Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
BMC Cancer ; 15: 813, 2015 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-26506988

RESUMO

BACKGROUND: To evaluate the long-term results of chemoradiotherapy (CRT) for stage II-III thoracic esophageal cancer mainly by comparing results of three protocols retrospectively. METHODS: Between 2000 and 2012, 298 patients with stage II-III thoracic esophageal cancer underwent CRT. Patients in Group A received two cycles of cisplatin (CDDP) at 70 mg/m(2) (day 1 and 29) and 5-fluorouracil (5-FU) at 700 mg/m(2)/24 h (day 1-4 and 29-32) with radiotherapy (RT) of 60 Gy without a break. Patients in Group B received two cycles of CDDP at 40 mg/m(2) (day 1, 8, 36 and 43) and 5-FU at 400 mg/m(2)/24 h (day 1-5, 8-12, 36-40 and 43-47) with RT of 60 Gy with a 2-week break. Patients in Group C received two cycles of nedaplatin at 70 mg/m(2) (day 1 and 29) and 5-FU at 500 mg/m(2)/24 h (day 1-4 and 29-32) with RT of 60-70 Gy without a break. Differences in prognostic factors between the groups were analyzed by univariate and multivariate analyses. RESULTS: The 5-year overall survival rates for patients in Group A, Group B and Group C were 52.4, 45.2 and 37.2%, respectively. The 5-year overall survival rates for patients in Stage II, Stage III (non-T4) and Stage III (T4) were 64.0, 40.1 and 22.5%, respectively. The 5-year overall survival rates for patients who received 1 cycle and 2 cycles of concomitant chemotherapy were 27.9 and 46.0%, respectively. In univariate analysis, stage, performance status and number of concomitant chemotherapy cycles were significant prognostic factors (p < 0.001, p = 0.008 and p < 0.001, respectively). In multivariate analysis, stage, protocol and number of concomitant chemotherapy cycles were significant factors (p < 0.001, p = 0.043 and p < 0.001, respectively). CONCLUSIONS: The protocol used in Group A may be an effective protocol of CRT for esophageal cancer. It may be important to complete the scheduled concomitant chemotherapy with the appropriate intensity of CRT.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimiorradioterapia/tendências , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/terapia , Idoso , Quimiorradioterapia/métodos , Neoplasias Esofágicas/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/tendências , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Fatores de Tempo
2.
Int J Clin Oncol ; 20(5): 1005-11, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25708593

RESUMO

BACKGROUND: This multi-institutional study was conducted to clarify the clinicopathological features of squamous cell carcinomas of the vulva. METHODS: The medical records of vulvar cancer patients treated between 2002 and 2012 were retrospectively reviewed following approval by the Institutional Review Board of each institution. RESULTS: One hundred and eleven patients with vulvar malignancies were included. Of these, 63 patients had squamous cell carcinoma (57 %). Initial treatment was surgery, radiation therapy (RT), and concurrent chemoradiotherapy (CCRT) in 34 (54 %), 15 (24 %), and 11 (17 %) patients, respectively. Nineteen, 11, 26, and 7 patients had stage I, II, III, and IV disease, respectively. Of the 34 patients who had surgical treatment, 50 % had stage I disease, while 74 % of those who received CCRT had stage III or IV disease. Complete response (CR) rates for the surgery, RT, and CCRT groups were 73, 60, and 64 %, respectively. The 5-year survival rates for stage I/II and III/IV disease were 64 and 39 %, respectively (P = 0.019). The 5-year survival rates for the surgery, RT, and CCRT groups were 53, 38, and 50 %, respectively, and the prognosis of patients treated with surgery or CCRT was significantly better than that of patients who received RT (P < 0.05). In multivariate analysis, clinical response to initial treatment was an independent prognostic factor (P < 0.001). CONCLUSIONS: Although many patients had advanced-stage disease in the CCRT group, the therapeutic outcome for the surgery and CCRT groups was similar. Thus, CCRT may be a promising treatment for squamous cell carcinoma of the vulva.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias Vulvares/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Vulvares/terapia , Adulto Jovem
3.
Rev Sci Instrum ; 95(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38743570

