimate how heat constraints translate into site-specific impacts on sustained activity level. We predict buntings would become behaviourally constrained at operative temperatures above 11.7°C, whereupon they must reduce provisioning rates to avoid overheating. Low-Arctic sites had larger fluctuations in solar radiation, consistently producing daily periods when operative temperatures exceeded 11.7°C. However, high-latitude birds faced entire, consecutive days when parents would be unable to sustain required provisioning rates. These data indicate that Arctic warming is probably already disrupting the breeding performance of cold-specialist birds and suggests counterintuitive and severe negative impacts of warming at higher latitude breeding locations.

780 Are E-Scooters Safe for Widespread Public Use? A Case Series Examining Severe Facial Injuries Secondary to E-Scooter Accidents

E-scooter use is becoming commonplace across the UK as an increasing number of towns and cities launch trials with pay-as-you-go e-scooter companies. In addition, e-scooters are cheap method of transport, easily available for an individual to purchase online, without restriction. We present two cases of patients having suffered complex facial injuries secondary to e-scooter accidents.

The first is a 38-year-old male, who was thrown from an e-scooter and had associated loss of consciousness. CT facial bones demonstrated extensive fractures to the bilateral maxillary and frontal sinuses, nasal bones, bilateral orbital floors, and mandible. The Le Fort II and mandibular fractures were fixed in two procedures. The patient has ongoing neuropathic pain around the right mandibular condyle and is receiving input from orthognathic specialists.

The second patient is a 60-year-old male, who collided with the rear of a car and was thrown forward, hitting his face on the tarmac. CT facial bones showed a Le Fort II fracture pattern and a fractured left inferior orbital rim, with extensive surgical emphysema of the face. He underwent plating of the bilateral Le Fort II fractures and application of intermaxillary fixation wires.

With little to no enforcement of personal protective equipment use and safety advice whilst utilising e-scooter services, the number of people suffering serious injuries from using such equipment is set to skyrocket. Increased awareness and education around the danger of e-scooters needs to be addressed and should be prioritised by local authorities and public health services.

Lipid nanoparticle formulations for optimal RNA-based topical delivery to murine airways

INTRODUCTION

Lipid nanoparticles (LNP) have been successfully used as a platform technology for delivering nucleic acids to the liver. To broaden the application of LNPs in targeting non-hepatic tissues, we developed LNP-based RNA therapies (siRNA or mRNA) for the respiratory tract. Such optimized LNP systems could offer an early treatment strategy for viral respiratory tract infections such as COVID-19.

METHODS

We generated a small library of six LNP formulations with varying helper lipid compositions and characterized their hydrodynamic diameter, size distribution and cargo entrapment properties. Next, we screened these LNP formulations for particle uptake and evaluated their potential for transfecting mRNA encoding green fluorescence protein (GFP) or SARS-CoV2 nucleocapsid-GFP fusion reporter gene in a human airway epithelial cell line in vitro. Following LNP-siGFP delivery, GFP protein knockdown efficiency was assessed by flow cytometry to determine %GFP+ cells and median fluorescence intensity (MFI) for GFP. Finally, lead LNP candidates were validated in Friend leukemia virus B (FVB) male mice via intranasal delivery of an mRNA encoding luciferase, using in vivo bioluminescence imaging.

RESULTS

Dynamic light scattering revealed that all LNP formulations contained particles with an average diameter of <100 nm and a polydispersity index of <0.2. Human airway epithelial cell lines in culture internalized LNPs with differential GFP transfection efficiencies (73-97%). The lead formulation LNP6 entrapping GFP or Nuc-GFP mRNA demonstrated the highest transfection efficiency (97%). Administration of LNP-GFP siRNA resulted in a significant reduction of GFP protein expression. For in vivo studies, intranasal delivery of LNPs containing helper lipids (DSPC, DOPC, ESM or DOPS) with luciferase mRNA showed significant increase in luminescence expression in nasal cavity and lungs by at least 10 times above baseline control.

CONCLUSION

LNP formulations enable the delivery of RNA payloads into human airway epithelial cells, and in the murine respiratory system; they can be delivered to nasal mucosa and lower respiratory tract via intranasal delivery. The composition of helper lipids in LNPs crucially modulates transfection efficiencies in airway epithelia, highlighting their importance in effective delivery of therapeutic products for airways diseases.

