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Crocker I, Fox T, Shu H, Schreibmann E. Cone-Beam CT (CBCT) Image Guidance for In-Room Frameless Stereotactic Radiotherapy Positioning of Brain Tumor Patients. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.2026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Schreibmann E, Crocker I, Gozbasi H, Ahmed S, Savelsbergh M, Fox T. SU-DD-A2-01: 4D Dose Verification of Treatment Plans Involving Intra-Fraction Motion. Med Phys 2007. [DOI: 10.1118/1.2760345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Crocker I. Gabor Than Award Lecture 2006: pre-eclampsia and villous trophoblast turnover: perspectives and possibilities. Placenta 2007; 28 Suppl A:S4-13. [PMID: 17379302 DOI: 10.1016/j.placenta.2007.01.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2006] [Revised: 01/23/2007] [Accepted: 01/26/2007] [Indexed: 11/26/2022]
Abstract
Placental apoptosis is exaggerated in pre-eclampsia and cytotrophoblast proliferation is enhanced. This imbalance may be a primary pathogenic event, whereby excessive syncytiotrophoblast apoptosis counters cytotrophoblast fusion, promoting the liberation of syncytial material which perturbs the maternal vascular endothelium. We have previously shown that primary trophoblasts and explant cultured villous fragments from pre-eclamptic pregnancies elicit greater levels of terminal differentiation and apoptosis. This review considers current opinions in trophoblast cell turnover in normal pregnancy and pre-eclampsia. In the context of other findings, this review highlights: (i) the disparity in expression of pro-apoptotic transcription factor p53 in the syncytiotrophoblast in pre-eclampsia, (ii) the importance of reactive oxygen species and hypoxia in initiating villous trophoblast apoptosis and (iii) the concept that aberrant intervillous haemodynamics, as opposed to oxygen per se, initiates excessive syncytiotrophoblast shedding. Finally, therapeutic ways of restoring the syncytiotrophoblast in pre-eclampsia and preventing excessive placental apoptosis are considered, including a role for mitotic manipulators and growth factor replacement strategies.
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Iruloh CG, D'Souza SW, Speake PF, Crocker I, Fergusson W, Baker PN, Sibley CP, Glazier JD. Taurine transporter in fetal T lymphocytes and platelets: differential expression and functional activity. Am J Physiol Cell Physiol 2007; 292:C332-41. [PMID: 16956961 DOI: 10.1152/ajpcell.00634.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transplacental transfer of taurine, a β-amino acid essential for fetal and neonatal development, constitutes the primary source of taurine for the fetus. Placental transport of taurine is compromised in pregnancies complicated by intrauterine growth restriction, resulting in a reduced concentration of taurine in cord plasma. This could impact on fetal cellular metabolism as taurine represents the most abundant intracellular amino acid in many fetal cell types. In the present study, we have used pure isolates of fetal platelets and T lymphocytes from cord blood of placentas, from normal, term pregnancies, as fetal cell types to examine the cellular uptake mechanisms for taurine by the system β transporter and have compared gene and protein expression for the taurine transporter protein (TAUT) in these two cell types. System β activity in fetal platelets was 15-fold higher compared with fetal T lymphocytes ( P < 0.005), mirroring greater TAUT mRNA expression in platelets than T lymphocytes ( P < 0.005). Cell-specific differences in TAUT protein moieties were detected with a doublet of 75 and 80 kDa in fetal platelets compared with 114 and 120 kDa in fetal T lymphocytes, with relatively higher expression in platelets. We conclude that greater system β activity in fetal platelets compared with T lymphocytes is the result of relatively greater TAUT mRNA and protein expression. This study represents the first characterization of amino acid transporters in fetal T lymphocytes.
