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Thomas W. Griffin - One of the best experts on this subject based on the ideXlab platform.

  • Fast Neutron Radiation therapy. Results of phase III randomized trials in head and neck, lung, and prostate cancers.
    Acta oncologica (Stockholm Sweden), 1994
    Co-Authors: Wui Jin Koh, Thomas W. Griffin, George E. Laramore, Keith J. Stelzer, Kenneth J. Russell
    Abstract:

    The results of phase III trials comparing Neutrons to photons for head and neck squamous cell cancers, non-small cell lung cancers, and prostate adenocarcinomas are reviewed, with emphasis given to the most recent U.S. National Cancer Institute sponsored randomized clinical studies in which Fast Neutrons were delivered using modern, hospital-based, high-energy, isocentric-capable cyclotrons. In locally advanced squamous cell head and neck cancers, Neutrons showed no convincing advantage over photons. Fast Neutron radiotherapy may have provided a therapeutic benefit in selected patients with inoperable non-small cell lung cancers. For locally advanced prostate adenocarcinomas, Neutron therapy resulted in significantly superior clinical and histological loco-regional tumor control, which may translate to improved survival with additional follow-up. In general, severe late complications were more frequent with Neutrons, especially in patients treated on older physics laboratory-based equipment. Even with mod...

  • Enhancement of Fast Neutron beams with boron Neutron capture therapy. A mechanism for achieving a selective, concomitant tumor boost.
    Acta oncologica (Stockholm Sweden), 1994
    Co-Authors: Thomas A. Buchholz, George E. Laramore, Peter Wootton, John C. Livesey, D. Scott Wilbur, Rudolph Risler, Mark Phillips, John Jacky, Thomas W. Griffin
    Abstract:

    Both Fast Neutron radiotherapy and boron Neutron capture therapy (BNCT) have been utilized to treat malignant disease. Herein we discuss the potential of combining these treatments to enhance the effectiveness of Fast Neutron therapy through a concomitant BNCT boost. Using a Fast Neutron beam generated from a 50 MeV proton on beryllium reaction, we have determined that 0.1% of the beam per microgram of boron-10 per gram of tissue (μg/g) can be deposited via BNCT. Our mathematical modeling predicts that BNCT enhancement of our beam will lead to an additional 1–2 logs of tumor cell kill for boron-10 concentrations of 30–50 μg/g. We have validated this via V-79 cell line in vitro measurements. A Poisson model estimation of how this additional cell kill will influence local tumor control, predicts that BNCT enhancement of Fast Neutron Radiation will lead to a clinically significant improvement in outcome.

  • Fast Neutron radiotherapy for locally advanced prostate cancer final report of a Radiation therapy oncology group randomized clinical trial
    American Journal of Clinical Oncology, 1993
    Co-Authors: George E. Laramore, Thomas W. Griffin, Kenneth J. Russell, John M. Krall, Frank J. Thomas, Moshe H. Maor, F R Hendrickson, K L Martz, L. W. Davis
    Abstract:

    Between June 1977 and April 1983 the Radiation Therapy Oncology Group (RTOG) sponsored a Phase III randomized trial investigating the use of Fast Neutron radiotherapy for patients with locally advanced (Stages C and D1) adenocarcinoma of the prostate gland. Patients were randomized to receive either conventional photon Radiation or Fast Neutron Radiation used in a mixed-beam (Neutron/photon) treatment schedule. A total of 91 analyzable patients were entered into the study, and the two patient groups were balanced with respect to the major prognostic variables. Actuarial curves are presented for local/regional control and "overall" survival. Ten-year results for clinically assessed local control are 70% for the mixed-beam group versus 58% for the photon group (p = 0.03) and for survival are 46% for the mixed-beam group versus 29% for the photon group (p = 0.04). This study suggests that a regional method of treatment can influence both local tumor control and survival in patients with locally advanced adenocarcinoma of the prostate gland.

  • Fast Neutron Radiation therapy.
    Critical Reviews in Oncology Hematology, 1992
    Co-Authors: Thomas W. Griffin
    Abstract:

    Fast Neutron Radiation therapy was first used as a cancer treatment tool by Robert Stone at the Lawrence Berkeley Laboratory in 1938 [l]. Using the Berkeley cyclotron, Dr. Stone treated a series of patients with advanced malignancies in various locations to high doses. Almost all of the long-term survivors from that clinical trial had severe Radiation sequelae in their normal tissues. This result was initially thought to be due to an increased relative biological effectiveness (RBE) of Neutrons for late effects, and deterred further clinical investigation of Fast Neutrons for approximately 20 years. Later experiments, however, showed that the

  • The role of Fast Neutron Radiation therapy in the management of advanced salivary gland malignant neoplasms.
    Cancer, 1992
    Co-Authors: Thomas A. Buchholz, Brian R. Griffin, George E. Laramore, Wui‐jin ‐j Koh, Thomas W. Griffin
    Abstract:

