Biomarkers for Radiation Biodosimetry and Injury Assessment after Mixed-field (Neutron and Gamma) Radiation in the Mouse Total-body Irradiation Model

The risk of potential radiation exposure scenarios that include detonation of nuclear weapons, terrorist attacks on nuclear reactors, and the use of conventional explosives to disperse radioactive substances has increased in recent years. The majority of radiation biodosimetry and countermeasure studies have been performed using photon radiation even though many exposure scenarios predict mixed-field (neutron and photon) radiation. Hence, there is a need to evaluate biomarkers and accurately determine exposure levels of mixed-field combinations of neutrons and photons for an individual. These biomarkers will be critical for biodosimetry triage, treatment, and follow-up visits with such individuals. We evaluated the utility of multiple blood biomarkers for early response assessment of radiation exposure using a mouse (B6D2F1, males and females) total-body irradiation model exposed to a mixed-field (neutrons and gamma rays) using the Armed Forces Radiobiology Research Institute's Mark F nuclear research reactor. Total-body irradiation was given as a single exposure over a dose range from 1.5 to 6 Gy, dose rates of 0.6 and 1.9 Gy min, and different proportions of neutrons and gammas: either (67% neutrons + 33% gammas) or (30% neutrons + 70% gammas). Blood was collected 1, 2, 4, and 7 d after total-body irradiation. Radiation-responsive protein biomarkers were measured using the Meso Scale Diagnostics' high-throughput MULTI-ARRAY plate-format platform (QuickPlex 120 Imager) and enzyme-linked immunosorbent assay kits. Results demonstrate (1) dose- and time-dependent changes in fms-related tyrosine kinase 3 ligand, interleukins IL-5, IL-10, IL-12, and IL-18, granulocyte and granulocyte-macrophage colony-stimulating factors, thrombopoietin, erythropoietin, acute-phase proteins (serum amyloid A and lipopolysaccharide binding protein), surface plasma neutrophil (CD45) and lymphocyte (CD27) markers, ratio of CD45 to CD27, and procalcitonin; (2) dose- and time-dependent changes in blood cell counts (lymphocytes, neutrophils, platelets, red blood cells, and ratio of neutrophils to lymphocytes); (3) levels of IL-18, granulocyte and granulocyte-macrophage colony-stimulating factors, serum amyloid A, and procalcitonin were significantly higher in animals irradiated with 67% neutrons + 33% gammas compared to those irradiated with 30% neutrons + 70% gammas (p < 0.015), while no significant differences (p > 0.114) were observed in hematological biomarker counts; (4) exposure with 3-fold difference in dose rate (0.6 or 1.9 Gy min) revealed no significant differences in hematological and protein biomarker levels (p > 0.154); and (5) no significant differences in hematological and protein biomarker levels were observed in the sex-comparison study for any radiation dose at any time after exposure (p > 0.088). Results show that the dynamic changes in the levels of selected hematopoietic cytokines, organ-specific biomarkers, and acute-phase protein biomarkers reflect the time course and severity of acute radiation syndrome and may function as prognostic indicators of acute radiation syndrome outcome. These studies supplement an ongoing effort to deliver U.S. Federal Drug Administration-approved biodosimetry capabilities, which assess mixed-field radiation exposure.

Comparison of Biodosimetry Biomarkers for Radiation Dose and Injury Assessment After Mixed-Field (Neutron and Gamma) and Pure Gamma Radiation in the Mouse Total-Body Irradiation Model

The detonation of a nuclear weapon and the occurrence of a nuclear accident represent possible mass-casualty events with significant exposure to mixed neutron and gamma radiation fields in the first few minutes after the event with the ensuing fallout, extending for miles from the epicenter, that would result primarily in photon (gamma- and/or x-ray) exposure. Circulating biomarkers represent a crucial source of information in a mass-casualty radiation exposure triage scenario. We evaluated multiple blood biodosimetry and organ-specific biomarkers for early-response assessment of radiation exposure using a mouse (B6D2F1, males and females) total-body irradiation model exposed to Co gamma rays over a broad dose range (3-12 Gy) and dose rates of either 0.6 or 1.9 Gy min and compared the results with those obtained after exposure of mice to a mixed field (neutrons and gamma rays) using the Armed Forces Radiobiology Research Institute Co gamma-ray source and TRIGA Mark F nuclear research reactor. The mixed-field studies were performed previously over a broad dose range (1.5-6 Gy), with dose rates of either 0.6 or 1.9 Gy min, and using different proportions of neutrons and gammas: either (67% neutrons + 33% gammas) or (30% neutrons + 70% gammas). Blood was collected 1, 2, 4, and 7 d after total-body irradiation. Results from Co gamma-ray studies demonstrate: (1) significant dose- and time-dependent reductions in circulating mature hematopoietic cells; (2) dose- and time-dependent changes in fms-related tyrosine kinase 3 ligand, interleukins IL-5, IL-10, IL-12, and IL-18, granulocyte colony-stimulating factors, thrombopoietin, erythropoietin, acute-phase proteins (serum amyloid A and lipopolysaccharide binding protein), surface plasma neutrophil (CD45) and lymphocyte (CD27) markers, ratio of CD45 to CD27, procalcitonin but not in intestinal fatty acid binding protein; (3) no significant differences were observed between dose-rate groups in hematological and protein profiles (fms-related tyrosine kinase 3 ligand, IL-5, IL-12, IL-18, erythropoietin, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, CD27, CD45, and ratio of CD45 to CD27) for any radiation dose at any time after exposure (p > 0.148); (4) no significant differences were observed between sex groups in hematological and protein profiles (fms-related tyrosine kinase 3 ligand, IL-18, erythropoietin, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, serum amyloid A, CD45) for any radiation dose at any time after exposure (p > 0.114); and (5) PCT level significantly increased (p < 0.008) in mice irradiated with 12 Gy on day 7 post-total-body irradiation without significant differences between groups irradiated at dose rates of either 0.6 or 1.9 Gy min (p > 0.287). Radiation-quality comparison results demonstrate that: (1) equivalent doses of pure gamma rays and mixed-field radiation do not produce equivalent biological effects, and hematopoietic syndrome occurs at lower doses of mixed-field radiation; (2) ratios of hematological and protein biomarker means in the Co study compared to mixed-field studies using 2× Co doses vs. 1× TRIGA radiation doses (i.e., 3 Gy Co vs. 1.5 Gy TRIGA) ranged from roughly 0.2 to as high as 26.5 but 57% of all ratios fell within 0.7 and 1.3; and (3) in general, biomarker results are in agreement with the relative biological effectiveness = 1.95 (Dn/Dt = 0.67) reported earlier by Armed Forces Radiobiology Research Institute scientists in mouse survival countermeasure studies.

