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1.
Clin Transl Radiat Oncol ; 48: 100836, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39258242

RESUMO

Background: For adult patients with grade 1-3 gliomas, identifying patients with an indication for proton therapy (PT) can be challenging due to sparse evidence supporting its benefits. In this study, we aimed to ensure national consensus and develop a decision support tool to aid clinicians in identifying patients with grade 1-3 gliomas eligible for PT. Methods: Sixty-one historic patients referred for postoperative radiotherapy for glioma grade 1-3 were included in this study and had new photon therapy and PT plans calculated. These plans along with clinical parameters were presented to neurooncologists with experience in treating brain tumours. The patients were presented at three workshops (WSs), where each neurooncologist individually had to choose between photon and proton therapy. Important parameters were selected using cross validation. Multivariable logistic regression was used to predict the neurooncologists' treatment modality choice. Results: At the three WSs 23, 24 and 19 randomly selected patients were presented. Seventy-five percent of the neurooncologists agreed for 14 patients (61%), 16 patients (67%) and 15 patients (79%) at WS1, WS2 and WS3. Age at radiotherapy and difference in mean dose (ΔDmean) to the residual brain were significant predictors of the choice of treatment modality, p < 0.001. Model coefficients were: ßage = 0.07 per year (95% confidence interval [CI] = 0.05-0.09), and ßΔdose = -0.27 per Gy (95% CI=-0.36--0.18). Conclusion: Higher degree of agreement was reached. Age and ΔDmean to the residual brain significantly predicted the choice of radiation modality. We have developed a decision support model which may aid in the selection of patients with glioma grade 1-3 to PT.

2.
Contemp Clin Trials ; 138: 107419, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38142774

RESUMO

BACKGROUND: Cognitive impairment is a common late effect in child and adult brain cancer survivors (BCS). Still, there is a dearth of research aimed at therapeutic interventions and no standard treatment options for most BCS. OBJECTIVE: To describe 1) a novel neuropsychological rehabilitation program for BCS - the "I'm aware: Patients And Carers Together" (ImPACT) program, and 2) two studies that aim to assess the feasibility of the ImPACT program in child and adult BCS, respectively. The program adapts the holistic neuropsychological approach pioneered by Leonard Diller and Yehuda Ben-Yishay to an outpatient setting. METHODS: Two feasibility studies are described: 1) A single-armed study with 15 child BCS (10-17 years) (ImPACT Child); and 2) a randomized waitlist-controlled trial with 26 adult BCS (>17 years) (ImPACT Adult). In both studies, patients will undergo an 8-week program together with a cohabiting carer. Primary outcomes (i.e., cognitive and neurobehavioral symptoms), and secondary outcomes (i.e., behavioral and psychological symptoms, e.g., quality of life, fatigue) will be assessed at four time points: pre-, mid-, and post intervention, and 8 weeks follow-up. Adult waitlist controls will be assessed at equivalent time points and will be included in the intervention group after all study assessments. Semi-structured interviews will be conducted at follow-up. EXPECTED OUTCOMES: Results will provide feasibility data in support of future larger scale trials. DISCUSSION: The findings could potentially improve the management of cognitive impairment in BCS and transform available services. The program can be delivered in-person or remotely and harnesses existing resources in patients' lives.


Assuntos
Sobreviventes de Câncer , Disfunção Cognitiva , Neoplasias , Adulto , Criança , Humanos , Encéfalo , Cuidadores/psicologia , Qualidade de Vida , Adolescente , Estudos de Viabilidade , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Clin Transl Radiat Oncol ; 43: 100670, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37736140

RESUMO

Aims: The number of Proton Therapy (PT) facilities is still limited worldwide, and the access to treatment could be characterized by patients' logistic and economic challenges. Aim of the present survey is to assess the support provided to patients undergoing PT across Europe. Methods: Through a personnel contact, an online questionnaire (62 multiple-choice and open-ended questions) via Microsoft Forms was administered to 10 European PT centers. The questionnaire consisted of 62 questions divided into 6 sections: i) personal data; ii) general information on clinical activity; iii) fractionation, concurrent systemic treatments and technical aspects of PT facility; iv) indication to PT and reimbursement policies; v) economic and/ or logistic support to patients vi) participants agreement on statements related to the possible limitation of access to PT. A qualitative analysis was performed and reported. Results: From March to May 2022 all ten involved centers filled the survey. Nine centers treat from 100 to 500 patients per year. Paediatric patients accounted for 10-30%, 30-50% and 50-70% of the entire cohort for 7, 2 and 1 center, respectively. The most frequent tumours treated in adult population were brain tumours, sarcomas and head and neck carcinomas; in all centers, the mean duration of PT is longer than 3 weeks. In 80% of cases, the treatment reimbursement for PT is supplied by the respective country's Health National System (HNS). HNS also provides economic support to patients in 70% of centers, while logistic and meal support is provided in 20% and 40% of centers, respectively. PT facilities offer economic and/or logistic support in 90% of the cases. Logistic support for parents of pediatric patients is provided by HNS only in one-third of centers. Overall, 70% of respondents agree that geographic challenges could limit a patient's access to proton facilities and 60% believe that additional support should be given to patients referred for PT care. Conclusions: Relevant differences exist among European countries in supporting patients referred to PT in their logistic and economic challenges. Further efforts should be made by HNSs and PT facilities to reduce the risk of inequities in access to cancer care with protons.