Prediction of Cognitive Decline for Enrichment of Alzheimer's Disease Clinical Trials

BACKGROUND

A key issue to Alzheimer's disease clinical trial failures is poor participant selection. Participants have heterogeneous cognitive trajectories and many do not decline during trials, which reduces a study's power to detect treatment effects. Trials need enrichment strategies to enroll individuals who are more likely to decline.

OBJECTIVES

To develop machine learning models to predict cognitive trajectories in participants with early Alzheimer's disease and presymptomatic individuals over 24 and 48 months respectively.

DESIGN

Prognostic machine learning models were trained from a combination of demographics, cognitive tests, APOE genotype, and brain imaging data.

SETTING

Data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), National Alzheimer's Coordinating Center (NACC), Open Access Series of Imaging Studies (OASIS-3), PharmaCog, and a Phase 3 clinical trial in early Alzheimer's disease were used for this study.

PARTICIPANTS

A total of 2098 participants who had demographics, cognitive tests, APOE genotype, and brain imaging data, as well as follow-up visits for 24-48 months were included.

MEASUREMENTS

Baseline magnetic resonance imaging, cognitive tests, demographics, and APOE genotype were used to separate decliners, defined as individuals whose CDR-Sum of Boxes scores increased during a predefined time window, from stable individuals. A prognostic model to predict decline at 24 months in early Alzheimer's disease was trained on 1151 individuals who had baseline diagnoses of mild cognitive impairment and Alzheimer's dementia from ADNI and NACC. This model was validated on 115 individuals from a placebo arm of a Phase 3 clinical trial and 76 individuals from the PharmaCog dataset. A second prognostic model to predict decline at 48 months in presymptomatic populations was trained on 628 individuals from ADNI and NACC who were cognitively unimpaired at baseline. This model was validated on 128 individuals from OASIS-3.

RESULTS

The models achieved up to 79% area under the curve (cross-validated and out-of-sample). Power analyses showed that using prognostic models to recruit enriched cohorts of predicted decliners can reduce clinical trial sample sizes by as much as 51% while maintaining the same detection power.

CONCLUSIONS

Prognostic tools for predicting cognitive decline and enriching clinical trials with participants at the highest risk of decline can improve trial quality, derisk endpoint failures, and accelerate therapeutic development in Alzheimer's disease.

A Comprehensive Evaluation of ZrC Nanoparticle in Combined Photothermal and Radiation Therapy for Treatment of Triple-Negative Breast Cancer

Because of the difficulty in treating triple-negative breast cancer (TNBC), the search for treatments has never stopped. Treatment opinions remain limited for triple-negative breast cancer (TNBC). The current treatment approach of using photothermal therapy (PTT) is often imprecise and has limited penetration below the surface of the skin. On the other hand, radiation therapy (RT) has its unavoidable disadvantages, such as side effects or ineffectiveness against hypoxic tumor microenvironment (TME). In this study, we proposed the use of ZrC nanoparticles in conjunction with RT/PTT to enhance antitumor and antimetastatic effect. We modified the ZrC nanoparticle with bovine serum albumin (BSA) and folic acid (FA), sizing desirable about 100nm. The photothermal conversion efficiency was calculated to be 40.51% and sensitizer enhancement ration (SER) was 1.8. With addition of ZrC NPs, more DNA were damaged in γ-H2AX and more ROS were detected with immunofluorescence. In vitro and vivo, the combined therapy with ZrC NPS showed the best effect of tumor cell inhibition and safety. Our results provide evidence that the combination of ZrC NPs, PT, and RT is effective in of TNBC, making it a great potential application for cancer therapy in clinic.

Requirements for Additional Strength Biowaivers for Modified Release Solid Oral Dosage Forms in International Pharmaceutical Regulators Programme Participating Regulators and Organisations: Differences and Commonalities

This article describes an overview of waivers of in vivo bioequivalence studies for additional strengths in the context of the registration of modified release generic products and is a follow-up to the recent publication for the immediate release solid oral dosage forms. The current paper is based on a survey among the participating members of the Bioequivalence Working Group for Generics (BEWGG) of the International Pharmaceutical Regulators Program (IPRP) regarding this topic. Most jurisdictions consider the extrapolation of bioequivalence results obtained with one (most sensitive) strength of a product series as less straightforward for modified release products than for immediate release products. There is consensus that modified release products should demonstrate bioequivalence not only in the fasted state but also in the fed state, but differences exist regarding the necessity of additional multiple dose studies. Fundamental differences between jurisdictions are revealed regarding requirements on the quantitative composition of different strengths and the differentiation of single and multiple unit dosage forms. Differences in terms of in vitro dissolution requirements are obvious, though these are mostly related to possible additional comparative investigations rather than regarding the need for product-specific methods. As with the requirements for immediate release products, harmonization of the various regulations for modified release products is highly desirable to conduct the appropriate studies from a scientific point of view, thus ensuring therapeutic equivalence.