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Jewsbury S, Sheikh N, Crocker I, Baker PN, Myers JE. Plasma uric acid levels do not correlate to plasma-evoked changes in endothelial function in women with preeclampsia. Eur J Obstet Gynecol Reprod Biol 2006; 137:118-9. [PMID: 17129658 DOI: 10.1016/j.ejogrb.2006.10.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2006] [Revised: 10/25/2006] [Accepted: 10/26/2006] [Indexed: 11/20/2022]
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Kaneda H, Honda Y, Morino Y, Fox T, Crocker I, Lansky AJ, Yock PG, Bonan R, Fitzgerald PJ. Safety of beta radiation exposure to the non-target segment: an intravascular ultrasound dosimetric analysis. THE JOURNAL OF INVASIVE CARDIOLOGY 2006; 18:309-12. [PMID: 16816435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
BACKGROUND The use of longer radioactive seed trains to avoid geographic miss may lead to greater radiation exposure to distal vasculature due to the natural tapering of coronary arteries. The aim of this study was to use IVUS-based dosimetric analysis to evaluate the effect of beta-radiation on angiographically normal, noninjured distal segments. METHODS We analyzed 17 in-stent restenosis cases (stent length: 20 +/- 8 mm) treated with a 40 mm 90Sr/Y source train. The prescribed dose was 18.4 Gy (reference less than or equal to 3.3 mm) or 23 Gy (reference > 3.3 mm) at 2 mm from the source. Noninjured, but fully radiated, distal reference sites were determined by angiography. Based upon the three-dimensional vessel contours obtained at baseline, the minimum dose delivered to 90% of plaque volume (Dv90) was determined. Vessel, plaque and lumen volumes and Dv90 were computed in every 2 mm subsegment (n = 52). RESULTS On average, no significant serial change was observed in plaque area (5.0 +/- 2.5 mm3/mm post-treatment to 5.6 +/- 3.1 mm3/mm at 8-month follow up; p = 0.09), vessel area (10.2 +/- 3.7 to 10.3 +/- 4.0 mm3/mm; p = 0.84), or lumen area (5.2 +/- 2.0 to 4.7 +/- 1.8 mm3/mm; p = 0.19). Subsegment analysis, however, revealed a wide range of dose distribution, with a significant positive correlation between Dv90 and plaque increase (p = 0.008), as well as vessel change (p < 0.001), representing dose-dependent positive vessel remodeling following beta radiation. Consequently, no significant relationship was observed between Dv90 and lumen change. CONCLUSIONS Detailed IVUS-based dosimetric analysis demonstrated that beta radiation promoted positive remodeling, preventing lumen loss despite a mild increase in plaque mass on angiographically normal, noninjured distal segments.
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Gatcombe H, Lawson J, Phuphanich S, Crocker I. Treatment related myelitis in hodgkin’s lymphoma following stem cell transplant, chemotherapy and radiation: a case report and review of the literature. J Neurooncol 2006; 79:293-8. [PMID: 16617406 DOI: 10.1007/s11060-006-9140-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 02/27/2006] [Indexed: 11/30/2022]
Abstract
Radiation myelitis, while rare, is one of the most devastating complications of radiation treatment. We report here a case of a 25-year-old Middle Eastern man with progressive myelopathy 21 months following low dose irradiation of the cord in the context of high dose chemotherapy and stem cell rescue and a review of the literature.
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Bugg GJ, Crocker I, Baker PN, Johnston TA, Taggart MJ. The effect of superoxide free radicals on human myometrial contractility in vitro. Eur J Obstet Gynecol Reprod Biol 2006; 125:140-1. [PMID: 16459009 DOI: 10.1016/j.ejogrb.2005.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 09/12/2005] [Accepted: 09/21/2005] [Indexed: 10/25/2022]
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Lee EK, Fox T, Crocker I. Simultaneous beam geometry and intensity map optimization in intensity-modulated radiation therapy. Int J Radiat Oncol Biol Phys 2006; 64:301-20. [PMID: 16289912 DOI: 10.1016/j.ijrobp.2005.08.023] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 06/23/2005] [Accepted: 08/08/2005] [Indexed: 11/28/2022]
Abstract
PURPOSE In current intensity-modulated radiation therapy (IMRT) plan optimization, the focus is on either finding optimal beam angles (or other beam delivery parameters such as field segments, couch angles, gantry angles) or optimal beam intensities. In this article we offer a mixed integer programming (MIP) approach for simultaneously determining an optimal intensity map and optimal beam angles for IMRT delivery. Using this approach, we pursue an experimental study designed to (a) gauge differences in plan quality metrics with respect to different tumor sites and different MIP treatment planning models, and (b) test the concept of critical-normal-tissue-ring--a tissue ring of 5 mm thickness drawn around the planning target volume (PTV)--and its use for designing conformal plans. METHODS AND MATERIALS Our treatment planning models use two classes of decision variables to capture the beam configuration and intensities simultaneously. Binary (0/1) variables are used to capture "on" or "off" or "yes" or "no" decisions for each field, and nonnegative continuous variables are used to represent intensities of beamlets. Binary and continuous variables are also used for each voxel to capture dose level and dose deviation from target bounds. Treatment planning models were designed to explicitly incorporate the following planning constraints: (a) upper/lower/mean dose-based constraints, (b) dose-volume and equivalent-uniform-dose (EUD) constraints for critical structures, (c) homogeneity constraints (underdose/overdose) for PTV, (d) coverage constraints for PTV, and (e) maximum number of beams allowed. Within this constrained solution space, five optimization strategies involving clinical objectives