4.
Clin Transl Radiat Oncol ; 31: 86-92, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34693039

RESUMO

AIM: This study aimed to explore associations between radiation dose and patient-reported outcomes in patients with a primary non-glioblastoma brain tumour treated with radiation therapy (RT), with a focus on health-related quality-of-life (HRQoL) and self-reported cognitive function. METHODS: In this cross-sectional study, 78 patients who had received RT for a non-glioblastoma primary brain tumour, underwent neuropsychological testing and completed questionnaires on HRQoL, cognitive function, fatigue, depression, anxiety and perceived stress. The study explores the association between HRQoL scores, self-reported cognitive function and radiation doses to total brain, brainstem, hippocampus, thalamus, temporal lobes and frontal lobes. In addition, we examined correlations between neuropsychological test scores and self-reported cognitive function. RESULTS: The median time between RT and testing was 4.6 years (range 1-9 years). Patients who had received high mean radiation doses to the total brain had low HRQoL scores (Cohen's d = 0.50, p = 0.04), brainstem (d = 0.65, p = 0.01) and hippocampus (d = 0.66, p = 0.01). High mean doses to the total brain were also associated with low scores on self-reported cognitive functioning (Cohen's d = 0.64, p = 0.02), brainstem (d = 0.55, p = 0.03), hippocampus (d = 0.76, p < 0.01), temporal lobes (d = 0.70, p < 0.01) and thalamus (d = 0.64, p = 0.01). Self-reported cognitive function correlated well with neuropsychological test scores (correlation range 0.27-0.54.). CONCLUSIONS: High radiation doses to specific brain structures may be associated with impaired HRQoL and self-reported cognitive function with potentially negative implications to patients' daily lives. Patient-reported outcomes of treatment-related side-effects and their associations with radiation doses to the brain and its sub-structures may provide important information on radiation tolerance to the brain and sub-structures.

5.
Acta Oncol ; 60(11): 1392-1398, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34213401

RESUMO

BACKGROUND: Survivors of pediatric brain tumors are susceptible to neurovascular disease after radiotherapy, with dose to the chiasm or Circle of Willis (CW) as risk factors. The aims of this study were to develop a delineation atlas of neurovascular structures, to investigate the doses to these structures in relation to tumor location and to investigate potential dose surrogates for the CW dose. MATERIAL AND METHODS: An atlas of the CW, the large intracranial arteries and the suprasellar cistern (SC) was developed and validated. Thirty proton plans from previously treated pediatric brain tumor patients were retrieved and grouped according to tumor site: 10 central, 10 lateralized, and 10 posterior fossa tumors. Based on the atlas, neurovascular structures were delineated and dose metrics (mean dose (Dmean) and maximal dose (Dmax)) to these structures and the already delineated chiasm were evaluated. The agreement between dose metrics to the CW vs. chiasm/SC was investigated. The minimal Hausdorff distance (HDmin) between the target and SC was correlated with the SC Dmean. RESULTS: The median Dmean/Dmax to the CW were 53 Gy(RBE)/55 Gy(RBE) in the central tumors, 18 Gy(RBE)/25 Gy(RBE) in the lateralized tumors and 30 Gy(RBE)/49 Gy(RBE) in the posterior fossa tumors. There was a good agreement between the Dmax/Dmean to the CW and the SC for all cases (R2=0.99), while in the posterior fossa group, the CW Dmax was underestimated when using the chiasm as surrogate (R2=0.76). Across all patients, cases with HDmin < 10 mm between the target and the SC received the highest SC Dmean. CONCLUSION: The pattern of dose to neurovascular structures varied with the tumor location. For all locations, SC doses could be used as a surrogate for CW doses. A minimal distance larger than 10 mm between the target and the SC indicated a potential for neurovascular dose sparing.


