A Prospective Trial of Single-Fraction Radiation to the Tumor Bed with a Novel Breast-Specific Stereotactic Radiation Therapy Device: The GammaPod.

Purpose: Radiation therapy for early-stage breast cancer is typically delivered in a hypofractionated regimen to the whole breast followed by a tumor bed boost. This results in a treatment course of approximately 4 weeks. In this study, the tumor bed boost was delivered in a single fraction as part of a safety and feasibility study for FDA clearance of the device. Methods and Materials: Eligible women with early-stage breast cancer underwent lumpectomy followed by radiation therapy. Patients underwent breast immobilization using a system specific to the GammaPod followed by CT simulation, boost treatment planning, and boost treatment delivery all in a single treatment day. Patients then started whole-breast radiation therapy within 1 week of the boost treatment. Patients and treatments were assessed for safety and feasibility. Acute toxicities were recorded. Results: A single-fraction boost of 8 Gy was delivered to the tumor bed before a course of whole-breast radiation. The GammaPod treatment was successfully delivered to 14 of 17 enrolled patients. Acute toxicities from all radiation therapy, inclusive of the boost and whole-breast radiation, were limited to grade 1 events. Conclusions: The GammaPod device successfully delivered a single-fraction boost treatment to the tumor bed with no change in expected acute toxicities. The results of this study led to FDA clearance of the device through the Investigational Device Exemption process at the FDA. The GammaPod is in clinical use at 4e institutions nationally and internationally, with additional sites pending in 2023.

Radiation Dose-Volume-Response Relationships for Adverse Events in Childhood Cancer Survivors: Introduction to the Scientific Issues in PENTEC.

At its very core, radiation oncology involves a trade-off between the benefits and risks of exposing tumors and normal tissue to relatively high doses of ionizing radiation. This trade-off is particularly critical in childhood cancer survivors (CCS), in whom both benefits and risks can be hugely consequential due to the long life expectancy if the primary cancer is controlled. Estimating the normal tissue-related risks of a specific radiation therapy plan in an individual patient relies on predictive mathematical modeling of empirical data on adverse events. The Pediatric Normal-Tissue Effects in the Clinic (PENTEC) collaborative network was formed to summarize and, when possible, to synthesize dose-volume-response relationships for a range of adverse events incident in CCS based on the literature. Normal-tissue clinical radiation biology in children is particularly challenging for many reasons: (1) Childhood malignancies are relatively uncommon-constituting approximately 1% of new incident cancers in the United States-and biologically heterogeneous, leading to many small series in the literature and large variability within and between series. This creates challenges in synthesizing data across series. (2) CCS are at an elevated risk for a range of adverse health events that are not specific to radiation therapy. Thus, excess relative or absolute risk compared with a reference population becomes the appropriate metric. (3) Various study designs and quantities to express risk are found in the literature, and these are summarized. (4) Adverse effects in CCS often occur 30, 50, or more years after therapy. This limits the information content of series with even very extended follow-up, and lifetime risk estimates are typically extrapolations that become dependent on the mathematical model used. (5) The long latent period means that retrospective dosimetry is required, as individual computed tomography-based radiation therapy plans gradually became available after 1980. (6) Many individual patient-level factors affect outcomes, including age at exposure, attained age, lifestyle exposures, health behaviors, other treatment modalities, dose, fractionation, and dose distribution. (7) Prospective databases with individual patient-level data and radiation dosimetry are being built and will facilitate advances in dose-volume-response modeling. We discuss these challenges and attempts to overcome them in the setting of PENTEC.

Reporting Standards for Complication Studies of Radiation Therapy for Pediatric Cancer: Lessons From PENTEC.

