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1.
J Magn Reson Imaging ; 32(1): 155-64, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20578023

RESUMO

PURPOSE: To assess the reproducibility of relaxivity- and susceptibility-based dynamic contrast-enhanced magnetic resonance imaging (MRI) in the benign and malignant prostate gland and to correlate the kinetic parameters obtained. MATERIALS AND METHODS: Twenty patients with prostate cancer underwent paired scans before and after androgen deprivation therapy. Quantitative parametric maps for T(1)- and T(2)*-weighted parameters were calculated (K(trans), k(ep),v(e), IAUC(60), rBV, rBF, and R(2)*). The reproducibility of and correlation between each parameter were determined using standard methods at both timepoints. RESULTS: T(1)-derived parameters are more reproducible than T(2)*-weighted measures, both becoming more variable following androgen deprivation (variance coefficients for prostate K(trans) and rBF increased from 13.9%-15.8% and 42.5%-90.8%, respectively). Tumor R(2)* reproducibility improved after androgen ablation (23.3%-11.8%). IAUC(60) correlated strongly with K(trans), v(e), and k(ep) (all P < 0.001). R(2)* did not correlate with other parameters. CONCLUSION: This study is the first to document the variability and repeatability of T(1)- and T(2)*-weighted dynamic MRI and intrinsic susceptibility-weighted MRI for the various regions of the human prostate gland before and after androgen deprivation. These data provide a valuable source of reference for groups that plan to use dynamic contrast-enhanced MRI or intrinsic susceptibility-weighted MRI for the assessment of treatment response in the benign or malignant prostate.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/diagnóstico , Idoso , Análise de Variância , Meios de Contraste , Gadolínio DTPA , Humanos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Próstata/patologia , Doenças Prostáticas/diagnóstico , Reprodutibilidade dos Testes
2.
Radiother Oncol ; 91(1): 120-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18992952

RESUMO

PURPOSE: Phase II studies in laryngeal and bladder carcinoma of accelerated radiotherapy with carbogen and nicotinamide (RT+CON) suggested a therapeutic advantage. Therefore, a randomized phase-III trial of RT+CON in locally advanced bladder carcinoma compared to radiotherapy (RT) alone was undertaken. METHODS: One hundred and sixty-five patients with muscle-invasive transitional cell bladder carcinoma were randomized to RT alone and 168 to RT+CON. This paper reports on compliance and toxicity to nicotinamide (NAM) and carbogen and on early radiation-induced adverse bowel and urinary events. RESULTS: Of those receiving RT+CON, 65-69% accepted all doses of NAM. Sixty-four percent of patients presented Grade 1 NAM toxicity (nausea or vomiting), which was severe in 13%. Compliance to carbogen was 85% and none (32 fractions) and 2% (20 fractions) of patients presented severe toxicity. The highest prevalence of severe radiation acute morbidity was seen for urinary frequency (RT: 18% and RT+CON: 15%) and for diarrhea (RT: 3% and RT+CON: 5%). CONCLUSIONS: There is no indication of an increase in radiation-induced morbidity by combining the tumour radiosensitizers carbogen and nicotinamide with radiotherapy. Late morbidity and treatment outcome will ultimately determine if there is a therapeutic benefit.


Assuntos
Dióxido de Carbono/uso terapêutico , Carcinoma de Células de Transição/radioterapia , Niacinamida/uso terapêutico , Oxigênio/uso terapêutico , Radiossensibilizantes/uso terapêutico , Neoplasias da Bexiga Urinária/radioterapia , Idoso , Idoso de 80 Anos ou mais , Dióxido de Carbono/efeitos adversos , Carcinoma de Células de Transição/patologia , Fracionamento da Dose de Radiação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Niacinamida/efeitos adversos , Oxigênio/efeitos adversos , Radiossensibilizantes/efeitos adversos , Dosagem Radioterapêutica , Resultado do Tratamento , Neoplasias da Bexiga Urinária/patologia
3.
Nucl Med Biol ; 35(4): 393-400, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18482676

RESUMO

Positron emission tomography scanning using the radiotracer-labeled copper (II)-diacetyl-bis(N(4)-methylthiosemicarbazone) has been proposed as a noninvasive method for evaluating tumor hypoxia. Tumor hypoxia results in a more aggressive tumor phenotype together with resistance to both radiotherapy and chemotherapy. A noninvasive technique for evaluation of tumor hypoxia is not currently available. Validation of this technique would provide clinicians with a tool for determining the most appropriate cancer therapy, prognostic information, and subvolume delineation for the radiotherapy dose escalation to the radioresistant hypoxic regions within a tumor. This review article describes the background to the development of this tracer, its proposed retention mechanism, biodistribution dosimetry and the preclinical and clinical studies to date. It outlines the potential use of this radiotracer for imaging in the field of oncology.


