23 research outputs found

    Isospin character of low-lying states in 56Fe.

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    Low-lying states in {sup 56}Fe, up to an excitation energy of about 4 MeV, have been investigated by means of inelastic proton and deuteron scattering experiments at {ital E}{sub {ital p}}=65 and 400 MeV and at {ital E}{sub {ital d}}=56 MeV, respectively. Measured cross sections and analyzing powers have been compared with coupled-channels calculations using collective form factors; calculations in both the Schr{umlt o}dinger and Dirac formalisms have been carried out for the proton data. For each probe, the matrix elements have been deduced for transitions from the ground state and from the 2{sub 1}{sup +} state to six quadrupole (2{sup +}) states to one octupole (3{sub 1}{sup {minus}}) and two hexadecapole (4{sub 1}{sup +} and 4{sub 2}{sup +}) states. The obtained matrix elements and the previous values from {gamma} decay or electron inelastic scattering have been used to evaluate the isospin character of the transitions. To discuss the quadrupole mixed-symmetry states in {sup 56}Fe, the deduced neutron ({ital M}{sub {ital n}}) and proton ({ital M}{sub {ital p}}) components of the matrix elements, or equivalently the isoscalar ({ital M}{sub {ital s}}) and isovector ({ital M}{sub {ital v}}) parts, have been compared with theoretical calculations based on the neutron-proton interacting bosonmore » model and on the shell model evaluated in a full {ital f}-{ital p} configuration space. {copyright} {ital 1996 The American Physical Society.}« les

    Proton Beam Therapy for Large Hepatocellular Carcinoma

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    PurposeTo investigate the safety and efficacy of proton beam therapy (PBT) in patients with large hepatocellular carcinoma (HCC).Methods and MaterialsTwenty-two patients with HCC larger than 10 cm were treated with proton beam therapy at our institution between 1985 and 2006. Twenty-one of the 22 patients were not surgical candidates because of advanced HCC, intercurrent disease, or old age. Median tumor size was 11 cm (range, 10–14cm), and median clinical target volume was 567 cm3 (range, 335–1,398 cm3). Hepatocellular carcinoma was solitary in 18 patients and multifocal in 4 patients. Tumor types were nodular and diffuse in 18 and 4 patients, respectively. Portal vein tumor thrombosis was present in 11 patients. Median total dose delivered was 72.6 GyE in 22 fractions (range, 47.3–89.1 GyE in 10–35 fractions).ResultsThe median follow-up period was 13.4 months (range, 1.5–85 months). Tumor control rate at 2 years was 87%. One-year overall and progression-free survival rates were 64% and 62%, respectively. Two-year overall and progression-free survival rates were 36% and 24%, respectively. The predominant tumor progression pattern was new hepatic tumor development outside the irradiated field. No late treatment-related toxicity of Grade 3 or higher was observed.ConclusionsThe Bragg peak properties of PBT allow for improved conformality of the treatment field. As such, large tumor volumes can be irradiated to high doses without significant dose exposure to surrounding normal tissue. Proton beam therapy therefore represents a promising modality for the treatment of large-volume HCC. Our study shows that PBT is an effective and safe method for the treatment of patients with large HCC

    A Prospective Study of Hypofractionated Proton Beam Therapy for Patients with Hepatocellular Carcinoma

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    PURPOSE: To evaluate the efficacy and safety of hypofractionated proton beam therapy for patients with hepatocellular carcinoma (HCC). METHODS AND MATERIALS: Between September 2001 and August 2004, 51 patients with HCC greater than 2 cm away from the porta hepatis or gastrointestinal tract were treated with proton beam therapy to 66 Gy-equivalents (GyE) in 10 fractions. RESULTS: Overall survival rates were 49.2 and 38.7% at 3 and 5 years after treatment. Local control rates were 94.5 and 87.8% at 3 and 5 years after treatment. Posttreatment serum alpha-fetoprotein values were significantly reduced when compared with pretreatment values (p < 0.0001). Patients experienced only minor acute reactions of Grade 1 or less, and 3 patients experienced late sequelae of Grade 2 or higher. However, there were no treatment-related deaths. CONCLUSIONS: Hypofractionated proton beam therapy is safe and well-tolerated by patients with HCC located greater than 2 cm away from the porta hepatis or gastrointestinal tract and may be effective alternative to other modalities