Assuntos
Neoplasias Encefálicas , Terapia com Prótons , Radioterapia de Intensidade Modulada , Neoplasias Encefálicas/radioterapia , Criança , Círculo Arterial do Cérebro , Humanos , Órgãos em Risco , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
6.
Acta Oncol ; 59(9): 1118-1122, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32441550

RESUMO

Background: Brain metastases (BMs) are an uncommon presentation of metastatic colorectal cancer (mCRC) with reported incidence of about 2-4%. Today, there is an increased awareness towards a metastasis directed treatment approach with either surgical resection, stereotactic radiotherapy (SRT) or both. We examined patient characteristics and survival for patients treated with a localized modality for BM from CRC in a nationwide population-based study.Methods: A registry-based cohort study of all patients with a resected primary colorectal cancer and localized treatment of BM during 2000-2013. We computed descriptive statistics and analysed overall survival by the Kaplan-Meier method and Cox regression.Results: A total of 38131 patients had surgery for a primary CRC and 235 patients were recorded with a metastasis directed treatment for BM, comprising resection alone (n = 158), SRT alone (n = 51) and combined resection and SRT (n = 26). Rectal primary tumor (48.9% vs. 36.2%, p < .001) and lung metastasectomy (11.9 vs 2.8%, p < .001) were more frequent in the BM group. The median survival of patients receiving localized treatment for BM was 9.6 months (95% confidence interval (CI) 7.2-10.8). The 1- and 5-year overall survival were 41.7% (95% CI 35-48%) and 11.2% (95% CI 6.9-16.3%). In multivariate analysis, nodal stage was associated with increased mortality with a hazard ratio of 1.63 (95% CI 1.07-2.60, p = .03) for N2 stage with reference to N0.Conclusion: We report a median overall survival of 9.6 months for patients receiving localized treatment for BM from CRC. Lung metastases and rectal primary tumor are more common in the population treated for BM.


Assuntos
Neoplasias Encefálicas/terapia , Neoplasias Colorretais/cirurgia , Neoplasias Pulmonares/cirurgia , Metastasectomia/estatística & dados numéricos , Radiocirurgia/estatística & dados numéricos , Idoso , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/secundário , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Terapia Combinada/métodos , Terapia Combinada/estatística & dados numéricos , Dinamarca/epidemiologia , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/estatística & dados numéricos , Pneumonectomia/estatística & dados numéricos , Prognóstico , Sistema de Registros/estatística & dados numéricos , Análise de Sobrevida , Resultado do Tratamento
7.
Acta Oncol ; 58(12): 1706-1713, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31464155

RESUMO

Background: Hepatocellular carcinoma (HCC) incidence is rising worldwide, especially due to increased detection of early-stage or small-sized tumors. Nevertheless, most of the patients are still not qualified for surgical resection at diagnosis due to the localization of the tumor, underlying liver disease or comorbidities. Stereotactic body radiation therapy (SBRT) is a radiotherapy modality which can deliver a high dose of radiation to the target tissue with a high degree of precision. It shows promise in terms of efficacy and morbidity.Material and methods: The aim of this systematic review is to summarize current knowledge on patient-specific outcomes of SBRT for small HCC including overall survival, local control, the effect of dose escalation and the toxicity of the treatment. The systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). After a comprehensive database search, 16 studies (973 patients with 1034 lesions) were included in qualitative and quantitative analyses; 14 of them were retrospective.Results: Average tumor diameter was 23 mm and 95% of patients were in good general condition. Median BED10 (biologically equivalent dose calculated for α/ß ratio of 10 Gy) was 100 Gy (range 59.5-180 Gy). Mean weighted local control across studies was 94%, 92% and 93% at 1, 2, and 3 years, respectively. Mean weighted overall survival across studies was 90.9%, 67.5% and 73.4% at 1, 2, and 3 years, respectively. There were 171 grade 1-2 toxicities (17.5%) and 53 ≥ grade 3 toxicities (5.3%). There was no treatment-associated mortality.Conclusion: SBRT offers high local control with overall survival that is comparable with radiofrequency ablation and surgery. Quality of findings, especially on toxicities, is decreased by incomplete reporting and retrospective designs of published studies. Therefore, there is a need for better reporting and prospective studies to univocally recommend SBRT as a definitive treatment option in the guidelines for small HCCs.


