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Title: Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04)

Abstract

Dose control and measurement plans for the SPEAR3 Booster and storage ring have taken place during the SPEAR3 commissioning. The initial commissioning period (SPEAR3 start-up) covered the time period from the beginning of November 2003 to the early part of March 2004. The period from the beginning of March to the beginning of August 2004 has been mostly dedicated to the scientific program. The initial commissioning period was characterized with frequent injection and significantly higher losses. In comparison, the scientific program period was characterized with more stable beam operation with limited number of injections per day and lower beam losses. Three types of dose measurements, passive, active and special measurements, were implemented around the SPEAR3 Booster and storage ring. Based on the expected radiation hazards, several dose control measures were adopted at several stages of the commissioning. In the early stages of commissioning, areas within 4.5 m from the walls of the Booster and storage ring were designated as Radiation Areas (RA). Areas outside RA were classified as Radiologically Controlled Area (RCA). Access to these areas required less training than the radiation areas. A monthly review of the accelerator operation conditions and radiation measurement results were used to determine themore » changes needed for the RA classification status and associated dose control measures.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
899562
Report Number(s):
SLAC-PUB-12309
TRN: US0701976
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Radiation Measurements
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; CLASSIFICATION; COMMISSIONING; CONTROLLED AREAS; RADIATION HAZARDS; RADIATIONS; STORAGE RINGS; TRAINING; Other,SAFETY, SYNCHRAD