Assuntos
Hipóxia/diagnóstico por imagem , Neoplasias/diagnóstico por imagem , Compostos Organometálicos/farmacocinética , Radioterapia (Especialidade)/métodos , Tiossemicarbazonas/farmacocinética , Animais , Hipóxia Celular , Complexos de Coordenação , Radioisótopos de Cobre/farmacocinética , Desenho de Fármacos , Humanos , Taxa de Depuração Metabólica , Cintilografia , Distribuição Tecidual
4.
Int J Radiat Oncol Biol Phys ; 67(2): 417-24, 2007 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-17236965

RESUMO

PURPOSE: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). METHODS AND MATERIALS: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. RESULTS: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. CONCLUSION: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center.


Assuntos
Volume Sanguíneo/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/radioterapia , Volume Sanguíneo/fisiologia , Permeabilidade Capilar/fisiologia , Permeabilidade Capilar/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Cuidados Paliativos , Estudos Prospectivos , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X/métodos
5.
Int J Radiat Oncol Biol Phys ; 67(5): 1375-80, 2007 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-17275203

RESUMO

PURPOSE: The tumor vascular effects of radiotherapy and subsequent administration of the vascular disrupting agent combretastatin A4 phosphate (CA4P) were studied in patients with advanced non-small-cell lung cancer using volumetric dynamic contrast-enhanced computed tomography (CT). PATIENTS AND METHODS: Following ethical committee approval and informed consent, 8 patients receiving palliative radiotherapy (27 Gy in six fractions, twice weekly) also received CA4P (50 mg/m(2)) after the second fraction of radiotherapy. Changes in dynamic CT parameters of tumor blood volume (BV) and permeability surface area product (PS) were measured for the whole tumor volume, tumor rim, and center after radiotherapy alone and after radiotherapy in combination with CA4P. RESULTS: After the second fraction of radiotherapy, 6 of the 8 patients showed increases in tumor PS (23.6%, p = 0.011). Four hours after CA4P, a reduction in tumor BV (22.9%, p < 0.001) was demonstrated in the same 6 patients. Increase in PS after radiotherapy correlated with reduction in BV after CA4P (r = 0.77, p = 0.026). At 72 h after CA4P, there was a sustained reduction in tumor BV of 29.4% (p < 0.001). Both increase in PS after radiotherapy and reduction in BV after CA4P were greater at the rim of the tumor. The BV reduction at the rim was sustained to 72 h (51.4%, p = 0.014). CONCLUSION: Radiotherapy enhances the tumor antivascular activity of CA4P in human non-small-cell lung cancer, resulting in sustained tumor vascular shutdown.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Estilbenos/uso terapêutico , Volume Sanguíneo/efeitos dos fármacos , Volume Sanguíneo/efeitos da radiação , Permeabilidade Capilar/efeitos dos fármacos , Permeabilidade Capilar/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Terapia Combinada , Meios de Contraste , Feminino , Humanos , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Masculino , Tomografia Computadorizada por Raios X/métodos
6.
Int J Radiat Oncol Biol Phys ; 68(4): 1065-71, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17637389

