RESUMO
BACKGROUND: Patients with a pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for oesophageal cancer may benefit from non-surgical management. The aim of this study was to determine the diagnostic performance of visual response assessment of the primary tumour after nCRT on T2-weighted (T2W) and diffusion-weighted (DW) MRI. METHODS: Patients with locally advanced oesophageal cancer who underwent T2W- and DW-MRI (1·5 T) before and after nCRT in two hospitals, between July 2013 and September 2017, were included in this prospective study. Three radiologists evaluated T2W images retrospectively using a five-point score for the assessment of residual tumour in a blinded manner and immediately rescored after adding DW-MRI. Histopathology of the resection specimen was used as the reference standard; ypT0 represented a pCR. Sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC) and interobserver agreement were calculated. RESULTS: Twelve of 51 patients (24 per cent) had a pCR. The sensitivity and specificity of T2W-MRI for detection of residual tumour ranged from 90 to 100 and 8 to 25 per cent respectively. Respective values for T2W + DW-MRI were 90-97 and 42-50 per cent. AUCs for the three readers were 0·65, 0·66 and 0·68 on T2W-MRI, and 0·71, 0·70 and 0·70 on T2W + DW-MRI (P = 0·441, P = 0·611 and P = 0·828 for readers 1, 2 and 3 respectively). The κ value for interobserver agreement improved from 0·24-0·55 on T2W-MRI to 0·55-0·71 with DW-MRI. CONCLUSION: Preoperative assessment of residual tumour on MRI after nCRT for oesophageal cancer is feasible with high sensitivity, reflecting a low chance of missing residual tumour. However, the specificity was low; this results in overstaging of complete responders as having residual tumour and, consequently, overtreatment.
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Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/terapia , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia Adjuvante , Imagem de Difusão por Ressonância Magnética , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/terapia , Terapia Neoadjuvante , Neoplasia Residual/diagnóstico por imagem , Idoso , Esofagectomia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Mantle cell lymphoma (MCL) rarely presents as early-stage disease, but clinical observations suggest that patients who present with early-stage disease may have better outcomes than those with advanced-stage disease. PATIENTS AND METHODS: In this 13-institution study, we examined outcomes among 179 patients with early-stage (stage I or II) MCL in an attempt to identify prognostic factors that influence treatment selection and outcome. Variables examined included clinical characteristics, treatment modality, response to therapy, sites of failure, and survival. RESULTS: Patients were predominantly male (78%) with head and neck being the most common presenting sites (75%). Most failures occurred outside the original disease site (79%). Although the administration of radiation therapy, either alone or with chemotherapy, reduced the risk of local failure, it did not translate into an improved freedom from progression or overall survival (OS). The treatment outcomes were independent of treatment modality. The 10-year OS for patients treated with chemotherapy alone, chemo-radiation therapy and radiation therapy alone were 69%, 62%, and 74% (P = 0.79), and the 10-year freedom from progression were 46%, 43%, and 31% (P = 0.64), respectively. CONCLUSION: Given the excellent OS rates regardless of initial therapy in patients with early-stage MCL, de-intensified therapy to limit treatment-related toxicity is a reasonable approach.
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Linfoma de Célula do Manto/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Quimiorradioterapia , Feminino , Humanos , Linfoma de Célula do Manto/terapia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Abdominal radiotherapy for testicular cancer (TC) increases risk for second stomach cancer, although data on the radiation dose-response relationship are sparse. METHODS: In a cohort of 22,269 5-year TC survivors diagnosed during 1959-1987, doses to stomach subsites were estimated for 92 patients who developed stomach cancer and 180 matched controls. Chemotherapy details were recorded. Odds ratios (ORs) were estimated using logistic regression. RESULTS: Cumulative incidence of second primary stomach cancer was 1.45% at 30 years after TC diagnosis. The TC survivors who received radiotherapy (87 (95%) cases, 151 (84%) controls) had a 5.9-fold (95% confidence interval (CI) 1.7-20.7) increased risk of stomach cancer. Risk increased with increasing stomach dose (P-trend<0.001), with an OR of 20.5 (3.7-114.3) for ⩾50.0 Gy compared with <10 Gy. Radiation-related risks remained elevated ⩾20 years after exposure (P<0.001). Risk after any chemotherapy was not elevated (OR=1.1; 95% CI 0.5-2.5; 14 cases and 23 controls). CONCLUSIONS: Radiotherapy for TC involving parts of the stomach increased gastric cancer risk for several decades, with the highest risks after stomach doses of ⩾30 Gy. Clinicians should be aware of these excesses when previously irradiated TC survivors present with gastrointestinal symptoms and when any radiotherapy is considered in newly diagnosed TC patients.