Assuntos
Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Radiocirurgia , Idoso , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Modelos Estatísticos , Estudos Prospectivos , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Estudos Retrospectivos , Resultado do Tratamento , Carga Tumoral
8.
Radiother Oncol ; 123(2): 182-188, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28169042

RESUMO

BACKGROUND: Radical local treatment of pulmonary metastases is practiced with increasing frequency due to acknowledgment and better understanding of oligo-metastatic disease. This study aimed to develop a nomogram predicting overall survival (OS) after stereotactic body radiotherapy (SBRT) for pulmonary metastases. PATIENTS AND METHODS: A multi-institutional database of 670 patients treated with SBRT for pulmonary metastases was used as training cohort. Cox regression analysis with bidirectional variable elimination was performed to identify factors to be included into the nomogram model to predict 2-year OS. The calibration rate of the nomogram was assessed by plotting the actual Kaplan-Meier 2-year OS against the nomogram predicted survival. The nomogram was externally validated using two separate monocentric databases of 145 and 92 patients treated with SBRT for pulmonary metastases. RESULTS: The median follow up of the trainings cohort was 14.3months, the 2-year and 5-year OS was 52.6% and 23.7%, respectively. Karnofsky performance index, type of the primary tumor, control of the primary tumor, maximum diameter of the largest treated metastasis and number of metastases (1 versus >1) were significant prognostic factors in the Cox model (all p<0.05). The calculated concordance-index for the nomogram was 0.73 (concordance indexes of all prognostic factors between 0.54 and 0.6). Based on the nomogram the training cohort was divided into 4 groups and 2-year OS ranged between 24.2% and 76.1% (predicted OS between 30.2% and 78.4%). The nomogram discriminated between risk groups in the two validation cohorts (concordance index 0.68 and 0.67). CONCLUSIONS: A nomogram for prediction of OS after SBRT for pulmonary metastases was generated and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting. KEY MESSAGE: A nomogram for prediction of overall survival after stereotactic body radiotherapy (SBRT) for pulmonary metastases was developed and externally validated. This tool might be helpful for interdisciplinary discussion and evaluation of local and systemic treatment options in the oligo-metastatic setting.


Assuntos
Neoplasias Pulmonares/radioterapia , Nomogramas , Radiocirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Acta Oncol ; 55(8): 1009-15, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27100215

RESUMO

Background Adaptive radiotherapy is introduced in the management of urinary bladder cancer to account for day-to-day anatomical changes. The purpose of this study was to determine whether an adaptive plan selection strategy using either the first four cone beam computed tomography scans (CBCT-based strategy) for plan creation, or the interpolation of bladder volumes on pretreatment CT scans (CT-based strategy), is better in terms of tumor control probability (TCP) and normal tissue sparing while taking the clinically applied fractionation schedules also into account. Material and methods With the CT-based strategy, a library of five plans was created. Patients received 55 Gy to the bladder tumor and 40 Gy to the non-involved bladder and lymph nodes, in 20 fractions. With the CBCT-based strategy, a library of three plans was created, and patients received 70 Gy to the tumor, 60 Gy to the bladder and 48 Gy to the lymph nodes, in 30-35 fractions. Ten patients were analyzed for each adaptive plan selection strategy. TCP was calculated applying the clinically used fractionation schedules, as well as a rescaling of the dose from 55 to 70 Gy for the CT-based strategy. For rectum and bowel, equivalent doses in 2 Gy fractions (EQD2) were calculated. Results The CBCT-based strategy resulted in a median TCP of 75%, compared to 49% for the CT-based strategy, the latter improving to 72% upon rescaling the dose to 70 Gy. A median rectum V30Gy (EQD2) of 26% [interquartile range (IQR): 8-52%] was found for the CT-based strategy, compared to 58% (IQR: 55-73%) for the CBCT-based strategy. Also the bowel doses were lower with the CT-based strategy. Conclusions Whereas the higher total bladder TCP for the CBCT-based strategy is due to prescription differences, the adaptive strategy based on CT scans results in the lowest rectum and bowel cavity doses.


Assuntos
Fracionamento da Dose de Radiação , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias da Bexiga Urinária/radioterapia , Tomografia Computadorizada de Feixe Cônico/métodos , Marcadores Fiduciais , Humanos , Modelos Biológicos , Órgãos em Risco/efeitos da radiação , Reto/efeitos da radiação
10.
J Biomater Sci Polym Ed ; 26(16): 1085-99, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26300365