A model combining age, equivalent uniform dose and IL-8 may predict radiation esophagitis in patients with non-small cell lung cancer

BACKGROUND AND PURPOSE

To study whether cytokine markers may improve predictive accuracy of radiation esophagitis (RE) in non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

A total of 129 patients with stage I-III NSCLC treated with radiotherapy (RT) from prospective studies were included. Thirty inflammatory cytokines were measured in platelet-poor plasma samples. Logistic regression was performed to evaluate the risk factors of RE. Stepwise Akaike information criterion (AIC) and likelihood ratio test were used to assess model predictions.

RESULTS

Forty-nine of 129 patients (38.0%) developed grade ≥2 RE. Univariate analysis showed that age, stage, concurrent chemotherapy, and eight dosimetric parameters were significantly associated with grade ≥2 RE (p < 0.05). IL-4, IL-5, IL-8, IL-13, IL-15, IL-1α, TGFα and eotaxin were also associated with grade ≥2 RE (p < 0.1). Age, esophagus generalized equivalent uniform dose (EUD), and baseline IL-8 were independently associated grade ≥2 RE. The combination of these three factors had significantly higher predictive power than any single factor alone. Addition of IL-8 to toxicity model significantly improves RE predictive accuracy (p = 0.019).

CONCLUSIONS

Combining baseline level of IL-8, age and esophagus EUD may predict RE more accurately. Refinement of this model with larger sample sizes and validation from multicenter database are warranted.

Prediction of Radiation Esophagitis in Non-Small Cell Lung Cancer Using Clinical Factors, Dosimetric Parameters, and Pretreatment Cytokine Levels

Radiation esophagitis (RE) is a common adverse event associated with radiotherapy for non-small cell lung cancer (NSCLC). While plasma cytokine levels have been correlated with other forms of radiation-induced toxicity, their association with RE has been less well studied. We analyzed data from 126 patients treated on 4 prospective clinical trials. Logistic regression models based on combinations of dosimetric factors [maximum dose to 2 cubic cm (D2cc) and generalized equivalent uniform dose (gEUD)], clinical variables, and pretreatment plasma levels of 30 cytokines were developed. Cross-validated estimates of area under the receiver operating characteristic curve (AUC) and log likelihood were used to assess prediction accuracy. Dose-only models predicted grade 3 RE with AUC values of 0.750 (D2cc) and 0.727 (gEUD). Combining clinical factors with D2cc increased the AUC to 0.779. Incorporating pretreatment cytokine measurements, modeled as direct associations with RE and as potential interactions with the dose-esophagitis association, produced AUC values of 0.758 and 0.773, respectively. D2cc and gEUD correlated with grade 3 RE with odds ratios (ORs) of 1.094/Gy and 1.096/Gy, respectively. Female gender was associated with a higher risk of RE, with ORs of 1.09 and 1.112 in the D2cc and gEUD models, respectively. Older age was associated with decreased risk of RE, with ORs of 0.992/year and 0.991/year in the D2cc and gEUD models, respectively. Combining clinical with dosimetric factors but not pretreatment cytokine levels yielded improved prediction of grade 3 RE compared to prediction by dose alone. Such multifactorial modeling may prove useful in directing radiation treatment planning.

Radiation-induced lung toxicity in non-small-cell lung cancer: Understanding the interactions of clinical factors and cytokines with the dose-toxicity relationship

BACKGROUND AND PURPOSE

Current methods to estimate risk of radiation-induced lung toxicity (RILT) rely on dosimetric parameters. We aimed to improve prognostication by incorporating clinical and cytokine data, and to investigate how these factors may interact with the effect of mean lung dose (MLD) on RILT.