RESUMO

This study was aimed at developing a dose-rate dosimeter to measure the instantaneous dose rate of a commercially available medical linear accelerator. A dose-rate dosimeter composed of a silicon photodiode (Si-PD), a complementary metal-oxide semiconductor single operational amplifier, a resistor of 20 MΩ, a capacitor of 100 pF, and a mini-substrate measuring 16 × 16 mm2 was evaluated. Voltage outputs from the proposed dosimeter were measured using an analog-to-digital converter on a microcomputer. A custom-made x-ray tube generator at an energy of 120 kV with a tube current ranging from 0.1 to 2.0 mA was used for the dose-rate calibration. Dose-rate calibration was performed 83.3 mm from an x-ray source using a commercially available semiconductor dosimeter. The developed Si-PD dosimeter could measure up to 0.6 Gy/s at a distance of 19.3 mm from the x-ray source. Measurements were also performed using a medical linear accelerator in a 10 MV flattening filter-free mode at depths of 0, 25, 50, and 100 mm with an irradiation field of 100 × 100 mm2 at a constant distance of 1000 mm from the source to the dosimeter. A peak voltage variation corresponding to the instantaneous dose rate was observed using a sampling period of 1.0 ms, and the peak voltages decreased with the depth. The detected pulse numbers were 512, 484, 491, and 511 at depths of 0, 25, 50, and 100 mm, respectively.

4.
Anticancer Res ; 44(1): 403-407, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38159973

RESUMO

BACKGROUND/AIM: Despite the global rise in the incidence of human papillomavirus (HPV)-positive oropharyngeal carcinoma (OPC) in recent years, its prevalence and oncological outcomes in patients living in rural areas of Northern Japan has not been explored and should be investigated. PATIENTS AND METHODS: A total of 105 patients with oropharyngeal squamous cell carcinoma who underwent HPV screening and received first-line treatment were included in this study. The annual changes in the number of patients, survival rates, and clinical factors affecting prognosis were examined. RESULTS: The HPV-positive rate in patients with OPC was low, with the lowest rate of 10.0% in 2013 and the highest rate of 46.7% in 2020. The number of HPV-negative cases remained almost unchanged, whereas the overall number of cases increased with the increasing number of HPV-positive cases. Additionally, HPV-positive cases exhibited a fairly good prognosis. CONCLUSION: The number of OPC cases increased not only in urban areas, but also in rural areas. HPV-positive cases had better outcomes than HPV-negative cases.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/terapia , Japão/epidemiologia , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/diagnóstico , Estudos Retrospectivos , Neoplasias Orofaríngeas/epidemiologia , Neoplasias Orofaríngeas/terapia , Neoplasias Orofaríngeas/patologia , Prognóstico , Papillomaviridae
5.
Cancer Diagn Progn ; 4(4): 459-463, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38962536

RESUMO

Background/Aim: Treatments for early laryngeal squamous cell carcinoma (SCC) include radiotherapy (RT), chemoradiotherapy (CRT), and larynx-preserving surgery. In this study, early laryngeal SCC was treated with RT in patients with stage I (T1N0) tumors and with CRT and docetaxel (DOC) in patients with stage II (T2N0) tumors and the treatment results and effectiveness of the chemotherapy were compared. Patients and Methods: A total of 78 patients with early-stage laryngeal SCC were enrolled in this study. The T1N0 patients received radiation for the primary lesions as outpatients at a total dose of 63-70 Gy. By contrast, the T2N0 patients were hospitalized and treated with CRT, receiving a total radiation dose of 66-70 Gy. Docetaxel (DOC, 10 mg/m2) was administered intravenously once a week for 6-8 consecutive weeks concurrently with radiotherapy. The adverse events and survival rates with local control rates were examined. Results: The number of non-glottic T2N0 patients was significantly higher than that of T1N0 patients. Although all patients completed their treatment schedule, significantly more grade 3 adverse events were observed in the T2N0 patients, in particular mucositis and dermatitis, than in T1N0 patients. The 5-year overall survival rate, disease specific survival rate, local control rate, and laryngeal preserve rate of the T1N0 and T2N0 patients were 86.1, 93.3, 88.6, and 94.3% and 85.9, 88.0, 93.1, and 93.1%, respectively. Conclusion: CRT with docetaxel showed the best therapeutic outcomes for the treatment of laryngeal SCC in patients with T2N0 tumours, with a higher local control rate, effective laryngeal preservation, and relatively few adverse events.