RESUMO

PURPOSE: To investigate the ability of blood oxygen level-dependent (BOLD) MRI to depict clinically significant prostate tumor hypoxia. METHODS AND MATERIALS: Thirty-three patients with prostate carcinoma undergoing radical prostatectomy were studied preoperatively, using gradient echo sequences without and with contrast medium enhancement, to map relative tissue oxygenation according to relaxivity rates and relative blood volume (rBV). Pimonidazole was administered preoperatively, and whole-mount sections of selected tumor-bearing slices were stained for pimonidazole fixation and tumor and nontumor localization. Histologic and imaging parameters were independently mapped onto patient prostate outlines. Using 5-mm grids, 861 nontumor grid locations were compared with 237 tumor grids (with >50% tumor per location) using contingency table analysis with respect to the ability of imaging to predict pimonidazole staining. RESULTS: Twenty patients completed the imaging and histologic protocols. Pimonidazole staining was found in 33% of nontumor and in 70% of tumor grids. The sensitivity of the MR relaxivity parameter R(2)* in depicting tumor hypoxia was high (88%), improving with the addition of low rBV information (95%) without changing specificity (36% and 29%, respectively). High R(2)* increased the positive predictive value for hypoxia by 6% (70% to 76%); conversely, low R(2)* decreased the likelihood of hypoxia being present by 26% (70% to 44%) and by 41% (71% to 30%) when combined with rBV information. CONCLUSION: R(2)* maps from BOLD-MRI have high sensitivity but low specificity for defining intraprostatic tumor hypoxia. This together with the negative predictive value of 70% when combined with blood volume information makes BOLD-MRI a potential noninvasive technique for mapping prostatic tumor hypoxia.


Assuntos
Hipóxia Celular , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/fisiopatologia , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Nitroimidazóis/farmacocinética , Oxigênio/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Radiossensibilizantes/farmacocinética , Coloração e Rotulagem/métodos
7.
J Clin Oncol ; 23(24): 5560-7, 2005 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-16110017

RESUMO

PURPOSE: Accelerated repopulation is a main reason for locoregional failure after fractionated radiotherapy for head and neck squamous cell carcinoma (HNSCC). Epidermal growth factor receptor (EGFR) is a key controller of cellular proliferation in HNSCC, which stimulated the current study to look for a direct link between EGFR status and a possible clinical advantage of accelerated radiotherapy. PATIENTS AND METHODS: Immunohistochemical staining for EGFR was performed in 304 patients with available pretreatment tumor biopsy material among 918 patients randomized to receive continuous hyperfractionated accelerated radiotherapy versus conventionally fractionated radiotherapy. The EGFR index was estimated as the proportion of tumor cells with EGFR membrane staining. RESULTS: Significant benefit in locoregional tumor control from continuous hyperfractionated accelerated radiotherapy was seen in patients with HNSCC with high EGFR expression (2P = .010) but not in those with low EGFR expression (2P = .85). EGFR status had no significant effect on survival or rate of distant metastases. The EGFR index was significantly associated with histologic grade and microvessel density. There was moderate support for an association between EGFR status and subsite within the head and neck region but no significant association with Ki-67 index, Ki-67 pattern, p53 index, p53 intensity, bcl-2 expression, or cyclin D1 index. CONCLUSION: This study indicates a key role for the EGFR receptor in determining the proliferative cellular response to fractionated radiotherapy in HNSCC. It also shows that we can select the dose-fractionation regime that has the greatest chance of benefiting the patient. These results also encourage further development of EGFR targeting combined with fractionated radiotherapy in HNSCC.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/radioterapia , Receptores ErbB/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biópsia , Fracionamento da Dose de Radiação , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Modelos de Riscos Proporcionais , Estatísticas não Paramétricas , Resultado do Tratamento
8.
Eur J Cancer ; 42(3): 363-71, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16386890

RESUMO

This study investigated the influence of pre-treatment proliferation characteristics, assessed by Ki-67 staining, in patients treated in the CHART trial of accelerated radiotherapy in head and neck cancer. Histological material from 402 patients was collected and stained for the presence and pattern of Ki-67 staining. Locoregional control and overall survival were the main clinical endpoints. Increasing Ki-67 positivity was associated with decreasing differentiation (P < 0.001) and increasing N-stage (P < 0.004). Increasing N-stage was also associated with the progression of proliferation pattern from marginal to random (P < 0.001). Using a multivariate model, a trend was seen towards a greater benefit from CHART in the lower Ki-67 tumours (P = 0.08); this became significant by pooling the low and intermediate Ki-67 groups in comparison with the high Ki-67 group (P = 0.032). Tumours with marginal proliferation pattern showed a lower hazard ratio with CHART versus conventional for locoregional control (P = 0.005). The data presented in this study do not support that a high pre-treatment Ki-67 is associated with a therapeutic benefit from accelerated radiotherapy.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Proliferação de Células , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/radioterapia , Antígeno Ki-67/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/radioterapia , Radioterapia/métodos , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
9.
Int J Radiat Oncol Biol Phys ; 65(1): 91-9, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16563659