MATERIALS AND METHODS

Data from 125 patients treated from 2004 to 2013 with definitive radiotherapy for stages I-III NSCLC on four prospective clinical trials were analyzed. Plasma levels of 30 cytokines were measured pretreatment, and at 2 and 4weeks midtreatment. Penalized logistic regression models based on combinations of MLD, clinical factors, and cytokine levels were developed. Cross-validated estimates of log-likelihood and area under the receiver operating characteristic curve (AUC) were used to assess accuracy.

RESULTS

In prognosticating grade 3 or greater RILT by MLD alone, cross-validated log-likelihood and AUC were -28.2 and 0.637, respectively. Incorporating clinical features and baseline cytokine levels increased log-likelihood to -27.6 and AUC to 0.669. Midtreatment cytokine data did not further increase log-likelihood or AUC. Of the 30 cytokines measured, higher levels of 13 decreased the effect of MLD on RILT, corresponding to a lower odds ratio for RILT per Gy MLD, while higher levels of 4 increased the association.

CONCLUSIONS

Although the added prognostic benefit from cytokine data in our model was modest, understanding how clinical and biologic factors interact with the MLD-RILT relationship represents a novel framework for understanding and investigating the multiple factors contributing to radiation-induced toxicity.

Principal component analysis identifies patterns of cytokine expression in non-small cell lung cancer patients undergoing definitive radiation therapy

Background/Purpose

Radiation treatment (RT) stimulates the release of many immunohumoral factors, complicating the identification of clinically significant cytokine expression patterns. This study used principal component analysis (PCA) to analyze cytokines in non-small cell lung cancer (NSCLC) patients undergoing RT and explore differences in changes after hypofractionated stereotactic body radiation therapy (SBRT) and conventionally fractionated RT (CFRT) without or with chemotherapy.

Methods

The dataset included 141 NSCLC patients treated on prospective clinical protocols; PCA was based on the 128 patients who had complete CK values at baseline and during treatment. Patients underwent SBRT (n = 16), CFRT (n = 18), or CFRT (n = 107) with concurrent chemotherapy (ChRT). Levels of 30 cytokines were measured from prospectively collected platelet-poor plasma samples at baseline, during RT, and after RT. PCA was used to study variations in cytokine levels in patients at each time point.

Results

Median patient age was 66, and 22.7% of patients were female. PCA showed that sCD40l, fractalkine/C3, IP10, VEGF, IL-1a, IL-10, and GMCSF were responsible for most variability in baseline cytokine levels. During treatment, sCD40l, IP10, MIP-1b, fractalkine, IFN-r, and VEGF accounted for most changes in cytokine levels. In SBRT patients, the most important players were sCD40l, IP10, and MIP-1b, whereas fractalkine exhibited greater variability in CFRT alone patients. ChRT patients exhibited variability in IFN-γ and VEGF in addition to IP10, MIP-1b, and sCD40l.

Conclusions

PCA can identify potentially significant patterns of cytokine expression after fractionated RT. Our PCA showed that inflammatory cytokines dominate post-treatment cytokine profiles, and the changes differ after SBRT versus CFRT, with vs without chemotherapy. Further studies are planned to validate these findings and determine the clinical significance of the cytokine profiles identified by PCA.

Plasma Levels of IL-8 and TGF-β1 Predict Radiation-Induced Lung Toxicity in Non-Small Cell Lung Cancer: A Validation Study

PURPOSE AND OBJECTIVES

We previously reported that the combination of mean lung dose (MLD) and inflammatory cytokines interleukin-8 (IL-8) and transforming growth factor-β1 (TGF-β1) may provide a more accurate model for radiation-induced lung toxicity (RILT) prediction in 58 patients with non-small cell lung cancer (NSCLC). This study is to validate the previous findings with new patients and to explore new models with more cytokines.

METHODS AND MATERIALS

One hundred forty-two patients with stage I-III NSCLC treated with definitive radiation therapy (RT) from prospective studies were included. Sixty-five new patients were used to validate previous findings, and all 142 patients were used to explore new models. Thirty inflammatory cytokines were measured in plasma samples before RT and 2 weeks and 4 weeks during RT (pre, 2w, 4w). Grade ≥2 RILT was defined as grade 2, and higher radiation pneumonitis or symptomatic pulmonary fibrosis was the primary endpoint. Logistic regression was performed to evaluate the risk factors of RILT. The area under the curve (AUC) for the receiver operating characteristic curves was used for model assessment.

RESULTS

Sixteen of 65 patients (24.6%) experienced RILT2. Lower pre IL-8 and higher TGF-β1 2w/pre ratio were associated with higher risk of RILT2. The AUC increased to 0.73 by combining MLD, pre IL-8, and TGF-β1 2w/pre ratio compared with 0.61 by MLD alone to predict RILT. In all 142 patients, 29 patients (20.4%) experienced grade ≥2 RILT. Among the 30 cytokines measured, only IL-8 and TGF-β1 were significantly associated with the risk of RILT2. MLD, pre IL-8 level, and TGF-β1 2w/pre ratio were included in the final predictive model. The AUC increased to 0.76 by combining MLD, pre IL-8, and TGF-β1 2w/pre ratio compared with 0.62 by MLD alone.