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Neoplasias Induzidas por Radiação/etiologia , Neoplasias Gástricas/etiologia , Neoplasias Testiculares/radioterapia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Relação Dose-Resposta à Radiação , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Sobreviventes , Adulto JovemRESUMO
BACKGROUND: Although elevated risks of pancreatic cancer have been observed in long-term survivors of Hodgkin lymphoma (HL), no prior study has assessed the risk of second pancreatic cancer in relation to radiation dose and specific chemotherapeutic agents. PATIENTS AND METHODS: We conducted an international case-control study within a cohort of 19 882 HL survivors diagnosed from 1953 to 2003 including 36 cases and 70 matched controls. RESULTS: Median ages at HL and pancreatic cancer diagnoses were 47 and 60.5 years, respectively; median time to pancreatic cancer was 19 years. Pancreatic cancer risk increased with increasing radiation dose to the pancreatic tumor location (Ptrend = 0.005) and increasing number of alkylating agent (AA)-containing cycles of chemotherapy (Ptrend = 0.008). The odds ratio (OR) for patients treated with both subdiaphragmatic radiation (≥10 Gy) and ≥6 AA-containing chemotherapy cycles (13 cases, 6 controls) compared with patients with neither treatment was 17.9 (95% confidence interval 3.5-158). The joint effect of these two treatments was significantly greater than additive (P = 0.041) and nonsignificantly greater than multiplicative (P = 0.29). Especially high risks were observed among patients receiving ≥8400 mg/m(2) of procarbazine with nitrogen mustard or ≥3900 mg/m(2) of cyclophosphamide. CONCLUSION: Our study demonstrates for the first time that both radiotherapy and chemotherapy substantially increase pancreatic cancer risks among HL survivors treated in the past. These findings extend the range of nonhematologic cancers associated with chemotherapy and add to the evidence that the combination of radiotherapy and chemotherapy can lead to especially large risks.
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Doença de Hodgkin/complicações , Neoplasias Induzidas por Radiação/epidemiologia , Neoplasias Pancreáticas/epidemiologia , Neoplasias Pancreáticas/etiologia , Adulto , Idoso , Estudos de Casos e Controles , Relação Dose-Resposta à Radiação , Feminino , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/patologia , Doença de Hodgkin/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/patologia , Neoplasias Pancreáticas/induzido quimicamente , Radioterapia/efeitos adversos , Fatores de RiscoRESUMO
STUDY QUESTION: How does the successful cryopreservation of semen affect the odds of post-treatment fatherhood among Hodgkin lymphoma (HL) survivors? SUMMARY ANSWER: Among 334 survivors who wanted to have children, the availability of cryopreserved semen doubled the odds of post-treatment fatherhood. WHAT IS KNOWN ALREADY: Cryopreservation of semen is the easiest, safest and most accessible way to safeguard fertility in male patients facing cancer treatment. Little is known about what proportion of patients achieve successful semen cryopreservation. To our knowledge, neither the factors which influence the occurrence of semen cryopreservation nor the rates of fatherhood after semen has been cryopreserved have been analysed before. STUDY DESIGN, SIZE, DURATION: This is a cohort study with nested case-control analyses of consecutive Hodgkin survivors treated between 1974 and 2004 in multi-centre randomized controlled trials. A written questionnaire was developed and sent to 1849 male survivors. PARTICIPANTS/MATERIALS, SETTING, METHODS: Nine hundred and two survivors provided analysable answers. The median age at treatment was 31 