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ABSTRACT: Hemangiopericytomas (HPCs) are rare tumors in the central nervous system (CNS) and in extra-CNS sites. The authors of this report used the Surveillance, Epidemiology, and End Results (SEER) Program to study prognostic factors in patients with HPC.
The SEER database was analyzed for patients who were diagnosed with HPC tumors from 1973 to 2007. Patients were stratified into CNS and extra-CNS groups. Univariate and multivariate analyses were performed for the overall survival (OS) endpoint using major demographic factors (age, race, and sex) and disease factors (tumor site).
In total, 655 patients with HPC were stratified into a CNS group (n = 199) and an extra-CNS group (n = 456). The patients with extra-CNS HPC were statistically older (mean age, 53 years vs 49 years; P = .008) and were more likely to have larger tumors (median greatest dimension, 7.0 cm vs 5.2 cm; P < .001). Patients who had CNS tumors had better OS and cause-specific survival (CSS) compared with patients who had extra-CNS tumors (P < .001 for both). Negative predictors of OS on multivariate analysis included extra-CNS tumor site (hazard ratio [HR], 1.6; P = .005) and older age (ages 40-59 years: HR, 2.08; P = .032; ages 60-79 years: HR, 3.9; P < .001; aged ≥80 years: HR, 7.7; P < .001).
The current analysis demonstrated that patients with extra-CNS HPCs had worse OS and CSS than patients with CNS HPCs. Cancer 2012. © 2012 American Cancer Society.
Cancer 04/2012; 118(21):5331-8. · 4.77 Impact Factor
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ABSTRACT: Volumetric-modulated arc therapy (VMAT) has been previously evaluated for several tumor sites and has been shown to provide significant dosimetric and delivery benefits when compared with intensity-modulated radiation therapy (IMRT). To date, there have been no published full reports on the benefits of VMAT use in pancreatic patients compared with IMRT. Ten patients with pancreatic malignancies treated with either IMRT or VMAT were retrospectively identified. Both a double-arc VMAT and a 7-field IMRT plan were generated for each of the 10 patients using the same defined tumor volumes, organs at risk (OAR) volumes, dose, fractionation, and optimization constraints. The planning tumor volume (PTV) maximum dose (55.8 Gy vs. 54.4 Gy), PTV mean dose (53.9 Gy vs. 52.1 Gy), and conformality index (1.11 vs. 0.99) were statistically similar between the IMRT and VMAT plans, respectively. The VMAT plans had a statistically significant reduction in monitor units compared with the IMRT plans (1109 vs. 498, p < 0.001). In addition, the doses to the liver, small bowel, and spinal cord were comparable between the IMRT and VMAT plans. However, the VMAT plans demonstrated a statistically significant reduction in the mean left kidney V(25) (9.4 Gy vs. 2.3 Gy, p = 0.018), mean right kidney V(15) (53.4 Gy vs. 45.9 Gy, p = 0.035), V(20) (32.2 Gy vs. 25.5 Gy, p = 0.016), and V(25) (21.7 Gy vs. 14.9 Gy, p = 0.001). VMAT was investigated in patients with pancreatic malignancies and compared with the current standard of IMRT. VMAT was found to have similar or improved dosimetric parameters for all endpoints considered. Specifically, VMAT provided reduced monitor units and improved bilateral kidney normal tissue dose. The clinical relevance of these benefits in the context of pancreatic cancer patients, however, is currently unclear and requires further investigation.
Medical dosimetry: official journal of the American Association of Medical Dosimetrists 12/2011; 37(3):271-5. · 1.26 Impact Factor
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ABSTRACT: To compare the characteristics and outcome of adults and children diagnosed with Wilms' tumor.
The Surveillance, Epidemiology and End Results (SEER) database was analyzed for patients diagnosed with Wilms' tumor between 1973 and 2007. Patients were stratified into pediatric (<16 years) or adult (≥16 years) groups. Overall survival was the primary endpoint.
A total of 2342 patients (2190 pediatric and 152 adult) with Wilms' tumor were identified. Adult patients were statistically more likely to be staged as localized than pediatric patients (62.5% vs 44.7%), to not receive any lymph node sampling (57.9% vs 16.2%), and to not receive any radiation treatment (74.3% vs 53.9%). Adults had a statistically worse overall survival (OS) than pediatric patients (5-year OS, 69% vs 88%, P<.001) despite the earlier tumor stage. When stratified by treatment era, the OS of all patients treated after 1981 was statistically higher than those treated before (5-year OS, 75% vs 89%, P<.001). Significant predictors of OS on univariate analysis for adults included treatment era, SEER stage, surgery, and radiation treatment. Significant predictors of OS on multivariate analysis of all patients included adult status (hazard ratio, 4.14; P<.001), treatment era, SEER stage, and surgery.
Adults in the SEER database had statistically worse OS than pediatric patients despite previous studies showing comparable outcome when treated on protocol. The worse outcome of SEER adults likely stems from incorrect diagnosis, inadequate staging and undertreatment. We recommend lymph node samplings for all adult Wilms' tumor patients and collaboration with pediatric oncologists.