CONCLUSIONS

We validated that a combination of mean lung dose, pre IL-8 level, and TGF-β1 2w/pre ratio provided a more accurate model to predict the risk of RILT2 compared with MLD alone.

Metabolic response assessment with 18F-FDG PET/CT: inter-method comparison and prognostic significance for patients with non-small cell lung cancer

OBJECTIVE

This study aimed to (1) compare the agreement of two evaluation methods of metabolic response in patients with non-small cell lung cancer (NSCLC) and determine their prognostic value and (2) explore an optimal cutoff of metabolic reduction to distinguish a more favorable subset of responders.

METHODS

This is a secondary analysis of prospective studies. Enrolled patients underwent 18F-PET/CT within 2 weeks before, during, and months after radiotherapy (post-RT). Metabolic response was assessed using both Peter MacCallum (PM) method of qualitative visual assessment and University of Michigan (UM) method of semiquantitative measurement. The agreement between two methods determined response, and their prediction of outcome was analyzed.

RESULTS

Forty-four patients with median follow-up of 25.2 months were analyzed. A moderate agreement was observed between PM- and UM-based response assessment (Kappa coefficient = 0.434), unveiling a significant difference in CMR rate (p = 0.001). Categorical responses derived from either method were significantly predictive of overall survival (OS) and progression-free survival (PFS) (p < 0.0001). Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS. A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.

CONCLUSIONS

There was a modest discrepancy in metabolic response rates between PM and UM criteria, though both could offer predictive classification for survival. The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

Timing and intensity of changes in FDG uptake with symptomatic esophagitis during radiotherapy or chemo-radiotherapy

Purpose

To study whether esophageal FDG activity changes by time of mid-course of fractionated radiotherapy (RT), and whether these changes are associated with radiation esophagitis in patients with non-small cell lung cancer (NSCLC).

Methods

Fifty patients with stage I-III NSCLC were enrolled prospectively and, all received ≥60 Gy RT. FDG-PET/CT scans were acquired prior to, and during-RT after delivery of 45 Gy. Normalized standardized uptake values (NSUV), defined by the esophageal maximum SUV relative to intravascular background level in the aortic arch, were sampled in the esophagus at the level of the primary tumor, sternal notch, aortic arch, carina, and gastro-esophageal junction. Symptomatic radiation esophagitis was defined as an event.

Results

Compared to baseline, esophageal NSUV increased significantly during-RT at the level of the primary tumor (1.09 ± 0.05 vs.1.28 ± 0.06, p = 0.001), but did not change at other levels in the esophagus. 16 patients had radiation esophagitis events and these patients had significantly higher during-RT to baseline NSUV ratios than those without esophagitis (1.46 ± 0.12, 95% CI 1.20-1.71; vs. 1.11 ± 0.05, 95% CI 1.01-1.21, p = 0.002). Maximum esophageal dose (p = 0.029), concurrent chemotherapy (p = 0.022) and esophageal FDG PET NSUV ratio (during-RT to baseline, p = 0.007), were independent factors associated with esophagitis and area under curves (AUC) were 0.76, 0.70 and 0.78, respectively. Combining esophageal maximum dose and FDG PET NSUV Ratio at the tumor level increased AUC to 0.85 (p = 0.016).

Conclusion

FDG uptake increased in esophagus during-RT and this increase may predict radiation esphagitis during later course of treatment.

Serum miRNA signature to identify a patient’s resistance to high-dose radiation therapy for unresectable non-small cell lung cancer

7580

Background: There is a growing literature on unique profiles of serum micro RNAs (miRNAs) expression to predict clinical outcome of metastatic and early stage non-small cell lung cancer (NSCLC). However, the predictive role of circulating miRNAs in unresectable NSCLC treated with definitive radiation therapy (RT) is unknown. Methods: 134 patients with inoperable/unresectable NSCLC treated with definitive RT (18-month minimum follow-up) were eligible. Serum samples were collected prospectively before treatment. 100 patients had enough serum and reliable miRNA profile quality, which were randomly divided into training and validation sets (50 patients each). MiRNA profiling was performed using real-time PCR-based array, containing a panel of 84 miRNAs detectable in human bodily fluids. Spiked-in cel-miR-39 was used for normalization. Stepwise regression Cox model building was used to build a miRNA signature on the training set, which was then assessed on the validation set both alone and with clinical factors. Results: The median age was 67 years; 76% were stages III and 79% received chemoradiation; the median physical dose was 70.0 Gy. A serum hsa-miR-885/hsa-miR-7 signature was identified as significant predictors for overall survival (OS) in the training set, which was validated by the validation set (p=0.02). After adjustment for GTV Volume and KPS, the only two significant clinical factors in univariate analysis, this signature remained significant (p=0.04). In the high-dose RT group (>70 Gy, n=45), individuals with low-risk had a significantly longer OS than patients with high-risk (70.7 vs. 18.8 months, p=0.007); while in the low-dose RT group (≤70 Gy, n=55), no significant association was observed (OS, 22.0 vs. 13.3 months, p=0.43). Conclusions: Circulating hsa-miR-885/hsa-miR-7 signature may be used as a putative non-invasive biomarker for predicting survival and radiation resistance in unresectable NSCLC, which may potentially help to select patients who will not benefit from high-dose radiation. Independent validation studies are needed to confirm our findings. Clinical trial information: NCT01190527.