RESUMO

A temporary barrier separating scaffold zones seeded with different cell types prevents faster growing cells from overgrowing co-cultured cells within the same construct. This barrier should allow sufficient nutrient diffusion through the scaffold. The aim of this study was to test the effect of two variants of collagen-based barriers on macromolecule diffusion, viability, and the spreading efficiency of primary ligament cells on embroidered scaffolds. Two collagen barriers, a thread consisting of a twisted film tape and a sponge, were integrated into embroidered poly(lactic-co-caprolactone) and polypropylene scaffolds, which had the dimension of lapine anterior cruciate ligaments (ACL). A diffusion chamber system was designed and established to monitor nutrient diffusion using fluorescein isothiocyanate-labeled dextran of different molecular weights (20, 40, 150, 500 kDa). Vitality of primary lapine ACL cells was tested at days 7 and 14 after seeding using fluorescein diacetate and ethidium bromide staining. Cell spreading on the scaffold surface was measured using histomorphometry. Nuclei staining of the cross-sectioned scaffolds revealed the penetration of ligament cells through both barrier types. The diffusion chamber was suitable to characterize the diffusivity of dextran molecules through embroidered scaffolds with or without integrated collagen barriers. The diffusion coefficients were generally significantly lower in scaffolds with barriers compared to those without barriers. No significant differences between diffusion coefficients of both barrier types were detected. Both barriers were cyto-compatible and prevented most of the ACL cells from crossing the barrier, whereby the collagen thread was easier to handle and allowed a higher rate of cell spreading.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/citologia , Colágeno/química , Células do Tecido Conjuntivo/citologia , Teste de Materiais/métodos , Engenharia Tecidual , Alicerces Teciduais/química , Animais , Ligamento Cruzado Anterior/metabolismo , Ligamento Cruzado Anterior/cirurgia , Bovinos , Adesão Celular , Ensaios de Migração Celular/métodos , Movimento Celular , Sobrevivência Celular , Células Cultivadas , Células do Tecido Conjuntivo/metabolismo , Cultura em Câmaras de Difusão , Feminino , Humanos , Teste de Materiais/instrumentação , Microscopia Eletrônica de Varredura , Poliésteres/química , Polipropilenos/química , Coelhos , Propriedades de Superfície
11.
Phys Med Biol ; 59(14): 3749-59, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24936956

RESUMO

When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose-response relationships. We investigated this for rectal bleeding using dose-volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3 mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13 mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5 mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman-Kutcher-Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2 Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9 Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose-response estimations. From the perspective of predictive modeling, our results suggest that variations within 10 mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice thickness variations within this range.


Assuntos
Processamento de Imagem Assistida por Computador , Órgãos em Risco/efeitos da radiação , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Conformacional , Reto/efeitos da radiação , Tomografia Computadorizada por Raios X , Estudos de Coortes , Relação Dose-Resposta à Radiação , Humanos , Masculino , Órgãos em Risco/diagnóstico por imagem , Reto/diagnóstico por imagem , Estudos Retrospectivos
12.
Phys Med Biol ; 59(11): 2787-800, 2014 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-24801205

RESUMO

Gold markers implanted in or near a tumor can be used as x-ray visible landmarks for image based tumor localization. The aim of this study was to develop and demonstrate fast and reliable real-time segmentation of multiple liver tumor markers in intra-treatment kV and MV images and in cone-beam CT (CBCT) projections, for real-time motion management. Thirteen patients treated with conformal stereotactic body radiation therapy in three fractions had 2-3 cylindrical gold markers implanted in the liver prior to treatment. At each fraction, the projection images of a pre-treatment CBCT scan were used for automatic generation of a 3D marker model that consisted of the size, orientation, and estimated 3D trajectory of each marker during the CBCT scan. The 3D marker model was used for real-time template based segmentation in subsequent x-ray images by projecting each marker's 3D shape and likely 3D motion range onto the imager plane. The segmentation was performed in intra-treatment kV images (526 marker traces, 92,097 marker projections) and MV images (88 marker traces, 22,382 marker projections), and in post-treatment CBCT projections (42 CBCT scans, 71,381 marker projections). 227 kV marker traces with low mean contrast-to-noise ratio were excluded as markers were not visible due to MV scatter. Online segmentation times measured for a limited dataset were used for estimating real-time segmentation times for all images. The percentage of detected markers was 94.8% (kV), 96.1% (MV), and 98.6% (CBCT). For the detected markers, the real-time segmentation was erroneous in 0.2-0.31% of the cases. The mean segmentation time per marker was 5.6 ms [2.1-12 ms] (kV), 5.5 ms [1.6-13 ms] (MV), and 6.5 ms [1.8-15 ms] (CBCT). Fast and reliable real-time segmentation of multiple liver tumor markers in intra-treatment kV and MV images and in CBCT projections was demonstrated for a large dataset.


