44 research outputs found
Automatic liver detection and standardised uptake value evaluation in whole-body Positron Emission Tomography/Computed Tomography scans
Total Skin Electron Therapy Stanford Technique Evolution With Monte Carlo Simulation Toward Personalized Treatments For Cutaneous Lymphoma
Current Total Skin Electron Therapy (TSET) Stanford technique for cutaneous
lymphoma, established in the 70's, involves a unique irradiation setup, i.e.
patient's position and beam arrangement, for all patients with ensuing great
variability in dose distribution and difficult dose optimization. A
Geant4-based simulation has been developed to explore the possibility of
personalizing the dose to each patient's anatomy. To achieve this optimization
of the treatment method, this project enrolls different aspects of the clinical
and computational techniques: starting with the knowledge of the experimental
parameters involving TSET practice, passing through an innovative approach to
model the patient's anatomy, a precise description of the electron beam and a
validated configuration of the physics models handling the interactions of the
electrons and of secondary particles. The Geant4-based simulation models the
patient as a tessellated solid derived from the optical scan of her/his body,
realistically reproduces the irradiation environment in detail and calculates
the energy deposition corresponding to each facet of the patient's scanned
surface. The resulting three-dimensional dose distribution constitutes the
basis for the personalization of the medical treatement as appropriate to each
patient's specific characteristics.Comment: Presented at the 2022 IEEE Nuclear Science Symposiu
A prognostic model integrating PET-derived metrics and image texture analyses with clinical risk factors from GOYA
Image texture analysis (radiomics) uses radiographic images to quantify characteristics that may identify tumour heterogeneity and associated patient outcomes. Using fluoroâdeoxyâglucose positron emission tomography/computed tomography (FDGâPET/CT)âderived data, including quantitative metrics, image texture analysis and other clinical risk factors, we aimed to develop a prognostic model that predicts survival in patients with previously untreated diffuse large Bâcell lymphoma (DLBCL) from GOYA (NCT01287741). Image texture features and clinical risk factors were combined into a random forest model and compared with the international prognostic index (IPI) for DLBCL based on progressionâfree survival (PFS) and overall survival (OS) predictions. Baseline FDGâPET scans were available for 1263 patients, 832 patients of these were cellâofâorigin (COO)âevaluable. Patients were stratified by IPI or radiomics features plus clinical risk factors into lowâ, intermediateâ and highârisk groups. The random forest model with COO subgroups identified a clearer highârisk population (45% 2âyear PFS [95% confidence interval (CI) 40%â52%]; 65% 2âyear OS [95% CI 59%â71%]) than the IPI (58% 2âyear PFS [95% CI 50%â67%]; 69% 2âyear OS [95% CI 62%â77%]). This study confirms that standard clinical risk factors can be combined with PETâderived image texture features to provide an improved prognostic model predicting survival in untreated DLBCL
Correlation between delayed-enhancement magnetic resonance and nitrate myocardial Tc-99m tetrofosmin scintigraphy in myocardial infarction: a case report
The neutrophil to lymphocyte ratio (NLR) and the presence of large nodal mass are independent predictors of early response: A subanalysis of the prospective phase II PET-2-adapted HD0607 trial
The neutrophil to lymphocyte ratio (NLR) and the lymphocyte to monocyte ratio (LMR) can reflect both the myeloid dysfunction and T-cell immune suppression and have prognostic significance
Response-Adapted Postinduction Strategy in Patients With Advanced-Stage Follicular Lymphoma: The FOLL12 Study
Purpose: We compared 2 years of rituximab maintenance (RM) with a response-adapted postinduction approach in patients with follicular lymphoma who responded to induction immunochemotherapy. Methods: We randomly assigned treatment-naĂŻve, advanced-stage, high-tumor burden follicular lymphoma patients to receive standard RM or a response-adapted postinduction approach on the basis of metabolic response and molecular assessment of minimal residual disease (MRD). The experimental arm used three types of postinduction therapies: for complete metabolic response (CMR) and MRD-negative patients, observation; for CMR and MRD-positive (end of induction or follow-up) patients, four doses of rituximab (one per week, maximum three courses) until MRD-negative; and for non-CMR patients, one dose of ibritumomab tiuxetan followed by standard RM. The study was designed as noninferiority trial with progression-free survival (PFS) as the primary end point. Results: Overall, 807 patients were randomly assigned. After a median follow-up of 53 months (range 1-92 months), patients in the standard arm had a significantly better PFS than those in the experimental arm (3-year PFS 86% v 72%; P < .001). The better PFS of the standard vs experimental arm was confirmed in all the study subgroups except non-CMR patients (n = 65; P = .274). The 3-year overall survival was 98% (95% CI, 96 to 99) and 97% (95% CI, 95 to 99) in the reference and experimental arms, respectively (P = .238). Conclusion: A metabolic and molecular response-adapted therapy as assessed in the FOLL12 study was associated with significantly inferior PFS compared with 2-year RM. The better efficacy of standard RM was confirmed in the subgroup analysis and particularly for patients achieving both CMR and MRD-negative
The Strategies to Homogenize PET/CT Metrics: The Case of Onco-Haematological Clinical Trials
Positron emission tomography (PET) has been a widely used tool in oncology for staging lymphomas for a long time. Recently, several large clinical trials demonstrated its utility in therapy management during treatment, paving the way to personalized medicine. In doing so, the traditional way of reporting PET based on the extent of disease has been complemented by a discrete scale that takes in account tumour metabolism. However, due to several technical, physical and biological limitations in the use of PET uptake as a biomarker, stringent rules have been used in clinical trials to reduce the errors in its evaluation. Within this manuscript we will describe shortly the evolution in PET reporting, examine the main errors in uptake measurement, and analyse which strategy the clinical trials applied to reduce them
The Strategies to Homogenize PET/CT Metrics: The Case of Onco-Haematological Clinical Trials
Positron emission tomography (PET) has been a widely used tool in oncology for staging lymphomas for a long time. Recently, several large clinical trials demonstrated its utility in therapy management during treatment, paving the way to personalized medicine. In doing so, the traditional way of reporting PET based on the extent of disease has been complemented by a discrete scale that takes in account tumour metabolism. However, due to several technical, physical and biological limitations in the use of PET uptake as a biomarker, stringent rules have been used in clinical trials to reduce the errors in its evaluation. Within this manuscript we will describe shortly the evolution in PET reporting, examine the main errors in uptake measurement, and analyse which strategy the clinical trials applied to reduce them
Geant4 model for the stopping power of low energy negatively charged hadrons
An original model is presented for the simulation of the energy loss of negatively charged hadrons; it calculates the stopping power of these negatively charged particles by regarding the target atoms as an ensemble of quantum harmonic oscillators. Antiproton stopping powers calculated with this model for different elements are shown to be in satisfactory agreement with experimental data