Total lesion glycolysis (TLG) at baseline FDG-PET/CT compared with maximum standard uptake value (SUVmax) to predict survival in non-small cell lung cancer (NSCLC)

7579

Background: SUVmaxat baseline FDG-PET has been reported as a significant prognostic factor while recent studies suggest that metabolic tumor volume (MTV) may be more important factor in patients with NSCLC. We hypothesized that TLG is a better prognostic factor than either SUVmax or MTV alone for overall survival (OS) and progression free survival (PFS) in NSCLC because it integrates both volumetric and biologic activity. Methods: The study population included a prospectively recruited cohort of stage I-III NSCLC patients treated with chemoradiation. FDG PET/CT scans were performed within 2 weeks from treatment start. The SUV in the tumor was normalized to that of the background level in the middle of ascending aorta to minimize the confounding effect from inter-scan variation in SUV measurement. MTV was delineated by auto-threshold at 1.5 times background level in the aorta followed by knowledge based manual editing. Mean and maximum SUV normalized to the background level were computed. TLG was calculated as the product of lesion SUVmean and MTV. Results: A total of 96 patients with minimum follow-up of 1 year were eligible. The median follow-up among survivors was 30 months. Univariate analysis demonstrated that MTV and TLG were significant factors for both OS and PFS (all P<0.05). There was a significant correlation between SUVmean and PFS (P=0.013), but there was no significant association between SUVmean and OS. SUVmax was not a significant factor for either OS or PFS (all P>0.05). Under multivariate Cox regression analysis, MTV (HR= 2.62, P= 0.003) and NSUVmean (HR=0.351, P=0.003) were significantly associated with PFS; but only TLG was significantly associated with OS (HR=2.14, P=0.006)adjusted by of TNM stage and other clinical factors. Conclusions: These results support our hypothesis that metabolic tumor volume and biologic average glucose metabolic activity of this volume are more important prognostic factors for overall prognosis than SUVmax in NSCLC patients treated with chemoradiation. Should this be validated by independent studies, future clinical trial should take this into consideration for individualized care.

Poor baseline pulmonary function may not increase the risk of radiation-induced lung toxicity

PURPOSE

Poor pulmonary function (PF) is often considered a contraindication to definitive radiation therapy for lung cancer. This study investigated whether baseline PF was associated with radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) receiving conformal radiation therapy (CRT).

METHODS AND MATERIALS

NSCLC patients treated with CRT and tested for PF at baseline were eligible. Baseline predicted values of forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and diffusion capacity of lung for carbon monoxide (DLCO) were analyzed. Additional factors included age, gender, smoking status, Karnofsky performance status, coexisting chronic obstructive pulmonary disease (COPD), tumor location, histology, concurrent chemotherapy, radiation dose, and mean lung dose (MLD) were evaluated for RILT. The primary endpoint was symptomatic RILT (SRILT), including grade ≥2 radiation pneumonitis and fibrosis.

RESULTS

There was a total of 260 patients, and SRILT occurred in 58 (22.3%) of them. Mean FEV1 values for SRILT and non-SRILT patients were 71.7% and 65.9% (P=.077). Under univariate analysis, risk of SRILT increased with MLD (P=.008), the absence of COPD (P=.047), and FEV1 (P=.077). Age (65 split) and MLD were significantly associated with SRILT in multivariate analysis. The addition of FEV1 and age with the MLD-based model slightly improved the predictability of SRILT (area under curve from 0.63-0.70, P=.088).

CONCLUSIONS

Poor baseline PF does not increase the risk of SRILT, and combining FEV1, age, and MLD may improve the predictive ability.

Automated renal stone volume measurement by noncontrast computerized tomography is more reproducible than manual linear size measurement

PURPOSE

We compared the reproducibility of automated volume and manual linear measurements using same study supine and prone, low dose, noncontrast computerized tomography series.

MATERIALS AND METHODS

The patient cohort comprised 50 consecutive adults with a mean age of 56.4 years in whom renal calculi were identified during computerized tomography colonography screening. The largest stone per patient was assessed with the supine and prone computerized tomography series serving as mutual controls. Automated stone volume was derived using a commercially available coronary artery calcium scoring tool. Supine-prone reproducibility for automated volume was compared with intra-observer supine-prone manual linear measurement. Interobserver variability was also assessed for manual linear measurements of the same supine or prone series.

RESULTS

Mean ± SD linear size and volume of the 50 index calculi was 4.5 ± 2.7 mm (range 1.8 to 16) and 141.7 ± 456.1 mm(3), respectively. The mean supine-prone error for automated stone volume was 16.3% compared with an average 11.7% 1-dimensional intra-observer error for manual axial measurement. Only 2 of 15 cases with a volume error of greater than 20% were 5 mm or greater in linear size. The average interobserver linear error for the same computerized tomography series was 26.3% but automated volume measurement of the same series did not vary.