RESUMO

PURPOSE: To investigate the presence of hypoxia in human prostate carcinoma by using pimonidazole immunohistochemical labeling in radical prostatectomy specimens. METHODS AND MATERIALS: Forty-three patients (median age, 69 years; range, 49-83 years) with localized prostate adenocarcinoma received 0.5 gm/m2 i.v. pimonidazole 16-24 h before radical prostatectomy. Hypoxia was detected with a monoclonal antibody directed against pimonidazole and scored in formalin-fixed, paraffin-embedded sections. Median and maximal vessel counts were measured with CD34. RESULTS: Thirty-seven patients completed the study. Pimonidazole binding was present in prostate carcinomas in 34 of 37 patients (92%) and in benign prostatic hyperplasia in 35 of 37 patients (95%). A positive correlation of 3+ pimonidazole binding with Gleason score was demonstrated (Spearman's rank, p = 0.044). Vascularity scores did not correlate with hypoxic status or clinical prognostic parameters. CONCLUSION: Prostate carcinoma and benign prostatic hyperplasia have significant areas of hypoxia; greater hypoxia scores are seen with more aggressive prostate cancer. It is postulated that a hypoxic microenvironment within the prostate might be responsible for the promotion of secondary genetic alterations and angiogenic stimulation, leading to malignant progression, a more aggressive cell phenotype, and greater radioresistance. Modification of radiation regimens to specifically target hypoxia might improve local tumor control.


Assuntos
Hipóxia Celular/fisiologia , Nitroimidazóis/farmacocinética , Neoplasias da Próstata/metabolismo , Radiossensibilizantes/farmacocinética , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/imunologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Nitroimidazóis/imunologia , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/patologia
10.
AJR Am J Roentgenol ; 187(4): 1079-84, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16985160

RESUMO

OBJECTIVE: To date, quantitative assessment of tumor vascularity using perfusion CT has been limited to a single tumor level, with the potential for measurement error in heterogeneous tumors. We aimed to determine if greater z-axis tumor coverage improves the reproducibility of perfusion CT measurements in lung cancer. SUBJECTS AND METHODS: Paired perfusion studies were performed on 10 patients who had histologically confirmed advanced non-small cell lung cancer. Using 16-MDCT, multiple sequential volumetric acquisitions encompassing the entire tumor were acquired after infusion of i.v. contrast material. Using Patlak analysis, median values of tumor permeability (mL/100 mL/min) and blood volume (mL/100 mL) were measured for 10-mm z-axis coverage, and for 40-mm z-axis coverage in each of the paired perfusion studies. Measurement reproducibility was evaluated using Bland-Altman statistics. RESULTS: Mean difference (95% limits of agreement) for tumor permeability was 1.4 (-4.0 to 6.8) for 10-mm coverage and 0.8 (-3.6 to 5.2) for 40-mm coverage. Mean difference (95% limits of agreement) for blood volume was 1.9 (-5.1 to 8.9) for 10-mm coverage and 1.4 (-3.7 to 6.6) for 40-mm coverage. The coefficient of variation for permeability was 18.7% for 10-mm coverage, improving to 11.9% for 40-mm coverage. The coefficient of variation for blood volume was 41.7% for 10-mm coverage, improving to 32.6% for 40-mm coverage. CONCLUSION: Our results show that an improvement in tumor perfusion measurement reproducibility may be achieved with greater z-axis coverage.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/irrigação sanguínea , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Idoso , Volume Sanguíneo , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Carga Tumoral
11.
Clin Cancer Res ; 10(11): 3745-54, 2004 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15173081