    Proton Beam Therapy for Hepatocellular Carcinoma Associated with Portal Vein Tumor Thrombosis

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    Background and Purpose: The prognosis of patients with advanced hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is extremely poor, as effective treatment options are limited. The authors performed a retrospective review to evaluate the efficacy of proton-beam therapy (PBT) for patients presenting with PVTT in the setting of HCC.Patients and Methods: Between February 1991 and September 2005, 35 patients with HCC and tumor thrombi in the main trunk or major branches of the portal vein presented for consideration of PBT. Their tumor sizes ranged from 25 mm to 130 mm (median, 60 mm). A median total dose of 72.6 GyE in 22 fractions was delivered over 31 days to a target volume that encompassed both the primary hepatic lesion and the PVTT.Results: 32 patients were progression-free during a median follow-up period of 21 months (range, 2-88 months) and three patients experienced disease progression. Local progression-free survival rates were 46% at 2 years and 20% at 5 years, and the median local progression-free survival was 21month. Acute toxicity &#8805; grade 3 was observed in three patients, and no patient experienced late toxicity &#8805; grade 3. None of the patients had to discontinue treatment as a result of toxicity.Conclusion: PBT improved local control and significantly prolonged survival in HCC patients with PVTT

    Comparisons of dose-volume histograms for proton-beam versus 3-D conformal x-ray therapy in patients with stage I non-small cell lung cancer.

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    PURPOSE: Dose-volume histograms (DVHs) were reviewed to determine if there is an advantage of the two modalities when treating patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: 24 stage I NSCLC patients who underwent proton-beam therapy (PBT) from June 2003 to May 2007 were included in this study. Based on the same clinical target volumes (CTVs), treatment planning was made to cover CTV within 90% isodose lines. Each patient was evaluated by two sets of DVHs, one for PBT and the other for three-dimensional conformal X-ray therapy (3D-CRT). RESULTS: For all patients, the 95% isodose line covered 86.4% of the CTV for PBT, and 43.2% for 3D-CRT. PBT was associated with significantly lower mean doses to the ipsilateral lung, total lung, heart, esophagus, and spinal cord than 3D-CRT. PBT offered reduced radiation doses to the lung when evaluated in terms of percentage lung volumes receiving > or = 5 Gy (V(5)), > or = 10 Gy (V(10)), and > or = 20 Gy (V(20)) when compared to 3D-CRT. CONCLUSION: PBT is advantageous over 3D-CRT in reducing doses to the lung, heart, esophagus, and spinal cord in treating stage I NSCLC

    Proton Beam Therapy for Hepatocellular Carcinoma: The University of Tsukuba Experience

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    BACKGROUND:: The authors have published a series of studies evaluating the safety and efficacy of proton beam therapy for the treatment of hepatocellular carcinoma in a variety of clinical settings. In the current study, they retrospectively reviewed their entire experience treating hepatocellular carcinoma patients with proton beam therapy at their hospital-based facility at the University of Tsukuba. METHODS:: From November 2001 to December 2007, 333 patients with hepatocellular carcinoma were treated with proton beam therapy at the University of Tsukuba. A total of 318 patients were included in this study. Total dose delivered and fractionation scheme were determined by protocols that varied based on location of tumor. Survival rates and prognostic factors were assessed. RESULTS:: Overall actuarial survival rates at 1-year, 3-years, and 5-years were 89.5% (95% confidence interval [95% CI], 85.7-93.1%), 64.7% (95% CI, 56.6-72.9%), and 44.6% (95% CI, 29.7-59.5%), respectively. Child-Pugh liver function (hazards ratio [HR], 2.84; P 125 mL (P < .05). CONCLUSIONS:: The authors have shown proton beam therapy to be both safe and effective for the treatment of patients with hepatocellular carcinoma. They strongly recommend the consideration of proton beam therapy in patients for whom other treatment options are risky or contraindicated

