Pilot study on 18 F-FDG PET/CT for detection of inflammatory changes in blood-induced knee arthropathy in a rabbit model

RATIONALE

¹⁸ F-FDG-PET/CT has a potential role in the early detection of haemophilic arthritis, at a time when treatment may still avoid further joint degeneration. The purposes of this pilot study were to determine the ability of ¹⁸ F-FDG-PET/CT to detect inflammatory changes associated with blood-induced arthropathy in knees of a rabbit model.

METHODS

Ten juvenile rabbits were imaged at baseline and weeks 5 and 17 post intraarticular autologous blood injections (ABI). Five rabbits in group 1 (G1) had ABI into the same knee joint every 2 weeks (total, eight injections). Five rabbits in group 2 (G2) had only two injections into the same knee, at weeks 5 and 17. Images were assessed visually and semi-quantitatively by measuring maximal standardized uptake values (SUVmax) and standardized uptake ratio (SUR = SUVmax in affected knee/SUVmax in non-affected knee).

RESULTS

More rabbits in G1 than G2 presented with positive chronic inflammatory synovial scores at week 17. Mean iron staining scores in injected knees were greater for G1 than for G2 (P = 0.049). No increased uptake was identified in the injected knees in any of the rabbits at baseline or at week 5. At week 17, all G1 rabbits demonstrated increased uptake in their affected knees with higher mean SUVmax (1.5) than normal knees (1.0) (P < 0.02). None of the G2 rabbits showed asymmetric increased uptake. The SUR of G1 was higher at week 17 compared to baseline (P < 0.01) and week 5 (P < 0.01). The SUR at week 17 was higher for G1 than for G2 (1.13) rabbits (P < 0.01).

CONCLUSION

¹⁸ F-FDG-PET is able to detect the inflammatory changes associated with haemophilic arthropathy in this experimental model.

Longitudinal assessment of bone loss using quantitative ultrasound in a blood-induced arthritis rabbit model

INTRODUCTION

Osteoporosis is common in haemophilic arthropathy. Quantitative ultrasound (QUS) can be a suitable alternative for dual-energy x-ray absorptiometry for diagnosing osteoporosis in haemophiliacs due to its lack of ionizing radiation, and ease to use.

AIM

We investigated the intra- and inter-operator reliability of QUS, its responsiveness to bone growth, its ability to differentiate bone adjacent to blood-injected vs. control joints, and the effect of soft tissues on the speed of sound (SOS) QUS values in a juvenile white New Zealand rabbit model of blood-induced arthritis.

METHODS

Eight of 16 rabbits were injected with autologous blood (0.1 mL kg(-1) ) 8 times over a 17-week period, the remaining eight rabbits served as controls. SOS was measured at baseline, weeks 8 and 17 in vivo and after the bones were excised on week 17.

RESULTS

Intra- and inter-operator coefficients of variation for QUS data were <5% and intraclass correlation coefficients were >60% for 22/27 (81.5%) of bones assessed. The level of interval increase in SOS values from baseline to week 17 was significantly different in tibiae of injected, contralateral to injected and non-injected knee groups by anova (P = 0.01). In vivo (mean ± SD, 4147.17 ± 96.27 m s(-1) ) and postmortem (4457.85 ± 104.00 m s(-1) ) measurements on week 17 differed (P < 0.01) indicating an effect of soft tissues on SOS.

CONCLUSION

In conclusion, QUS' acceptable reliability, its responsiveness to growth-related changes and its ability to discriminate injected and non-injected joints make this technique a plausible candidate as a diagnostic tool for osteoporosis in the paediatric haemophilic population if these results are confirmed upon animal-human translation.