6.
J Clin Med ; 13(11)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38893025

RESUMO

Background/Objectives: Particle beam therapy (PBT) was approved in April 2018 for head and neck malignancies and has since been introduced as a radical therapy for parotid malignancies. However, its prevalence and effectiveness in relation to surgical treatment have not been investigated. Methods: In this study, we evaluated 36 patients with parotid malignancy who underwent surgery (n = 26) or PBT (n = 10) and then analyzed the annual changes in the number of patients, survival rates, and clinical factors affecting prognosis. Results: Of the ten patients who opted for PBT, two and eight patients underwent PBT before and after 2018, respectively. There was a significant difference between these two groups of patients (p = 0.04). Of the ten patients who underwent PBT, five patients were recurrent cases; meanwhile, all twenty-six patients who underwent surgery were receiving initial treatment. Only one patient in each group had local recurrence after the treatment. Conclusions: The use of PBT as a radical therapy for parotid malignancies has been increasing since 2018, and patients with recurrent tumors tended to choose PBT. The outcome of the patients who underwent PBT did not seem to be inferior compared with those of the patients who underwent surgery. The histopathological type was a crucial issue in the outcomes of patients who underwent radical therapy for parotid malignancies.

7.
Int J Clin Oncol ; 18(2): 273-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22318782

RESUMO

BACKGROUND: The purpose of this phase I trial of S-1 chemotherapy in combination with pelvic radiotherapy for locally recurrent rectal cancer was to determine the maximum tolerated dose (MTD), recommended dose (RD), and dose-limiting toxicity (DLT) of S-1. METHODS: We enrolled 9 patients between April 2005 and March 2009. Radiotherapy (total dose, 60 Gy in 30 fractions) was given to the gross local recurrent tumor and pelvic nodal metastases using three-dimensional radiotherapy planning. We administered oral S-1 twice a day on days 1-14 and 22-35 during radiotherapy. The dose of S-1 was initially 60 mg/m(2)/day and was increased to determine the MTD and RD for this regimen. RESULTS: DLT appeared at dose level 2 (70 mg/m(2)/day) in 2 patients, who experienced grade 3 enterocolitis and consequently required suspension of S-1 administration for longer than 2 weeks. Hematological toxicity was mild and reversible. At the initial evaluation, complete regression and partial regression were seen in 1 patient (11%) and 2 patients (22%), respectively. CONCLUSION: This phase I trial of S-1 chemotherapy with pelvic radiotherapy for locally recurrent rectal cancer revealed that the MTD for S-1 was 70 mg/m(2)/day and the RD was 60 mg/m(2)/day.