RESUMO

PURPOSE: Identification of factors that assist prediction of tumor response to radiotherapy may aid in refining treatment strategies and improving outcome. Possible association of molecular marker expression profiles with locoregional control of head and neck squamous cell carcinoma was investigated in a randomized trial of conventional versus continuous hyperfractionated accelerated radiotherapy (CHART). EXPERIMENTAL DESIGN: Tumor material was obtained from 402 patients. Immunohistochemistry was used to assess Ki-67, CD31, p53, Bcl-2, and cyclin D1 expression. A hierarchical clustering algorithm with a Bayesian information criterion was used to group tumors with similar marker expression; resulting expression profiles were then compared in terms of their difference in outcome after CHART and conventionally fractionated radiotherapy. RESULTS: Molecular marker profile was an independent prognostic factor for locoregional control. This was confirmed in multivariate analysis, including clinical variables such as tumor and nodal status, primary site, histological grade, age, and gender (P < 0.001 and P = 0.006 for local and nodal relapse, respectively). In particular, Bcl-2-positive tumors responded significantly better than average in both arms of the trial. Tumors negative for p53- and Bcl-2, with high and randomly patterned Ki-67 expression, responded worse than average with no benefit from CHART. Tumors with similarly negative p53 and Bcl-2, but low Ki-67 staining, with an organized pattern, benefit significantly from CHART schedule. CONCLUSIONS: This study demonstrates the potential of molecular profiles to predict radiotherapy response of head and neck squamous cell carcinoma and for treatment stratification. Distinct expression profiles correlate with three distinct clinical phenotypes, including good locoregional control, poor locoregional control, and an outcome strongly dependent upon fractionation schedule.


Assuntos
Biomarcadores Tumorais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/radioterapia , Algoritmos , Teorema de Bayes , Análise por Conglomerados , Ciclina D1/biossíntese , Fracionamento da Dose de Radiação , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/biossíntese , Masculino , Molécula-1 de Adesão Celular Endotelial a Plaquetas/biossíntese , Modelos de Riscos Proporcionais , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Radioterapia/métodos , Dosagem Radioterapêutica , Estatística como Assunto , Fatores de Tempo , Proteína Supressora de Tumor p53/biossíntese
12.
Eur J Cancer ; 40(18): 2734-41, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15571955

RESUMO

The prognostic significance of a panel of molecular biomarkers in head and neck squamous cell carcinoma (HNSCC) for first failure site (primary (T), nodal (N) or distant (M)) was analysed in 309 patients randomised to continuous hyperfractionated accelerated radiotherapy (CHART) vs. conventionally fractionated radiotherapy. Multivariate competing risks analysis was performed using an accelerated failure-time model. First-order interactions between each marker and trial arm were also tested. Bcl2-positivity increased the time to T- and N-failures, increasing cyclin D1 score decreased the time to N-failures. A random proliferative pattern and low Ki-67 decreased the time to M-failures. A high CD31 score was associated with a significantly longer time to T-failure after CHART, but not after conventional fractionation. Risks of T-, N- and M-failures could be estimated for individual patients. Competing risks analysis of failure sites allows the rational selection of patients for more aggressive loco-regional or systemic therapy.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/radioterapia , Recidiva Local de Neoplasia/diagnóstico , Métodos Epidemiológicos , Feminino , Humanos , Imuno-Histoquímica , Masculino , Prognóstico , Falha de Tratamento
13.
Int J Radiat Oncol Biol Phys ; 59(4): 1190-5, 2004 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-15234055

RESUMO

INTRODUCTION: The laboratory phenomenon of low dose hyper-radiosensitivity (LDHRS) describes excess cell kill at doses below 1 Gy relative to that predicted by the linear quadratic model. These data have stimulated the investigation of whether LDHRS can be exploited clinically. METHODS: Patients with metastatic tumor nodules to skin were recruited. The nodules were measured in three dimensions, consecutively numbered according to volume, and randomized, in matched pairs, to receive either conventionally fractionated radiotherapy (1.5 Gy/day) or ultrafractionated radiotherapy (0.5 Gy TDS: 4-h gap). Both groups were treated for 12 days. Measurements were taken Days 0, 5, 8, 12, and 26 and monthly until regrowth occurred. Tumor volumes were normalized to those on Day 0 and plotted against time from the start of treatment. Time to regrowth to original volume was calculated and compared between groups using the Wilcoxon signed rank test. RESULTS: Eight patients with a total of 40 paired nodules were analyzed; 36 nodules have regrown and are therefore evaluable. Analysis of the whole data set demonstrates a two-tailed p-value of 0.14 in favor of the "ultrafractionated" treatment. Analysis of the tumors generally accepted as being radioresistant and known to show LDHRS in vitro demonstrates a two-tailed p value of 0.009. CONCLUSIONS: LDHRS can be demonstrated in tumors clinically. An "ultrafractionated" radiotherapy regime produces significantly increased growth delay in radioresistant malignant tumors.