were analyzed: optimize total intensity to PTV, optimize total intensity and then optimize conformity, optimize total intensity and then optimize homogeneity, minimize total dose to critical structures, minimize total dose to critical structures and optimize conformity simultaneously. We emphasize that the objectives that include optimizing conformity make use of the critical-normal-tissue-ring. Three tumor sites: head-and-neck, pediatric brain, and prostate are used for comparison. RESULTS The critical-normal-tissue-ring acts as a good device for enforcing conformity. Trends in the characteristics and quality of plans resulting from each model were observed. Attempts to reduce dose to critical structures tend to worsen PTV conformity (1.542 to 3.092) and homogeneity (1.223 to 1.984), depending on the relative size and spatial distance of the critical structures to the PTV. When the critical structures are relatively small compared with the PTV (as in the case for the pediatric brain tumor, where each is less than 15% in volume), dose reduction to critical structures is accompanied by much worse scores in conformity (2.482) and homogeneity (1.984). When the critical structures are larger, as in the case of head-and-neck (approximately 50%), the conformity and homogeneity deterioration is less significant (1.542 and 1.239, respectively). There is a clear tradeoff between homogeneity, conformity, and minimum dose to organs at risk (OARs). For head-and-neck and pediatric brain tumor, the model that minimizes total dose to critical structures and optimizes conformity simultaneously offers a compromise among these factors, resulting in reduced critical structure dose with conformal and homogeneous plans. In the prostate case, the tumor is smaller than the two large nearby critical structures, and all models provide very homogeneous PTV dose distribution. However, minimizing dose to critical structures worsens conformity, as it spreads the radiation to the area surrounding the PTV. The maximum dose to the critical structures also increases slightly. Compared with plans used in the clinic which generally have uniformly spaced beam angles, the optimal clinically acceptable plans obtained via the methods herein do not have equispaced beams. The optimal beam angles returned appear to be nonintuitive, and depend on PTV size and geometry and the spatial relationship between the tumor and critical structures. CONCLUSIONS The MIP model described allows simultaneous optimization over the space of beamlet fluence weights and beam and couch angles. Based on experiments with tumor data, this approach can return good plans that are clinically acceptable and practical. This work distinguishes itself from recent IMRT research in several ways. First, in previous methods beam angles are selected before intensity map optimization. Herein, we employ 0/1 variables to model the set of candidate beams, and thereby allow the optimization process itself to select optimal beams. Second, instead of incorporating dose-volume criteria within the objective function as in previous work, herein, a combination of discrete and continuous variables associated with each voxel provides a mechanism to strictly enforce dose-volume criteria within the constraints. Third, using the construct of critical-normal-tissue-ring within the objective function can enhance the achievement of conformal plans. Based on the three tumor sites considered, it appears that volume and spatial geometry with respect to the PTV are important factors to consider when selecting objectives to optimize, and in estimating how well suited a particular model is for achieving a specified goal.
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Padavala S, Pope N, Baker P, Crocker I. An imbalance between vascular endothelial growth factor and its soluble receptor in placental villous explants of intrauterine growth-restricted pregnancies. ACTA ACUST UNITED AC 2005; 13:40-7. [PMID: 16303323 DOI: 10.1016/j.jsgi.2005.09.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES Human umbilical vascular endothelial cells (HUVECs), seeded on Matrigel (BD Biosciences, Bedford, UK), undergo an angiogenic-like process. We hypothesized that placental explants from normal pregnancies, maintained in cultures of different oxygen, would liberate factors that could be measured in this system. We further tested the angiogenic potential of placentae from intrauterine growth-restricted (IUGR) pregnancies and the effects of vascular endothelial growth factor (VEGF) blockade. METHODS Placental villous explants were maintained in culture at 3% and 20% O2. The resultant media was added to HUVECs seeded on 80% Matrigel. Cells were incubated at 6% O2 in accordance with the natural placental environment. After 6 hours, cells were fixed and stained and the length and number of tubules measured by morphometric imaging. Finally, VEGF and soluble VEGF receptor (sVEGFR-1) were recorded in the explant conditioned media. RESULTS Within the angiogenic assay, recombinant human VEGF significantly enhanced tubule outgrowth (branching and elongation) and this effect was blocked with neutralising antibody. Compared to 20% O2, media of placental explants conditioned at 3% O2 significantly encouraged tubule length and numbers. Again this affect was ablated by VEGF blockade. In cases of IUGR, conditioned media at 3% O2 showed a significant reduction in tubule growth. This was paralleled by a decline in available VEGF brought about an exaggeration in liberated sVEGFR-1. Notably, venous cord serum from IUGR pregnancies showed a similar elevation in sVEGFR-1. CONCLUSION Under restricted oxygen, placental angiogenic potential is suppressed in IUGR pregnancies through the overproduction of placental sVEGFR-1. This reduction may discourage normal placental vascularization and impact on fetal development.