The major aim of Pediatric Normal Tissue Effects in the Clinic (PENTEC) was to synthesize quantitative published dose/-volume/toxicity data in pediatric radiation therapy. Such systematic reviews are often challenging because of the lack of standardization and difficulty of reporting outcomes, clinical factors, and treatment details in journal articles. This has clinical consequences: optimization of treatment plans must balance between the risks of toxicity and local failure; counseling patients and their parents requires knowledge of the excess risks encountered after a specific treatment. Studies addressing outcomes after pediatric radiation therapy are particularly challenging because: (a) survivors may live for decades after treatment, and the latency time to toxicity can be very long; (b) children's maturation can be affected by radiation, depending on the developmental status of the organs involved at time of treatment; and (c) treatment regimens frequently involve chemotherapies, possibly modifying and adding to the toxicity of radiation. Here we discuss: basic reporting strategies to account for the actuarial nature of the complications; the reporting of modeling of abnormal development; and the need for standardized, comprehensively reported data sets and multivariate models (ie, accounting for the simultaneous effects of radiation dose, age, developmental status at time of treatment, and chemotherapy dose). We encourage the use of tools that facilitate comprehensive reporting, for example, electronic supplements for journal articles. Finally, we stress the need for clinicians to be able to trust artificial intelligence models of outcome of radiation therapy, which requires transparency, rigor, reproducibility, and comprehensive reporting. Adopting the reporting methods discussed here and in the individual PENTEC articles will increase the clinical and scientific usefulness of individual reports and associated pooled analyses.

Radiation Therapy Technology Advances and Mitigation of Subsequent Neoplasms in Childhood Cancer Survivors.

PURPOSE: In this Pediatric Normal Tissue Effects in the Clinic (PENTEC) vision paper, challenges and opportunities in the assessment of subsequent neoplasms (SNs) from radiation therapy (RT) are presented and discussed in the context of technology advancement. METHODS AND MATERIALS: The paper discusses the current knowledge of SN risks associated with historic, contemporary, and future RT technologies. Opportunities for research and SN mitigation strategies in pediatric patients with cancer are reviewed. RESULTS: Present experience with radiation carcinogenesis is from populations exposed during widely different scenarios. Knowledge gaps exist within clinical cohorts and follow-up; dose-response and volume effects; dose-rate and fractionation effects; radiation quality and proton/particle therapy; age considerations; susceptibility of specific tissues; and risks related to genetic predisposition. The biological mechanisms associated with local and patient-level risks are largely unknown. CONCLUSIONS: Future cancer care is expected to involve several available RT technologies, necessitating evidence and strategies to assess the performance of competing treatments. It is essential to maximize the utilization of existing follow-up while planning for prospective data collection, including standardized registration of individual treatment information with linkage across patient databases.

Systematic review and pooled analysis of the impact of treatment-induced lymphopenia on survival of glioblastoma patients.

PURPOSE/OBJECTIVE(S): Treatment related lymphopenia is a known toxicity for glioblastoma (GBM) patients and several single-institution studies have linked lymphopenia with poor survival outcomes. We performed a systematic review and pooled analysis to evaluate the association between lymphopenia and overall survival (OS) for GBM patients undergoing chemotherapy and radiation therapy (RT). MATERIALS/METHODS: Following PRISMA guidelines, a systematic literature review of the MEDLINE database and abstracts from ASTRO, ASCO, and SNO annual meetings was conducted. A pooled analysis was performed using inverse variance-weighted random effects to generate a pooled estimate of the hazard ratio of association between lymphopenia and OS. RESULTS: Ten of 104 identified studies met inclusion criteria, representing 1,718 patients. The lymphopenia cutoff value varied (400-1100 cells/uL) and as well as the timing of its onset. Studies were grouped as time-point (i.e., lymphopenia at approximately 2-months post-RT) or time-range (any lymphopenia occurrence from treatment-start to approximately 2-months post-RT. The mean overall pooled incidence of lymphopenia for all studies was 31.8%, and 11.8% vs. 39.9% for time-point vs. time-range studies, respectively. Lymphopenia was associated with increased risk of death, with a pooled HR of 1.78 (95% CI 1.46-2.17, P < 0.00001) for the time-point studies, and a pooled HR of 1.38 (95% CI 1.24-1.55, P < 0.00001) for the time-point studies. There was no significant heterogeneity between studies. CONCLUSION: These results strengthen observations from previous individual single-institution studies and better defines the magnitude of the association between lymphopenia with OS in GBM patients, highlighting lymphopenia as a poor prognostic factor.

Psychosocial Factors That Influence a Woman's Decision to Enroll in a Clinical Trial: Implications on How to Improve Clinical Trial Enrollment Among Black Women.