SP1.1.13Assessing quantitative FIT within the colorectal two-week wait pathway as a triage tool to focus endoscopy services

Aims

Quantitative Faecal Immunochemical test (qFIT) is highly specific for luminal colonic pathology. This study models the potential impact on health care services of its introduction as a tool of triage for the 2-week wait referrals pathway. The Model utilises the recently published NICEFIT tudy.

Methods

All symptoms and results for patients within the colorectal two-week wait pathway are prospectively collated into a relational database. We modelled the impact of introducing targeted FIT testing to those patients without anaemia, rectal mass or overt rectal bleeding. Based on the recent NICEFIT Study, we set a population positivity value of 37% at 2µg/g with sensitivity of identifying colorectal cancer of 97%.

Results

4240 patients were referred in 12 months up to till July 2019. 1333 referrals met the modelled criteria. These 1333 patient events generated 1619 investigations in 1227 patients. Malignancy was found in 4.3% of the investigated referrals (2.8% colorectal, 1.5% extracolonic). By applying FIT to the selected demographics with a positive value of 37%, the number of colonoscopies would fall by 63% (from 815 to 303) with estimated cost saving of £192,000. The FIT negative group would be investigated by selective cross-sectional imaging, with selected use of endoscopy as needed.

Conclusion

The high sensitivity of FIT permits its application as a screening tool in selected symptomatic patients. This can reduce the number of colonoscopies performed by almost 63% within a defined patient group. This would reduce the waiting time for positive high-risk patients as well as cutting overall costs.

EP.TU.296A Significant Difference in Cancer Proportions Between Two Modelled Cohorts Investigated by 2-WeekWait (2WW) Colorectal referral pathway

Aim

To compare the proportions of malignancy between two modelled cohorts of referred and investigated by our colorectal 2 WW referrals pathway.

Methods

Two modelled cohorts were analysed from our prospectively maintained colorectal 2WW referrals database from August 2018 to July 2019. One cohort (group A) included patients without anemia, rectal mass or overt rectal bleeding. The other (group B) included the rest of referrals. Data collected and analysed in each group included total numbers of referrals, investigated referrals and malignancy proportion in each group. One tailed Z test was used to analysis statistical difference.

Results

4240 referrals were made to our colorectal 2 WW pathway during the given period. 1333 (31%) were group A and 2907 (69%) were group B. Total number of patients investigated in group A was 1227, of those only 34 (2.8%) were colorectal cancer and 18 (1.5%) were extracolonic cancer. One the other hand, 2705 patients were investigated in group B, colorectal malignancy were found in 142 (5.3%) patients and 33 (1.2%) were extracolonic. There was a significant difference (p &lt; 0.05) in total number of malignancies between Group A (53/4.3%) and Group B (175/6.5%).

Conclusion

While the 2 Week-Wait referral pathway plays an important role in rapid testing and identifying colorectal cancer, there was a difference between malignancy distribution within the referrals. this difference doesn’t reflect a clinical significance but it can be a good stratification tool.

Snow Buntings Maintain Winter-Level Cold Endurance While Migrating to the High Arctic

Arctic breeding songbirds migrate early in the spring and can face winter environments requiring cold endurance throughout their journey. One such species, the snow bunting (Plectrophenax nivalis), is known for its significant thermogenic capacity. Empirical studies suggest that buntings can indeed maintain winter cold acclimatization into the migratory and breeding phenotypes when kept captive on their wintering grounds. This capacity could be advantageous not only for migrating in a cold environment, but also for facing unpredictable Arctic weather on arrival and during preparation for breeding. However, migration also typically leads to declines in the sizes of several body components linked to metabolic performance. As such, buntings could also experience some loss of cold endurance as they migrate. Here, we aimed to determine whether free-living snow buntings maintain a cold acclimatized phenotype during spring migration. Using a multi-year dataset, we compared body composition (body mass, fat stores, and pectoralis muscle thickness), oxygen carrying capacity (hematocrit) and metabolic performance (thermogenic capacity – Msum and maintenance energy expenditure – BMR) of birds captured on their wintering grounds (January–February, Rimouski, QC, 48°N) and during pre-breeding (April–May) in the Arctic (Alert, NU, 82°). Our results show that body mass, fat stores and Msum were similar between the two stages, while hematocrit and pectoralis muscle thickness were lower in pre-breeding birds than in wintering individuals. These results suggest that although tissue degradation during migration may affect flight muscle size, buntings are able to maintain cold endurance (i.e., Msum) up to their Arctic breeding grounds. However, BMR was higher during pre-breeding than during winter, suggesting higher maintenance costs in the Arctic.