Abstract P3-14-11: Microarray data analysis and long term outcomes of NCIC-CTG MA.22: Neoadjuvant epirubicin and docetaxel with pegfilgrastim support for locally advanced breast cancer

Background: 93 patients were enrolled in sequential phase 1 and 2 trials of epirubicin (E) and docetaxel (D) given at 3 (cohort A) or 2 weekly (cohort B) intervals. We previously reported clinical (93%) and pathologic response rates (pCR 7%) as well as the association of fall in tumour RNA integrity (RIN) with response (ASCO 2010). Here we report the results of microarray analysis of tumor specimens pre-and mid-treatment to determine genes which are differentially expressed in different groups. Methods: 6 core biopsies were collected for all patients pre-, mid- and post-treatment with ED. 3 cores were used for standard pathologic assessment while 3 were used for gene expression assessment using Agilent full genome microarrays. Pre- and mid-treatment cores were used with Agilent Feature Extraction Software to assess microarrays; and baseline continuous (% positive) immunohistochemical ER, PR, HER2, and Topo2 were investigated by schedule and dose. RNAs with RIN &gt; = 5.0 were subjected to microarray analysis. NIH BRB array tools were used for investigations of differential gene expressions. K-M curves were generated for the phase 2 cohorts for disease free (DFS) and event free survival (EFS), and for ER− PR− and ER or PR+ subgroups. Results: Of the 93 patients, 47 were in cohort A and 46 in cohort B. Median overall survival was 6.34 years on study. DFS at 50 months was 55% for A (phase 2) and 67% for B (phase 2), while EFS was 55% for A and 63% for B. For ER or PR+ DFS and EFS were 60% and for ER− PR− DFS and EFS were 63%. 134 arrays were available in total: 57 from A, 68 from B with 11 reference breast tumour RNAs for standardization. Patients with and without microarrays were not significantly different. Pre-treatment, we found 3 differentially expressed genes in A and 6 in B between patients who did and did not have RIN &gt; = 5.0 at mid-treatment. Comparing CR to non-CR (PR, SD, PD), 40 genes were found for A and 2 genes for B. Many genes were also differentially expressed in A and B when analyzed by pathologic factors ER, PR, HER2, Topo2, schedule and dose. Mid-treatment, 4,365 genes in A and 18,770 genes in B were significantly different from pre-treatment. Conclusion: At 50 months, DFS was 55% for 3 weekly and 67% for 2 weekly schedules of ED. The genes identified in each cohort pretreatment will be investigated further for relevance to predicting sensitivity or resistance to E or D.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-11.

Functional imaging of neoadjuvant chemotherapy response in women with locally advanced breast cancer using diffuse optical spectroscopy

3591

Background: Functional imaging with tomographic near infrared diffuse optical spectroscopy (DOS) can quantitatively measure tissue parameters such as the concentration of deoxy-hemoglobin (Hb), oxy-hemoglobin (HbO2), percent water (%water), and scattering power (SP). The purpose of this study was to evaluate the correlation between DOS functional parameters with pathologic outcomes. Methods: Patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy or chemoradiotherapy were recruited to this study (n=10). Five scans were conducted per patient: a baseline scan taken up to 3 days prior to treatment and at 1 week, 4 weeks, 8 weeks, and after neoadjuvant treatment prior to surgery. Pulsed near-infrared laser light was used to scan the suspended breast at four different wavelengths and data was used for tomographic reconstruction. Volume-of-interest (VOI) weighted tissue Hb, HbO2, %water, and SP corresponding to the tumour was calculated and compared to pathological response as determined from full mount mastectomy specimens. Results: For all 10 patients the tumour-based VOI was significantly different than background tissue for all functional parameters (p<0.001). Five patients had a good pathologic response. Four patients were considered non-responders. One patient initially had a poor clinical response to chemotherapy but after a change in chemotherapy had a good clinical response. Responders and non-responders were significantly different for all of the functional parameters (p<0.05) at the 4 week scan. In the 5 patients with a good response the mean drop in Hb, HbO2, %water, and SP from baseline to the 4 week scan was 70.4% (SD=18.6), 66.5% (SD=24.5), 59.6% (SD=30.9), and 60.7% (SD=29.2), respectively. In contrast, the 4 non- responders had a mean drop of 17.7% (SD=9.8), 18.0% (SD=20.8), 15.4% (SD=11.7), and 12.6% (SD=10.2), for Hb, HbO2, %water and SP, respectively. Conclusions: Functional imaging using tomographic DOS parameters of Hb, HbO2, %water and SP could be used as an early detector of final pathologic tumour response. This could be evaluated in the future to assess response and potentially adjust chemotherapy regimens.

No significant financial relationships to disclose.