years. The median follow-up after cryopreservation was 13 years (range 5-36). MAIN RESULTS AND THE ROLE OF CHANCE: Three hundred and sixty-three out of 902 men (40%) cryopreserved semen before the start of potentially gonadotoxic treatment. The likelihood of semen cryopreservation was influenced by age, treatment period, disease stage, treatment modality and education level. Seventy eight of 363 men (21%) used their cryopreserved semen. Men treated between 1994 and 2004 had significantly lower odds of cryopreserved semen use compared with those treated earlier, whereas alkylating or second-line (chemo)therapy significantly increased the odds of use; no other influencing factors were identified. We found an adjusted odds ratio of 2.03 (95% confidence interval 1.11-3.73, P = 0.02) for post-treatment fatherhood if semen cryopreservation was performed. Forty-eight out of 258 men (19%) who had children after HL treatment became a father using cryopreserved semen. LIMITATIONS, REASONS FOR CAUTION: Data came from questionnaires and so this study potentially suffers from response bias. We could not perform an analysis with correction for duration of follow-up or provide an actuarial use rate due to lack of dates of semen utilization. We do not have detailed information on either the techniques used in cryopreserved semen utilization or the number of cycles needed. STUDY FUNDING/COMPETING INTERESTS: Lance Armstrong Foundation, Dutch Cancer Foundation, René Vogels Stichting, no competing interests.
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Criopreservação , Fertilidade , Doença de Hodgkin/terapia , Preservação do Sêmen , Sêmen , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Estudos de Coortes , Doença de Hodgkin/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , SobreviventesRESUMO
BACKGROUND: The introduction of rituximab significantly improved the prognosis of diffuse large B-cell lymphoma (DLBCL), emphasizing the importance of evaluating the long-term consequences of exposure to radiotherapy, alkylating agents and anthracycline-containing (immuno)chemotherapy among DLBCL survivors. METHODS: Long-term risk of subsequent malignant neoplasms (SMNs) was examined in a multicenter cohort comprising 2373 5-year DLBCL survivors treated at ages 15-61 years in 1989-2012. Observed SMN numbers were compared with expected cancer incidence to estimate standardized incidence ratios (SIRs) and absolute excess risks (AERs/10 000 person-years). Treatment-specific risks were assessed using multivariable Cox regression. RESULTS: After a median follow-up of 13.8 years, 321 survivors developed one or more SMNs (SIR 1.5, 95% CI 1.3-1.8, AER 51.8). SIRs remained increased for at least 20 years after first-line treatment (SIR ≥20-year follow-up 1.5, 95% CI 1.0-2.2, AER 81.8) and were highest among patients ≤40 years at first DLBCL treatment (SIR 2.7, 95% CI 2.0-3.5). Lung (SIR 2.0, 95% CI 1.5-2.7, AER 13.4) and gastrointestinal cancers (SIR 1.5, 95% CI 1.2-2.0, AER 11.8) accounted for the largest excess risks. Treatment with >4500 mg/m2 cyclophosphamide/>300 mg/m2 doxorubicin versus ≤2250 mg/m2/≤150 mg/m2, respectively, was associated with increased solid SMN risk (hazard ratio 1.5, 95% CI 1.0-2.2). Survivors who received rituximab had a lower risk of subdiaphragmatic solid SMNs (hazard ratio 0.5, 95% CI 0.3-1.0) compared with survivors who did not receive rituximab. CONCLUSION: Five-year DLBCL survivors have an increased risk of SMNs. Risks were higher for survivors ≤40 years at first treatment and survivors treated with >4500 mg/m2 cyclophosphamide/>300 mg/m2 doxorubicin, and may be lower for survivors treated in the rituximab era, emphasizing the need for studies with longer follow-up for rituximab-treated patients.