167 The Experience and Outcomes of Elective Urgent and Cancer Surgery in A District General Hospital in The United Kingdom During Covid-19 Pandemic

Background

Many urgent and elective surgeries were postponed to cope with the Coronavirus disease (COVID-19) pandemic, with latest data found a substantial postoperative mortality risk (25·6%, 18.9%) after emergency and elective surgery, respectively.

Our institution was one of the first trust to offer essential elective surgery using a “COVID-free” designated site during the start of the pandemic.

The aim of this study is to analyse the clinical outcomes of patients who underwent essential elective procedures during the virus outbreak in the UK.

Method

Retrospective analysis of outcomes all patients who had undergone urgent elective and cancer surgery, from 30th March 2020 to 21st May 2020, using an implemented “Super Green Pathway”.

The primary endpoints were 30 days mortality and COVID related morbidities, and the secondary endpoints were surgical related complications and oncological outcomes.

Results

92 patients (Male:45%; Female:55%) across 5 surgical specialties were identified. There was no record of mortality in our cohort. Only 1 patient was tested positive for SARS-CoV-2, 18 days after the initial operation without any pulmonary complications.

Conclusions

It is possible to mitigate the high mortality risk of postoperative complications associated with COVID-19, with no delay to essential surgeries for cancer patients, thus delivering safe practice during the pandemic.

A Survey of the Regulatory Requirements for the Waiver of In Vivo Bioequivalence Studies of Generic Products in Certain Dosage Forms by Participating Regulators and Organisations of the International Pharmaceutical Regulators Programme

The requirements to waive in vivo bioequivalence studies for immediate release solid oral dosage forms based on the Biopharmaceutics Classifications System (BCS) are well known, and biowaivers[1] for other types of oral dosage forms based on pre-defined criteria may also be acceptable. Similarly, biowaivers for dosage forms such as injectable products may also be allowed if certain criteria are met. The current paper summarises the biowaiver requirements for oral solutions and suspensions, soft gelatin capsules and injectable products (intravenous injections, subcutaneous and intramuscular injections, emulsions for injection and micellar solutions for injection) among the participants of the Bioequivalence Working Group for Generics (BEWGG) of the International Pharmaceutical Regulators Programme (IPRP). A review of the requirements indicated that there was a trend towards convergence when the dosage form became less complex; however, the most common approach used by each of the jurisdictions was a case-by-case approach given that most jurisdictions do not have well defined guidelines to support all possible scenarios. Even in the simplest case of intravenous solutions, the acceptability of qualitative changes in excipients differ between the IPRP members.  Notwithstanding the differences, the dissemination of the information is a first step towards regulatory convergence regarding biowaivers for certain dosage forms and should be useful for pharmaceutical companies currently developing generic medicinal products for IPRP jurisdictions.  

Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas

Long-term monitoring is critical to guide conservation strategies and assess the impacts of climatic changes and anthropogenic activities. In High Arctic ecosystems, information on distribution and population trends of plants is dramatically lacking. During two field expeditions in 2018 and 2019, we conducted a systematic floristic survey together with opportunistic collecting in the polar desert surrounding Alert (Nunavut, Canada) to update past vascular plant inventories. We recorded 58 species, of which 54 species were recorded over the last seven decades, and four species that are additions to the local flora (Draba pauciflora R. Brown, Festuca edlundiae S.G. Aiken, Consaul, &amp; Lefkovitch, Festuca hyperborea Holmen ex Frederiksen, and &times;Pucciphippsia vacillans (T. Fries) Tzvelev). With the addition of 19 species that were previously reported but not found in our survey, we estimate the species richness in the study area at 77 species.