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Lawson J, Fox T, Elder E, Davis L, Keller J, Crocker I. Implementation of On-Board Imaging (OBI) and Quantification of Resultant Patient Shifts. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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87
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Anderson C, Miyagi T, Xie Z, Reddi H, Odero-Marah V, Johnstone P, Crocker I, Chung L. Probing Radiation Effects on Prostate Cancer and Bone Stroma Interactions. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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88
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Ryu S, Crocker I, Stieber V, Ye X, Fisher JD, Grossman S. Perfusion and diffusion MRI in the assessment of the antivascular effect of arsenic trioxide combined with radiotherapy for glioblastoma multiforme: NABTT phase I study. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.1538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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89
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Daayana S, Baker P, Crocker I. An image analysis technique for the investigation of variations in placental morphology in pregnancies complicated by preeclampsia with and without intrauterine growth restriction. ACTA ACUST UNITED AC 2005; 11:545-52. [PMID: 15582500 DOI: 10.1016/j.jsgi.2004.06.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE The purpose of this study was to use visual image analysis to observe changes in the morphology and composition of placental villi in pregnancies complicated by preeclampsia (PE) and intrauterine growth restriction (IUGR). METHODS Placental biopsies from nine normal pregnancies, five cases of PE, five cases of IUGR, and five cases of PE with IUGR (PE x IUGR) were randomly sampled. Formalin-fixed, wax-embedded sections were stained with hematoxylin and eosin (H&E) and subjected to image analysis. The placental areas occupied by villi, syncytiotrophoblast, and syncytial cytoplasm and nuclei were quantified. RESULTS Significantly smaller placentas were obtained from growth-restricted pregnancies. PE, with and without IUGR, had no effect on the total area occupied by villi or intervillous space. IUGR alone showed a real and consistent reduction in villous area (56.0 +/- 2.4% vs 43.6 +/- 3.3%, P <.03). While the ratio of syncytial to villous areas were noticeably reduced in all cases of PE (0.38 +/- 0.03 vs 0.24 +/- 0.07, P <.05), this ratio remained unchanging in IUGR. Birth weight was positively correlated to both placental size and total villous area occupied. Moreover, increasingly positive relationships were recorded between both syncytiotrophoblast area and syncytiotrophoblast cytoplasm and birth weight (P <.01 and P <.001, respectively). CONCLUSION These measurements point to impoverished villus development in idiopathic IUGR. The observed changes in PE with IUGR were more akin to PE without growth restriction than IUGR alone. This suggests that idiopathic IUGR and IUGR in PE have a separate etiology, idiopathic IUGR arising through a reduction in villous area alone, and IUGR in PE caused by changes in syncytiotrophoblast quantity, more specifically the amount of syncytiotrophoblast cytoplasm.
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Anderson C, Kulkarni A, Douglas J, Ghazzal Z, Lieberman H, William W, James K, Viola V, Crocker I. β-coronary vascular brachytherapy following commercial approval-the Emory experience. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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91
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Narayan P, Crocker I, Elder E, Olson J. Safety and efficacy of concurrent interstitial radiation and hyperthermia in the treatment of progressive malignant brain tumors. Oncol Rep 2004. [DOI: 10.3892/or.11.1.97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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92
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Narayan P, Crocker I, Elder E, Olson JJ. Safety and efficacy of concurrent interstitial radiation and hyperthermia in the treatment of progressive malignant brain tumors. Oncol Rep 2004; 11:97-103. [PMID: 14654910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
High activity 125I brachytherapy has efficacy in selected recurrent malignant brain tumors, but limited efficacy and risk of radiation necrosis have prompted investigation of additional adjunctive therapies. This study aims to assess the toxicity of interstitial conductive hyperthermia used concurrently with 125I brachytherapy for the treatment of recurrent brain malignancies. Twelve patients with recurrent malignant brain tumors were implanted using afterloading catheters intended to deliver 50 Gy at the isodose line encompassing the enhancing tumor with a 5-mm margin and heated to 41.5 degrees C for 48 h. The average implant volume was 18 cc with 5.3 catheters containing 9.4 sources with a total activity of 265 mCi. Serious toxicities included 8 motor deficits, 2 mood alterations, 4 seizures and 2 catheter wound cerebrospinal fluid leaks. Median survival was 10.35 months with the best responses being 6 with stable disease and 2 with partial responses. Reoperation rate for radiation necrosis was 33%. Concurrent conductive thermoradiotherapy is feasible but is associated with serious toxicity. There is no suggestion of improved survival with thermoradiotherapy over brachytherapy alone. Given the degree of toxicity observed, alternative approaches to improving local control of these tumors are being explored.