    Fifty-three patients with locally advanced salivary gland malignant neoplasm were treated with Fast Neutron Radiation therapy. All patients received treatment for gross inoperable, residual unresectable, or recurrent disease--clinical situations in which results using photon irRadiation were suboptimal. With a median follow-up of 42 months and a minimum follow-up of 1 year, locoregional tumor control in the treatment field was achieved in 92% (48 of 52) of patients. An additional eight patients had regional failures outside the treatment field, resulting in an overall locoregional tumor control rate of 77% (40 of 52). The 5-year actuarial locoregional control rates were 65% overall and 75% in patients with node-positive disease. Grouping patients according to prior treatment status, actuarial 5-year locoregional control rates were 92% for patients treated definitively (without a prior surgical procedure), 63% for those treated postoperatively for gross residual disease, and 51% for those treated for recurrent disease after a surgical procedure. The P values associated with these differences were 0.12 and 0.01, respectively. There were no instances of Radiation-induced facial nerve damage. This study suggests that Neutron irRadiation alone should be the therapy of choice in the treatment of advanced-stage salivary gland tumors and that surgery should be limited to those patients in whom disease-free margins can be obtained. The potential morbidity of a debulking surgical procedure before Neutron irRadiation is not warranted by an improvement in loco-regional control over that achievable with Neutron therapy alone.

George E. Laramore - One of the best experts on this subject based on the ideXlab platform.

  • Positron emission tomography-guided conformal Fast Neutron therapy for glioblastoma multiforme.
    Neuro-oncology, 2008
    Co-Authors: Keith J. Stelzer, George E. Laramore, James G. Douglas, David A. Mankoff, Daniel L. Silbergeld, Kenneth A. Krohn, Alexander M. Spence
    Abstract:

    Glioblastoma multiforme (GBM) continues to be a difficult therapeutic challenge. Our study was conducted to determine whether improved survival and tumor control could be achieved with modern delivery of Fast Neutron Radiation using three-dimensional treatment planning. Ten patients were enrolled. Eligibility criteria included pathologic diagnosis of GBM, age >or=18 years, and KPS >or=60. Patients underwent MRI and (18)F-fluorodeoxyglucose PET (FDG PET) as part of initial three-dimensional treatment planning. Sequential targets were treated with noncoplanar fields to a total dose of 18 Gy in 16 fractions over 4 weeks. Median and 1-year overall survival were 55 weeks and 60%, respectively. One patient remains alive at last follow-up 255 weeks after diagnosis. Median progression-free survival was 16 weeks, and all patients had tumor progression by 39 weeks. Treatment was clinically well tolerated, but evidence of mild to moderate gliosis and microvascular sclerosis consistent with Radiation injury was observed at autopsy in specimens taken from regions of contralateral brain that received approximately 6-10 Gy. Fast Neutron Radiation using modern imaging, treatment planning, and beam delivery was feasible to a total dose of 18 Gy, but tumor control probability was poor in comparison to that predicted from a dose-response model based on older studies. Steep dose-response curves for both tumor control and neurotoxicity continue to present a challenge to establishing a therapeutic window for Fast Neutron Radiation in GBM, even with modern techniques.

  • Fast Neutron Radiation therapy. Results of phase III randomized trials in head and neck, lung, and prostate cancers.
    Acta oncologica (Stockholm Sweden), 1994
    Co-Authors: Wui Jin Koh, Thomas W. Griffin, George E. Laramore, Keith J. Stelzer, Kenneth J. Russell
    Abstract:

    The results of phase III trials comparing Neutrons to photons for head and neck squamous cell cancers, non-small cell lung cancers, and prostate adenocarcinomas are reviewed, with emphasis given to the most recent U.S. National Cancer Institute sponsored randomized clinical studies in which Fast Neutrons were delivered using modern, hospital-based, high-energy, isocentric-capable cyclotrons. In locally advanced squamous cell head and neck cancers, Neutrons showed no convincing advantage over photons. Fast Neutron radiotherapy may have provided a therapeutic benefit in selected patients with inoperable non-small cell lung cancers. For locally advanced prostate adenocarcinomas, Neutron therapy resulted in significantly superior clinical and histological loco-regional tumor control, which may translate to improved survival with additional follow-up. In general, severe late complications were more frequent with Neutrons, especially in patients treated on older physics laboratory-based equipment. Even with mod...