Assuntos
Tolerância a Radiação , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/secundário , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Humanos , Leiomiossarcoma/radioterapia , Leiomiossarcoma/secundário , Modelos Lineares , Linfoma não Hodgkin/radioterapia , Masculino , Análise por Pareamento , Melanoma/radioterapia , Melanoma/secundário , Pessoa de Meia-Idade
14.
Int J Radiat Oncol Biol Phys ; 55(3): 568-75, 2003 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-12573743

RESUMO

PURPOSE: To investigate compliance to the prescribed dose-fractionation schedule in five randomized controlled trials of altered fractionation in radiotherapy for head-and-neck carcinoma. METHODS AND MATERIALS: Individual patient data from 2566 patients participating in the European Organization for Research and Treatment of Cancer (EORTC) 22791, EORTC 22811, EORTC 22851, Princess Margaret Hospital (PMH), and continuous hyperfractionated accelerated radiotherapy (CHART) head-and-neck trials were merged in the fractionation IMPACT (Intergroup Merger of Patient data from Altered or Conventional Treatment schedules) study database. The ideal treatment time was defined as the minimum time required to deliver a prescribed schedule. Compliance to the prescribed overall treatment time was quantified as the difference between the actual and the ideal overall time. An overall measure of compliance in an individual patient, the total dose lost (TDL), was calculated as the dose lost due to prolongation of therapy (assuming a D(prolif) of 0.64 Gy/day) plus the difference between the prescribed and the actual dose given. RESULTS: The time in excess of the ideal ranged up to 97 days (average 3.9 days), and 25% of the patients had delays of 6 days or more. World Health Organization (WHO) performance status and nodal stage had a significant effect on TDL. TDL was significantly higher in the conventional than in the altered arm of the EORTC 22851 and CHART trials. In the PMH trial, TDL was significantly higher in the hyperfractionation than in the conventional arm. Centers participating in the three EORTC trials varied significantly in their compliance. There was a significant improvement in compliance in patients treated more recently. CONCLUSIONS: Even in randomized controlled trials, compliance to the prescribed radiation therapy schedule may be relatively poor, especially after conventional fractionation. This affects the interpretation of the outcome of these trials.


Assuntos
Fracionamento da Dose de Radiação , Fidelidade a Diretrizes , Neoplasias de Cabeça e Pescoço/radioterapia , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Europa (Continente) , Indicadores Básicos de Saúde , Humanos , Estudos Multicêntricos como Assunto , Estatísticas não Paramétricas
15.
Radiother Oncol ; 72(2): 159-68, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15297134

RESUMO

BACKGROUND AND PURPOSE: Hypoxia and proliferation are important determinants of radiation responsiveness; prospective measures of these before radiotherapy may enable individualisation of treatment schedules. Immunohistochemical techniques offer a potential means of achieving this in routine biopsy material. MATERIAL AND METHODS: Cellular hypoxia as measured by pimonidazole fixation and immunohistochemistry has been evaluated in a series of human bladder cancers with dual staining of sections for pimonidazole and either the vascular markers, CD31/34, or proliferation markers, Ki-67 or cyclin A. Twenty one tumour specimens were examined suitable for the double staining technique. RESULTS: The median hypoxic fraction was 9% (range 0-38). Seven tumours did not stain for pimonidazole and 11 exhibited necrosis. The mean vascular density ranged from 16.7 to 160.6 vessels per mm2. The median hot spot count was 30 (range 16-43). There was a statistically significant increase in vessel density in hypoxic compared to oxic regions measured by both vessel density (P = 0.02) and hot spot count (P = 0.004). Proliferation indices decreased from oxic to hypoxic areas close to blood vessels. CONCLUSIONS: We have demonstrated that bladder cancer exhibits a range of hypoxia, proliferation and vascular density which may be used to form the basis for patient selection for hypoxia modification, accelerated radiotherapy and vascular targeting agents.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células de Transição/química , Carcinoma de Células de Transição/patologia , Neovascularização Patológica/metabolismo , Neoplasias da Bexiga Urinária/química , Neoplasias da Bexiga Urinária/patologia , Antígenos CD34/análise , Carcinoma de Células de Transição/irrigação sanguínea , Hipóxia Celular , Proliferação de Células , Ciclina A/análise , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Masculino , Estadiamento de Neoplasias , Nitroimidazóis/análise , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Radiossensibilizantes/análise , Coloração e Rotulagem/métodos , Neoplasias da Bexiga Urinária/irrigação sanguínea
16.
Radiother Oncol ; 70(3): 319-29, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15064019

