Evaluation of Irradiated Mandibles Using Emission Tomography, Bone Scans, and Radiography

This study compared radiographs, bone scans, and computed emission tomograms with histologic findings in irradiated mandibles of adult Rhesus monkeys. Although osteocytes were lost in the path of the beam, many vessels were partially or totally occluded, the periosteum degenerated, the marrow became fibrotic, and cancellous bone proliferated abundantly, no changes were noted with radiography, conventional bone scanning, or computed emission tomograms. These clinical methods of examination may misrepresent the true condition of irradiated bone because of inadequate sensitivity or balance among factors that control radioactive tracer uptake in bone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68112/2/10.1177_00220345800590120201.pd

Impact of 18F-fluoro-deoxy-glucose positron emission tomography (FDG-PET) in recurrent colorectal cancer

Purpose: The aim of the study was to evaluate the diagnostic performance, the prognosis factors and the therapeutic impact of 18F-FDG positron emission tomography (FDG-PET) in the detection of recurrent colorectal cancers. Methods: Sixty PET/CT with 18F-FDG and CT were performed in 52 patients, at the Paul Papin cancer center between 2003 and 2005, following suspicion of colorectal cancer relapse. The FDG-PET impact on the clinical management was studied by examination of multidisciplinary concertations results. Survival analysis were realized with a mean follow up of 2.2 years. Results: Recurrence was confirmed for 50 explorations by histologic (n = 32), radiologic (n = 14) or clinical (n = 4) findings. Twenty patients died during the time of the study. On a patient based analysis, FDG-PET sensitivity, specificity and overall accuracy were 90, 90, 90% respectively compared with 74, 50 and 70% for CT. FDG-PET changed the clinical management in 18 cases (30%). A positive FDG-PET signal, more than one hepatic lesion, more than two lymph node lesions detected on FDG-PET and more than two hepatic lesions on CT were characterized as bad prognostic factors for survival. Multivariate analysis showed that the only independent bad prognostic factor was the FDG-PET detection of more than two liver lesions. Conclusion: These results confirmed the important impact of FDG-PET in the clinical management of patients with a suspected recurrence of colorectal cancer

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

Background Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.Methods Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.Results for pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using >= 4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. for pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. for pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.Conclusions the agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.Canadian Cancer SocietyOntario Ministry of Health and Long-Term CareHanna Family Chair in Surgical OncologySunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Toronto, ON M4N 3M5, CanadaSunnybrook Hlth Sci Ctr, Dept Med Imaging, Toronto, ON M4N 3M5, CanadaUniversidade Federal de São Paulo, Dept Surg, São Paulo, BrazilQueens Univ, Dept Community Hlth & Epidemiol, Kingston, ON, CanadaUniv Toronto, Div Biostat, Dalla Lana Sch Publ Hlth, Toronto, ON, CanadaInst Clin Evaluat Sci, Toronto, ON, CanadaSunnybrook Hlth Sci Ctr, Div Surg Oncol, Odette Canc Ctr, Toronto, ON M4N 3M5, CanadaUniv Toronto, Dept Hlth Policy Management & Evaluat, Toronto, ON, CanadaUniversidade Federal de São Paulo, Dept Surg, São Paulo, BrazilCanadian Cancer Society: 019325Web of Scienc

Assessment of Healthy Tissue Metabolism to Predict Outcomes in Oncologic [18F]FDG PET/CT