Assuntos
Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/radioterapia , Ácido Oxônico/administração & dosagem , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/radioterapia , Tegafur/administração & dosagem , Idoso , Terapia Combinada , Combinação de Medicamentos , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Doses de Radiação , Neoplasias Retais/patologia
8.
Med Biol Eng Comput ; 61(8): 2197-2205, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37380785

RESUMO

In this study, a newly developed capacitor dosimeter was evaluated using electron beams commonly utilized in radiotherapy. The capacitor dosimeter comprised a silicon photodiode, 0.47-µF capacitor, and dedicated terminal (dock). Before electron beam irradiation, the dosimeter was charged using the dock. The doses were measured without using a cable by reducing the charging voltages using the currents from the photodiode during irradiation. A commercially available parallel-plane-type ionization chamber and solid-water phantom were used for dose calibration with an electron energy of 6 MeV. In addition, the depth doses were measured using a solid-water phantom at electron energies of 6, 9, and 12 MeV. The doses were proportional to the discharging voltages, and the maximum dose difference in the calibrated doses measured using a two-point calibration was approximately 5% in the range of 0.25-1.98 Gy. The depth dependencies at energies of 6, 9, and 12 MeV corresponded to those measured using the ionization chamber.


Assuntos
Elétrons , Silício , Dosímetros de Radiação , Imagens de Fantasmas , Água , Dosagem Radioterapêutica , Radiometria
9.
Cureus ; 15(12): e49936, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38179399

RESUMO

Enfortumab vedotin for urothelial carcinoma is a potentially effective anti-tumor drug that can be used in 3rd-line therapy or later, even in relatively advanced stages of the disease. Here, we present two cases of treatment using enfortumab vedotin with subsequent radiotherapy for primary lesions, and long-term disease control was achieved. The first case involved a 78-year-old man previously treated with pembrolizumab following gemcitabine plus carboplatin for lower ureteral carcinoma with multiple lung and lymph node metastases. Six months after the initiation of enfortumab vedotin, the primary tumor and metastases notably shrank. However, the primary tumor regrew, and radiotherapy was initiated along with enfortumab vedotin. The second case involved a 60-year-old man who was initially treated with avelumab following gemcitabine plus cisplatin for bladder cancer with multiple lymph node metastases. After two months of enfortumab vedotin, the primary and metastatic lesions shrunk. However, the primary tumor regrew, and radiotherapy was initiated. In both cases, the primary tumor and metastases recorded long-term shrinkage. The combination of radiotherapy and enfortumab vedotin may be an effective treatment option.

10.
J Radiat Res ; 64(2): 428-437, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36610798

RESUMO

This study investigated the effectiveness and safety of low-dose salvage craniospinal irradiation (CSI) for recurrent germinoma. We retrospectively reviewed long-term tumor control and late adverse effects in 15 recurrent germinoma patients treated at our hospital between 1983 and 2019. Following the first recurrence of germinoma, seven were treated with 24-30 Gy of salvage CSI, three underwent non-CSI, and five were treated with only chemotherapy. CSI achieved a significantly better recurrence-free survival rate after the first recurrence compared to other strategies (100% vs 33%, p < 0.001: log-rank test). To evaluate the safety of salvage CSI, we assessed the outcomes at the final follow-up of seven patients who received salvage CSI at first recurrence and three patients who received salvage CSI at second recurrence. The median follow-up period was 220 months after initial treatment. Five patients who received 40-50 Gy of radiation therapy or underwent multiple radiation therapy before salvage CSI were classified into Group A, whereas five patients treated with platinum-based chemotherapy and 24-32 Gy of radiation therapy to the primary site, whole ventricle, or whole brain were classified into Group B. In Group A, one had endocrine dysfunction and the other had visual dysfunction. None were socially independent. Meanwhile, in Group B, no endocrine or visual dysfunction was found, and three patients were socially independent. Salvage CSI achieved excellent tumor control in recurrent germinoma and was safe in patients initially treated with low-dose radiation therapy and chemotherapy.


Assuntos
Neoplasias Encefálicas , Radiação Cranioespinal , Germinoma , Humanos , Estudos Retrospectivos , Germinoma/radioterapia , Germinoma/tratamento farmacológico , Germinoma/patologia , Neoplasias Encefálicas/tratamento farmacológico , Encéfalo/patologia , Dosagem Radioterapêutica , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/patologia , Seguimentos
11.
Clin Case Rep ; 10(8): e04149, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36052027

RESUMO

This case report highlights the need for clinicians to monitor patients with rhabdomyosarcoma for pancreatic metastasis to ensure that proper treatment is quickly provided, thereby improving outcomes.