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Crocker I. Considerations on radiation source selection and utilization in vascular brachytherapy. THE JOURNAL OF INVASIVE CARDIOLOGY 2003; 15:664-7; quiz 668. [PMID: 14608142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Three radiation sources have been approved for commercial use in vascular brachytherapy. The beta sources ((90)Strontium and (32)Phosphorous) are more popular because of less radiation protection concerns than gamma sources. Because (90)Strontium has a longer half-life than (32)Phosphorous, it requires less frequent source exchanges. Also, because (90)Strontium is more penetrating, a similar benefit can be achieved with lower delivered doses. Based on these advantages, (90)Strontium is the preferred isotope for vascular brachytherapy.
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Costa R, Joyal M, Harel F, Fox T, Crocker I, Arsenault A, Gregoire J, Bonan R. Treatment of bifurcation in-stent restenotic lesions with beta radiation using strontium 90 and sequential positioning pullback technique: procedural details and clinical outcomes. THE JOURNAL OF INVASIVE CARDIOLOGY 2003; 15:469-73; quiz 474. [PMID: 12890881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
BACKGROUND In-stent restenotic lesions have been problematic for many patients with the need for multiple repeat percutaneous coronary interventions (PCI). The need for repeat PCI has been significantly reduced in patients since the advent of vascular brachytherapy. In-stent restenosis resulting in bifurcation presents even more of a challenge. The use of radiation therapy for the treatment of this kind of lesion has not yet been reported. The purpose of this paper is to present five cases of radiation therapy in bifurcation in-stent restenotic lesions using the intraluminal beta radiation catheter delivery system (Beta-Cath System, Novoste Corporation, Norcross, Georgia). METHODS We reviewed the database of patients enrolled in our Compassionate Use Registry between August 1999 and April 2002. The data is reported for 5 patients who received radiation in both branches of bifurcation lesions with the Beta-Cath catheter system. RESULTS The mean diameter of the vessels was 3.1 mm 0.5 mm. The dose administered was from 18.3 to 23 Gy, with an overlap of 3.3 to 10.3 mm; the hinge angle between the branches went from 43.3 to 65.4 . Angiographic follow-up was obtained at 6 months in 4 patients, with a single patient showing a focal (< 5 mm) edge lesion treated by balloon angioplasty (TVR no TLR). No aneurysms or zones of ectasia were noted. CONCLUSION Beta radiation with the Beta-Cath catheter system appears to be safe, secure and clinically useful in in-stent restenotic bifurcation lesions.