PURPOSE: Black women with breast cancer often present with more aggressive disease compared with other races, contributing to an increased risk of cancer mortality. Despite this inequity, Black women remain severely underrepresented in breast cancer clinical trials. We aim to characterize factors that influence a woman's decision to enroll in a clinical trial, with the goal of identifying clinical interventions to aid in the recruitment of vulnerable groups. METHODS AND MATERIALS: A cross-sectional, descriptive study was conducted using a questionnaire adapted from 2 prevalidated surveys investigating factors influencing clinical trial enrollment. The survey was administered to women with curable breast cancer during a single follow-up visit at 4 different sites within a university medical system where all patients are screened for clinical trial eligibility. Chi-square tests and Mann-Whitney U tests were used to assess associations or differences between the populations. RESULTS: One hundred ninety-four out of 209 women completed the survey, giving a compliance rate of 93%. Twenty-six percent of women self-identified as Black, most women were located at community sites (67.1%), most women had diagnoses of early-stage disease (I: 57.7%, II: 29.4%), and 81% of women had some collegiate-level education. Black women were younger at diagnosis (P = .005) and less likely to be married (P = .012) but more often lived with family members (P = .003) and had a lower median income (P < .001). According to the survey, Black women were less likely to trust their care team (P = .032), more likely to believe that research ultimately harms minorities (P < .001), and had a stronger belief in God's will determining illness and wellness (P < .001). Recurring themes of trust in the health care team, patient education, and advancement of cancer treatments were discussed in the focus groups. CONCLUSIONS: Failure to offer clinical trials and mistrust in research institutions may pose the greatest hindrances to the enrollment of Black women in clinical trials. Empowering women through education and fostering trustworthy relationships can encourage greater clinical trial participation.

Brain and Brain Stem Necrosis After Reirradiation for Recurrent Childhood Primary Central Nervous System Tumors: A PENTEC Comprehensive Review.

PURPOSE: Reirradiation is increasingly used in children and adolescents/young adults (AYA) with recurrent primary central nervous system tumors. The Pediatric Normal Tissue Effects in the Clinic (PENTEC) reirradiation task force aimed to quantify risks of brain and brain stem necrosis after reirradiation. METHODS AND MATERIALS: A systematic literature search using the PubMed and Cochrane databases for peer-reviewed articles from 1975 to 2021 identified 92 studies on reirradiation for recurrent tumors in children/AYA. Seventeen studies representing 449 patients who reported brain and brain stem necrosis after reirradiation contained sufficient data for analysis. While all 17 studies described techniques and doses used for reirradiation, they lacked essential details on clinically significant dose-volume metrics necessary for dose-response modeling on late effects. We, therefore, estimated incidences of necrosis with an exact 95% CI and qualitatively described data. Results from multiple studies were pooled by taking the weighted average of the reported crude rates from individual studies. RESULTS: Treated cancers included ependymoma (n = 279 patients; 7 studies), medulloblastoma (n = 98 patients; 6 studies), any CNS tumors (n = 62 patients; 3 studies), and supratentorial high-grade gliomas (n = 10 patients; 1 study). The median interval between initial and reirradiation was 2.3 years (range, 1.2-4.75 years). The median cumulative prescription dose in equivalent dose in 2-Gy fractions (EQD22; assuming α/ß value = 2 Gy) was 103.8 Gy (range, 55.8-141.3 Gy). Among 449 reirradiated children/AYA, 22 (4.9%; 95% CI, 3.1%-7.3%) developed brain necrosis and 14 (3.1%; 95% CI, 1.7%-5.2%) developed brain stem necrosis with a weighted median follow-up of 1.6 years (range, 0.5-7.4 years). The median cumulative prescription EQD22 was 111.4 Gy (range, 55.8-141.3 Gy) for development of any necrosis, 107.7 Gy (range, 55.8-141.3 Gy) for brain necrosis, and 112.1 Gy (range, 100.2-117 Gy) for brain stem necrosis. The median latent period between reirradiation and the development of necrosis was 5.7 months (range, 4.3-24 months). Though there were more events among children/AYA undergoing hypofractionated versus conventionally fractionated reirradiation, the differences were not statistically significant (P = .46). CONCLUSIONS: Existing reports suggest that in children/AYA with recurrent brain tumors, reirradiation with a total EQD22 of about 112 Gy is associated with an approximate 5% to 7% incidence of brain/brain stem necrosis after a median follow-up of 1.6 years (with the initial course of radiation therapy being given with conventional prescription doses of ≤2 Gy per fraction and the second course with variable fractionations). We recommend a uniform approach for reporting dosimetric endpoints to derive robust predictive models of late toxicities following reirradiation.