    Proton Beam Therapy for Large Hepatocellular Carcinoma

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    PURPOSE: To investigate the safety and efficacy of proton beam therapy (PBT) in patients with large hepatocellular carcinoma (HCC). METHODS AND MATERIALS: Twenty-two patients with HCC larger than 10 cm were treated with proton beam therapy at our institution between 1985 and 2006. Twenty-one of the 22 patients were not surgical candidates because of advanced HCC, intercurrent disease, or old age. Median tumor size was 11 cm (range, 10-14cm), and median clinical target volume was 567 cm(3) (range, 335-1,398 cm(3)). Hepatocellular carcinoma was solitary in 18 patients and multifocal in 4 patients. Tumor types were nodular and diffuse in 18 and 4 patients, respectively. Portal vein tumor thrombosis was present in 11 patients. Median total dose delivered was 72.6 GyE in 22 fractions (range, 47.3-89.1 GyE in 10-35 fractions). RESULTS: The median follow-up period was 13.4 months (range, 1.5-85 months). Tumor control rate at 2 years was 87%. One-year overall and progression-free survival rates were 64% and 62%, respectively. Two-year overall and progression-free survival rates were 36% and 24%, respectively. The predominant tumor progression pattern was new hepatic tumor development outside the irradiated field. No late treatment-related toxicity of Grade 3 or higher was observed. CONCLUSIONS: The Bragg peak properties of PBT allow for improved conformality of the treatment field. As such, large tumor volumes can be irradiated to high doses without significant dose exposure to surrounding normal tissue. Proton beam therapy therefore represents a promising modality for the treatment of large-volume HCC. Our study shows that PBT is an effective and safe method for the treatment of patients with large HCC

    Thoracic Radiotherapy for Mediastinal Nodal Recurrence

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    Radiotherapy has been used to treat loco-regional recurrences located at various intra-thoracic sites, but longterm survival of these patients has been rarely observed. We report herein a lung adenocarcinoma patient with locoregional recurrence, who was successfully treated with high-dose radiotherapy. The patient could survive with no evidence of recurrence 5 years after thoracic irradiation. It is probably safe to administrate high-dose radiotherapy for some loco-regional recurrent patients with favorable prognostic factors such as good PS, no body weight loss. Further studies will be required to define a favorable subset of patients most likely to benefit from an aggressive approach

    Chronic Eosinophilic Pneumonia with Subpleural Curvilinear Shadow

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    We report a rare case of chronic eosinophilic pneumonia with subpleural curvilinear shadow. CT scan showed a patchy consolidation in the bilateral upper lungs. In addition, subpleural curvilinear shadow was found in the bilateral upper lungs. A bronchoalveolar lavage obtained from the right middle lobe showed 25 % eosinophils. Although very rare, we should therefore keep in mind that patients, who have patchy consolidation with areas of subpleural curvilinear shadow in the bilateral upper lungs, may have chronic eosinophilic pneumonia

    Malignant Myoepithelioma in the Maxillary Sinus: Case Report and Review of the Literature

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    Malignant myoepithelioma of the head and neck usually arises in the salivary glands. We experienced a rare case with malignant myoepithelioma in the maxillary sinus. A 47-year-old woman with malignant myoepithelioma in the maxillary sinus underwent partial maxillectomy. However, local recurrence occurred 28 months after surgery and she was subsequently treated with radiation therapy with proton beams. The recurrent tumor showed complete response and the patient was alive with no evidence of disease 30 months after irradiation. No therapy-related severe toxicities were observed. A rare case with malignant myoepithelioma in the maxillary sinus was successfully treated with radiation therapy
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