RESUMO

BACKGROUND AND PURPOSE: The laboratory phenomenon of low dose hyper-radiosensitivity (LDHRS) describes an excess of cell kill at doses below 1Gy relative to that predicted by the linear quadratic model. These data have stimulated clinical investigation into LDHRS in vivo. PATIENTS AND METHODS: Skin was used as a model of normal human tissue. Two studies were initiated investigating the response to low doses of radiation. Study 1 compared once daily skin doses of approximately 0.5 and >1.0Gy in 24 patients receiving pelvic radiotherapy. Skin biopsies before and during radiotherapy were analysed histologically to assess the basal cell density (BCD). Study 2 compared two regimens of equal dose/time intensity--an ultrafractionated regimen (0.5Gy TDS x 12 days) with a conventional regimen (1.5Gy OD x 12 days). Skin biopsies taken during treatment assessed BCD and proliferative index. In both studies the changes in BCD were compared using non-linear regression analysis. RESULTS: Study 1. The results show a significantly greater reduction in BCD in the low dose group when BCD is plotted against dose. This effect is lost when BCD is plotted against time Study 2. The results demonstrate a significantly greater reduction in BCD in the higher dose/fraction arm. The proliferative response was similar in both treatment groups. CONCLUSIONS: These data suggest that LDHRS does not occur in skin following doses of approximately 0.5Gy/fraction when regimens of equal dose/time intensity are compared. As only small volumes of normal tissue were irradiated it is difficult to predict the biological relevance of this with respect to larger field low dose per fraction irradiation regimens or risk of cancer induction. Equally we cannot extrapolate to effects resulting from exposure to doses <0.5Gy or to the effects of low doses on other endpoints.


Assuntos
Pele/efeitos da radiação , Biópsia por Agulha , Contagem de Células , Divisão Celular , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-1/análise , Masculino , Neoplasias da Próstata/radioterapia , Dosagem Radioterapêutica , Pele/citologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/secundário , Neoplasias Uterinas/radioterapia
17.
Radiother Oncol ; 73(2): 237-49, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15542172

RESUMO

BACKGROUND AND PURPOSE: The European Society for Therapeutic Radiology and Oncology was funded by the EU for a project on recording providing education, and ameliorating the consequences of treatment (REACT). An European audit was carried out as part of which to assess the usefulness of current follow-up practices. PATIENTS AND METHODS: Over a 4-month period in 15 cancer centres in 10 countries, patients attending for routine follow-up completed a questionnaire covering their expectations of and satisfaction with the visit. This was matched with a questionnaire completed by the physician about the content and usefulness of the consultation. The feasibility of a short toxicity scale developed by Dische and Saunders was also investigated. RESULTS: In total, 2303 matched questionnaires were analysed. Forty percent of the patients had symptoms or medical problems related to their disease. In 18% there was a positive finding on clinical examination. In 28% investigations were undertaken part of departmental routine practice. Ten percent of the investigations showed an abnormal result. Ninety nine percent of physicians and 85% of the patients expressed satisfaction. Using the short toxicity scale rates of recording toxicity could be increased from 28 to 93%. CONCLUSIONS: There is wide variation in follow-up practices among European centres. There was a low incidence of positive findings clinically or with routine investigations. A simple scale for recording morbidity has proved easy to use by departments, which have not routinely used one of the standard measures. Further work will attempt to produce an European guideline for effective routine follow-up after radiotherapy.


