Hypofractionated Stereotactic Radiation Therapy Dosimetric Tolerances for the Inferior Aspect of the Brachial Plexus: A Systematic Review

We sought to systematically review and summarize dosimetric factors associated with radiation-induced brachial plexopathy (RIBP) after stereotactic body radiation therapy (SBRT) or hypofractionated image guided radiation therapy (HIGRT). From published studies identified from searches of PubMed and Embase databases, data quantifying risks of RIBP after 1- to 10-fraction SBRT/HIGRT were extracted and summarized. Published studies have reported <10% risks of RIBP with maximum doses (Dmax) to the inferior aspect of the brachial plexus of 32 Gy in 5 fractions and 25 Gy in 3 fractions. For 10-fraction HIGRT, risks of RIBP appear to be low with Dmax < 40 to 50 Gy. For a given dose value, greater risks are anticipated with point volume-based metrics (ie, D0.03-0.035cc: minimum dose to hottest 0.03-0.035 cc) versus Dmax. With SBRT/HIGRT, there were insufficient published data to predict risks of RIBP relative to brachial plexus dose-volume exposure. Minimizing maximum doses and possibly volume exposure of the brachial plexus can reduce risks of RIBP after SBRT/HIGRT. Further study is needed to better understand the effect of volume exposure on the brachial plexus and whether there are location-specific susceptibilities along or within the brachial plexus structure.

Radiation-induced inferior brachial plexopathy after stereotactic body radiotherapy: Pooled analyses of risks

INTRODUCTION

Radiation-induced brachial plexopathy (RIBP), resulting in symptomatic motor or sensory deficits of the upper extremity, is a risk after exposure of the brachial plexus to therapeutic doses of radiation. We sought to model dosimetric factors associated with risks of RIBP after stereotactic body radiotherapy (SBRT).

METHODS

From a prior systematic review, 4 studies were identified that included individual patient data amenable to normal tissue complication probability (NTCP) modelling after SBRT for apical lung tumors. Two probit NTCP models were derived: one from 4 studies (including 221 patients with 229 targets and 18 events); and another from 3 studies (including 185 patients with 192 targets and 11 events) that similarly contoured the brachial plexus.

RESULTS

NTCP models suggest ≈10% risks associated with brachial plexus maximum dose (Dmax) of ∼32-34 Gy in 3 fractions and ∼40-43 Gy in 5 fractions. RIBP risks increase with increasing brachial plexus Dmax. Compared to previously published data from conventionally-fractionated or moderately-hypofractionated radiotherapy for breast, lung and head and neck cancers (which tend to utilize radiation fields that circumferentially irradiate the brachial plexus), SBRT (characterized by steep dose gradients outside of the target volume) exhibits a much less steep dose-response with brachial plexus Dmax > 90-100 Gy in 2-Gy equivalents.

CONCLUSIONS

A dose-response for risk of RIBP after SBRT is observed relative to brachial plexus Dmax. Comparisons to data from less conformal radiotherapy suggests potential dose-volume dependences of RIBP risks, though published data were not amenable to NTCP modelling of dose-volume measures associated with RIBP after SBRT.

Patient Perceptions of Sexual Orientation and Gender Identity Data Collection in an Outpatient Radiation Oncology Setting

PURPOSE

Sexual and gender minority patients with cancer experience significant health disparities requiring tailored care. Collecting sexual orientation and gender identity (SOGI) data in the electronic medical record (EMR) could allow care to be tailored and is in line with radiation oncology's mission to better serve diverse patients. This article describes a systematic method for collecting SOGI data for all patients starting radiation treatment in a department of radiation oncology (DRO).

METHODS AND MATERIALS

During a 3-month experimental period, DRO staff administered a demographic questionnaire and attitude survey to new adult patients. SOGI demographic data, entered into the EMR by nursing staff, were extracted and analyzed for all patients from the experimental period and from the 3 months prior (control period). Descriptive and categorical data completion rates were compared between the experimental and control periods using independent-samples t tests and Pearson χ2 tests.