Limited heat tolerance in an Arctic passerine: Thermoregulatory implications for cold-specialized birds in a rapidly warming world

Arctic animals inhabit some of the coldest environments on the planet and have evolved physiological mechanisms for minimizing heat loss under extreme cold. However, the Arctic is warming faster than the global average and how well Arctic animals tolerate even moderately high air temperatures (T a) is unknown.Using flow-through respirometry, we investigated the heat tolerance and evaporative cooling capacity of snow buntings (Plectrophenax nivalis; ≈31 g, N = 42), a cold specialist, Arctic songbird. We exposed buntings to increasing T a and measured body temperature (T b), resting metabolic rate (RMR), rates of evaporative water loss (EWL), and evaporative cooling efficiency (the ratio of evaporative heat loss to metabolic heat production).Buntings had an average (±SD) T b of 41.3 ± 0.2°C at thermoneutral T a and increased T b to a maximum of 43.5 ± 0.3°C. Buntings started panting at T a of 33.2 ± 1.7°C, with rapid increases in EWL starting at T a = 34.6°C, meaning they experienced heat stress when air temperatures were well below their body temperature. Maximum rates of EWL were only 2.9× baseline rates at thermoneutral T a, a markedly lower increase than seen in more heat-tolerant arid-zone species (e.g., ≥4.7× baseline rates). Heat-stressed buntings also had low evaporative cooling efficiencies, with 95% of individuals unable to evaporatively dissipate an amount of heat equivalent to their own metabolic heat production.Our results suggest that buntings' well-developed cold tolerance may come at the cost of reduced heat tolerance. As the Arctic warms, and this and other species experience increased periods of heat stress, a limited capacity for evaporative cooling may force birds to increasingly rely on behavioral thermoregulation, such as minimizing activity, at the expense of diminished performance or reproductive investment.

The role of technology in melanoma screening and diagnosis

Melanoma presents challenges for timely and accurate diagnosis. Expert panels have issued risk-based screening guidelines, with recommended screening by visual inspection. To assess how recent technology can impact the risk/benefit considerations for melanoma screening, we comprehensively reviewed non-invasive visual-based technologies. Dermoscopy increases lesional diagnostic accuracy for both dermatologists and primary care providers; total body photography and sequential digital dermoscopic imaging also increase diagnostic accuracy, are supported by automated lesion detection and tracking, and may be best suited to use by dermatologists for longitudinal follow-up. Specialized imaging modalities using non-visible light technology have unproven benefit over dermoscopy and can be limited by cost, access, and training requirements. Mobile apps facilitate image capture and lesion tracking. Teledermatology has good concordance with face-to-face consultation and increases access, with increased accuracy using dermoscopy. Deep learning models can surpass dermatologist accuracy, but their clinical utility has yet to be demonstrated. Technology-aided diagnosis may change the calculus of screening; however, well-designed prospective trials are needed to assess the efficacy of these different technologies, alone and in combination to support refinement of guidelines for melanoma screening.

Robotic partial nephrectomy: The current status

Introduction:

Since its introduction, robotic partial nephrectomy (RPN) has become increasingly popular, in part as a result of several advances in technique. The purpose of this paper is to review these techniques as well as the perioperative, functional, and oncologic outcomes after RPN and compare these outcomes to those after laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN).

Methods:

A literature review was performed to identify papers and meta-analyses that compared outcomes after RPN to OPN or LPN. All meta-analyses were included in this review.

Results:

Technical advances that have contributed to improved outcomes after RPN include the first-assistant sparing technique, the sliding clip technique, early unclamping, and selective arterial clamping. All five meta-analyses that compared LPN to RPN found that RPN was associated with a shorter warm ischemia time (WIT), but that there were no differences in estimated blood loss (EBL) or operative times. Those meta-analyses that compared intraoperative and postoperative complications, conversion to open or radical nephrectomy, length of stay (LOS), and postoperative estimated glomerular filtration rate (eGFR) either found no difference or favored RPN. Four meta-analyses compared RPN to OPN. All four found that EBL, LOS, and postoperative complications favor RPN. There were no significant differences in intraoperative complications, conversion to radical nephrectomy, or positive surgical margin rates. One meta-analysis found that eGFR was better after RPN. Operative time and WIT generally favored OPN.

Conclusions:

Several techniques have been described to improve outcomes after RPN. We believe that the literature shows that RPN is as good if not better than both LPN and OPN and has become the preferred surgical approach.

P3778Long-term outcome of non-pharmacologial treatment of atrial fibrillation in hypertrophic cardiomyopathy: a large single-centre experience

Introduction

Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) and is generally associated with a significant deterioration of clinical status. Non-pharmacological treatment such as surgical and catheter ablation has become an established therapy for symptomatic AF but in patients with HCM often having a chronically increased left atrial pressure and extensive atrial cardiomyopathy the long-term outcome is uncertain.