  • Enhancement of Fast Neutron beams with boron Neutron capture therapy. A mechanism for achieving a selective, concomitant tumor boost.
    Acta oncologica (Stockholm Sweden), 1994
    Co-Authors: Thomas A. Buchholz, George E. Laramore, Peter Wootton, John C. Livesey, D. Scott Wilbur, Rudolph Risler, Mark Phillips, John Jacky, Thomas W. Griffin
    Abstract:

    Both Fast Neutron radiotherapy and boron Neutron capture therapy (BNCT) have been utilized to treat malignant disease. Herein we discuss the potential of combining these treatments to enhance the effectiveness of Fast Neutron therapy through a concomitant BNCT boost. Using a Fast Neutron beam generated from a 50 MeV proton on beryllium reaction, we have determined that 0.1% of the beam per microgram of boron-10 per gram of tissue (μg/g) can be deposited via BNCT. Our mathematical modeling predicts that BNCT enhancement of our beam will lead to an additional 1–2 logs of tumor cell kill for boron-10 concentrations of 30–50 μg/g. We have validated this via V-79 cell line in vitro measurements. A Poisson model estimation of how this additional cell kill will influence local tumor control, predicts that BNCT enhancement of Fast Neutron Radiation will lead to a clinically significant improvement in outcome.

  • Fast Neutron radiotherapy for locally advanced prostate cancer final report of a Radiation therapy oncology group randomized clinical trial
    American Journal of Clinical Oncology, 1993
    Co-Authors: George E. Laramore, Thomas W. Griffin, Kenneth J. Russell, John M. Krall, Frank J. Thomas, Moshe H. Maor, F R Hendrickson, K L Martz, L. W. Davis
    Abstract:

    Between June 1977 and April 1983 the Radiation Therapy Oncology Group (RTOG) sponsored a Phase III randomized trial investigating the use of Fast Neutron radiotherapy for patients with locally advanced (Stages C and D1) adenocarcinoma of the prostate gland. Patients were randomized to receive either conventional photon Radiation or Fast Neutron Radiation used in a mixed-beam (Neutron/photon) treatment schedule. A total of 91 analyzable patients were entered into the study, and the two patient groups were balanced with respect to the major prognostic variables. Actuarial curves are presented for local/regional control and "overall" survival. Ten-year results for clinically assessed local control are 70% for the mixed-beam group versus 58% for the photon group (p = 0.03) and for survival are 46% for the mixed-beam group versus 29% for the photon group (p = 0.04). This study suggests that a regional method of treatment can influence both local tumor control and survival in patients with locally advanced adenocarcinoma of the prostate gland.

  • The role of Fast Neutron Radiation therapy in the management of advanced salivary gland malignant neoplasms.
    Cancer, 1992
    Co-Authors: Thomas A. Buchholz, Brian R. Griffin, George E. Laramore, Wui‐jin ‐j Koh, Thomas W. Griffin
    Abstract:

    Fifty-three patients with locally advanced salivary gland malignant neoplasm were treated with Fast Neutron Radiation therapy. All patients received treatment for gross inoperable, residual unresectable, or recurrent disease--clinical situations in which results using photon irRadiation were suboptimal. With a median follow-up of 42 months and a minimum follow-up of 1 year, locoregional tumor control in the treatment field was achieved in 92% (48 of 52) of patients. An additional eight patients had regional failures outside the treatment field, resulting in an overall locoregional tumor control rate of 77% (40 of 52). The 5-year actuarial locoregional control rates were 65% overall and 75% in patients with node-positive disease. Grouping patients according to prior treatment status, actuarial 5-year locoregional control rates were 92% for patients treated definitively (without a prior surgical procedure), 63% for those treated postoperatively for gross residual disease, and 51% for those treated for recurrent disease after a surgical procedure. The P values associated with these differences were 0.12 and 0.01, respectively. There were no instances of Radiation-induced facial nerve damage. This study suggests that Neutron irRadiation alone should be the therapy of choice in the treatment of advanced-stage salivary gland tumors and that surgery should be limited to those patients in whom disease-free margins can be obtained. The potential morbidity of a debulking surgical procedure before Neutron irRadiation is not warranted by an improvement in loco-regional control over that achievable with Neutron therapy alone.

H.w. Kraner - One of the best experts on this subject based on the ideXlab platform.

  • Fast Neutron Radiation damage effects on high resistivity silicon junction detectors
    Journal of Electronic Materials, 1992
    Co-Authors: H.w. Kraner
    Abstract:

    P ^ + −n^ −n ^ + silicon Radiation detectors made of high resistivity Si material (ρ ≥ 2 kΩ-cm) were irradiated to a Neutron fluence of a few times of 10^13 n/cm^2. Dependence of detector leakage current, reverse bias capacitance, and effective doping concentration of the Si substrate on the Neutron fluence have been systematically studied. It has been found that the detector leakage current increases linearly with Neutron fluence in the range studies, with a damage constant of α = 9 × 10^−17 A/cm (ΔI = αΔAϕ_n @#@) , and the C-V characteristics of detectors irradiated to ϕ_n > 10^12 n/cm^2 become frequency dependent. Models using several defect levels in the band gap are proposed to describe the frequency dependent C-V effects and the electrical field profile after high Neutron fluence irRadiation.