RESULTS

A total of 788 patients were included in this analysis: 368 in the control period and 420 in the experimental period. Of the 420 patients enrolled in the experimental period, 267 (63.6%) were offered a survey, of whom 211 (79.0%) completed the survey. There were higher rates of sexual orientation responses entered into the EMR for the experimental group compared with the control group (56.9% vs 27.1%; P <.001), with the highest response rates for patients who completed a survey (82.9%). Ten patients (2.9%) identified as gay or lesbian and 100% identified as cisgender. The majority of patients were not upset by the form, with only 11 patients (5.2%) stating that any specific question caused them distress.

CONCLUSIONS

Collecting SOGI data via a demographic form is feasible in an outpatient DRO. This approach was well received by the majority of patients and could lead to provision of higher-quality, tailored care.

Sexual and gender minority cultural humility training for oncology settings: An example of iterative adaptation and implementation

Background

Multiple national organizations recommend that cancer care providers and oncology practices be responsive to the needs of sexual and gender minority (SGM) patients. Oncology practices have attempted to incorporate this recommendation through SGM-focused cultural humility training interventions. It is unclear how best to adapt and implement such training across practices. This manuscript outlines one process for adapting a widely-used SGM training from The Fenway Institute to the context of oncology settings using the Framework for Reporting Adaptations and Modifications-Enhanced (FRAME) model.

Methods

We conducted training sessions in two oncology care settings: a breast oncology center and a radiation oncology department. Subsequently, we conducted in-depth interviews with the three trainers involved in adapting The Fenway Institute's training to these two practices. Two independent investigators coded the interviews using components of the FRAME model as an analytic guide.

Results

Training team members described the mechanisms by which FRAME adaption occurred both proactively and reactively; the importance of involving SGM-identified trainers of diverse backgrounds as well as champions from within oncology practices in which trainings were conducted; the importance of adapting both the context and content of training to be relevant to oncology audiences; and the ways in which fidelity to the core principles of improving health care for SGM patients was maintained throughout the process.

Discussion

SGM cultural humility training for oncology providers and staff must undergo iterative adaptation to address the political and social context of specific practice environments and advocate for broader institutional culture change to achieve responsiveness to SGM health needs.

Risk of adverse pathological features for intermediate risk prostate cancer: Clinical implications for definitive radiation therapy

BACKGROUND

Intermediate risk prostate cancer represents a largely heterogeneous group with diverse disease extent. We sought to establish rates of adverse pathological features important for radiation planning by analyzing surgical specimens from men with intermediate risk prostate cancer who underwent immediate radical prostatectomy, and to define clinical pathologic features that may predict adverse outcomes.

MATERIALS AND METHODS

A total of 1552 men diagnosed with intermediate risk prostate cancer who underwent immediate radical prostatectomy between 1/1/2005 and 12/31/2015 were reviewed. Inclusion criteria included available preoperative PSA level, pathology reports of transrectal ultrasound-guided prostate biopsy, and radical prostatectomy. Incidences of various pathological adverse features were evaluated. Patient characteristics and clinical disease features were analyzed for their predictive values.

RESULTS

Fifty percent of men with high risk features (defined as PSA >10 but <20 or biopsy primary Gleason pattern of 4) had pathological upstage to T3 or higher disease. The incidence of upgrade to Gleason score of 8 or higher and the incidence of lymph node positive disease was low. Biopsy primary Gleason pattern of 4, and PSA greater than 10 but less than 20, affected adverse pathology in addition to age and percent positive biopsy cores. Older age and increased percentage of positive cores were significant risk factors of adverse pathology.

CONCLUSION

Our findings underscore the importance of comprehensive staging beyond PSA level, prostate biopsy, and CT/bone scan for men with intermediate risk prostate cancer proceeding with radiation in the era of highly conformal treatment.