Cancer 09/2011; 118(9):2541-51. · 4.77 Impact Factor
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ABSTRACT: An early and reliable assessment of therapeutic efficacy during the treatment of cancer is essential to achieve an optimal treatment regimen and patient outcome. The use of labeled peptides to monitor tumor response is associated with several advantages. For example, peptides are very stable, non-immunogenic, are easy to label for imaging, they undergo rapid clearance from the circulation, can penetrate tumor tissue, and are inexpensive to synthesize. In this review, studies using recombinant and non-recombinant peptides to monitor the response of glioblastoma multiforme, lung, breast, pancreas, colon, prostate, and skin carcinomas to radiation and/or chemotherapeutics such as camptothecin, doxorubicin, etoposide, 5-fluorouracil, paclitaxel, AG3340, sunitinib, and dasatinib, are presented. A consideration of the imaging techniques available to monitor peptide localization, including near-infrared (NIR) fluorescence, magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography, is also included. Peptides that have been successfully used to monitor various tumor types and therapies have been shown to target proteins that undergo changes in expression in response to treatment, endothelial cells that respond to radiation, or mediators of apoptosis. Peptides that are able to selectively bind responsive versus unresponsive tumors have also been identified. Therefore, the advantages associated with the use of peptides, combined with the capacity for selected peptides to assess tumor response as demonstrated in various studies, support the use of labeled peptides to evaluate the effectiveness of a given cancer therapy.
Current Pharmaceutical Biotechnology 01/2011; 12(2):320-335. · 2.81 Impact Factor
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ABSTRACT: Exposure of tumor cells to ionizing radiation (IR) is widely known to induce a number of cellular changes. One way that IR can affect tumor cells is through the development of neoantigens which are new molecules that tumor cells express at the cell membrane following some insult or change to the cell. There have been numerous reports in the literature of changes in both tumor and tumor vasculature cell surface molecule expression following treatment with IR. The usefulness of neoantigens for imaging and therapeutic applications lies in the fact that they are differentially expressed on the surface of irradiated tumor cells to a greater extent than on normal tissues. This differential expression provides a mechanism by which tumor cells can be "marked" by radiation for further targeting. Drug delivery vehicles or imaging agents conjugated to ligands that recognize and interact with the neoantigens can help to improve tumor-specific targeting and reduce systemic toxicity with cancer drugs. This article provides a review of the molecules that have been reported to be expressed on the surface of tumor cells in response to IR either in vivo or in vitro. Additionally, we provide a discussion of some of the methods used in the identification of these antigens and applications for their use in drug delivery and imaging.
American journal of cancer research. 01/2011; 1(3):390-412.
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ABSTRACT: To introduce an educational intervention-specifically, a specialized training course-and perform a formative evaluation of the effect of the intervention on novice reader interpretation of computed tomography (CT) colonographic data.
The study was institutional review board approved. Ten normal and 50 abnormal cases, those of 60 patients with 93 polyps-61 polyps 6-9 mm in diameter and 32 polyps 10 mm or larger-were selected from a previously published trial. Seven novice readers underwent initial training that consisted of a 1-day course, reading assignments, a self-study computer module (with 61 limited data sets), observation of an expert interpreting three cases, and full interpretation of 10 cases with unblinding after each case. After training, the observers independently interpreted 60 cases by means of primary two-dimensional reading with unblinding after each case. For each case, the reading time and the location and maximal diameter of the polyp(s) were recorded. A t test was used to evaluate the observers' improvements, and empirical receiver operating characteristic (ROC) curves were constructed.
By-patient sensitivities and specificities were determined for each observer. The lowest by-patient sensitivity at the 6 mm or larger polyp threshold was 86%, with 90% specificity. Four observers had 100% by-patient sensitivity at the 10 mm or larger polyp threshold, with 82%-97% specificity. For polyps 10 mm or larger, mean sensitivity and specificity were 98% and 92%, respectively. For the last 20 cases, the average interpretation time per case was 25 minutes. The range of areas under the ROC curve across observers was low: 0.86-0.95.
In the described polyp-enriched cohort, novice CT colonographic data readers achieved high sensitivity and good specificity at formative evaluation of a comprehensive training program. Use of a similar comprehensive training method might reduce interreader variability in interpretation accuracy and be useful for reader certification.
Radiology 11/2008; 249(1):167-77. · 5.73 Impact Factor
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ABSTRACT: In this retrospective study, the authors hypothesized that magnetic resonance imaging (MRI) would alter partial breast irradiation (PBI) eligibility by identifying cancers outside the PBI volume compared with mammography alone.
Since 2002, MRI was used nonselectively at the authors' institution for the staging of patients with nonmetastatic breast cancer. Of 450 consecutive patients with invasive breast cancer, 110 patients who were eligible for PBI were identified by using criteria outlined by National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Oncology Group trial 0413 based on mammography, ultrasonography, and initial pathology. In that trial, patients were randomized (stage I/II invasive cancers that measured <or=3 cm and <or=3 positive lymph nodes) to receive either whole-breast radiotherapy or PBI. MRI reports were reviewed to determine whether MRI identified secondary lesions 1) within the same quadrant (multifocal), 2) in a different quadrant (multicentric), or 3) in the contralateral breast. These lesions were pathologically proven carcinoma and would have rendered the patient ineligible for PBI.
MRI identified secondary lesions in 10% of patients (95% confidence interval [CI], 4.4%-15.6%). Multifocal disease was identified in 3.6% (95% CI, 1.4%-9%), multicentric disease was identified in 4.5% (95% CI, 2%-10.2%), and contralateral disease was identified in 1.8% (95% CI, 0.5%-6.4%). The proportion of patients with false-positive MRI findings was 4.5% (95% CI, 2%-10.2%). The positive predictive value of MRI was 72.2% (95% CI, 46.4%-89.3%).
MRI identified frequent secondary cancers that would not be removed routinely by surgery or targeted in the radiation field if treated with PBI. The current data suggest that MRI should be considered to assess PBI eligibility to minimize potential local failures.
Cancer 10/2008; 113(9):2408-14. · 4.77 Impact Factor