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Crocker I, Fox T. Source selection in vascular brachytherapy. THE JOURNAL OF INVASIVE CARDIOLOGY 2003; 15 Suppl A:17A-18A. [PMID: 12668836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
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Morino Y, Kaneda H, Fox T, Takagi A, Hassan AHM, Bonan R, Crocker I, Lansky AJ, Laskey WK, Suntharalingam M, Bonneau HN, Yock PG, Honda Y, Fitzgerald PJ. Delivered dose and vascular response after beta-radiation for in-stent restenosis: retrospective dosimetry and volumetric intravascular ultrasound analysis. Circulation 2002; 106:2334-9. [PMID: 12403663 DOI: 10.1161/01.cir.0000036367.17043.03] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Observations from previous intracoronary radiation therapy trials noted a considerable discrepancy between the prescribed radiation dose and the dose actually delivered. The aims of this study were to investigate the effect of actual delivered dose on vascular changes and to test the appropriateness of the current dose prescription. METHODS AND RESULTS Serial volumetric intravascular ultrasound (IVUS) analysis was performed in 30 in-stent restenosis cases treated with a 40-mm (90)Sr/Y source train. The fixed dose was prescribed at 2 mm from the centerline of the source train (18.4 Gy at 2 mm for reference diameter < or =3.35 mm and 23 Gy for diameter > or =3.36 mm). Only stent segments with full radiation coverage and device injury were enrolled and divided into 2-mm-long subsegments (n=202). D(S90)EEM (the minimum dose absorbed by 90% of the external elastic membrane surface) was calculated as the delivered dose corresponding to each segment, assuming that the radiation catheter occupied the same position in the vessel as the IVUS catheter. Mean D(S90)EEM of 23.5+/-5.82 Gy (range 12.3 to 41.7 Gy) was delivered to these subsegments. Overall, intimal hyperplasia volume remained constant from postintervention to follow-up (2.23+/-1.10 to 2.32+/-1.09 mm3/m; P=NS). Regression analysis revealed there was no correlation between delivered dose intensity and changes in intimal hyperplasia volume. No particular dose-dependent complications were appreciated in this delivered dose range. CONCLUSIONS The current dose-prescription protocol of (90)Sr/Y radiation to native in-stent restenosis lesions may provide substantial inhibition of neointimal reproliferation regardless of the actual delivered dose intensity.
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Mayr M, Crocker I, Butker E, Williams H, Cotsonis G, Olson J. Results of interstitial brachytherapy for malignant brain tumors. Int J Oncol 2002. [DOI: 10.3892/ijo.21.4.817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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98
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Crocker I, Lawson N, Fletcher J. Effect of pregnancy and obstructive jaundice on inflammatory diseases: the work of P S Hench revisited. Ann Rheum Dis 2002; 61:307-10. [PMID: 11874831 PMCID: PMC1754059 DOI: 10.1136/ard.61.4.307] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Hench considered that cortisone improved inflammatory joint symptoms during pregnancy and obstructive jaundice. However, the improved symptoms are probably due to changes in the proportions of fatty acids in plasma and inflammatory cell phospholipids. These changes decrease the superoxide anions and eicosanoids produced and also reduce tumour necrosis factor alpha production.
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Kaneda H, Honda Y, Morino Y, Takagi A, Hassan AH, Fox T, Crocker I, Lansky AJ, Yock PG, Bonan R, Fitzgerald PJ. Excessive beta-radiation exposure to the non-target segment: an intravascular ultrasound dosimetric analysis. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)80054-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stubbs JB, Frankel RH, Schultz K, Crocker I, Dillehay D, Olson JJ. Preclinical evaluation of a novel device for delivering brachytherapy to the margins of resected brain tumor cavities. J Neurosurg 2002; 96:335-43. [PMID: 11838809 DOI: 10.3171/jns.2002.96.2.0335] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The objectives of this study were to evaluate the safety and performance of a new brachytherapy applicator in the treatment of resected brain tumors in a canine model. METHODS The brachytherapy applicator is an inflatable balloon catheter that is implanted in the resection cavity remaining after a brain tumor has been debulked. After implantation the balloon is inflated with Iotrex, a sterile solution containing organically bound iodine-125. The low-energy photons emitted by the iodine-125 deposit a therapeutic radiation dose across short distances from the surface of the balloon. After delivery of a prescribed radiation dose to the targeted volume, the radioactive fluid is retrieved and the catheter removed. Small resections of the right frontal lobe were performed in large dogs. Magnetic resonance (MR) images were obtained and used to assess tissue response and to measure the conformance between the resection cavity wall and the balloon surface. In four animals a dose ranging from 36 to 59 Gy was delivered. Neurological status and histological characteristics of the brain were assessed in all dogs. Implantation and explantation as well as inflation and deflation of the device were easily accomplished and well tolerated. The device was easily visualized on MR images, which demonstrated the expected postsurgical changes. The resection cavity and the balloon were highly conformal (range 93-100%). Histological changes to the cavity margin were consistent with those associated with surgical trauma. Additionally, radiation-related changes were observed at the margins of the resection cavity in dogs in which the brain was irradiated. CONCLUSIONS This balloon catheter and 125I radiotherapy solution system can safely and reliably deliver radiation to the margins of brain cavities created by tumor resection. Results of this study showed that intracranial pressure changes due to balloon inflation and deflation were unremarkable and characteristic of the imaging properties and radiation safety profile of the device prior to its clinical evaluation. Clinically relevant brachytherapy (adequate target volume and total dose) was accomplished in all four animals subjected to treatment.
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