  • Fast Neutron Radiation Damage Effects on High Resistivity Silicon Junction Detectors. Revision
    1992
    Co-Authors: H.w. Kraner
    Abstract:

    P{sup +}{minus}n{sup {minus}}{minus}n{sup +} silicon Radiation detectors made of high resistivity Si material ({rho} {ge} 2 k{Omega}-cm) were irradiated to a Neutron fluence of a few times of 10{sup 13} n/cm{sup 2}. Dependence of detector leakage current, reverse bias capacitance, and effective doping concentration of the Si substrate on the Neutron fluence have been systematically studied. It has been found that the detector leakage current increases linearly with Neutron fluence in the range studies, with a damage constant of {alpha} = 9 {times} 10{sup {minus}17} A/cm ({Delta}I = {alpha}V{Delta}{phi}{sub n}), and the C-V characteristics of detectors irradiated to {phi}{sub n} > 10{sup 12} n/cm{sup 2} become frequency dependent. Models using several defect levels in the band gap are proposed to describe the frequency dependent C-V effects and the electrical field profiles after high Neutron fluence irRadiation.

  • Fast Neutron Radiation effects in silicon detectors fabricated by different thermal oxidation processes
    IEEE Transactions on Nuclear Science, 1992
    Co-Authors: H.w. Kraner
    Abstract:

    High resistivity silicon detectors along with MOS capacitors made on five silicon dioxides with different thermal conditions (975 degrees C to 1200 degrees C) have been exposed to Fast Neutron irRadiation up to the fluence of a few times 10/sup 14/ n/cm/sup 2/. New measurement techniques such as capacitance-voltage of MOS capacitors and current-voltage and back-to-back diodes (p/sup +/-n/sup -/-p/sup +/ if n/sup -/ is not inverted to p) or resistors (p/sup +/-p-p/sup +/ if inverted) have been introduced in this study in monitoring the possible type-inversion (n to p) under high Neutron fluence. No type-inversion in the material underneath SiO/sub 2/ and the p/sup +/ contact has been observed for detectors made on the five oxides up to the Neutron fluence of a few times 10/sup 13/ n/cm/sup 2/. However, it has been found that detectors made on higher temperature oxides (>or=1100 degrees C) exhibited less leakage current increase at high Neutron fluence. >

  • Effects of Fast Neutron Radiation on the electrical properties of silicon detectors
    Nuclear Instruments and Methods in Physics Research Section A: Accelerators Spectrometers Detectors and Associated Equipment, 1991
    Co-Authors: Wei Chen, H.w. Kraner
    Abstract:

    Abstract Effects of Neutron Radiation on electrical properties of Si detectors have been studied. At high Neutron fluence (φn ≥ 1012 n/cm2), C-V characteristics of detectors with high resistivities ( ρ ≥ 1 k Ω cm ) become frequency dependent. A two-trap level model describing this frequency dependent effect is proposed. Room temperature anneal of Neutron damaged (at LN2 temperature) detectors shows three anneal stages, while two anneal stages were observed in elevated temperature anneal.

Justin E Anderson - One of the best experts on this subject based on the ideXlab platform.

  • genome resilience and prevalence of segmental duplications following Fast Neutron irRadiation of soybean
    Genetics, 2014
    Co-Authors: Yungtsi Bolon, Jean Michel Michno, Jeffrey Roessler, Pudota B Bhaskar, Landon Ries, Austin A Dobbels, Benjamin W Campbell, Nathan Young, Adrian O Stec, Justin E Anderson
    Abstract:

    Fast Neutron Radiation has been used as a mutagen to develop extensive mutant collections. However, the genome-wide structural consequences of Fast Neutron Radiation are not well understood. Here, we examine the genome-wide structural variants observed among 264 soybean [Glycine max (L.) Merrill] plants sampled from a large Fast Neutron-mutagenized population. While deletion rates were similar to previous reports, surprisingly high rates of segmental duplication were also found throughout the genome. Duplication coverage extended across entire chromosomes and often prevailed at chromosome ends. High-throughput resequencing analysis of selected mutants resolved specific chromosomal events, including the rearrangement junctions for a large deletion, a tandem duplication, and a translocation. Genetic mapping associated a large deletion on chromosome 10 with a quantitative change in seed composition for one mutant. A tandem duplication event, located on chromosome 17 in a second mutant, was found to cosegregate with a short petiole mutant phenotype, and thus may serve as an example of a morphological change attributable to a DNA copy number gain. Overall, this study provides insight into the resilience of the soybean genome, the patterns of structural variation resulting from Fast Neutron mutagenesis, and the utility of Fast Neutron-irradiated mutants as a source of novel genetic losses and gains.

G. Blosser - One of the best experts on this subject based on the ideXlab platform.