Improving Pediatric Normal Tissue Radiation Dose-Response Modeling in Children With Cancer: A PENTEC Initiative.

The development of normal tissue radiation dose-response models for children with cancer has been challenged by many factors, including small sample sizes; the long length of follow-up needed to observe some toxicities; the continuing occurrence of events beyond the time of assessment; the often complex relationship between age at treatment, normal tissue developmental dynamics, and age at assessment; and the need to use retrospective dosimetry. Meta-analyses of published pediatric outcome studies face additional obstacles of incomplete reporting of critical dosimetric, clinical, and statistical information. This report describes general methods used to address some of the pediatric modeling issues. It highlights previous single- and multi-institutional pediatric dose-response studies and summarizes how each PENTEC taskforce addressed the challenges and limitations of the reviewed publications in constructing, when possible, organ-specific dose-effect models.

Comparison of Risks of Late Effects From Radiation Therapy in Children Versus Adults: Insights From the QUANTEC, HyTEC, and PENTEC Efforts.

Pediatric Normal Tissue Effects in the Clinic (PENTEC) seeks to refine quantitative radiation dose-volume relationships for normal-tissue complication probabilities (NTCPs) in survivors of pediatric cancer. This article summarizes the evolution of PENTEC and compares it with similar adult-focused efforts (eg, Quantitative Analysis of Normal Tissue Effects in the Clinic [QUANTEC] and Hypofractionated Treatment Effects in the Clinic [HyTEC]) with respect to content, oversight, support, scope, and methodology of literature review. It then summarizes key organ-specific findings from PENTEC in an attempt to compare NTCP estimates in children versus adults. In brief, select normal-tissue risks within developing organs and tissues (eg, maldevelopment of musculoskeletal tissue, teeth, breasts, and reproductive organs) are primarily relevant only in children. For some organs and tissues, children appear to have similar (eg, brain for necrosis, optic apparatus, parotid gland, liver), greater (eg, brain for neurocognition, cerebrovascular, breast for lactation), less (ovary), or perhaps slightly less (eg, lung) risks of toxicity versus adults. Similarly, even within the broad pediatric age range (including adolescence), for some endpoints, younger children have greater (eg, hearing and brain for neurocognition) or lesser (eg, ovary, thyroid) risks of radiation-associated toxicities. NTCP comparisons in adults versus children are often confounded by marked differences in treatment paradigms that expose normal tissues to radiation (ie, cancer types, prescribed radiation therapy dose and fields, and chemotherapy agents used). To add to the complexity, it is unclear if age is best analyzed as a continuous variable versus with age groupings (eg, infants, young children, adolescents, young adults, middle-aged adults, older adults). Further work is needed to better understand the complex manner in which age and developmental status affect risk.

A User's Guide and Summary of Pediatric Normal Tissue Effects in the Clinic (PENTEC): Radiation Dose-Volume Response for Adverse Effects After Childhood Cancer Therapy and Future Directions.

Pediatric Normal Tissue Effects in the Clinic (PENTEC) is an international multidisciplinary effort that aims to summarize normal-tissue toxicity risks based on published dose-volume data from studies of children and adolescents treated with radiation therapy (RT) for cancer. With recognition that children are uniquely vulnerable to treatment-related toxic effects, our mission and challenge was to assemble our group of physicians (radiation and pediatric oncologists, subspecialists), physicists with clinical and modeling expertise, epidemiologists, and other scientists to develop evidence-based radiation dosimetric guidelines, as affected by developmental status and other factors (eg, other cancer therapies and host factors). These quantitative toxicity risk estimates could serve to inform RT planning and thereby improve outcomes. Tandem goals included the description of relevant medical physics issues specific to pediatric RT and the proposal of dose-volume outcome reporting standards to inform future studies. We created 19 organ-specific task forces and methodology to unravel the wealth of data from heterogeneous published studies. This report provides a high-level summary of PENTEC's genesis, methods, key findings, and associated concepts that affected our work and an explanation of how our findings may be interpreted and applied in the clinic. We acknowledge our predecessors in these efforts, and we pay homage to the children whose lives informed us and to future generations who we hope will benefit from this additional step in our path forward.