Assuntos
Tomografia Computadorizada de Feixe Cônico/normas , Marcadores Fiduciais , Processamento de Imagem Assistida por Computador/métodos , Fígado/diagnóstico por imagem , Radiocirurgia/normas , Humanos , Fatores de Tempo
13.
Phys Med Biol ; 57(21): 7089-100, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23051686

RESUMO

Variations in bladder position, shape and volume cause uncertainties in the doses delivered to this organ during a course of radiotherapy for pelvic tumors. The purpose of this study was to evaluate the potential of dose accumulation based on repeat imaging and deformable image registration (DIR) to improve the accuracy of bladder dose assessment. For each of nine prostate cancer patients, the initial treatment plan was re-calculated on eight to nine repeat computed tomography (CT) scans. The planned bladder dose-volume histogram (DVH) parameters were compared to corresponding parameters derived from DIR-based accumulations as well as DVH summation based on dose re-calculations. It was found that the deviations between the DIR-based accumulations and the planned treatment were substantial and ranged (-0.5-2.3) Gy and (-9.4-13.5) Gy for D(2%) and D(mean), respectively, whereas the deviations between DIR-based accumulations and DVH summation were small and well within 1 Gy. For the investigated treatment scenario, DIR-based bladder dose accumulation did not result in substantial improvement of dose estimation as compared to the straightforward DVH summation. Large variations were found in individual patients between the doses from the initial treatment plan and the accumulated bladder doses. Hence, the use of repeat imaging has a potential for improved accuracy in treatment dose reporting.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Órgãos em Risco/efeitos da radiação , Neoplasias da Próstata/radioterapia , Doses de Radiação , Radioterapia de Intensidade Modulada/efeitos adversos , Bexiga Urinária/efeitos da radiação , Fenômenos Biomecânicos , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
14.
Domest Anim Endocrinol ; 34(3): 254-60, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17851017

RESUMO

Desmopressin is a synthetic analogue of the hypothalamic peptide vasopressin and binds to specific pituitary vasopressin (V3) receptors. The V3-receptor is overexpressed in pituitary corticotrope tumors and the injection of desmopressin induces a marked ACTH and cortisol release in human patients with pituitary- (PDH), but not adrenal tumor (AT) dependent hyperadrenocorticism. In this prospective study, we investigated the effects of desmopressin on serum cortisol levels in 80 dogs suspected of Cushing's syndrome. The aim was to find a sensitive and specific test to exclude AT. According to standard tests the dogs were divided into 3 groups (group 1=other disease, n=27; group 2=PDH, n=46; group 3=AT, n=7). Desmopressin was injected as an i.v. bolus of 4microg and serial blood samples were collected before and after 30, 60 and 90min. Desmopressin significantly stimulated cortisol release in dogs with PDH (median 51%, range -24 to 563%; p<0.0001), whereas no increase was seen in dogs with AT (median -12%, range -44 to 5%; p=0.063) and in controls (median +7%, range -36 to 196%; p=0.131). Using a cut off value of 10% increase over baseline, it was possible to exclude AT in 75% of patients. The results of this study suggest that the desmopressin test could be a useful tool in differentiating pituitary from adrenal dependent Cushing's syndromes. Additional dogs with adrenocortical tumor must be tested in order to recommend its use in clinical practice.


Assuntos
Síndrome de Cushing/diagnóstico , Desamino Arginina Vasopressina , Doenças do Cão/diagnóstico , Neoplasias das Glândulas Suprarrenais/veterinária , Animais , Síndrome de Cushing/sangue , Diagnóstico Diferencial , Cães , Hidrocortisona/sangue , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/veterinária , Estudos Prospectivos , Curva ROC
15.
Scand J Surg ; 96(3): 209-13, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17966746

RESUMO

BACKGROUND AND AIM: Colorectal cancer is a common cancer in the Nordic countries and 50% of the patients develop liver metastases. Liver resection may result in long term survival. Proper staging is therefore essential and CT is the standard imaging modality. We examined whether additional FDG-PET improves therapeutic management of patients with colorectal liver metastases. PATIENTS AND METHODS: Fifty-four consecutive patients were enrolled. Each patient had a treatment plan made based on our standard evaluation. The patients then had a PET scan and the treatment plan was re-evaluated, taking these results into account. RESULTS: In 76% of the cases, PET did not change the treatment plan due to complete concordance with CT. In another 19% of the cases, the plan was altered due to finding of more liver lesions by PET than by CT (four patients), fewer or no liver lesions (three patients), and extrahepatic lesions not visible on CT (three patients). In 5% of the cases, non-concordance between PET and CT did not change the therapeutic plan. CONCLUSION: Pre-treatment FDG-PET, used supplementary to CT, improved the treatment plan in one fifth of the patients with colorectal liver metastases.