Citation Formats

Khater, Hesham, Liu, James, Prinz, Alyssa, Allan, Jim, Rokni, Sayed, and /SLAC. Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04). United States: N. p., 2007. Web.
Khater, Hesham, Liu, James, Prinz, Alyssa, Allan, Jim, Rokni, Sayed, & /SLAC. Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04). United States.
Khater, Hesham, Liu, James, Prinz, Alyssa, Allan, Jim, Rokni, Sayed, and /SLAC. Mon . "Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04)". United States. doi:. https://www.osti.gov/servlets/purl/899562.
@article{osti_899562,
title = {Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04)},
author = {Khater, Hesham and Liu, James and Prinz, Alyssa and Allan, Jim and Rokni, Sayed and /SLAC},
abstractNote = {Dose control and measurement plans for the SPEAR3 Booster and storage ring have taken place during the SPEAR3 commissioning. The initial commissioning period (SPEAR3 start-up) covered the time period from the beginning of November 2003 to the early part of March 2004. The period from the beginning of March to the beginning of August 2004 has been mostly dedicated to the scientific program. The initial commissioning period was characterized with frequent injection and significantly higher losses. In comparison, the scientific program period was characterized with more stable beam operation with limited number of injections per day and lower beam losses. Three types of dose measurements, passive, active and special measurements, were implemented around the SPEAR3 Booster and storage ring. Based on the expected radiation hazards, several dose control measures were adopted at several stages of the commissioning. In the early stages of commissioning, areas within 4.5 m from the walls of the Booster and storage ring were designated as Radiation Areas (RA). Areas outside RA were classified as Radiologically Controlled Area (RCA). Access to these areas required less training than the radiation areas. A monthly review of the accelerator operation conditions and radiation measurement results were used to determine the changes needed for the RA classification status and associated dose control measures.},
doi = {},
journal = {Radiation Measurements},
number = ,
volume = ,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}
  • Purpose: A new type of treatment planning system called SHAREPLAN has been studied, which enables the transfer of treatment plans generated for helical tomotherapy delivery to plans that can be delivered on C-arm linacs. The purpose is to ensure continuous patient treatment during periods of unscheduled downtime for the TomoTherapy unit, particularly in clinics without a backup unit. The purpose of this work was to verify that the plans generated in this novel planning system are deliverable and accurate. The work consists primarily of beam commissioning, verification of the beam model, and measurements verifying that generated plans are deliverable withmore » sufficient accuracy. Methods: The beam commissioning process involves input of general geometric properties of the modeled linac, profiles and depth dose curves for a specific photon nominal energy (6 MV), and the automated modeling of other beam properties. Some manual tuning of the beam model is required. To evaluate its accuracy, the confidence limit concept [J. Venselaar et al., ''Tolerances for the accuracy of photon beam dose calculations of treatment planning systems,'' Radiother. Oncol. 60, 191-201 (2001)] was used, which is a method supported by ESTRO. Measurements were conducted with a 2D diode array at the commissioned linac as a final check of the beam model and to evaluate whether the generated plans were deliverable and accurate. Results: The comparison and evaluation of calculated data points and measured data according to the method applied confirmed the accuracy of the beam model. The profiles had a confidence limit of 1.1% and the depth dose curves had a confidence limit of 1.7%, both of which were well below the tolerance limit of 2%. Plan specific QC measurements and evaluation verified that different plans generated in the TPS were deliverable with sufficient accuracy at the commissioned linac, as none of the 160 beams for the 20 different plans evaluated had a fraction of approved data points below 90%, the local clinical approval criterion for delivery QA measurements. Conclusions: This study is a validation of the new TPS as it verifies that the generated plans are deliverable at a commissioned linac with adequate accuracy. A thorough investigation of the treatment plan quality will require a separate study. The TPS is proving to be a useful and time-saving complement, especially for clinics having a single unit for helical delivery among its conventional linacs.« less
  • Beam lifetime studies for the SPEAR3 storage ring are presented. The three lifetime components are separated with lifetime measurements under various combinations of beam currents and fill patterns and vertical scraper scans. Touschek lifetime is studied with rf voltage scans and with the horizontal or vertical scrapers inserted. The measurements are explained with calculations based on the calibrated lattice model. Quantum lifetime measurements are performed with reduced longitudinal and horizontal apertures, respectively, from which we deduce the radiation energy loss down to a few keV per revolution and the horizontal beam size.
  • Purpose: To present the long-term outcome and morbidity of high-dose-rate brachytherapy (HDR-BT) combined with external beam radiotherapy (EBRT) for localized prostate cancer. Methods and Materials: Between September 1991 and December 1998, 209 consecutive patients with no prior androgen suppression were treated with HDR-BT plus EBRT. The median follow-up was 7.25 years (range, 5-12 years). The patients were stratified into three risk groups: low (Stage T2a or less, Gleason score {<=}6, and prostate-specific antigen [PSA] level {<=}10 ng/mL), intermediate (Stage T2b,c, Gleason score 7, and PSA level 10-20 ng/mL), and high (Stage T3, Gleason score 8-10, and PSA level >20). Fourmore » definitions of PSA progression were compared with the general clinical failure outcome: the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, nadir plus 2.0 ng/mL, two consecutive rises {>=}0.5 ng/mL, and PSA level >0.2 ng/mL. Morbidity was scored using Radiation Therapy Oncology Group criteria. Results: The general clinical control rate was 90% (188 of 209), and the general clinical failure rate was 10% (21 of 209). The overall survival rate was 79%, and the cause-specific survival rate was 97%. The PSA progression-free survival (ASTRO definition) rate was 90%, 87%, and 69% for the low-, intermediate-, and high-risk groups, respectively. The nadir plus 2 ng/mL and two rises {>=}0.5 definitions correlated better with the actual clinical outcome than did the ASTRO and PSA >0.2 ng/mL definitions. The rate of Grade 3 and 4 late urinary morbidity was 6.7% and 1%, respectively, mostly occurring in patients who had undergone post-RT transurethral prostate resection. No late Grade 3 or 4 rectal morbidity developed. The sexual potency preservation rate was 67%. Conclusion: Our 10-year results have demonstrated HDR-BT plus EBRT is a proven treatment for all stages of localized prostate cancer. The morbidity was low, but post-RT transurethral resection should be avoided.« less
  • Purpose: To assess the intermediate clinical outcomes of medically inoperable patients with endometrial cancer treated with definitive Rotte 'Y' applicator high-dose-rate brachytherapy (HDRB) over a 10-year period. Methods and Materials: Forty-nine inoperable patients were treated with HDRB from 1997 to 2007. Forty three (84%) were markedly obese (body mass index >35 kg/m{sup 2}). Thirty-one patients (63.3%) underwent two-dimensional treatment planning, whereas 18 patients (36.7%) underwent three-dimensional treatment planning. Thirty five of the patients (71.4%) were first treated with external beam radiotherapy (EBRT). For patients receiving EBRT in addition to HDRB, the median Y-applicator dose was 20 Gy in 5 fractions;more » for patients receiving HDRB alone it was 35 Gy in 5 fractions. All patients received two Y-applicator treatments per day. Results: Median follow-up time for all patients was 33 months. Acute HDRB toxicities were limited to Grade 1 and 2 occurring in 5 patients. One patient had a myocardial infarction. Four patients had late Grade 2 or 3 toxicity. Three patients had local recurrence (median time to recurrence, 16 months). The 3- and 5-year actuarial cause-specific survival rates were 93% and 87%, respectively; the overall survival rate was 83% and 42%, respectively, at 3 and 5 years. Conclusions: Twice-daily HDRB using a Y-applicator is a well-tolerated and efficacious regimen for the definitive treatment of medically inoperable patients with early-stage endometrial cancer. The recent incorporation of three-dimensional treatment planning has the potential to further decrease treatment morbidities.« less
  • Purpose: To evaluate an extreme hypofractionation regimen with 54 Gy in nine fractions provided by high-dose-rate (HDR) brachytherapy as monotherapy for prostate cancer by reporting 5-year clinical results. Methods and Materials: Between 1996 and 2005, 112 patients with localized prostate cancer were treated with HDR brachytherapy without external beam radiotherapy. Of the 112 patients, 15 were considered low risk, 29 intermediate risk, and 68 as high risk. The prescribed dose was uniformly 54 Gy in nine fractions within 5 days. Of the 112 patients, 94 also received hormonal therapy. The median follow-up time was 5.4 years. Results: All the patientsmore » safely completed the treatment regimen. The 5-year prostate-specific antigen (PSA) failure-free, local control, disease-free survival, and overall survival rate was 83%, 97%, 87%, and 96%, respectively. The 5-year PSA failure-free rate for low-, intermediate-, and high-risk patients was 85% (95% confidence interval, 66-100%), 93% (95% confidence interval, 83-100%), and 79% (95% confidence interval, 69-89%), respectively. The significant prognostic factors for PSA failure were the initial PSA level (p = .029) and younger age (p = .019). The maximal toxicities observed were Grade 3 using the Common Terminology Criteria for Adverse Events, version 3.0, for both acute and late toxicity (6 and 3 patients had acute and late Grade 3 toxicity, respectively). Late Grade 2 toxicity was observed in 13 patients. Conclusion: Monotherapeutic HDR brachytherapy with an extreme hypofractionation regimen of 54 Gy in nine fractions associated with hormonal therapy was feasible, and its toxicity was acceptable. The interim tumor control rate at a median 5.4 years was promising, even for patients with locally advanced disease. This dose-fractionation scheme might be referred to by other terms, such as stereotactic body radiotherapy. Studies with longer follow-up periods and from multiple institutions are needed to confirm the efficacy of this novel approach.« less