Survival of Patients With Second Primary Hodgkin Lymphoma

INTRODUCTION

The increased risk for second malignancies after Hodgkin lymphoma (HL) diagnosis is well known. However, to our knowledge, no study has investigated the outcomes of patients diagnosed with HL after an antecedent malignancy (HL-2). We aimed to investigate overall survival (OS), disease-specific survival (DSS), and correlates of survival in HL-2 using the Surveillance, Epidemiology and End Results (SEER) database.

PATIENTS AND METHODS

HL-2 patients (n = 821) identified from the 2000-2014 SEER-18 registries were compared to first primary HL patients (HL-1, n = 31,355) from the same registries. Multivariable, propensity score-matched (PSM), and competing risks regression analyses were conducted to assess the effect of antecedent malignancy on survival.

RESULTS

Hematologic (n = 309, 37.6%), prostate (n = 169, 20.6%), and breast (n = 76, 9.3%) malignancies were common antecedent malignancies in HL-2. Median latency between antecedent malignancy and HL diagnosis was 39 months. Median ages at HL diagnosis for HL-1 and HL-2 were 36 and 66 years, respectively (P < .001). The 5-year OS and HL-DSS rates for HL-2 versus HL-1 were 53.2% versus 82.7% and 79.1% versus 90.9%, respectively (P < .001). On multivariable analysis, antecedent malignancy was associated with decreased OS (hazard ratio [HR] = 1.27; 95% confidence interval [CI], 1.13-1.42; P < .001). With PSM balancing across covariables, antecedent malignancy was associated with decrements in HL-DSS (HR = 1.46; 95% CI, 1.12-1.92; P = .006) and OS (HR = 2.09; 95% CI, 1.74-2.51; P < .001).

CONCLUSION

The decrement in DSS in HL-2 relative to HL-1 may be related to biological differences in HL, age, and/or other unanalyzed factors. Further study of HL-2 patients is warranted.

Descriptive analysis and early-stage consumer acceptance of yogurts fermented with carrot juice

This research explored the sensory characteristics and consumer acceptance of novel probiotic unsweetened yogurts. Yogurts were made with 4 carrot juice levels (8, 16, 24, and 32%), 2 firmness levels (regular, 45g/L milk solids; firm, 90g/L milk solids), and 2 starter cultures (C1, C2). The sensory profile characterized the color intensity (before and after stirring), carrot flavor, sourness, and 7 texture/mouth-feel attributes (astringency, chalkiness, mouth-coating, thickness, smoothness, creaminess, and graininess). The influence of carrot juice level and firmness level were evaluated using ANOVA, polynomial contrasts, and principal component analysis. Mean scores and standard errors were calculated. Consumer acceptance panels in Wolfville, Nova Scotia (n=56), and in Vancouver, British Columbia (Asian n=72, non-Asian n=72), evaluated the hedonic responses to the C1 and C2 formulations, respectively. We observed increases in color intensity, carrot flavor, creaminess, mouth-coating, and chalkiness with increasing carrot juice levels, as well as increases in color intensity, carrot flavor, creaminess, mouth-coating, thickness, and astringency with increasing milk solids concentrations of the C1 and C2 yogurts. Mean hedonic scores for color, appearance, and texture/mouth-feel were greater than hedonic scores for aroma, flavor/taste, and overall liking. This research identified the sensory qualities that need further development and demonstrated the importance of early-stage consumer acceptance research for directing new product development.