CONCLUSIONS

Automated noncontrast computerized tomography renal stone volume is more reproducible than manual linear size measurement and it avoids the often large interobserver variability seen with manual assessment. Since small linear differences correspond to much larger volume changes, greater absolute volume errors are acceptable. Automated volume measurement may be an improved clinical parameter to use for following the renal stone burden.

211. Proteomic identification of caldesmon as one of the physiological substrates of proprotein convertase 6 during decidualisation

We have previously demonstrated that proprotein convertase 5/6 (PC6), a member of the proprotein convertase (PC) family, is a critical endometrial factor for implantation. PC6 is upregulated in the endometrium specifically at implantation in association with epithelial differentiation (in human and monkey) and stromal cell decidualisation (in the mouse, human and monkey). Knockdown of endometrial PC6 during early pregnancy in mice in vivo led to complete failure of implantation, while blocking of PC6 production in human endometrial stromal cells in vitro inhibited decidualisation. PCs convert a range of precursor proteins of important functions into their bioactive forms; they are thus regarded as critical ‘master switch’ molecules. We hypothesise that PC6 exerts its roles in the endometrium by regulating proteins of diverse functions essential for implantation. In this study, we utilised proteomic technology and aimed to identify proteins that are specifically cleaved by PC6 in human endometrial stromal cells (HESC) during decidualisation. HESC were decidualised with cyclic AMP, the cell lysates were treated with and without recombinant human PC6-A (rPC6-A), and the 2D Differential in Gel Electrophoresis (2D DiGE) protein profiles were compared between the two treatments. We identified several proteins which were differentially cleaved following the addition of rPC6-A. Mass spectrometric analysis confirmed that the most abundant of these were caldesmon, tropomyosin-2, tropomyosin-4, hypoxia Inducible factor-1 and chloride intracellular channel-1. These proteins showed spot shifts in hPC6-A treated HESC lysates consistent with hPC6-A cleavage. western blot analysis confirmed the specific cleavage of caldesmon by PC6 in HESCs, and immunohistochemical analysis showed co-localisation of caldesmon and PC6 in decidual cells in human endometrial tissue. Given that caldesmon is a structural protein previously found to be involved in actin filament reorganisation, our results strongly suggest that PC6 is a mediator of structural remodelling of stromal cells during decidualisation in the endometrium.

Low expression of HER2 protein in breast cancer is biologically significant

HER2 status is routinely tested using immunohistochemistry or FISH following the licensing of a therapeutic agent targeting HER2. However, neither of these methods provides quantitative information relating to the 70-80% of patients with levels of expression lower than the assay detection thresholds. In this study, radioimmunohistochemistry was used to detect quantitative HER2 protein expression in 178 breast cancers. Survival analysis was performed, as were correlations with known prognostic variables and with overexpression of other HER family members. It is demonstrated that the populations expressing very high and very low levels of HER2 are each associated with increased risk of cancer-specific death on survival analysis (p = 0.0043). The group with low levels of HER2 was more likely to be of higher grade, EGFR-positive and ER/HER3/HER4-negative. HER2-positive cases were frequently ER-negative/HER3-positive, whilst cases with normal HER2 expression were often ER-positive/HER4-positive. The aggressive nature of the tumour group with low HER2 expression may be explained by actions of other HER family members, particularly EGFR, but whether these or other factors have a negative regulatory effect on HER2 expression remains to be determined.

Correlation between radiographic findings of osteoarthritis and arthroscopic findings of articular cartilage degeneration within the patellofemoral joint

OBJECTIVES

To correlate radiographic findings of osteoarthritis on axial knee radiographs with arthroscopic findings of articular cartilage degeneration within the patellofemoral joint in patients with chronic knee pain.

SUBJECTS AND METHODS

The study group consisted of 104 patients with osteoarthritis of the patellofemoral joint and 30 patients of similar age with no osteoarthritis of the patellofemoral joint. All patients in the study group had an axial radiograph of the knee performed prior to arthroscopic knee surgery. At the time of arthroscopy, each articular surface of the patellofemoral joint was graded using the Noyes classification system. Two radiologists retrospectively reviewed the knee radiographs to determine the presence of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts. The sensitivity and specificity of the various radiographic features of osteoarthritis for the detection of articular cartilage degeneration within the patellofemoral joint were determined.

RESULTS

The sensitivity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 73%, 37%, 4%, and 0% respectively. The specificity of marginal osteophytes, joint-space narrowing, subchondral sclerosis, and subchondral cysts for the detection of articular cartilage degeneration within the patellofemoral joint was 67%, 90%, 100%, and 100% respectively.

CONCLUSION

Marginal osteophytes were the most sensitive radiographic feature for the detection of articular cartilage degeneration within the patellofemoral joint. Joint-space narrowing, subchondral sclerosis, and subchondral cysts were insensitive radiographic features of osteoarthritis, and rarely occurred in the absence of associated osteophyte formation.

Arthroscopic validation of radiographic grading scales of osteoarthritis of the tibiofemoral joint

OBJECTIVE

The purpose of this study was to use the Kellgren-Lawrence, Ahlback, and Brandt grading scales to correlate radiographic grade of osteoarthritis with the actual degree of articular cartilage degeneration within the tibiofemoral joint in patients with chronic knee pain.