Assuntos
Neoplasias Colorretais/diagnóstico por imagem , Fluordesoxiglucose F18 , Hepatectomia/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Adulto , Idoso , Neoplasias Colorretais/patologia , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Laparotomia/métodos , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
16.
Dtsch Med Wochenschr ; 131(6): 258-62, 2006 Feb 10.
Artigo em Alemão | MEDLINE | ID: mdl-16463228

RESUMO

BACKGROUND AND OBJECTIVE: Surgery is an effective method to treat patients with morbid obesity. However health insurance companies frequently refuse to cover the costs for the procedure despite an existing DRG-code for this operation. Individual medical expertise are necessary to receive reimbursement. In the present study the acceptance of medical expertise to receive cost coverage was analysed in our patients of the years 2000-2003 eligible for obesity surgery. PATIENTS AND METHODS: 617 medical expertise of patients eligible for obesity surgery in our hospital were reviewed and the acceptance rate was evaluated. Parameters such as body mass index, personal medical history, diets, comorbidity and prognosis were included. Expertise were submitted to the health care insurance companies and in case of acceptance the operation was performed. RESULTS: The average age of our patients was 39.1 +/- 11.2 years, 72.1% were female, 27.9% male. The average BMI was 47.5 +/- 7.4 kg/m2. There was a high incidence of comorbidity in these patients (58.7% arterial hypertension, 38.6% diabetes mellitus, 95.8% dyspnoea, 96.1% arthropathy, 89.0% psychosocial disorders). The difference between accepted and non-accepted regarding these secondary complications was not significant. 209 patients (33.8%) were operated. 14 patients of these paid the costs themselves. Only in 195 cases (31.6%) the health care insurance company covered the costs for the operation. CONCLUSION: The high number of refusals of medical expertise is not justified in view of the strict criteria for indication, the high frequency of comorbidity and the good results after the operation.


Assuntos
Cirurgia Bariátrica/economia , Reembolso de Seguro de Saúde/estatística & dados numéricos , Obesidade Mórbida/cirurgia , Adulto , Comorbidade , Diabetes Mellitus/epidemiologia , Dislipidemias/epidemiologia , Dispneia/epidemiologia , Fígado Gorduroso/epidemiologia , Feminino , Alemanha/epidemiologia , Humanos , Hipertensão/epidemiologia , Artropatias/epidemiologia , Masculino , Transtornos Mentais/epidemiologia , Obesidade Mórbida/economia , Obesidade Mórbida/epidemiologia , Guias de Prática Clínica como Assunto , Prognóstico , Estudos Retrospectivos
17.
Tijdschr Diergeneeskd ; 128(5): 140-4, 2003 Mar 01.
Artigo em Holandês | MEDLINE | ID: mdl-12645321

RESUMO

A 40-year-old manatee was referred with recurrent vesicular and ulcerative dermatosis for the past 15 years. During this period the animal was anorectic and lost weight. Differential diagnoses were formulated on the basis of the history and clinical signs. Skin scrapings, bacterial and fungal culture, cytological examination, blood examination, and histopathological examination of skin biopsies narrowed this list down to autoimmune dermatosis. Despite corticosteroid therapy the symptoms recurred and the animal died. Histopathological examination of post-mortem skin biopsies showed again autoimmune dermatosis, more specifically subepidermal bullous autoimmune dermatosis, as the most probable cause of the skin lesions. Post-mortem examination showed cardiac decompensation and chronic nephritis. It was impossible to estimate the possible contribution of the chronic dermatosis to the cause of death. The purpose of this case report is to show the importance of a systematic work-up of disease in exotic animals.


Assuntos
Doenças Autoimunes/veterinária , Dermatopatias Vesiculobolhosas/veterinária , Úlcera Cutânea/veterinária , Trichechus , Corticosteroides/uso terapêutico , Animais , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/tratamento farmacológico , Biópsia/veterinária , Diagnóstico Diferencial , Evolução Fatal , Masculino , Recidiva , Pele/imunologia , Pele/patologia , Dermatopatias Vesiculobolhosas/diagnóstico , Dermatopatias Vesiculobolhosas/tratamento farmacológico , Dermatopatias Vesiculobolhosas/imunologia , Úlcera Cutânea/diagnóstico , Úlcera Cutânea/tratamento farmacológico , Úlcera Cutânea/imunologia
18.
Gynecol Oncol ; 81(1): 58-62, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11277650