Risk of Subsequent Neoplasms in Childhood Cancer Survivors After Radiation Therapy: A Comprehensive PENTEC Review.

PURPOSE: A Pediatric Normal Tissue Effects in the Clinic (PENTEC) analysis of published investigations of central nervous system (CNS) subsequent neoplasms (SNs), subsequent sarcomas, and subsequent lung cancers in childhood cancer survivors who received radiation therapy (RT) was performed to estimate the effect of RT dose on the risk of SNs and the modification of this risk by host and treatment factors. METHODS AND MATERIALS: A systematic literature review was performed to identify data published from 1975 to 2022 on SNs after prior RT in childhood cancer survivors. After abstract review, usable quantitative and qualitative data were extracted from 83 studies for CNS SNs, 118 for subsequent sarcomas, and 10 for lung SNs with 4 additional studies (3 for CNS SNs and 1 for lung SNs) later added. The incidences of SNs, RT dose, age, sex, primary cancer diagnosis, chemotherapy exposure, and latent time from primary diagnosis to SNs were extracted to assess the factors influencing risk for SNs. The excess relative ratio (ERR) for developing SNs as a function of dose was analyzed using inverse-variance weighted linear regression, and the ERR/Gy was estimated. Excess absolute risks were also calculated. RESULTS: The ERR/Gy for subsequent meningiomas was estimated at 0.44 (95% CI, 0.19-0.68); for malignant CNS neoplasms, 0.15 (95% CI, 0.11-0.18); for sarcomas, 0.045 (95% CI, 0.023-0.067); and for lung cancer, 0.068 (95% CI, 0.03-0.11). Younger age at time of primary diagnosis was associated with higher risk of subsequent meningioma and sarcoma, whereas no significant effect was observed for age at exposure for risk of malignant CNS neoplasm, and insufficient data were available regarding age for lung cancer. Females had a higher risk of subsequent meningioma (odds ratio, 1.46; 95% CI, 1.22-1.76; P < .0001) relative to males, whereas no statistically significant sex difference was seen in risk of malignant CNS neoplasms, sarcoma SNs, or lung SNs. There was an association between chemotherapy receipt (specifically alkylating agents and anthracyclines) and subsequent sarcoma risk, whereas there was no clear association between specific chemotherapeutic agents and risk of CNS SNs and lung SNs. CONCLUSIONS: This PENTEC systematic review shows a significant radiation dose-response relationship for CNS SNs, sarcomas, and lung SNs. Given the linear dose response, improved conformality around the target volume that limits the high dose volume might be a promising strategy for reducing the risk of SNs after RT. Other host- and treatment-related factors such as age and chemotherapy play a significant contributory role in the development of SNs and should be considered when estimating the risk of SNs after RT among childhood cancer survivors.

Conditional Risks of Biochemical Failure and Prostate Cancer-Specific Death in Patients Undergoing External Beam Radiotherapy: A Secondary Analysis of 2 Randomized Clinical Trials.