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Linfoma Difuso de Grandes Células B , Segunda Neoplasia Primária , Humanos , Rituximab/efeitos adversos , Segunda Neoplasia Primária/epidemiologia , Segunda Neoplasia Primária/etiologia , Sobreviventes , Ciclofosfamida , Doxorrubicina , Linfoma Difuso de Grandes Células B/epidemiologiaAssuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença de Hodgkin/terapia , Oncologia/normas , Recidiva Local de Neoplasia/terapia , Assistência ao Convalescente/métodos , Assistência ao Convalescente/normas , Protocolos de Quimioterapia Combinada Antineoplásica/normas , Biópsia , Quimiorradioterapia/métodos , Europa (Continente) , Doença de Hodgkin/diagnóstico , Doença de Hodgkin/epidemiologia , Doença de Hodgkin/patologia , Humanos , Assistência de Longa Duração/métodos , Assistência de Longa Duração/normas , Linfonodos/patologia , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Oncologia/métodos , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Segunda Neoplasia Primária/diagnóstico , Tomografia por Emissão de Pósitrons/normas , Prognóstico , Indução de Remissão/métodos , Sociedades Médicas/normas , Sobrevivência , Tomografia Computadorizada por Raios X/normas , Resultado do TratamentoRESUMO
BACKGROUND: We evaluated the long-term results of radiotherapy for patients with gastric marginal zone lymphoma (GMZL). PATIENTS AND METHODS: We carried out a retrospective, multi-centre study of patients with low-grade GMZL treated by radiotherapy between 17 July 1981 and 25 March 2004. RESULTS: There were 102 eligible patients. Fifty-eight patients were previously untreated and 44 had recurrent/residual disease after prior treatment (HP eradication, chemotherapy and surgery in 35, 9 and 8 patients, respectively, and 7 had >1 prior therapy). Radiation fields included the stomach /involved nodes in 61 patients and whole abdomen in 41. The median radiotherapy dose to stomach was 40 Gy (range 26-46 Gy) in a median 22 fractions. With a median follow-up after radiotherapy of 7.9 years (range 0.3-24 years), 10- and 15-year freedom from treatment failure (FFTF) was 88% (95% CI 82%-95%). Risk factors for TF were a large-cell component (P = 0.036) and an exophytic growth pattern (P = 0.042). Radiotherapy field size, radiotherapy dose, and failure of prior therapy were not associated with inferior FFTF. Ten-year overall survival was 70% (95% CI 60%-82%). CONCLUSIONS: Radiotherapy achieves cure for the majority of patients with low-grade GMZL, including patients who have had prior therapy. Several features may predict a poorer outcome.
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Linfoma de Zona Marginal Tipo Células B/mortalidade , Linfoma de Zona Marginal Tipo Células B/radioterapia , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Testicular germ cell tumour (TGCT) patients are at increased risk of developing a contralateral testicular germ cell tumour (CTGCT). It is unclear whether TGCT treatment affects CTGCT risk. METHODS: The risk of developing a metachronous CTGCT (a CTGCT diagnosed ≥6 months after a primary TGCT) and its impact on patient's prognosis was assessed in a nationwide cohort comprising 3749 TGCT patients treated in the Netherlands during 1965-1995. Standardised incidence ratios (SIRs), comparing CTGCT incidence with TGCT incidence in the general population, and cumulative CTGCT incidence were estimated and CTGCT risk factors assessed, accounting for competing risks. RESULTS: Median follow-up was 18.5 years. Seventy-seven metachronous CTGCTs were diagnosed. The SIR for metachronous CTGCTs was 17.6 (95% confidence interval (95% CI) 13.9-22.0). Standardised incidence ratios remained elevated for up to 20 years, while the 20-year cumulative incidence was 2.2% (95% CI 1.8-2.8%). Platinum-based chemotherapy was associated with a lower CTGCT risk among non-seminoma patients (hazard ratio 0.37, 95% CI 0.18-0.72). The CTGCT patients had a 2.3-fold (95% CI 1.3-4.1) increased risk to develop a subsequent non-TGCT cancer and, consequently, a 1.8-fold (95% CI 1.1-2.9) higher risk of death than patients without a CTGCT. CONCLUSION: The TGCT patients remain at increased risk of a CTGCT for up to 20 years. Treatment with platinum-based chemotherapy reduces this risk.