12.
Phys Med ; 101: 28-35, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35872396

RESUMO

PURPOSE: We aimed to assess radiomics approaches for estimating three pulmonary function test (PFT) results (forced expiratory volume in one second [FEV1], forced vital capacity [FVC], and the ratio of FEV1 to FVC [FEV1/FVC]) using data extracted from chest computed tomography (CT) images. METHODS: This retrospective study included 85 lung cancer patients (mean age, 75 years ±8; 69 men) who underwent stereotactic body radiotherapy between 2012 and 2020. Their pretreatment chest breath-hold CT and PFT data before radiotherapy were obtained. A total of 107 radiomics features (Shape: 14, Intensity: 18, Texture: 75) were extracted using two methods: extraction of the lung tissue (<-250 HU) (APPROACH 1), and extraction of small blood vessels and lung tissue (APPROACH 2). The PFT results were estimated using the least absolute shrinkage and selection operator regression. Pearson's correlation coefficients (r) were determined for all PFT results, and the area under the curve (AUC) was calculated for FEV1/FVC (<70 %). Finally, we compared our approaches with the conventional formula (Conventional). RESULTS: For the estimated FEV1/FVC, the Pearson's r were 0.21 (P =.06), 0.69 (P <.01), and 0.73 (P <.01) for Conventional, APPROACH 1, and APPROACH 2, respectively; the AUCs for FEV1/FVC (<70 %) were 0.67 (95 % confidence interval [CI]: 0.55, 0.79), 0.82 (CI: 0.72, 0.91; P =.047) and 0.86 (CI: 0.78, 0.94; P =.01), respectively. CONCLUSIONS: The radiomics approach performed better than the conventional equation and may be useful for assessing lung function based on CT images.


Assuntos
Neoplasias Pulmonares , Tomografia Computadorizada por Raios X , Idoso , Humanos , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Masculino , Testes de Função Respiratória , Estudos Retrospectivos
13.
Anticancer Res ; 42(12): 6047-6056, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36456163

RESUMO

BACKGROUND/AIM: Although the efficacy of docetaxel, cisplatin, and 5-Fluorouracil (TPF) as induction chemotherapy has been confirmed, the therapeutic outcome and prognostic factors of concurrent chemoradiotherapy (CCRT) should be investigated. PATIENTS AND METHODS: Laboratory data of patients who underwent CCRT for advanced squamous cell carcinoma (SCC) of the head and neck were investigated to clarify the grade of side effects. Survival rates and prognostic scores were also calculated. Multivariate analysis was performed to examine the prognostic factors of the patients. RESULTS: Although there were significantly more advanced cases in the TPF group (n=72) than those in the cisplatin group (n=50), there were no significant differences in patient survival rates. In the TPF group, the lymphocyte count, albumin level, and C-reactive protein level of the patients before treatment were significantly correlated with patient outcomes. CONCLUSION: CCRT using the TPF regimen had remarkable treatment effects in advanced head and neck cancer.


Assuntos
Cisplatino , Neoplasias de Cabeça e Pescoço , Humanos , Docetaxel , Prognóstico , Quimiorradioterapia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Fluoruracila , Resultado do Tratamento
14.
Hepatogastroenterology ; 58(112): 1866-72, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22234055