Selectivity and potency of the retroprogesterone dydrogesterone in vitro

Dydrogesterone is widely used for menstrual disorders, endometriosis, threatened and habitual abortion and postmenopausal hormone replacement therapy. Although progestins have a promiscuous nature, dydrogesterone does not have clinically relevant androgenic, estrogenic, glucocorticoid or mineralocorticoid activities. To date, systematic biochemical characterization of this progestin and its active main metabolite, 20α-dihydrodydrogesterone, has not been performed in comparison to progesterone. The objective of this study was to evaluate the selectivity and potential androgenic/antiandrogenic effects of dydrogesterone and its metabolite in comparison to progesterone and medroxyprogesterone acetate by analyzing their interference with AR signaling in vitro. We characterized dydrogesterone and its metabolite for their binding and transactivation of androgen and other steroid hormone receptors and for their potential inhibitory effects against androgen biosynthetic enzymes, 17β-hydroxysteroid dehydrogenase types 3 and 5 and 5α-reductase types 1 and 2. We found that dydrogesterone resembled progesterone mainly in its progestogenic effects and less in its androgenic, anti-androgenic, glucocorticoid and antiglucocorticoid effects; whereas, 20α-dihydrodydrogesterone showed reduced progestogenic potency with no androgenic, glucocorticoid and mineralocorticoid effects. Effects on the androgen and glucocorticoid receptor differed depending on the technology used to investigate transactivation. Progesterone, but not dydrogesterone and 20α-dihydrodydrogesterone, exerted anti-androgenic effects at the pre-receptor level by inhibiting 5α-reductase type 2. Dydrogesterone, 20α-dihydrodydrogesterone and progesterone inhibited the biosynthesis of testosterone catalyzed by 17β-hydroxysteroid dehydrogenase types 3 and 5; however, due to their micromolar K(i) values, these activities appeared to be not of relevance at therapeutic levels. Overall, our data show that the anti-androgenic potential of dydrogesterone and 20α-dihydrodydrogesterone is less pronounced compared to progesterone.

Kappa opioid receptor screen with the Tango beta-arrestin recruitment technology and characterization of hits with second-messenger assays

Assays for high-throughput screening of G-protein-coupled receptors (GPCRs) have typically revolved around receptor binding, guanine nucleotide binding, and second-messenger assays measuring intracellular cAMP and calcium levels. New assay development has been directed toward G-protein-independent signaling pathways, including protein redistribution in response to activated receptors. beta-arrestin recruitment to agonist-stimulated GPCRs is the basis for the Transfluor, PathHunter, and Tango GPCR screening platforms. In the Tango GPCR technology, receptor activation results in the recruitment of a TEV protease:beta-arrestin fusion protein to the activated receptor where the TEV protease releases the GAL4-VP16 tethered to the target GPCR by a 7-amino acid TEV protease site. The release of the transcription factor results in expression of the beta-lactamase (bla) reporter gene. The authors performed a small library screen with a Tango cell line expressing the kappa opioid receptor and identified a series of compounds with a similar core chemical structure that were selective agonists for the kappa opioid receptor over the Amicro and delta opioid receptors. These compounds were validated in additional second-messenger assays, confirming the agonist activity of the identified compounds. These results provide insight into the value of screening compounds in multiple assay technologies to better characterize the compound's potency and efficacy.

Effect of hot water treatments on quality of highbush blueberries

Highbush blueberries, cv 'Burlington', were treated with 22, 45, 50, or 60 degrees C water for 15 or 30 s along with an untreated control. Fruit were then stored for 0, 1, 2, or 4 wk at 0 degrees C and 2 or 9 d at 20 degrees C prior to evaluation of microbial population and fruit quality. After 4 wk of storage, the hot water treatment at 60 degrees C resulted in 92% marketable berries, followed by 90% at 50 degrees C, 88% at 45 degrees C, and 83% at 22 degrees C compared with 76% in untreated controls. Decay incidence was reduced to 0.6%, 1.2%, 1.4%, or 2.8% with 60, 50, 45, or 22 degrees C water treatments, respectively, compared with 5.1% in controls following 4 wk at 0 degrees C and 2 d at 20 degrees C. After an additional 7 d at 20 degrees C, decay in fruit treated at 60 degrees C for 15 or 30 s remained at 1.8% and 0.4%, respectively, compared to 37.4% in controls. Weight loss of berries treated with hot water was 0.4% against 3.8% in controls, and shriveled and split berries were also reduced compared to controls (P<0.001). Aerobic plate count and yeast and mold count were reduced by 0.45 to 0.7 log at 60 degrees C for 30 s. Botrytis cinerea and Colletotrichum sp. were the dominant fungal pathogens causing decay of Burlington blueberries during storage. Hot water treatments also immediately induced an increase in ethanol and reduced fruit titratable acidity and soluble solids content, but had no significant effect on fruit firmness, pH, or most flavor volatile concentrations.

