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Proton Beam (proton + beam)

Distribution by Scientific Domains
Medical Sciences75%

Terms modified by Proton Beam

  • proton beam radiotherapy
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    Selected Abstracts

    A bladder preservation regimen using intra-arterial chemotherapy and radiotherapy for invasive bladder cancer: A prospective study

    INTERNATIONAL JOURNAL OF UROLOGY, Issue 2 2000
    Naoto Miyanaga
    Abstract Background: A prospective study was performed to investigate combined treatment with intra-arterial chemotherapy and radiation therapy for bladder preservation in locally invasive bladder cancer. Methods: Patients with invasive bladder cancer, stage T2,3N0M0, were included in the study. Intra-arterial chemotherapy was performed with three injections of methotrexate and cisplatin at 3-week intervals. Simultaneously, the patients underwent X-ray irradiation (40 Gy) of the small pelvic space. Where a post-treatment transurethral resection (TUR) biopsy showed no residual tumor, the tumor site was irradiated by a 30 Gy proton beam and the bladder was preserved. Where tumors remained, radical cystectomy was performed. Results: Between 1990 and 1996, 42 patients were treated according to this protocol. Post-treatment TUR biopsy and urine cytology showed no residual tumors in 39 of 42 cases (93%). The bladder was preserved in accordance with the study protocol in 36 cases. A median follow-up of 38 months showed 3-year non-recurrence in 72% of bladder-preserved patients and the rate of bladder preservation was 84%. The nine recurrences included eight cases of superficial bladder recurrence. One cancer death occurred among the bladder-preservation patients, giving 3-year survival and cause-specific survival rates of 84% and 100%, respectively. Although bladder function decreased slightly in compliance, bladder capacity was retained in almost all cases. Conclusions: This regimen is useful for bladder preservation in T2,3 locally invasive bladder cancer. Information from more cases and the results of more long-term observations are needed, as is an evaluation of appropriate subject selection and factors associated with quality of life issues, particularly regarding bladder function. [source]

    Positron source based on the 48V isotope dedicated to positron lifetime spectroscopy

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 11 2009
    Jerzy Dryzek
    Abstract In the paper we consider application of the 48V isotope as a source in the positron lifetime spectroscopy. The isotope was produced in the 48Ti(p,n)48V reaction using 15 MeV proton beam. As a target the natural titanium thin plate was used. The measurements using the typical positron lifetime spectrometer have shown the usefulness of the source obtained for this application. Due to its properties, the source may be used for measurements of positron annihilation characteristics in high temperature or aggressive environments. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    18 years experience of the use of proton beam in ophthalmic tumours

    ACTA OPHTHALMOLOGICA, Issue 2009
    L DESJARDINS
    Purpose Since 1991, more than 3000 patients were treated at Curie Institute by proton beam for uveal melanoma. All datas concerning tumor characteristics, treatment planning and follow up are registered in the data base Methods We have performed a retrospective review of patients treated before 2005. Patients were sent to Curie by their local ophtalmologist. Clip positioning and proton beam therapy with a dose of 60 grays in 4 fractions was scheduled; All patients were seen once a year in our clinic after treatment with liver ultrasounds twice a year. Results 2214 patients were treated, median age 61 years, median diameter 13,6 mm, median Thickness 4,7 mm. 20% of patients develloped metastasis,25% of patients died, 4% had local recurrences, 6,7% had secondary enucleations; With multivariate analysis Significant risk factors for metastasis were age (>60 ), tumor location, tumor diameter and tumor thickness( p<0,0001); Significant risk factor for local recurrence was tumor diameter (p<0,001) significant risk factor for secondary enucleation were tumor diameter (p<0,0001) and tumor thickness (p= 0,003) Neovascular glaucoma was 10% at 2years , 30% at 5 years and 34% at 10 years. Maculopathy was 40% at 2 years, 62% at 5 years and 66% at 10 years Optic neuropathy was 14% at 2 years, 29% at 5 years and 38% at 10 years At last follow up 36,2% of patients have more than 20/40 vision Conclusion Tumor control obtained by proton beam is excellent with a long follow up For big tumors news additional techniques like endoresections, additional TTT or antiVEGF could enhance globe preservation [source]