Importance: As patients achieve years of survival after treatment for prostate cancer, the risk of biochemical failure (BF) or prostate cancer-specific death (PCSD) may evolve over time, with clinical relevance to both patients and clinicians. Objective: To determine conditional BF-free survival, PSCD, and overall survival estimates for patients with low- or intermediate-risk prostate cancer enrolled in the Radiation Therapy Oncology Group (RTOG) 0126 and RTOG 0415 clinical trials. A secondary objective was to determine whether prognostic factors at diagnosis remain relevant at later points in follow-up. Design, Setting, and Participants: A pooled secondary analysis of patients treated with external-beam radiotherapy alone and enrolled in the prospective randomized clinical trials RTOG 0126 and RTOG 0415 was performed. Patients included for analysis were enrolled between March 2002 and December 2009 with a median follow-up of 6.9 years. Overall survival was calculated using the Kaplan-Meier method at various survivorship time points. Cumulative incidence was used to calculate BF rates using the Phoenix definition, as well as PCSD. Risk factors such as Gleason score, tumor (T) stage, prostate-specific antigen level, and the equivalent dose in 2 Gy fractions of prescribed dose were analyzed at different time points using multivariable Cox proportional hazards modeling. Data were analyzed from November 2021 to February 2023. Main Outcomes and Measures: Conditional risks of BF and PCSD after completion of external-beam radiotherapy. Results: A total of 2591 patients (median [IQR] age, 69 [63-73] years) were included in the study with a mean (range) PSA level of 7.1 (4.7-8.9) ng/mL, 1334 patients (51.5%) with a Gleason score 6 disease, and 1706 patients (65.8%) with T1 disease. Rates of BF from time of treatment were 1.63% (95% CI, 1.20%-2.18%) at 1 year, 7.04% (95% CI, 6.09%-8.08%) at 3 years, 12.54% (95% CI, 11.28%-13.88%) at 5 years, and 22.32% (95% CI, 20.46%-24.24%) at 8 years. For patients surviving 1, 3, and 5 years without BF, the rates of BF in the next 5 years were 14.20% (95% CI, 12.80%-15.66%), 17.19% (95% CI, 15.34%-19.14%), and 18.85% (95% CI, 16.21%-21.64%), respectively. At the initial time point, the rate of PCSD in the next 5 years was 0.66% (95% CI, 0.39%-1.04%). For patients who achieved 1, 3, 5, and 8 years of survivorship, the rates of PCSD in the next 5 years were 1.16% (95% CI, 0.77-1.67) at 1 year, 2.42% (95% CI, 1.74%-3.27%) at 3 years, 2.88% (95% CI, 2.01%-3.99%) at 5 years, and 3.49% (95% CI, 0.98%-8.73%) at 8 years. Conclusions and Relevance: In this secondary analysis of 2 randomized clinical trials of patients undergoing external beam radiotherapy for prostate cancer, the conditional risks of BF and death from prostate cancer increased with time for patients with low- and intermediate-risk prostate cancer treated with radiotherapy alone. These results could inform optimal trial design and may be helpful information for patients evaluated in follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT00033631; NCT00331773.

Immuno-oncologic signature of malignant transformation in oral squamous cell carcinoma.

OBJECTIVE: The purpose of this study is to identify the immuno-oncologic (IO) signature at the surgical tumor margin (TM) of oral squamous cell carcinoma (OSCC) that is involved in the process of malignant transformation. STUDY DESIGN: Under institutional review board approval, TM of 73 OSCC were investigated using immunohistochemistry for the immune biomarker, programmed death ligand-1 (PD-L1). NanoString 770 IO-focused gene set was analyzed in 5 pairs of TM and invasive tumor (T). PD-L1 regulation in response to interferon-gamma (IFN-γ) was investigated in an oral potentially malignant cell line (OPMC). RESULTS: Programmed death ligand-1 expression in the epithelial margin directly correlated with its expression in the underlying immune cells (P = .0082). Differential gene expression showed downregulation of PD-L1 and IFN-γ 6 gene signature in the TM relative to T pair.CD8 and macrophages were higher in TM. CNTFR, LYZ, C7, RORC, and FGF13 downregulation in T relative to TM. TDO2, ADAM12, MMP1, LAMC2, MB21D1, TYMP, OASL, COL5A1, exhausted_CD8, Tregs,and NK_CD56dim were upregulated in T relative to TM. Finally, IFN-γ induced upregulation of PD-L1 in the OPMC. CONCLUSIONS: Our work suggests a role for IFN-γ in PD-L1 upregulation in OPMC and presents novel IO transcriptional signatures for frankly invasive OSCC relative to TM.

The influence of patient position on ultrasound examination of the sciatic nerve in the popliteal fossa: A cross-sectional study.