RESUMO

OBJECTIVE: The purpose of this phase II study was to evaluate on an intent-to-treat basis the activity and toxicity of single-agent vinorelbine (VRL) as second-line chemotherapy of patients with platinum-resistant ovarian cancer. Platinum-resistant disease was defined as disease refractory to or relapsing within 12 months after finishing platinum-containing chemotherapy. METHODS: VRL (30 mg/m(2)) was administered intravenously as a bolus injection days 1 and 8 every 21 days. Initially, four courses of VRL were given. Patients with responding or stable disease received four more courses of VRL to a maximum of eight courses. RESULTS: Twenty-eight of 33 eligible patients were considered evaluable for response. The overall response rate was 21% (7/33) (95% CI: 7--35). Median time to progression was 3.1 months and median survival was 10.1 months. Toxicity was generally mild. Leukopenia was the dose-limiting toxicity. CALGB grade III/IV infection was observed in 15/0% of patients. The most important nonhematologic toxicities were nausea and constipation. Grade III/IV nausea was observed in 6/0% and grade III/IV constipation in 3/3% of patients. Peripheral neurotoxicity was only a minor problem with no grade III/IV toxicity. No patients stopped treatment because of toxicity and no toxic death was reported. CONCLUSION: VRL was generally well tolerated, but the activity in platinum-resistant ovarian cancer was only modest, although fully comparable to other second-line treatments. Further studies are required to define the role of VRL in combination chemotherapy for ovarian cancer.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Vimblastina/análogos & derivados , Vimblastina/uso terapêutico , Adulto , Idoso , Altretamine/administração & dosagem , Altretamine/efeitos adversos , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Injeções Intravenosas , Leucopenia/induzido quimicamente , Pessoa de Meia-Idade , Compostos Organoplatínicos/uso terapêutico , Terapia de Salvação , Vimblastina/administração & dosagem , Vimblastina/efeitos adversos , Vinorelbina
19.
Int J Radiat Oncol Biol Phys ; 49(2): 519-25, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11173149

RESUMO

PURPOSE: To investigate the correlation between tumor potential doubling time, Tpot, and mutations in the p53 gene, TP53, and the potential of these parameters to predict outcome of head and neck cancer patients treated with radiotherapy. METHODS AND MATERIALS: Data from two independent studies on Tpot and TP53 mutations were combined, including 58 patients with squamous cell carcinoma of the head and neck. Tpot was estimated on biopsies obtained 6-9 h after infusion of iododeoxyuridine by combined flow cytometry and immunohistology. TP53 mutations were detected using DGGE and sequenced. All patients received primary radiotherapy alone. RESULTS: The predictive value of Tpot alone was of borderline significance. However, in TP53 wild-type tumors, Tpot was a strong predictor of outcome, whereas Tpot in TP53 mutant tumors failed to provide any information. Tpot and TP53 were not associated with nodal control; however, there was a strong relationship with control in the T-position, disease-specific survival, and overall survival. CONCLUSION: Tpot can to be a relevant parameter for predicting outcome of radiotherapy in head and neck cancer but only in the subset of patients without mutations in the p53 gene.


Assuntos
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Divisão Celular/fisiologia , Genes p53/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Mutação/genética , Adulto , Idoso , Carcinoma de Células Escamosas/radioterapia , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/patologia , Neoplasias Laríngeas/radioterapia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Neoplasias Bucais/radioterapia , Estadiamento de Neoplasias , Neoplasias Faríngeas/genética , Neoplasias Faríngeas/patologia , Neoplasias Faríngeas/radioterapia , Prognóstico , Fatores de Tempo , Resultado do Tratamento
20.
Leuk Res ; 24(12): 999-1008, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11077113

RESUMO

We have investigated the effect of HGF in vivo and in vitro in MDS using a recently developed FCM assay involving the simultaneous measurement of cell surface antigens, DNA content, and BrdUrd or IodUrd incorporation. This allows for the determination of the dynamic cell kinetic parameters: LI, T(s), and T(pot) and we observed that in vitro HGF stimulation resulted in a significant decrease in mean T(pot) values from 6.6 to 3.5 days. Importantly, we demonstrated that in vivo GM-CSF administration to patients with RAEB resulted in a shortening of T(pot) within the 2 first weeks of GM-CSF treatment.


Assuntos
Ciclo Celular/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Síndromes Mielodisplásicas/patologia , Síndromes Mielodisplásicas/terapia , Idoso , Antígenos CD , Células da Medula Óssea/patologia , DNA/análise , Feminino , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Imunofenotipagem , Leucócitos Mononucleares/patologia , Leucopoese , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/genética , Células Tumorais Cultivadas
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