Reductions in tumor RNA integrity associated with clinical response to epirubicin/docetaxel chemotherapy in breast cancer patients

Abstract #6068

Background: Optimal doses and dosing intervals for neoadjuvant anthracycline/taxane chemotherapy are poorly studied. Moreover, biomarkers for measuring response to such combination regimens are unknown. This study investigated these issues in sequential phase I/II cohorts of women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel with pegfilgrastim support at 3- or 2-weekly intervals in association with the NCIC-CTG MA.22 clinical trial.&#x2028; Methods: Accrual has been completed for the 3-weekly regimen (maximum tolerated dose: epirubicin 105 mg/m2, taxotere 75 mg/m2), and continues for the phase II portion of the 2-weekly regimen. Six core biopsies were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of ER, PR, HER2 and Topo II expressed as % positive stain. Tumour RNA integrity (RIN) and tumor extent were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after haematoxylin/eosin staining, respectively. Associations between maximum and average RIN at the three time points and tumour extent, clinical response, pathologic complete response, or baseline levels of ER, PR, HER2 and Topo II were assessed using Spearman correlation coefficients after data transformation to improve symmetry and stabilize variances. The association between both RIN and tumour extent, and baseline drug dose was assessed using a 1-way ANOVA.&#x2028; Results: Low mid-treatment maximum RIN was associated with high drug dose level (p=0.05) and eventual pathologic complete response (p=0.01). Post-treatment, low maximum and average RIN were found to be associated with low tumor extent (p=0.004 and p=0.01, respectively). As well, low average RIN was significantly associated with clinical complete response post-treatment (p=0.01). As expected, post-treatment low tumor extent was significantly associated with pathologic complete response (p=0.01). High pre-treatment Topo II levels were also significantly associated with high RIN (p = 0.03). No association was observed between RIN and HER2, ER or PR.&#x2028; Discussion: The association of RIN with tumour extent, pathologic complete response, clinical response, a known risk factor (Topo II), and drug dose suggests that the RIN may represent an important new biomarker for measuring response to anthracycline/taxane combinations (and possible other chemotherapy regimens) in breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6068.

Assessing breast tissue density by transillumination breast spectroscopy (TIBS): an intermediate indicator of cancer risk

Risk assessment by parenchymal density pattern, a strong physical indicator of future breast cancer risk, is available with the onset of mammographic screening programmes. However, due to the use of ionizing radiation, mammography is not recommended for use in younger women, thereby rendering risk assessment unattainable at an earlier age. Visible and near infrared light was used on 292 women with radiologically normal mammograms to determine whether transillumination breast spectroscopy (TIBS) can identify women with a high parenchymal density pattern as an intermediate indicator of breast cancer risk. Principal component analysis (PCA) was used to reduce the spectral data and generate density scores for each woman. To assess the accuracy of TIBS, logistic regression was used to calculate crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) for each score. Receiver operator characteristic (ROC) curves and area under the curve (AUC) were also calculated for the crude and adjusted logistic models. Optical information relating to tissue chromophores, such as water, lipid and haemoglobin content, was sufficient to identify women with high parenchymal density. The resulting AUC for the final and most parsimonious multivariate logistic model was 0.922 (95% CI 0.878-0.967). TIBS provides information correlating to high parenchymal density and is a promising tool for risk assessment, particularly for younger women.

A hybrid breast biopsy system combining ultrasound and MRI

System design and initial phantom accuracy results for a novel biopsy system integrating both magnetic resonance (MR) and ultrasound (US) imaging modalities are presented. A phantom experiment was performed to investigate the efficacy of this hybrid guidance biopsy technique in a breast tissue mimicking phantom. A comparison between MR-guided core biopsy verses MR/US-guided core biopsy of phantom targets was realized using a scoring system based on the consistency of the acquired core samples (14 gauge). It was determined that the addition of US to guide needle placement improved the accuracy from an average score of 7.4 out of 10 (MRI guidance alone), to 9.6 (MRI/US guidance) over 21 trials. The average amount of needle tip correction resulting from the additional US information was determined to be 3.7 mm. This correction value is substantial, equal to approximately one radius of the intended targets. Hybrid US/MRI guided biopsy appears to offer a simple means to ensure accurate breast tissue sampling without the need for repeat MRI scans for verification or the need for real-time imaging in open MRI geometries.