Background: The use of 2-[18F]Fluoro-2-deoxy-d-glucose ([18F]FDG) in positron emission tomography/computed tomography (PET/CT) imaging is not specific to oncologic applications but reflects various pathologic processes with high metabolic activity. Thus, evaluating healthy tissue metabolism (HTM) based on [18F]FDG in cancer patients receiving cytotoxic anti-cancer treatment may provide prognostic information which could potentially assist in identifying patients at high risk of developing treatment-related adverse events (AEs) and those who may have poor outcome. However, unlike cancer imaging HTM assessment with [18F]FDG is lacking standardization in the research setting.Purpose: The main aim of this thesis was to review the applications of [18F]FDG PET/CT in the assessment of anti-cancer treatment-related AEs and to assess methods used in the literature to measure HTM. Further, to evaluate the repeatability and interobserver variation of HTM in lung cancer patients. Finally, HTM based on [18F]FDG uptake was assessed as an imaging biomarker to predicts AEs and outcomes in Hodgkin lymphoma (HL) patients. Methods: A comprehensive literature search was conducted in PubMed, Embase and Web of Science databases for published data on [18F]FDG uptake in different HT for assessment of AEs in cancer patients. Different common and modified methods of assessment were applied to measure [18F]FDG uptake in liver, spleen and other HT. Retrospective test-retest repeatability and interobserver analyses of HTM were also performed on 22 patients with non-small cell lung cancer who underwent [18F]FDG PET/CT of the thorax 2 days apart without intervening treatment (from a prospective study) to measure the maximum, mean and peak standardised uptake values (SUVmax, SUVmean and SUVpeak). Moreover, [18F]FDG uptake in 200 patients with advanced HL from the RATHL trial was retrospectively measured in bone marrow (BM), mediastinal blood pool (MBP), liver and spleen at baseline (PET0) and after 2 cycles of chemotherapy (PET2). Results: Out of the reviewed studies, (n = 80, 94%) reported an association between [18F]FDG uptake in HT and treatment-related AEs. Quantitative assessment using SUVmean was mainly applied in those studies to assess changes in HTM at multiple timepoint. Further evaluation of the liver, spleen and other HT showed that using SUVmean reduces bias across different methods. Further, applying fixed volume of interest (VOI) was comparable to more sophisticated approaches. In comparison to other PET metrics, SUVmean also showed better repeatability as expressed with the within-subject coefficient of variation (wCV) of 20% and high interobserver agreement of ≤10% in HT in the thorax; however, left ventricle uptake was highly variable in a test-retest analysis. In HL, HT uptake changed significantly during treatment. BM uptake at PET0 was associated with baseline haematological parameters, higher risk of neutropenia at cycles 1-2 and failure of early response. Non-responding patients with high BM uptake at PET2 had inferior progression-free survivor (PFS). Conclusion: Most of the studies reviewed from the literature reported an association between HTM and treatment-related AEs among different cancer types and treatment modalities. SUVmean was mainly used in those studies to correlate changes in HTM with treatment-related AEs which was shown to be more stable than SUVmax and SUVpeak. [18F]FDG uptake in uninvolved BM has a prognostic value in HL

Estudio multidisciplinar del Cancer Gastrico en la Población Jiennense. Epidemiología, Valor predictivo del estadiaje radiológico inicial (TCMD) y factores pronósticos histopatológicos asociados al tumor