Assuntos
Institutos de Câncer/normas , Continuidade da Assistência ao Paciente/normas , Auditoria Médica , Neoplasias/radioterapia , Satisfação do Paciente , Radioterapia (Especialidade)/normas , Instituições de Assistência Ambulatorial , Testes Diagnósticos de Rotina , Europa (Continente) , Seguimentos , Pesquisas sobre Atenção à Saúde , Humanos , Neoplasias/patologia , Qualidade da Assistência à Saúde , Inquéritos e Questionários
19.
J Clin Oncol ; 30(22): 2788-97, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22753901

RESUMO

PURPOSE: In lung cancer, randomized trials assessing hyperfractionated or accelerated radiotherapy seem to yield conflicting results regarding the effects on overall (OS) or progression-free survival (PFS). The Meta-Analysis of Radiotherapy in Lung Cancer Collaborative Group decided to address the role of modified radiotherapy fractionation. MATERIAL AND METHODS: We performed an individual patient data meta-analysis in patients with nonmetastatic lung cancer, which included trials comparing modified radiotherapy with conventional radiotherapy. RESULTS: In non-small-cell lung cancer (NSCLC; 10 trials, 2,000 patients), modified fractionation improved OS as compared with conventional schedules (hazard ratio [HR] = 0.88, 95% CI, 0.80 to 0.97; P = .009), resulting in an absolute benefit of 2.5% (8.3% to 10.8%) at 5 years. No evidence of heterogeneity between trials was found. There was no evidence of a benefit on PFS (HR = 0.94; 95% CI, 0.86 to 1.03; P = .19). Modified radiotherapy reduced deaths resulting from lung cancer (HR = 0.89; 95% CI, 0.81 to 0.98; P = .02), and there was a nonsignificant reduction of non-lung cancer deaths (HR = 0.87; 95% CI, 0.66 to 1.15; P = .33). In small-cell lung cancer (SCLC; two trials, 685 patients), similar results were found: OS, HR = 0.87, 95% CI, 0.74 to 1.02, P = .08; PFS, HR = 0.88, 95% CI, 0.75 to 1.03, P = .11. In both NSCLC and SCLC, the use of modified radiotherapy increased the risk of acute esophageal toxicity (odds ratio [OR] = 2.44 in NSCLC and OR = 2.41 in SCLC; P < .001) but did not have an impact on the risk of other acute toxicities. CONCLUSION: Patients with nonmetastatic NSCLC derived a significant OS benefit from accelerated or hyperfractionated radiotherapy; a similar but nonsignificant trend was observed for SCLC. As expected, there was increased acute esophageal toxicity.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma de Células Pequenas/radioterapia , Fracionamento da Dose de Radiação , Neoplasias Pulmonares/radioterapia , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma de Células Pequenas/mortalidade , Intervalo Livre de Doença , Esôfago/efeitos da radiação , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente
20.
Int J Radiat Oncol Biol Phys ; 80(3): 721-7, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20630668

RESUMO

PURPOSE: The antivascular effects of androgen deprivation have been investigated in animal models; however, there has been minimal investigation in human prostate cancer. This study tested the hypothesis that androgen deprivation causes significant reductions in human prostate tumor blood flow and the induction of hypoxia at a magnitude and in a time scale relevant to the neoadjuvant setting before radiotherapy. METHODS AND MATERIALS: Twenty patients were examined, each with five multi-parameter magnetic resonance imaging scans: two scans before the commencement of androgen suppression, one scan after 1 month of hormone treatment, and two further scans after 3 months of therapy. Quantitative parametric maps of the prostate informing on relative blood flow (rBF), relative blood volume (rBV), vascular permeability (transfer constant [K(trans)]), leakage space (v(e)) and blood oxygenation (intrinsic relaxivity [R(2)∗]) were calculated. RESULTS: Tumor blood volume and blood flow decreased by 83% and 79%, respectively, in the first month (p < 0.0001), with 74% of patients showing significant changes. The proportion of individual patients who achieved significant changes in T1 kinetic parameter values after 3 months of androgen deprivation for tumor measurements was 68% for K(trans) and 53% for v(e) By 3 months, significant increases in R(2)∗ had occurred in prostate tumor, with a rise of 41.1% (p < 0.0001). CONCLUSIONS: Androgen deprivation induces profound vascular collapse within 1 month of starting treatment. Increased R(2)∗ in regions of prostate cancer and a decrease in blood volume suggest a reduction in tumor oxygenation.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/tratamento farmacológico , Idoso , Anilidas/uso terapêutico , Volume Sanguíneo/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Hipóxia Celular/fisiologia , Gosserrelina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Nitrilas/uso terapêutico , Oxigênio/sangue , Estudos Prospectivos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Reprodutibilidade dos Testes , Fatores de Tempo , Compostos de Tosil/uso terapêutico
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