The association of breast mitogens with mammographic densities

Radiologically dense breast tissue (mammographic density) is strongly associated with risk of breast cancer, but the biological basis for this association is unknown. In this study we have examined the association of circulating levels of hormones and growth factors with mammographic density. A total of 382 subjects, 193 premenopausal and 189 postmenopausal, without previous breast cancer or current hormone use, were selected in each of five categories of breast density from mammography units. Risk factor information, anthropometric measures, and blood samples were obtained, and oestradiol, progesterone, sex hormone binding globulin, growth hormone, insulin-like growth factor-I and its principal binding protein, and prolactin measured. Mammograms were digitised and measured using a computer-assisted method. After adjustment for other risk factors, we found in premenopausal women that serum insulin-like growth factor-I levels, and in postmenopausal women, serum levels of prolactin, were both significantly and positively associated with per cent density. Total oestradiol and progesterone levels were unrelated to per cent density in both groups. In postmenopausal women, free oestradiol (negatively), and sex hormone binding globulin (positively), were significantly related to per cent density. These data show an association between blood levels of breast mitogens and mammographic density, and suggest a biological basis for the associated risk of breast cancer.

Aspergillus mycetoma in a secondary hydroxyapatite orbital implant: a case report and literature review

OBJECTIVE

The authors describe the first case report of a fungal abscess within a hydroxyapatite orbital implant in a patient who had undergone straightforward secondary hydroxyapatite implant surgery.

DESIGN

Case report and literature review.

INTERVENTION

Four months postoperatively after pegging and 17 months after original implant placement, chronic discharge and socket irritation became evident. Recurrent pyogenic granulomas were a problem, but no obvious area of dehiscence was present over the implant. The peg and sleeve were removed 31 months after pegging (44 months after original placement of the implant). The pain and discharge did not resolve, and the entire hydroxyapatite orbital implant was removed 45 months after sleeve placement and 58 months after initial implant placement. The pain and discharge settled rapidly.

MAIN OUTCOME MEASURES

Cultures and histopathology.

RESULTS

Results of bacterial cultures were negative. Results of histopathologic examination of the implant disclosed intertrabecular spaces with multiple clusters of organisms consistent with Aspergillus.

CONCLUSIONS

Persistent orbital discomfort, discharge, and pyogenic granulomas after hydroxyapatite implantation should cause concern regarding potential implant infection. The authors have now shown that this implant infection could be bacterial or fungal in nature. This is essentially a new form of orbital Aspergillus, that of a chronic infection limited to a hydroxyapatite implant.

Expression of WT1 in pediatric small cell tumors: report of two cases with a possible mesothelial origin

The WT1 gene is normally expressed in fetal kidney and mesothelium, and its expression has been suggested as a marker for Wilms tumor and mesothelioma. We examined WT1 expression levels by reverse-transcriptase polymerase chain reaction (RT-PCR) in 38 childhood small-cell tumors including Wilms tumor, embryonal and alveolar rhabdomyosarcoma, Ewing sarcoma, lymphoma, desmoplastic small round-cell tumor (DSRCT), synovial sarcoma, extrarenal rhabdoid tumor, and two tumors that were atypical for this group of tumors. WT1 expression was only detected in Wilms tumor, rhabdoid tumor, and in these two cases of uncertain histogenesis. Both arose in the peritoneal cavity and by immunohistochemistry were diffusely positive for vimentin, keratin, and desmin. Tonofilaments were identified by electron microscopy in one of the cases. RT-PCR failed to detect the t(11;22) translocation associated with DSRCT in either case. Our results suggest that WT1 expression is an unusual feature of childhood non-Wilms tumors and, in the right setting, it may indicate a mesothelial origin. The expression of WT1 may play a role in mesodermal cells acquiring epithelial characteristics, a concept supported by the mixed epithelial and mesenchymal phenotype of these two cases.

Alveolar soft part sarcoma: review of nine cases including two cases with unusual histology

AIM

Alveolar soft part sarcoma is a very rare tumour. Nine cases are reviewed in order to identify new aspects of this tumour.