Introduction/Purpose: Ultrasound-guided popliteal fossa sciatic nerve (PFSN) blocks are performed with patients in the supine, lateral or prone position. No known studies compare the quality of images obtained from each approach. This study examines the quality of supine and prone PFSN ultrasound images. Methods: Thirty-eight adult volunteers were sorted into two groups. Five regional anaesthesiologists performed ultrasound examinations of the PFSN on volunteers in supine and prone positions. Popliteal fossa sciatic nerve image quality was analysed with grayscale techniques and peer evaluation. Popliteal fossa sciatic nerve depth, distance from the popliteal crease and time until optimal imaging were recorded. Results: The grayscale ratio of the PFSN vs. the background was 1.83 (supine) and 1.75 (prone) (P = 0.034). Similarly, the grayscale ratio of the PFSN vs. the immediately adjacent area was 1.65 (supine) and 1.55 (prone) (P = 0.004). Mean depth of the PFSN was 1.6 cm (supine) and 1.7 cm (prone) (P = 0.009). Average distance from the popliteal crease to the PFSN was 5.9 cm (supine) and 6.6 cm (prone) (P = 0.02). Mean time to acquire optimal imaging was 36 s (supine) and 47 s (prone) (P = 0.002). Observers preferred supine positioning 53.8%, prone positioning 22.5% and no preference 23.7% of the time. Observers with strong preferences preferred supine imaging in 70.9% of cases. Conclusions: Supine ultrasound examination offered quicker identification of the PFSN, in a more superficial location, closer to the popliteal crease and with enhanced contrast to surrounding tissue, correlating with observer preferences for supine positioning. These results may influence ultrasound-guided PFSN block success rates, especially in difficult-to-image patients.

Complement component C1q is an immunological rheostat that regulates Fc:Fc[Formula: see text]R interactions.

Though binding sites for the complement factor C1q and the canonical fragment crystallizable (Fc) gamma receptors (Fc[Formula: see text]Rs) on immunoglobulin G (IgG) molecules overlap, how C1q decoration of immune complexes (ICs) influences their ability to engage Fc[Formula: see text]Rs remains unknown. In this report, we use recombinant human Fc multimers as stable IC mimics to show that C1q engagement of ICs directly and transiently inhibits their interactions with Fc[Formula: see text]RIII (CD16) on human natural killer (NK) cells. This inhibition occurs by C1q engagement alone as well as in concert with other serum factors. Furthermore, the inhibition of Fc[Formula: see text]RIII engagement mediated by avid binding of C1q to ICs is directly associated with IC size and dependent on the concentrations of both C1q and Fc multimers present. Functionally, C1q-mediated Fc blockade limits the ability of NK cells to induce the upregulation of the cosignaling molecule, 4-1BB (CD137), and to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Although C1q is traditionally viewed as a soluble effector molecule, we demonstrate that C1q may also take on the role of an "immunologic rheostat," buffering Fc[Formula: see text]R-mediated activation of immune cells by circulating ICs. These data define a novel role for C1q as a regulator of immune homeostasis and add to our growing understanding that complement factors mediate pleiotropic effects.

An Estimate of Local Failure in the TARGIT-A Trial of Pre-pathology Intraoperative Radiation Therapy for Early Breast Cancer.

PURPOSE: TARGIT-A was a pragmatic randomized noninferiority trial including women with early-stage breast cancer treated postlumpectomy with either external beam radiation therapy (EBRT) or 50 kV x-rays delivered intraoperatively with or without EBRT, as indicated. The long-term update of the pre-pathology cohort did not include a 10-year estimate of the primary endpoint of local failure (although tabular 5-year data was provided). Here, we used the data from the pre-pathology manuscript to estimate the cumulative incidence of local failure. METHODS AND MATERIALS: Using digitizer software and the published survival curves, we extracted the Kaplan-Meier rate of local recurrence-free survival and overall survival. The extracted data were calibrated to the published point-estimates to within ±0.5%. The data were then fit to parametric survival models, and overall survival and local recurrence-free survival curves were subtracted to give the estimate of local failure in the presence of the competing risk of death. Bootstrap resampling was used to assess for parameter uncertainty in the modeling process. RESULTS: Our analysis estimated that the risk of local failure at 10 years in the TARGIT-A pre-pathology cohort is approximately 1.7% with EBRT (95% confidence interval [CI], 0%-4.3%) and 5.5% in the pragmatic risk-adapted TARGIT strategy (95% CI, 2.9%-8.0%). A weighted average estimate suggests that the risk of local failure in low-risk women treated with TARGIT alone is approximately 6.6% at 10 years (95% CI, 3.3%-10.0%), with an estimated difference of 4.9% (95% CI, 0.6%-9.2%) compared with EBRT. CONCLUSIONS: These data allow for contextualization and informed decisions when considering megavoltage EBRT, kilovoltage intraoperatively, or omission of radiation therapy entirely.