El cáncer gástrico es una enfermedad virulenta que representa una importante causa de mortalidad por cáncer. En el año 2012, según la OMS, se estimaron casi un millón de nuevos casos, representando el 5º cáncer más común mundial. Pese a que la incidencia y mortalidad se han reducido en los últimos 50 años, aún constituye un gran problema de salud pública. Nuestra hipótesis de trabajo pretende evaluar los factores multidisciplinarios que implican la aparición del cáncer gástrico, seleccionando la población jiennense. Como objetivo principal, consideramos a factores epidemiológicos involucrados en el estadío de presentación del cáncer gástrico, así como el valor de la Tomografía Computerizada Multicorte (TCMD) en el estadiaje radiológico inicial versus los grados histológicos de extensión tumoral. Como objetivos específicos estudiamos correlaciones secundarias entre el estadiaje radiológico de la afectación parietal (T) por TC (T clínico) vs distintos parámetros clínicos e histológicos; y por otra parte entre factores pronósticos y predictivos . DESARROLLO: Nuestro estudio es observacional, realizado sobre cohorte retrospectiva, en un registro hospitalario multicéntrico. La inclusión se realizó prospectivamente tras la cirugía, con biopsia positiva para adenocarcinoma (104 pacientes). Establecimos criterios radiológicos de estadiaje tumoral basados en la literatura. El análisis estadístico se realizó según análisis descriptivo de las variables y mediante análisis bivariante del resto de objetivos. Resumen epidemiológico de la población jiennense: - edad media: 64, mayoritariamente varones (68,3%); localización predominante: antral (43%); media tamaño: 5,5 cm. - comorbilidad: 21% diabéticos, 23% hipertensos, 14% dislipémicos y 4,8% ansiedad - enfermedad péptica (principal factor de riesgo): 71% - sintomatología de alarma predominante: pérdida peso (37%) - analíticamente: cifras bajas de hemoglobina (44%), linfocitos (62%), HDL (44%), LDL (86%), proteínas (72%), ferritina (61%), hierro (74%), y discretamente aumentadas de CEA (76%), CA 19,9 (22%). En nuestro estudio a pesar de ser estadísticamente significativo, el grado de concordancia entre estadiaje T clínico e histológico es pobre, y entre estadiaje N clínico e histológico muy pobre. Se detectaron diferencias significativas entre los valores de tamaño en los diferentes estadíos histológicos correspondientes a estadios I y III. En las correlaciones entre Tipo Histológico y Tamaño ó Localización Tumoral no se demuestran diferencias estadísticamente significativas CONCLUSIÓN: Nuestros datos epidemiológicos generales son concordantes con la literatura, siendo necesario más estudios de investigación, dada la variabilidad y multiplicidad de factores implicados; y en el estudio de extensión (TC), nuestro estudio, aunque estadísticamente significativo, demostró un limitado grado de concordancia entre estadiaje clínico e histológico T y N. BIBLIOGRAFÍA: Kwee RM, Kwee TC (2007). Imaging in local staging of gastric cancer: a systematic review. J Clin Oncol 25 (15): 2107-2116 Ba-Ssalamah A, Prokop M, Uffmann M, Pokieser P, Teleky B, Lechner G (2003). Dedicated multidetector CT of the stomach: spectrum of diseases. Radiographics 23 (3): 625-44. Kim AY, Kim HJ, Ha HK (2005). Gastric cancer by multidetector row CT: preoperative staging. Abdominal Imaging 30 (4): 465-47

Employing early decision analytic modelling to inform economic evaluation in health care: theory & practice

Decision analytic modelling (DAM) is a mathematical technique which is used to structure and synthesise evidence in order to inform decision making, given uncertainty. Decision models are an ideal tool for undertaking economic evaluations as they enable a wide range of data on costs and effects to be synthesised within the model in order to derive cost-effectiveness outcomes. The iterative framework for economic appraisal has been proposed as good practice for undertaking economic evaluations (1), and DAM plays a key role within this framework. In particular there is a role for early stage DAM prior to primary research, to provide an indication of the potential cost-effectiveness of a new health technology (2) given current evidence, and the use of value of information (VOI) techniques to help inform further research priority setting. In practice, support and funding for early stage DAM and full exploitation of VOI techniques is rare. The aim of this thesis is to examine the role for early decision analytic modelling in informing research priorities and the design of future studies in a health care setting. This thesis explores the feasibility, merits and drawbacks of undertaking early DAM and considers potential reasons as to why it has not been more widely implemented. This thesis demonstrates the value and importance of early DAM; in both an ‘ideal’ setting and also in a less desirable, time-constrained setting. Applying early DAM and VOI techniques enables researchers to provide relevant conclusions and recommendations to decision makers, who can make informed decisions as to whether a new intervention should be adopted (or rejected), or whether further information is required to help make the decision; as opposed to making decisions based on subjective reasoning. There is considerable merit with employing early DAM for health care research, such as reduced uncertainty, reduction of costs and efficiency gains, however, some drawbacks exist in terms of whether it is always viable to fully exploit VOI analyses, which may hinder widespread support both inside and out-with the health economics community