RESUMO

BACKGROUND/AIMS: The feasibility of neoadjuvant chemoradiation therapy for cholangiocarcinoma, followed by conventional resection, has not been determined yet. Here, a phase I study of neoadjuvant chemoradiation therapy, named NACRAC, was performed to determine the maximum tolerated dose (MTD) and the recommended dose (RD) of gemcitabine when combined with external beam radiation therapy for resectable cholangiocarcinoma. METHODOLOGY: From August 2007 to June 2008, 12 patients provided informed consent. Preoperative radiation was administered in 1.8Gy daily fractions up to a total dose of 45Gy. Gemcitabine was administered at day 1 and 8 every three weeks. The initial dose of gemcitabine was started from 400mg/m2. RESULTS: One patient was not able to start treatment because of bleeding caused by a duodenal ulcer and cholangitis. At 800mg/m2 of gemcitabine, one patient out of three failed to complete the treatment because of Grade 3 hematological toxicity. In another three cases of 800mg/m2, the second case could not complete the treatment because of cholangitis. Then, 600mg/m2 was determined to be the MTD, and the RD dose decided as 600mg/m2. CONCLUSIONS: The RD of gemcitabine in NACRAC study was determined to be 600mg/m2. NACRAC study should proceed to a phase II trial to evaluate the effectiveness.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias dos Ductos Biliares/terapia , Ductos Biliares Intra-Hepáticos , Quimiorradioterapia , Colangiocarcinoma/terapia , Desoxicitidina/análogos & derivados , Terapia Neoadjuvante , Idoso , Neoplasias dos Ductos Biliares/patologia , Colangiocarcinoma/patologia , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gencitabina
15.
Tohoku J Exp Med ; 223(1): 55-60, 2011 01.
Artigo em Inglês | MEDLINE | ID: mdl-21212603

RESUMO

Prostate cancer is one of the common cancers in the world. In Japan, prostate brachytherapy (PB) with iodine-125 has become a treatment option for localized prostate cancer since 2003. Nevertheless, severe acute urinary toxicity (AUT) remains as one of the intractable side effects. We assessed AUT and the changes in international prostate symptom score (IPSS) before and after PB for localized prostate cancer. IPSS is a questionnaire tool for tracking the subjective urinary symptoms. Between 2006 and 2009, 104 eligible patients underwent PB with iodine-125 were analyzed. AUT was graded with the radiation therapy oncology group (RTOG) scale. Eligible patients filled out IPSS questionnaires before and after PB. Clinical and treatment-related factors were examined for correlation with the severity of AUT and the interval to IPSS resolution. AUT of RTOG Grade 0 (no changes) and Grade 2 was detected in one and 96 patients, respectively, whereas seven patients (6.7%) experienced AUT of Grade 3. Thus, the incidence of severe AUT (Grade 3) after PB was low. A greater number of needles (p = 0.012) were associated with AUT of RTOG Grade 3 on the univariate analysis. The median interval to IPSS resolution was 6 months (7 ± 6 months). Greater post-implant maximal IPSS (p < 0.001) was associated with slower IPSS resolution, whereas higher pre-implant IPSS (p < 0.001) was associated with faster IPSS resolution on the multivariate analysis. In conclusion, reducing the number of needles in PB may be helpful for decreasing the rate of severe AUT.


Assuntos
Braquiterapia/efeitos adversos , Neoplasias da Próstata/radioterapia , Índice de Gravidade de Doença , Transtornos Urinários/diagnóstico , Transtornos Urinários/etiologia , Idoso , Humanos , Radioisótopos do Iodo , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Retenção Urinária
16.
Rev Sci Instrum ; 92(12): 123101, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34972425

RESUMO

Herein, we evaluated a capacitor dosimeter under development by a manufacturer, which is designed to monitor the entrance dose in x-ray diagnosis and comprises a silicon x-ray diode (Si-XD), a 0.1 µF capacitor, and a dosimeter dock. The Si-XD is a high-sensitivity photodiode optimized for x-ray detection. The dosimeter was charged to 3.30 V using the dock before x-ray irradiation. The charging voltage was reduced by photocurrents flowing through the Si-XD during irradiation, and the discharging voltage was measured. For the fundamental characterization of this capacitor dosimeter, we investigated the x-ray tube-current and tube-voltage dependences of the measured dose using an industrial x-ray tube; the angular dependence was also investigated. A commercially available semiconductor dosimeter (RaySafe ThinX) was used for dose calibration. The doses were proportional to the tube current at a constant tube voltage of 100 kV and increased with increasing tube voltage at a constant tube current of 1.0 mA. The dose difference with respect to the commercially available semiconductor dosimeter was within 1.0% when the tube current was varied and it was within 3.0% when the tube voltage was varied. In the angular dependence measurement, a difference of up to 6.0% was observed as the angle varied from 0° to 355° in steps of 5°. The dose-calibration results indicated that the determination of the initial charging voltage was important for dose conversion using the capacitor dosimeter.