Development of homogeneous high-affinity agonist binding assays for 5-HT2 receptor subtypes

The serotonin (5-hydroxytryptamine) 5-HT2 receptor subfamily consists of three members, 5-HT2A, 5-HT2B, and 5-HT2C. These receptors share high homology in their amino acid sequence, have similar signaling pathways, and have been indicated to play important roles in feeding, anxiety, aggression, sexual behavior, mood, and pain. Subtype-selective agonists and antagonists have been explored as drugs for hypertension, Parkinson's disease, sleep disorders, anxiety, depression, schizophrenia, and obesity. In this study, we report the development of homogeneous agonist binding assays in a scintillation proximity assay (SPA) format to determine the high-affinity binding state of agonist compounds for the human 5-HT2C, 5-HT2A, and 5-HT2B receptors. The 5-HT2 agonist 1-(4- [125I]iodo-2,5-dimethoxyphenyl)-2-aminopropane ([125I]DOI) was used to label the high-affinity sites for the 5-HT2A and 5-HT2C receptors. The high-affinity sites for the 5-HT2B receptor were labeled with [3H]lysergic acid diethylamide. Total receptor expression was determined with the 5-HT2 antagonist [3H]mesulergine for the 5-HT2B and 5-HT2C receptors, and [3H]ketanserin for the 5-HT2A receptor. The agonist high-affinity binding sites accounted for 2.3% (5-HT(2C) receptor), 4.0% (5-HT2A receptor), and 22% (5-HT2B receptor) of the total receptor population. Competition binding studies using known agonists indicated high Z' values of the agonist binding assays in SPA format (Z' > 0.70). The Ki values of 5-HT, (R)(-)DOI, and VER-3323 for the 5-HT2A, 5-HT2B, and 5-HT2C receptors by SPA format were equivalent to published data determined by filtration binding assays. These results indicate that agonist binding assays in SPA format can be easily adapted to a high throughput assay to screen for selective 5-HT2C receptor agonists, as well as for selectivity profiling of the compounds.

Generation of Cell Lines for Drug Discovery Through Random Activation of Gene Expression: Application to the Human Histamine H3 Receptor

Target-based high-throughput screening (HTS) plays an integral role in drug discovery. The implementation of HTS assays generally requires high expression levels of the target protein, and this is typically accomplished using recombinant cDNA methodologies. However, the isolated gene sequences to many drug targets have intellectual property claims that restrict the ability to implement drug discovery programs. The present study describes the pharmacological characterization of the human histamine H3 receptor that was expressed using random activation of gene expression (RAGE), a technology that over-expresses proteins by up-regulating endogenous genes rather than introducing cDNA expression vectors into the cell. Saturation binding analysis using [125I]iodoproxyfan and RAGE-H3 membranes revealed a single class of binding sites with a K(D) value of 0.77 nM and a B(max) equal to 756 fmol/mg of protein. Competition binding studies showed that the rank order of potency for H3 agonists was N(alpha)-methylhistamine approximately (R)-alpha- methylhistamine > histamine and that the rank order of potency for H3 antagonists was clobenpropit > iodophenpropit > thioperamide. The same rank order of potency for H3 agonists and antagonists was observed in the functional assays as in the binding assays. The Fluorometic Imaging Plate Reader assays in RAGE-H3 cells gave high Z' values for agonist and antagonist screening, respectively. These results reveal that the human H3 receptor expressed with the RAGE technology is pharmacologically comparable to that expressed through recombinant methods. Moreover, the level of expression of the H3 receptor in the RAGE-H3 cells is suitable for HTS and secondary assays.