SUBJECTS AND METHODS

The study group consisted of 125 patients with symptomatic osteoarthritis of the tibiofemoral joint. For all patients, standing anteroposterior radiographs of the knee were obtained before arthroscopic knee surgery. Each articular surface of the tibiofemoral joint was graded at arthroscopy. Two radiologists retrospectively reviewed the knee radiographs without knowledge of the arthroscopic findings to determine the presence and severity of osteoarthritis of the tibiofemoral joint using the Kellgren-Lawrence, Ahlback, and Brandt grading scales. Correlation coefficients describing the relation between grade of osteoarthritis and severity of articular cartilage degeneration were calculated for each grading scale.

RESULTS

The correlation coefficients for the Kellgren-Lawrence, Ahlback, and Brandt grading scales were 0.49, 0.41, and 0.56, respectively. The differences between the correlation coefficients for the Kellgren-Lawrence and Ahlback grading scales and the correlation coefficients for the Brandt and Ahlback grading scales were statistically significant (p < 0.05). Many patients with no radiographic findings of osteoarthritis had significant articular cartilage degeneration within the tibiofemoral joint.

CONCLUSION

The Kellgren-Lawrence and Brandt grading scales were equally effective in defining the presence of and estimating the severity of osteoarthritis of the tibiofemoral joint but had only a moderately strong correlation with the actual degree of articular cartilage degeneration.

Subchondral Bone Marrow Edema in Patients with Degeneration of the Articular Cartilage of the Knee Joint

PURPOSE

To retrospectively determine at magnetic resonance (MR) imaging the prevalence of subchondral bone marrow edema beneath arthroscopically proved articular cartilage defects.

MATERIALS AND METHODS

The study was performed in compliance with HIPAA regulations, and a waiver of informed consent was obtained from the institutional review board before the study was performed. The study consisted of 132 patients (70 men, 62 women; average age, 53 years) with articular cartilage defects of the knee joint who underwent MR imaging of the knee and subsequent arthroscopic knee surgery. At the time of arthroscopy, each articular cartilage lesion was graded by using the Noyes classification system. MR examinations were retrospectively reviewed to determine the size, depth, and location of subchondral bone marrow edema without knowledge of the arthroscopic findings. Pairwise Fisher exact tests and two-sample t tests were used to correlate MR imaging findings of subchondral bone marrow edema with the arthroscopic grade of articular cartilage degeneration.

RESULTS

Subchondral bone marrow edema was seen beneath 105 (19%) of 554 articular cartilage defects identified at arthroscopy. It was not observed beneath any of the six grade 1 cartilage defects but was observed beneath eight (4.9%) of 163 grade 2A defects, 40 (14.4%) of 278 grade 2B defects, 54 (55.1%) of 98 grade 3A defects, and three (33.3%) of nine grade 3B defects. Subchondral bone marrow edema was also seen beneath four (1.4%) of 238 articular surfaces that appeared normal at arthroscopy. The mean depth and cross-sectional area of subchondral bone marrow edema increased with increasing grade of the articular cartilage lesion.

CONCLUSION

Higher grades of articular cartilage defects are associated with higher prevalence and greater depth and cross-sectional area of subchondral bone marrow edema.

Good management. Make boards work better

Performance reviews for trust boards are rare, despite their strategic importance. Cohesion between executives and non-executives, and willingness for board members to challenge one another, are critical. Too much challenge and too little trust can suppress innovation.

Management. Gently does it

Soft intelligence is information gathered from conversations, observations and experiences that allow judgements to be made. Research by York University shows that less than one in four of those interviewed used hard data to inform their judgements of NHS trusts. Sources of soft information can be direct: based on first-hand experiences; and indirect: the accounts and views of colleagues, patients, public, friends, journalists.

Effective boards. Born & bred

If a board is to be effective its members must understand their roles and share trust with their colleagues. Members must be prepared to challenge colleagues, conventions and their own assumptions. Individual responsibility dissolves in large groups. Successful boards avoid this phenomenon.

HER2 as a prognostic and predictive marker for breast cancer

In recent years investigators have looked at the human epidermal growth factor receptor-2 (HER2), which is overexpressed in 20%-30% of breast cancer patients, with regard to its role as a prognostic and predictive factor. Although many studies have suggested that HER2 overexpression may be associated with a poor clinical outcome, other studies have not fully supported this observation. The inconsistencies between studies may be due in part to discrepancies between different HER2 testing methods. To overcome this problem, a radioimmunohistochemical method was developed to quantitatively measure HER2 overexpression levels in breast tumor samples. The application of this method demonstrated that 85% of all breast tumor samples expressed HER2 at levels greater than normal. Of these, 23% expressed HER2 at levels between 45 and 480 times greater than normal, and this was associated with poor clinical outcome. The investigation of HER2 status as a predictor of response to therapy has also yielded many conflicting results. Overall, it appears that HER2 overexpression may correlate with resistance to hormonal therapy, sensitivity to anthracycline-based chemotherapy and resistance to CMF. With the development of targeted anti-HER2 therapies, assessment of HER2 status will be important in stratifying patients to the most appropriate treatment regimens.