METHODS AND RESULTS

The clinical course, histological, immunohistochemical and ultrastructural features of nine cases of alveolar soft part sarcoma were reviewed. Proliferative activity and p53 protein accumulation were assessed immunohistochemically. The patients were aged between 18 and 70 years. In the cases with sufficient follow-up, survival was variable with two patients dying within 5 months and four alive at 4 years. Histologically all tumours had an alveolar component but one case also had a spindle component and another case had a pseudoglandular pattern. Six cases showed desmin immunoreactivity, one was muscle-specific actin positive, two were positive for S100 protein and three were positive for vimentin. MIB-1 immunostaining was seen in up to 35% of cells. Two cases showed p53 protein accumulation.

CONCLUSIONS

There appeared to be no correlation between short term survival (4 years or less) and clinical presentation, adjuvant treatment, tumour size, histological grade, vascular invasion by tumour, proliferative index, or p53 protein accumulation. Although unusual, spindle cell or pseudoglandular components can be seen in alveolar soft part sarcoma.

Mammographic signs of potential relevance to breast cancer risk: the agreement of radiologists' classification

We have assessed the agreement of radiologists who quantitatively estimated the extent of various mammographic features of the breast. These features are of potential relevance to the estimation of the future risk of developing breast cancer. After preparation, in which various mammographic appearances and their classification were discussed and agreed upon, two radiologists, experienced in mammography, independently estimated the extent of various types of radiological density in 120 sets of mammograms, each comprised of two mediolateral and two craniocaudal views. The results showed a high level of agreement between the two radiologists in the classification of total mammographic densities (r = 0.89). For classification of specific types of density, agreement was best for homogeneous densities (r = 0.79), more intermediate for nodular densities (r = 0.71) and worst for linear densities (r = 0.48). These results show that radiologists can, with suitable preparation, identify total breast density, a mammographic sign relevant to a woman's risk of later developing breast cancer, with a high degree of agreement.

Mammographic densities as a criterion for entry to a clinical trial of breast cancer prevention

The most convincing evidence that a factor such as dietary fat is causally related to breast cancer would be obtained from a randomised controlled trial in which exposure to dietary fat intake was systematically varied. A limitation of randomised controlled trials of breast cancer prevention, however, is the large sample size required to detect plausible reductions in risk resulting from the intervention. We describe here experience over a period of 9 years with the use of one risk factor for breast cancer as a criterion for entry to a clinical trial of breast cancer prevention. The risk factor used was the presence of extensive densities in the breast tissue on mammography, which has been found by several investigators to be strongly associated with risk of breast cancer. Using this criterion for selection, 1800 subjects of mean age 46 years were enrolled between 1982 and 1986, and again between 1988 and the present. Throughout this period, the point estimate of annual invasive cancer incidence was approximately 6 per 1000 per year. The observed cancer incidence has been consistently 4-5 times the incidence expected from age-specific breast cancer incidence data for women living in Ontario. These data show that the selection of subjects for a clinical trial of breast cancer prevention using the criterion of extensive breast parenchymal densities does identify a group at substantially increased risk of breast cancer. Use of this criterion for the selection of subjects can substantially reduce the sample size required for a clinical trial of a preventive strategy.

Sensitivity and specificity of first screen mammography in the Canadian National Breast Screening Study: a preliminary report from five centers

Sensitivity and specificity of first screen mammography in a randomized screening trial at five centers are reported. A total of 23,101 women underwent mammography; in 139, breast cancer was detected at first screening; in 20, less than 12 months after first screening; and in 47, at second screening. All 206 cancer cases were histologically confirmed, and 174 were defined as being detectable at first screening. Average length of follow-up for all women was 3.2 years. Interpretations of first screen mammograms by the center radiologists were matched to known outcomes. Simultaneous blind review was performed by a single reference radiologist with mammograms from all 206 cancer cases and those of a random sample of 739 women not known to have breast cancer at 15 months or more after initial screening. Overall, the five screening centers achieved a sensitivity of 69% (range, 60%-78%), a specificity of 94% (range, 93%-96%), a positive predictive value of 8.6% (range, 3%-16%), and a negative predictive value of 99.7% (range, 99.6%-99.9%).