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Neoplasias Embrionárias de Células Germinativas/epidemiologia , Segunda Neoplasia Primária/epidemiologia , Neoplasias Testiculares/epidemiologia , Adulto , Idoso , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Embrionárias de Células Germinativas/patologia , Neoplasias Embrionárias de Células Germinativas/terapia , Segunda Neoplasia Primária/patologia , Prognóstico , Fatores de Risco , Análise de Sobrevida , Neoplasias Testiculares/patologia , Neoplasias Testiculares/terapiaRESUMO
BACKGROUND: Radiotherapy for breast cancer may expose the esophagus to ionizing radiation, but no study has evaluated esophageal cancer risk after breast cancer associated with radiation dose or systemic therapy use. DESIGN: Nested case-control study of esophageal cancer among 289 748 ≥5-year survivors of female breast cancer from five population-based cancer registries (252 cases, 488 individually matched controls), with individualized radiation dosimetry and information abstracted from medical records. RESULTS: The largest contributors to esophageal radiation exposure were supraclavicular and internal mammary chain treatments. Esophageal cancer risk increased with increasing radiation dose to the esophageal tumor location (P(trend )< 0.001), with doses of ≥35 Gy associated with an odds ratio (OR) of 8.3 [95% confidence interval (CI) 2.7-28]. Patients with hormonal therapy ≤5 years preceding esophageal cancer diagnosis had lower risk (OR = 0.4, 95% CI 0.2-0.8). Based on few cases, alkylating agent chemotherapy did not appear to affect risk. Our data were consistent with a multiplicative effect of radiation and other esophageal cancer risk factors (e.g. smoking). CONCLUSIONS: Esophageal cancer is a radiation dose-related complication of radiotherapy for breast cancer, but absolute risk is low. At higher esophageal doses, the risk warrants consideration in radiotherapy risk assessment and long-term follow-up.
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Intervalo Livre de Doença , Neoplasias Esofágicas/mortalidade , Neoplasias Induzidas por Radiação/etiologia , Segunda Neoplasia Primária/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas , Índice de Massa Corporal , Neoplasias da Mama/radioterapia , Estudos de Casos e Controles , Relação Dose-Resposta à Radiação , Neoplasias Esofágicas/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/tratamento farmacológico , Neoplasias Induzidas por Radiação/radioterapia , Segunda Neoplasia Primária/tratamento farmacológico , Segunda Neoplasia Primária/radioterapia , Dosagem Radioterapêutica , Risco , Fatores de Risco , Fumar , SobreviventesRESUMO
This consensus report of the EGILS (European Gastro-Intestinal Lymphoma Study) group includes recommendations on the management of gastric extranodal marginal zone B-cell lymphoma of MALT. They are based on data from the literature and on intensive discussions and votings of the experts during their annual meetings.
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Linfoma de Zona Marginal Tipo Células B/diagnóstico , Neoplasias Gástricas/diagnóstico , Infecções por Helicobacter/complicações , Helicobacter pylori , Humanos , Assistência de Longa Duração/métodos , Linfoma de Zona Marginal Tipo Células B/microbiologia , Linfoma de Zona Marginal Tipo Células B/terapia , Estadiamento de Neoplasias , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/terapia , Resultado do TratamentoRESUMO
BACKGROUND: Surgery alone for locally advanced oesophageal cancer is associated with low cure rates. The benefits and risks of neoadjuvant chemoradiation for patients with oesophageal cancer were evaluated. METHODS: A systematic review of publications between 2000 and 2008 on neoadjuvant chemoradiation for oesophageal cancer was undertaken. RESULTS: Thirty-eight papers comprising 3640 patients met the inclusion criteria. Chemoradiation regimens varied widely with a predominance of 5-fluorouracil/cisplatin chemotherapy. Chemoradiation-related toxicity was reported in only ten studies and consisted mainly of neutropenia. The chemoradiation-related mortality rate was 2.3 per cent. The mean R0 resection rate and pathological complete response (pCR) rate were 88.4 and 25.8 per cent respectively. Postoperative morbidity was not uniformly reported. The in-hospital mortality rate after oesophagectomy following chemoradiation was 5.2 per cent. Five-year survival rates varied from 16 to 59 per cent in all patients and from 34 to 62 per cent in those with a pCR. Chemoradiation had a temporary negative effect on quality of life. CONCLUSION: Neoadjuvant chemoradiation regimens for oesophageal cancer vary widely. Besides traditional outcome variables (such as survival), other parameters should be analysed (for example toxicity) to assess whether the risks of chemoradiation are sufficiently compensated for by the benefits.
Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Adenocarcinoma/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/cirurgia , Quimioterapia Adjuvante/efeitos adversos , Quimioterapia Adjuvante/métodos , Métodos Epidemiológicos , Neoplasias Esofágicas/cirurgia , Humanos , Recidiva Local de Neoplasia , Qualidade de Vida , Dosagem Radioterapêutica , Radioterapia Adjuvante/efeitos adversos , Radioterapia Adjuvante/métodos , Análise de Sobrevida , Resultado do TratamentoRESUMO
Macroscopic fibers of carbon nanotubes (CNT) have emerged as an ideal architecture to exploit the exceptional properties of CNT building blocks in applications ranging from energy storage to reinforcement in structural composites. Controlled synthesis and scalability are amongst the most pressing challenges to further materialize the potential of CNT fibers. This work shows that under floating catalyst chemical vapor conditions in the direct spinning method, used both in research and industry, the ceramic reactor tube plays an unsuspected active role in CNT growth, leading for example to doubling of reaction yield when mullite (Al4+2xSi2-2xO10-x(x ≈ 0:4)) is used instead of alumina (Al2O3), but without affecting CNT morphology in terms of number of layers, purity or degree of graphitization. This behaviour is confirmed for different carbon sources and when growing either predominantly single-walled or multi-walled CNTs by adjusting promotor concentration. Analysis of large Si-based impurities occasionally found in CNT fiber fabric samples, attributed to reactor tube fragments that end up trapped in the porous fibers, indicate that the role of the reactor tube is in catalyzing the thermal decomposition of hydrocarbons, which subsequently react with floating Fe catalyst nanoparticles and produce extrusion of the CNTs and formation of an aerogel. Reactor gas analysis confirms that extensive thermal decomposition of the carbon source occurs in the absence of Fe catalyst particles, and that the concentration of different carbon species (e.g. carbon dioxide and ethylene) is sensitive to the reactor tube type. These finding open new avenues for controlled synthesis of CNT fibers by decoupling precursor decomposition from CNT extrusion at the catalyst particle.
RESUMO
BACKGROUND AND PURPOSE: Accurate delineation of the primary tumour is vital to the success of radiotherapy and even more important for successful boost strategies, aiming for improved local control in oesophageal cancer patients. Therefore, the aim was to assess delineation variability of the gross tumour volume (GTV) between CT and combined PET-CT in oesophageal cancer patients in a multi-institutional study. MATERIALS AND METHODS: Twenty observers from 14 institutes delineated the primary tumour of 6 cases on CT and PET-CT fusion. The delineated volumes, generalized conformity index (CIgen) and standard deviation (SD) in position of the most cranial/caudal slice over the observers were evaluated. For the central delineated region, perpendicular distance between median surface GTV and each individual GTV was evaluated as in-slice SD. RESULTS: After addition of PET, mean GTVs were significantly smaller in 3 cases and larger in 1 case. No difference in CIgen was observed (average 0.67 on CT, 0.69 on PET-CT). On CT cranial-caudal delineation variation ranged between 0.2 and 1.5â¯cm SD versus 0.2 and 1.3â¯cm SD on PET-CT. After addition of PET, the cranial and caudal variation was significantly reduced in 1 and 2 cases, respectively. The in-slice SD was on average 0.16â¯cm in both phases. CONCLUSION: In some cases considerable GTV delineation variability was observed at the cranial-caudal border. PET significantly influenced the delineated volume in four out of six cases, however its impact on observer variation was limited.