Evaluating HER2 amplification and overexpression in breast cancer

The development of Herceptin (Trazumatab) makes testing for HER2 status important for choosing optimal therapy in breast cancer. This study addresses the precision, accuracy, and reproducibility of HER2 assays. HER2 was assessed retrospectively by immunohistochemistry (IHC) with Dako 'Herceptest', by IHC with the monoclonal antibody CB11, and by fluorescence in situ hybridization (FISH, PathVysion), in a series of 216 formalin-fixed breast carcinomas including 191 for which quantitative HER2 data from radioimmunohistochemistry (Q-IHC) were available. All tests were scored independently by two observers. Positivity rates varied between Herceptest (12.6%), FISH (19.4%), and CB11 IHC (28.5%). Kappa values showed that IHC-based tests were more susceptible to inter-observer variation (kappa=0.67 and 0.74 for Herceptest and CB11, respectively) than FISH (kappa=0.973). Overall test accuracy (see the Materials and methods section) for CB11 IHC (83.8%) was lower than Herceptest (87.4%) or FISH (93.2%). FISH predicted p185 HER2 overexpression (determined by Q-IHC) better (concordance index C.Ind. 0.90) than CB11 IHC (C.Ind.=0.85) or Herceptest (C.Ind.=0.81). Of 42 cases with gene amplification by FISH, 67% were positive in the Herceptest (2+ or 3+) vs. 83% with CB11. Of 174 cases negative by FISH, 96% were negative in the Herceptest and 68% with CB11. In conclusion, FISH is the most accurate, reproducible, and precise predictor of HER2 overexpression in routine diagnostic laboratories.

Competitive health policies and community health

Since 1992 there have been fundamental changes in health care policy in Victoria, Australia, as the state government moves to competitive market models of service delivery and the measurement of service provision through output based funding. The introduction of competitive relationships to the public health system has had a major impact in the primary health care sector, particularly on community health centres. Most community health centres in Victoria have traditionally been semi-independent agencies controlled by community based committees of management. Such policies have had huge implications for the management and organisation of these agencies, as they have led to different patterns of service delivery and different models of management practice, often devaluing traditional philosophical perspectives of 'primary health care practice'. Although many agencies have embraced change as providing opportunities for growth and development and to have more influence in the provision of mainstream public health care, primary health care models of practice should be supported for their intrinsic and increasing value.

Employment relationships in Victorian public hospitals: the Kennett years

From 1992 to 1999, the Kennett government in Victoria moved to competitive market models of service delivery and the measurement of service provision through casemix funding. Public hospital managers were given greater accountability for the costs and provision of service delivery and a new range of service providers, many from the private sector, entered the public health market. The decentralisation of the industrial relations system led to new developments in bargaining that brought both opportunities and problems. In the Victorian public health system there was an increasing emphasis on decentralisation in both service provision and employment relations. In this paper I suggest that there were contradictions in these developments for government, and new challenges and difficulties for employers, employees and trade unions.

The value of the human epidermal growth factor receptor-2 (HER2) as a prognostic marker

The prognosis for patients with breast cancer is determined by well-established pathological features associated with biological aggressiveness, histological grade, tumour size and nodal involvement. These remain the key determinants, despite the identification of numerous other potential biological markers. The use of prognostic indices, such as the Nottingham Prognostic Index (NPI), which combines and weights these factors, enables clinicians to predict outcome with a certain amount of accuracy. Approximately 20-30% of breast cancers express very high quantities of the human epidermal growth factor receptor-2 (HER2) protein and this is almost always associated with gene amplification. With the use of sensitive techniques, such as the radio-immunohistochemical method (rIHC) described herein, to quantify HER2 protein levels, up to a further 50% of such cancers will be found to express the HER2 receptor at least 4-fold higher than normal breast cells. Adding HER2 expression to the NPI helps to determine more accurately the prognosis for individual patients, particularly those with node-negative disease. Overall, the main value of HER2 measurement is likely to be in the prediction of response to therapies targeting the HER2 gene and protein.

The value of the human epidermal growth factor receptor-2 (HER2) as a prognostic marker

The prognosis for patients with breast cancer is determined by well-established pathological features associated with biological aggressiveness, histological grade, tumour size and nodal involvement. These remain the key determinants, despite the identification of numerous other potential biological markers. The use of prognostic indices, such as the Nottingham Prognostic Index (NPI), which combines and weights these factors, enables clinicians to predict outcome with a certain amount of accuracy. Approximately 20-30% of breast cancers express very high quantities of the human epidermal growth factor receptor-2 (HER2) protein and this is almost always associated with gene amplification. With the use of sensitive techniques, such as the radio-immunohistochemical method (rIHC) described herein, to quantify HER2 protein levels, up to a further 50% of such cancers will be found to express the HER2 receptor at least 4-fold higher than normal breast cells. Adding HER2 expression to the NPI helps to determine more accurately the prognosis for individual patients, particularly those with node-negative disease. Overall, the main value of HER2 measurement is likely to be in the prediction of response to therapies targeting the HER2 gene and protein.