Assuntos
Dosímetros de Radiação , Silício , Calibragem , Radiometria , Raios X
17.
Rev Sci Instrum ; 92(5): 053103, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243345

RESUMO

In an x-ray diagnosis, it is important to evaluate the entrance dose rate, as the dose rate of exposure becomes highest in that position. To investigate the effect of the entrance dose rate of x-ray CT scanners, a dose-rate dosimeter comprising a silicon x-ray diode (Si-XD), a CMOS dual operational amplifier, resistors, capacitors, and a mini-substrate measuring 20 × 17 mm2 were developed. The Si-XD is desirable for measuring the changing entrance dose rate, as it enables the reduction of the response time, dimensions, and cost of the dosimeter. The dosimeter was connected to a microcomputer (mbed), and the output voltages from the dosimeter were measured using an analog-digital converter in the mbed. The output voltages were proportional to the tube currents at a constant tube voltage of 100 kV using an industrial x-ray tube, and the calibrated dose rates corresponded well to those obtained using a commercially available semiconductor dosimeter. However, owing to the energy dependence of the dosimeter, the calibrated dose rate was ∼10% higher than that of a commercially available semiconductor dosimeter at the lower tube voltage. In the angular dependence of the dosimeter, the flatness measured from 60° to 120° was ∼103% in this study. A fundamental study for measuring the dose-rate variations with rotation was performed. The results showed a different profile than the angular dependence due to the distance from the source and the complex factors of the scattered radiation.

18.
OTO Open ; 5(3): 2473974X211045298, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568724

RESUMO

OBJECTIVE: To examine the safety and efficacy of concomitant chemoradiotherapy using a modified TPF regimen (docetaxel + cisplatin + 5-fluorouracil) in patients with advanced sinonasal squamous cell carcinoma (SNSCC). STUDY DESIGN: Retrospective study. SETTING: Tertiary center (university hospital). METHODS: Seven patients with previously untreated T3-T4 SNSCC were enrolled. They underwent radiotherapy once daily (total dose, 70 Gy) with 2 courses of concomitant 120-hour infusion of 5-fluorouracil (600 mg/m2/d), docetaxel (50 mg/m2, day 2), and cisplatin (60 mg/m2, day 2). RESULTS: Grade 4 leukopenia, grade 4 neutropenia, and grade 3 lymphopenia were observed in 1, 3, and 4 patients, respectively. Grade 4 creatinine elevation was observed in 1 patient. However, other grade 3 or 4 adverse events were not common. Complete response was obtained in all patients. At 60 months there was 85.7% disease-free survival and 100% overall. CONCLUSION: Concomitant chemoradiotherapy with a modified TPF regimen may be feasible and effective in patients with advanced SNSCC.