Purpose

The present study aimed to analyse the long-term outcome of AF ablation in HCM and the mechanism of recurrent atrial arrhythmias using high-density mapping systems.

Methods

A total of 65 patients (age 64.5±9.9 years, 42 (64.6%) male) with HCM undergoing AF ablation for symptomatic AF were included in our study. The ablation strategy for catheter ablation included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines if appropriate. In patients with suspected atrial tachycardia (AT) high-density activation and substrate mapping were performed. A surgical ablation at the time of an operative myectomy for left ventricular outflow tract obstruction was performed in 8 (12.3%) patients. The outcome was analysed using clinical assessment, Holter ECG and continuous rhythm monitoring of cardiac implantable electric devices.

Results

Paroxysmal AF was present in 27 (41.6%), persistent AF in 37 (56.9%) and primary AT in 1 (1.5%) patients. The mean left atrial diameter was 54.1±12.5 ml. In 11 (16.9%) patients with AT high-density mapping was used to characterize the mechanism of the ongoing tachycardia. After 1.9±1.2 ablation procedures and a follow-up of 48.5±37.2 months, ablation success was demonstrated in 58.9% of patients. The success rate for paroxysmal and persistent AF was 70.0% and 55.8%, respectively (p=0.023). Of those patients with AT high-density mapping guided ablation was successful in 44.4% of patients. The LA diameter of patients with a successful ablation was smaller (52.2 vs. 58.1 mm; p=0.003).

Conclusion

Non-pharmacological treatment of AF in HCM is effective during long-term follow-up. Paroxysmal AF and a smaller LA diameter are favourable for successful ablation. In patients with complex AT the use of high-density mapping can guide ablation resulting in further ablation success in a reasonable number of patients.

Hedgehog signaling in the airway epithelium of patients with chronic obstructive pulmonary disease

Genome-wide association studies have linked gene variants of the receptor patched homolog 1 (PTCH1) with chronic obstructive pulmonary disease (COPD). However, its biological role in the disease is unclear. Our objective was to determine the expression pattern and biological role of PTCH1 in the lungs of patients with COPD. Airway epithelial-specific PTCH1 protein expression and epithelial morphology were assessed in lung tissues of control and COPD patients. PTCH1 mRNA expression was measured in bronchial epithelial cells obtained from individuals with and without COPD. The effects of PTCH1 siRNA knockdown on epithelial repair and mucous expression were evaluated using human epithelial cell lines. Ptch1^+/− mice were used to assess the effect of decreased PTCH1 on mucous expression and airway epithelial phenotypes. Airway epithelial-specific PTCH1 protein expression was significantly increased in subjects with COPD compared to controls, and its expression was associated with total airway epithelial cell count and thickness. PTCH1 knockdown attenuated wound closure and mucous expression in airway epithelial cell lines. Ptch1^+/− mice had reduced mucous expression compared to wildtype mice following mucous induction. PTCH1 protein is up-regulated in COPD airway epithelium and may upregulate mucous expression. PTCH1 provides a novel target to reduce chronic bronchitis in COPD patients.

The Requirements for Additional Strength Biowaivers for Immediate Release Solid Oral Dosage Forms in International Pharmaceutical Regulators Programme Participating Regulators and Organisations: Differences and Commonalities

In relation to the registration of generic products, waivers of in vivo bioequivalence studies (biowaivers) are considered in three main cases: certain dosage forms for which bioequivalence is self-evident (e.g. intravenous solutions), biowaivers based on the Biopharmaceutics Classification System and biowaivers for additional strengths with respect to the strength for which in vivo bioequivalence has been shown. The objective of this article is to describe the differences and commonalities in biowaivers for additional strengths of immediate release solid oral dosage forms between the participating members of the International Pharmaceutical Regulators Program (IPRP). The requirements are based on five main aspects; the pharmacokinetics of the drug substance, the manufacturing process, the qualitative and quantitative composition of the different strengths, and the comparative dissolution profiles. For the pharmacokinetic aspects, many regulators/agencies have the same requirements. All strengths must be manufactured with the same process, although a few regulators/agencies accept small differences. In relation to the formulation aspects, the data required breaks down into three major approaches based initially on one of those of the EU, the USA or Japan, but there are some differences in these three major approaches with some country specific interpretations. Most regulators/agencies also have the same requirements for the dissolution data, though there are some notable exceptions.