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We present a new experimental setup devoted to the study of gas phase molecules and processes using broad band high spectral resolution rotational spectroscopy. A reactor chamber has been equipped with radio receivers similar to those used by radio astronomers to search for molecular emission in space. The whole Q (31.5-50 GHz) and W bands (72-116.5 GHz) are available for rotational spectroscopy observations. The receivers are equipped with 16×2.5 GHz Fast Fourier Transform spectrometers with a spectral resolution of 38.14 kHz allowing the simultaneous observation of the complete Q band and one third of the W band. The whole W band can be observed in three settings in which the Q band is always observed. Species such as CH3CN, OCS, and SO2 are detected, together with many of their isotopologues and vibrationally excited states, in very short observing times. The system permits automatic overnight observations and integration times as long as 2.4×105 seconds have been reached. The chamber is equipped with a radiofrequency source to produce cold plasmas and with four ultraviolet lamps to study photochemical processes. Plasmas of CH4, N2, CH3CN, NH3, O2, and H2, among other species, have been generated and the molecular products easily identified by their rotational spectrum, and mass spectrometry and optical spectroscopy. Finally, the rotational spectrum of the lowest energy conformer of CH3CH2NHCHO (N-Ethylformamide), a molecule previously characterized in microwave rotational spectroscopy, has been measured up to 116.5 GHz allowing the accurate determination of its rotational and distortion constants and its search in space.
RESUMO
We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactors and the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40 cm long gas cell placed in the beam path of the Aries 40 m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS, CS, SO2 (<10-3 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.
Assuntos
Neoplasias do Íleo , Valva Ileocecal , Tumores Neuroendócrinos , Humanos , Neoplasias do Íleo/diagnóstico por imagem , Neoplasias do Íleo/cirurgia , Valva Ileocecal/diagnóstico por imagem , Valva Ileocecal/patologia , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/cirurgiaRESUMO
We present evidence that high temperature CVD growth of SWNTs under conditions of continuous spinning of macroscopic fibers leads to an inherent predominance of high chiral angle CNTs, peaking at the armchair end. Raman, UV-vis-NIR absorption, and photoluminescence spectroscopy measurements show the prevalence of metallic SWNTs. The complete chiral angle distribution is obtained by electron diffraction of over 390 CNTs. It is biased towards high chiral angles and peaks at the armchair end (30°), in good agreement with the established atomistic models for SWNT growth from a liquid catalyst. Based on the Fe-C-S constituent binary and ternary phase diagrams, thermodynamic calculations of phase compositions from fast cooling and experimental evidence of a post-synthesis catalyst, the proposed thermodynamic path of the catalyst is to form a solid FCC Fe core and a liquid Fe-S shell. S in the outer liquid shell first stabilizes the edge of the nascent CNT, but once a graphitic wall forms it is rejected due to the high interfacial energy of the Fe-C-S alloy.
RESUMO
PURPOSE: To quantify the long-term risk of second primary cancers (SCs) in patients diagnosed with Hodgkin's disease (HD) during adolescence or young adulthood. PATIENTS AND METHODS: The risk of SCs was assessed in 1,253 patients diagnosed with HD before the age of 40 years and treated in two Dutch cancer centers between 1966 and 1986. The median follow-up duration was 14.1 years. RESULTS: In all, 137 patients developed SCs, compared with 19.4 cases expected on the basis of incidence rates in the general population (relative risk [RR] = 7.0; 95% confidence interval, 5.9 to 8.3). The 25-year actuarial risk of SC overall was 27.7%. The RR of solid tumors increased greatly with younger age at the first treatment of HD, not only for breast cancer but also for all other solid tumors, with RRs of 4.9, 6.9, and 12.7 for patients first treated at ages 31 to 39 years, 21 to 30 years, and = 20 years, respectively. Among patients first treated at the age of 20 years or younger, the RR of developing a solid tumor before the age of 40 years was significantly greater than the RR of solid tumor development at ages 40 to 49 years (RR = 27.9 v RR = 4.2; P =.0001). Patients who received salvage chemotherapy had significantly greater risk of solid cancers other than breast cancer than did patients whose treatment was restricted to initial radiotherapy or initial combined-modality treatment (RR = 9.4 and 4.7, respectively; P =. 004). CONCLUSION: After more than 20 years of follow-up, the risk of solid tumors is still much greater in survivors of HD than in the population at large. Reassuringly, the greatly increased risk of solid tumors in patients who were young (= 20 years of age) at the first treatment seems to decrease as these patients grow older. Our data suggest that chemotherapy may increase the risk of solid tumors from radiotherapy.