19.
BMC Cancer ; 10: 127, 2010 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-20374623

RESUMO

BACKGROUND: To evaluate the safety of focal dose escalation to regions with standardized uptake value (SUV) >2.0 using intensity-modulated radiation therapy (IMRT) by comparison of radiotherapy plans using dose-volume histograms (DVHs) and normal tissue complication probability (NTCP) for postoperative local recurrent rectal cancer METHODS: First, we performed conventional radiotherapy with 40 Gy/20 fr. (CRT 40 Gy) for 12 patients with postoperative local recurrent rectal cancer, and then we performed FDG-PET/CT radiotherapy planning for those patients. We defined the regions with SUV > 2.0 as biological target volume (BTV) and made three boost plans for each patient: 1) CRT boost plan, 2) IMRT without dose-painting boost plan, and 3) IMRT with dose-painting boost plan. The total boost dose was 20 Gy. In IMRT with dose-painting boost plan, we increased the dose for BTV+5 mm by 30% of the prescribed dose. We added CRT boost plan to CRT 40 Gy (summed plan 1), IMRT without dose-painting boost plan to CRT 40 Gy (summed plan 2) and IMRT with dose-painting boost plan to CRT 40 Gy (summed plan 3), and we compared those plans using DVHs and NTCP. RESULTS: D(mean) of PTV-PET and that of PTV-CT were 26.5 Gy and 21.3 Gy, respectively. V50 of small bowel PRV in summed plan 1 was significantly higher than those in other plans ((summed plan 1 vs. summed plan 2 vs. summed plan 3: 47.11 +/- 45.33 cm3 vs. 40.63 +/- 39.13 cm3 vs. 41.25 +/- 39.96 cm3 (p < 0.01, respectively)). There were no significant differences in V30, V40, V60, D(mean) or NTCP of small bowel PRV. CONCLUSIONS: FDG-PET-guided IMRT can facilitate focal dose-escalation to regions with SUV above 2.0 for postoperative local recurrent rectal cancer.


Assuntos
Fluordesoxiglucose F18 , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/radioterapia , Compostos Radiofarmacêuticos , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/radioterapia , Antimetabólitos Antineoplásicos/administração & dosagem , Relação Dose-Resposta à Radiação , Combinação de Medicamentos , Humanos , Recidiva Local de Neoplasia/tratamento farmacológico , Ácido Oxônico/administração & dosagem , Tomografia por Emissão de Pósitrons , Radioterapia de Intensidade Modulada/métodos , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/cirurgia , Tegafur/administração & dosagem
20.
Int J Clin Oncol ; 15(2): 184-90, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20217449

RESUMO

OBJECTIVES: The objectives of this study were to reveal the utility of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) within 7 days after chemoradiotherapy to predict prognosis in patients with postoperative recurrent esophageal cancer. MATERIALS AND METHODS: Patients scheduled to undergo concurrent chemoradiotherapy for postoperative locoregional recurrence of esophageal cancer were recruited. Selection criteria were: (1) locoregional recurrence, (2) no previous radiation therapy, (3) planning treatment with concurrent chemoradiotherapy, (4) FDG-PET performed <2 weeks before chemoradiotherapy, and (5) no serious diabetes. FDG-PET was performed <7 days after chemoradiotherapy. No more treatment after chemoradiotherapy was given until disease progression was diagnosed according to the Response Evaluation Criteria in Solid Tumors (RECIST). Correlations of FDG-PET findings with cause-specific survival and local control rates were investigated prospectively. RESULTS: Twenty patients were enrolled. Median observation period of patients who survived was 45.0 months. Median maximum standardized uptake value (SUV(max)) after chemoradiotherapy was 2.4, and median SUV(max) before chemoradiotherapy was 8.4. Cause-specific survival and local control rates were significantly better for patients with SUV(max) < or = 2.4 after chemoradiotherapy (log-rank test, P = 0.033 and 0.010, respectively). SUV(max) before chemoradiotherapy tended to be correlated only with cause-specific survival rate (log-rank test, P = 0.076). Change in metabolic activity of FDG was significantly correlated with local control rate (log-rank test, P = 0.042). CONCLUSIONS: FDG-PET performed even <7 days after chemoradiotherapy predicts prognosis in patients with postoperative recurrent esophageal cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/terapia , Esofagectomia , Fluordesoxiglucose F18 , Recidiva Local de Neoplasia , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Idoso , Quimioterapia Adjuvante , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/secundário , Feminino , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Radioterapia Adjuvante , Fatores de Tempo , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA