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PubMed2001

Complications and patient satisfaction following expander/implant breast reconstruction with and without radiotherapy.

PURPOSE: To compare the rates of complications and patient satisfaction among breast cancer patients treated with mastectomy and tissue expander/implant reconstruction with and without radiotherapy. METHODS AND MATERIALS: As part of the Michigan Breast Reconstruction Outcome Study (MBROS), breast cancer patients undergoing mastectomy with reconstruction were prospectively evaluated with respect to complications, general patient satisfaction with reconstruction, and esthetic satisfaction. Included in this study was a cohort of women who underwent breast reconstruction using an expander/implant (E/I). A subset of these patients also received radiotherapy (RT). At 1 and 2 years postoperatively, a survey was administered which included 7 items assessing both general satisfaction with their reconstruction and esthetic satisfaction. Complication data were also obtained at the same time points using hospital chart review. Radiotherapy patients identified in the University of Michigan Radiation Oncology database that underwent expander/implant reconstruction but not enrolled in the MBROS study were also added to the analysis. RESULTS: Eighty-one patients underwent mastectomy and E/I reconstruction. Nineteen patients received RT and 62 underwent reconstruction without RT. The median dose delivered to the reconstructed breast/chest wall, including boost, was 60.4 Gy (range, 50.0-66.0 Gy) in 1.8- to 2.0-Gy fractions. With a median follow-up of 31 months from the date of surgery, complications occurred in 68% (13/19) of the RT patients compared to 31% (19/62) in the no RT group (p = 0.006). Twelve of 81 patients (15%) had a breast reconstruction failure. Reconstruction failure was significantly associated with experiencing a complication (p = 0.0001) and the use of radiotherapy (p = 0.005). The observed reconstruction failure rates were 37% (7/19) and 8% (5/62) for patients treated with and without radiotherapy, respectively. Tamoxifen was associated with a borderline risk of complications (p = 0.07) and a significant risk of reconstruction failure (p = 0.01). Sixty-six patients of the study group completed the satisfaction survey; 15 patients did not. To offset potential bias for patients not completing the survey, we analyzed satisfaction data assuming "dissatisfaction" scores for surveys not completed. In the analysis of patients with unilateral E/I placement, reconstruction failure was significantly associated with a lower general satisfaction (p = 0.03). Ten percent of patients experiencing a reconstruction failure were generally satisfied compared to 23% who completed E/I reconstruction. In addition, tamoxifen use was associated with a significantly decreased esthetic satisfaction (p = 0.03). Radiotherapy was not associated with significantly decreased general or esthetic satisfaction. CONCLUSION: Irradiated patients had a higher rate of expander/implant reconstruction failure and complications than nonirradiated patients. Despite these differences, our pilot data suggest that both general satisfaction and patient esthetic satisfaction were not significantly different following radiotherapy compared to patients who did not receive RT. Although statistical power was limited in the present study and larger patient numbers are needed to validate these results, this study suggests comparable patient assessment of cosmetic outcome with or without radiotherapy in women who successfully complete expander/implant reconstruction.

Adult↗

PubMed2001

Individual biodosimetry at the natural radiation background level.

The present note describes new advancements to a valued tool in retrospective biodosimetry that lower the threshold of detection of radiation dose to 29 mGy. The advanced method is based on the electron paramagnetic resonance measurements of stable radiation-induced radicals in tooth enamel. Earlier this method had been used only for reconstruction of high radiation doses obtained accidentally. New opportunity of reconstruction of doses lower than 100 mGy opens a new realm of possibilities for assessing the health effects of ionizing radiation at the natural radiation background level.

Background Radiation↗

PubMedDate not supplied

The American Brachytherapy Society perspective on intravascular brachytherapy.

BACKGROUND: Recent clinical studies indicate that intravascular brachytherapy (IVB) can reduce the rate of restenosis substantially after angioplasty procedures. However, no clinical guidelines exist for optimal therapy. METHODS: The members of the IVB Subcommittee of the American Brachytherapy Society (ABS) identified the areas of consensus and controversies in IVB to issue the ABS perspective on IVB, based on analysis of published reports and the clinical experience of the members in brachytherapy. RESULTS: IVB is still experimental. The long-term efficacy, toxicity, the target tissue, and dose required for IVB are not established. The ABS recommends that IVB procedures must be performed, with careful attention to radiation-related issues, in the context of controlled multidisciplinary clinical trials with the approval of the institutional review board, the Nuclear Regulatory Commission, the Food and Drug Administration, and under an Investigational Device Exemption. The therapeutic radiologist, with a qualified radiation physicist, is responsible for dose prescription and delivery and needs to be present during the IVB procedure as part of this multidisciplinary team. The long-term outcome from these studies should be reviewed critically and published in peer-reviewed journals. The ABS endorsed the dosimetric guidelines of the American Association of Physicists in Medicine Task Group 60 (AAPM TG-60) report. The ABS recommends that dose specification be defined clearly; to allow comparisons between studies, the dose should be prescribed at 2 mm from the source for intracoronary brachytherapy and at an average luminal radius of +2 mm for peripheral vascular brachytherapy. The prescription doses at the above point is generally in the 12-18 Gy range. Comprehensive procedures for quality assurance, radiation protection, and emergencies should be in place before initiating an IVB program. Higher energy beta sources, lower energy gamma sources, dose-volume histograms, and correlation of three-dimensional reconstructions of delivered dose with patterns of failure are areas for further research. CONCLUSION: The ABS perspective on IVB is presented to assist the interventional team in developing protocols for the use of IVB in the prevention of restenosis. Long-term outcome data with a standardized reporting system are needed to establish the role of brachytherapy in preventing vascular restenosis. Endovascular brachytherapy is a new and evolving modality, and these recommendations are subject to modifications as new data become available.

Brachytherapy↗

PubMed2001

Optimizing radioimmunotherapy by matching dose distribution with tumor structure using 3D reconstructions of serial images.

The biological effect of radioimmunotherapy (RIT) is most commonly assessed in terms of the absorbed radiation dose. In tumor, conventional dosimetry methods assume a uniform radionuclide and calculate a mean dose throughout the tumor. However, the vasculature of solid tumors tends to be highly irregular and the systemic delivery of antibodies is therefore heterogeneous. Tumor-specific antibodies preferentially localize in the viable, radiosensitive parts of the tumor whereas non-specific antibodies can penetrate into the necrosis where the dose is wasted. As a result, the observed biological effect can be very different to the predicted effect from conventional dose estimates. The purpose of this study is to assess the potential for optimizing the biological effect of RIT by matching the dose-distribution with tumor structure through the selection of appropriate antibodies and radionuclides. Storage phosphor plate technology was used to acquire images of the antibody distribution in serial tumor sections. Images of the distributions of a trivalent (TFM), bivalent (A5B7-IgG), monovalent (MFE-23) and a non-specific antibody (MOPC) were obtained. These images were registered with corresponding images showing tumor morphology. Serial images were reconstructed to form 3D maps of the antibody distribution and tumor structure. Convolution of the image of antibody distribution with beta dose point kernals generated dose-rate distributions for 14C, 131I and 90Y. These were statistically compared with the tumor structure. The highest correlation was obtained for the multivalent antibodies combined with 131I, due to specific retention in viable areas of tumor coupled with the fact that much of the dose was deposted locally. With decreasing avidity the correlation also decreased and with the non-specific antibody this correlation was negative, indicating higher concentrations in the necrotic regions. In conclusion, the dose distribution can be optimized in tumor by selecting the appropriate antibodies and radionuclides. This has the potential to lead to a considerable enhancement of the efficacy of RIT in the clinic.

Adenocarcinoma↗

PubMed1997

Determination of 3D dose distribution from intracavitary brachytherapy of cervical cancer by MRI of irradiated ferrous sulphate gel.

BACKGROUND AND PURPOSE: MRI ferrous sulphate gel dosimetry has proven to be a valuable method for assessment of dose delivered in teletherapy. The intention of this study was to investigate ferrous sulphate gel as a possible dosimeter for intracavitary brachytherapy applications. MATERIALS AND METHODS: A plastic duplicate of a cervix ring applicator set was submerged in Fe2(+)-infused gelatin gel. The gel was subsequently irradiated by a stepwise moving 192Ir source, using automatic afterloading equipment (Microselectron, Nucletron-Oldelft International BV, Veenendaal, The Netherlands). A 3D dose distribution was reconstructed from MR images of the gel. RESULTS: The gel dose measurements were found to be of the same accuracy as TLD measurements. Isodose curves based on gel dosimetry and isodose curves computed by a dose planning system were generally less than 2 mm apart. MR images showing the position of the applicator set in a patient during treatment were used to obtain images describing patient anatomy in the sagittal and ring planes of the applicator set. Isodose curves computed from the gel measurements were then superimposed on these images, illustrating one possible way of linking dosimetrical and anatomical data. CONCLUSIONS: Our study shows that MRI ferrous sulphate gel dosimetry is a useful tool for studies of dose distributions in brachytherapy and their relation to critical organs. Possible improvements of the gel dosimeter lie in reducing the diffusion of ferric ions and increasing the radiation sensitivity of the gel.

Brachytherapy↗

PubMed2003

Tomographic mammography using a limited number of low-dose cone-beam projection images.

A method is described for using a limited number (typically 10-50) of low-dose radiographs to reconstruct the three-dimensional (3D) distribution of x-ray attenuation in the breast. The method uses x-ray cone-beam imaging, an electronic digital detector, and constrained nonlinear iterative computational techniques. Images are reconstructed with high resolution in two dimensions and lower resolution in the third dimension. The 3D distribution of attenuation that is projected into one image in conventional mammography can be separated into many layers (typically 30-80 1-mm-thick layers, depending on breast thickness), increasing the conspicuity of features that are often obscured by overlapping structure in a single-projection view. Schemes that record breast images at nonuniform angular increments, nonuniform image exposure, and nonuniform detector resolution are investigated in order to reduce the total x-ray exposure necessary to obtain diagnostically useful 3D reconstructions, and to improve the quality of the reconstructed images for a given exposure. The total patient radiation dose can be comparable to that used for a standard two-view mammogram. The method is illustrated with images from mastectomy specimens, a phantom, and human volunteers. The results show how image quality is affected by various data-collection protocols.

Absorptiometry, Photon↗

PubMed2005

Effects of aspirin and low-dose heparin in head and neck reconstruction using microvascular free flaps.

OBJECTIVE: The success of microvascular free-tissue transfer to the head and neck has been greatly increased secondary to increased experience, yet postoperative anticoagulation continues to be routinely used to prevent pedicle thrombosis. However, there is currently no consensus as to what the ideal regimen, if any, is recommended for postoperative anticoagulation. This study reviews the outcome and incidence of perioperative complications in patients undergoing free flaps for head and neck reconstruction, using a simple postoperative anticoagulation regimen of aspirin and subcutaneous heparin (SQH). DESIGN: Retrospective chart review. METHODS: With institutional review board approval, the charts of 261 patients undergoing free flap reconstruction from January 2000 to January 2004 were retrospectively reviewed. Patients who received a standard postoperative anticoagulation regimen of SQH (5000 U SC bid) and aspirin (325 mg PO qd) were included in the study (216 patients). Charts were reviewed for postoperative complications, specifically for free flap failure, vascular compromise (arterial insufficiency/venous congestion), and hematoma. RESULTS: There were six flap failures (2.8%), resulting in an overall free flap survival rate of 97.2%. There were six patients with venous congestion of the flap that required neck exploration (2.8%), and 12 patients with postoperative hematoma (5.6%), requiring surgical intervention. CONCLUSION: The free flap survival rate in patients undergoing head and neck reconstruction using this simple anticoagulation regimen of aspirin and SQH appears to be equivalent to the free flap survival rate in patients using other anticoagulation agents. In addition, aspirin and SQH do not increase the incidence of postoperative hematoma when compared with the other anticoagulation agents. Therefore, aspirin and SQH appear to be reliable postoperative anticoagulation agents for patients undergoing head and neck reconstruction using free flaps.

Adolescent↗

PubMed2006

[Comparison of 3D reconstructed images between the standard-dose and the low-dose chest CT].

OBJECTIVE: To evaluate the difference of the 3D image quality between the low-dose and the standard-dose chest CT. METHODS: Eleven patients were randomly scanned with the standard-dose CT and 9 with the low-dose CT. Quality of the images from both groups was evaluated by different postprocessing techniques. RESULTS: The effective tube current, total tube current, and CT dose index volume were (114.55 +/- 26.20) mAs, (1578.27 +/- 353.09) mAs, and (7.76 +/- 1.77) mGy, respectively, in the standard-dose scanning group, and were 20 mAs, (566.11 +/- 46.23) mAs, and (1.46 +/- 0.07) mGy, respectively, in the low-dose scanning group. All these indicators had significant differences between these two groups (P < 0.001). The image noises were (17.67 +/- 3.24) HU in standard-dose group and (31.61 +/- 9.42) HU in low-dose group (P < 0.001). As shown by different postprocessing techniques, the median score of the standard-dose group and the low-dose group were 4.52 and 4.78, respectively, which was not significantly different (P = 0.92). CONCLUSION: The low-dose CT scanned with 20 mAs effective tube current can remarkably reduce the radiation dose, and provide satisfactory postprocessing images for diagnosis.

Adult↗

PubMedDate not supplied

Breast cancer in limited-resource countries: treatment and allocation of resources.

Treating breast cancer under the constraints of significantly limited health care resources poses unique challenges that are not well addressed by existing guidelines. We present evidence-based guidelines for systematically prioritizing cancer therapies across the entire spectrum of resource levels. After consideration of factors affecting the value of a given breast cancer therapy (contribution to overall survival, disease-free survival, quality of life, and cost), we assigned each therapy to one of four incremental levels--basic, limited, enhanced, or maximal--that together map out a sequential and flexible approach for planning, establishing, and expanding breast cancer treatment services. For stage I disease, basic-level therapies are modified radical mastectomy and endocrine therapy with ovarian ablation or tamoxifen; therapies added at the limited level are breast-conserving therapy, radiation therapy, and standard-efficacy chemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil [CMF], or doxorubicin and cyclophosphamide [AC], epirubicin and cyclophosphamide [EC], or 5-fluorouracil, doxorubicin, and cyclophosphamide [FAC]); at the enhanced level, taxane chemotherapy and endocrine therapy with aromatase inhibitors or luteinizing hormone-releasing hormone (LH-RH) agonists; and at the maximal level, reconstructive surgery, dose-dense chemotherapy, and growth factors. For stage II disease, the therapy allocation is the same, with the exception that standard-efficacy chemotherapy is a basic-level therapy. For locally advanced breast cancer, basic-level therapies are modified radical mastectomy, neoadjuvant chemotherapy (CMF, AC, or FAC), and endocrine therapy with ovarian ablation or tamoxifen; the therapy added at the limited level is postmastectomy radiation therapy; at the enhanced level, breast-conserving therapy, breast-conserving whole-breast radiation therapy, taxane chemotherapy, and endocrine therapy with aromatase inhibitors or LH-RH agonists; and at the maximal level, reconstructive surgery and dose-dense chemotherapy and growth factors. For metastatic or recurrent disease, basic-level therapies are total mastectomy for ipsilateral in-breast recurrence, endocrine therapy with ovarian ablation or tamoxifen, and analgesics; therapies added at the limited level are radiation therapy and CMF or anthracycline chemotherapy; at the enhanced level, chemotherapy with taxanes, capecitabine, or trastuzumab, endocrine therapy with aromatase inhibitors, and bisphosphonates; and at the maximal level, chemotherapy with vinorelbine, gemcitabine, or carboplatin, growth factors, and endocrine therapy with fulvestrant. Compared with the treatment of early breast cancer, the treatment of advanced breast cancer is more resource intensive and generally has poorer outcomes, highlighting the potential benefit of earlier detection and diagnosis, both in terms of conserving scarce resources and in terms of reducing morbidity and mortality. Use of the scheme outlined here should help ministers of health, policymakers, administrators, and institutions in limited-resource settings plan, establish, and gradually expand breast cancer treatment services for their populations.

Aromatase Inhibitors↗

PubMed1991

Three-dimensional display in planning radiation therapy: a clinical perspective. Photon Treatment Planning Collaborative Working Group.

We describe the experience with 3-D display capabilities of four institutions engaged in a comparative three-dimensional treatment planning study. A high degree of interactivity was found to be desirable, which puts great demands on the hardware. Displays which were found particularly helpful included: display of multiple 2-D sections (transverse, sagittal, coronal and/or oblique) of one or more imaging studies; superimposition of outlines of structures of interest; superimposition of dose distributions displayed as isodose lines or as a color-wash overlay; beam's eye view displays of: structures displayed as contour-stacks or as shaded surfaces, dose distributions on the surface of structures, interactively viewed isodose surface displays, and digitally reconstructed radiographs. Dose-volume histograms provided valuable summarizations of dose data.

Humans↗

PubMed1993

Renal tolerance to nonhomogenous irradiation: comparison of observed effects to predictions of normal tissue complication probability from different biophysical models.

PURPOSE: A patient series was analyzed retrospectively as an example of whole organ kidney irradiation with an inhomogenous dose distribution to test the validity of biophysical models predicting normal tissue tolerance to radiotherapy. METHODS AND MATERIAL: From 1969 to 1984, 142 patients with seminoma were irradiated to the paraaortic region using predominantly rotational techniques which led to variable but partly substantial exposure of the kidneys. Median follow up was 8.2 (2.1-21) years and actuarial 10-year survival (Kaplan-Meier estimate) 82.8%. For all patients 3-dimensional dose distributions were reconstructed and normal tissue complication probabilities for the kidneys were generated from the individual dose volume histograms. To this respect different published biophysical algorithms had been introduced in a 3-dimensional-treatment planning system. RESULTS: In seven patients clinical manifest renal impairment was observed (interval 10-84 months). An excellent agreement between predicted and observed effects was seen for two volume-oriented models, whereas complications were overestimated by an algorithm based on critical element assumptions. CONCLUSIONS: Should these observations be confirmed and extended to different types of organs corresponding algorithms could easily be integrated into 3-dimensional-treatment planning programs and be used for comparing and judging different plans on a more biologically oriented basis.

Adult↗

PubMed2006

[Diagnosis of intraocular foreign bodies in multidetector-CT: influence of acquisition parameters on radiation dose and detectability].

PURPOSE: Determination of the influence of acquisition and reconstruction parameters on radiation dose and detectability of intraocular foreign bodies using multidetector CT (MDCT). MATERIALS AND METHODS: Porcine eyes with intraocular foreign bodies of a 0.3-mm quartz fiber and a 0.1-mm steel wire as well as 0.5 ml of blood in the vitreous were investigated using MDCT. The tube current was 500, 250, 100, and 50 mAs; the collimation was 16 x 0.75 mm and 16 x 1.5 mm; and the pitch was 0.5 and 0.75. Image reconstruction was performed using a soft tissue (H30), a bone algorithm (H60 s), and thin (0.7 and 2 mm, respectively) and thick (2 and 4 mm, respectively) reconstruction increments. The resulting data sets were then used to determine the signal difference to noise ratio (SDNR) between the foreign body and adjacent vitreous. RESULTS: Changes in tube current resulted in a proportional change in the radiation dose but only in the SDNR within a range of 1:2. Reducing the collimation from 1.5 mm to 0.75 mm resulted in a doubling of the SDNR at an approximately identical radiation dose. The series with a lower pitch at the same dose per volume showed a slightly higher SDNR. Reconstruction using a bone algorithm and thin increments resulted in an increase in the mean SDNR by a factor of 1.8 to 2.3. CONCLUSION: When diagnosing small intraocular foreign bodies using MDCT, the following parameters can yield an adequate SDNR while minimizing radiation exposure: tube current 50 mAs, pitch 0.5, collimation 16 x 0.75, bone algorithm, and reconstruction increment 0.7 mm.

Animals↗

PubMed1988

Effects of radiotherapy on mandibular reconstruction plates.

The radiation dose in the vicinity of metal mandibular implants was measured using lithium fluoride (TLD-100) thermoluminescent dosimeters. Dosimeters were positioned in contact with Vitallium and stainless steel (AO) reconstruction plates. Simple transmission was measured with a solid state detector removed from the implant at a depth of 2.5 cm in a polystyrene phantom. The measurements were made for a 6 mV photon beam from a linear accelerator. At points in front of, but in contact with the metal implants, the dose was greater by 23 percent for Vitallium and 17 percent for stainless steel than that with no implant. At contact behind the implant, the dose was reduced considerably: 14 percent for Vitallium and 13 percent for stainless steel. At remote points behind the implant, the dose was reduced due to attenuation.

Bone Plates↗

PubMed1988

A small, multi-element fingertip dosimeter for beta radiation.

Many occupations involve potential exposures, directly or indirectly, to sources of beta radiation. The region of highest exposure, in many cases, will be the extremities and in particular the fingertips of people handling beta sources. Because current extremity dosimeters can significantly underestimate beta doses to the fingertips, an improved fingertip beta dosimeter was developed. The dosimeter employs a multi-element, multi-filter concept by stacking four or five thin (0.13 mm) LiF-Teflon TLDs to form the beta detector element. The entire dosimeter is approximately 1 mm thick, flexible and rugged enough for field use without interference of the user's manual dexterity. The fingertip dosimeter provides data for determining the beta energy of each exposure. The beta energy can be used to determine the TLD correction factor for converting the TLD output to beta dose. The data can be used to reconstruct the beta depth dose curve and the depth dose curve can be used to calculate the beta dose in tissue at 7 mg cm-2, for legal reporting purposes, or at any other desired depth within the range of the beta radiation. Relationships between the effective mass absorption coefficient and beta energy and between the beta correction factor and beta energy were determined for use in this study. Beta sources were fabricated for these studies, and an extrapolation chamber was used to determine reference beta doses. Tests of the fingertip dosimeter were performed by exposing it to single beta sources and to multiple beta sources. The dosimeter should be useful for monitoring exposures to beta energies ranging from 0.29-2.5 MeV.

Beta Particles↗

PubMed2003

In vivo diode dosimetry for routine quality assurance in IMRT.

Due to the complexity of IMRT dosimetry, dose delivery evaluation is generally done using a treatment plan in which the optimized fluence distribution has been transferred to a test phantom for accessibility and simplicity of measurement. The actual patient doses may be reconstructed in vivo through the use of electronic portal imaging devices or films, but the assessment of absolute dose from these measurements is time-consuming and complicated. In our clinic we have instituted the use of routine diode dosimetry for IMRT patients following the same procedure used for standard radiation therapy patients in which each new treatment field is checked at the start of treatment. For standard cases the dose at dmax is calculated as part of the monitor unit calculation. For the IMRT cases, the dose contribution to the dmax depth for each field is taken from the treatment plan. We found that about 90% of the diode measurements agreed to within +/- 10% of the planned doses (45/51 fields) and 63% (32/51 fields) achieved +/- 5% agreement. By using this direct in vivo method to verify the clinical doses delivered, we have been able to make a uniform startup procedure for all patients while simplifying our IMRT QA process.

Humans↗

PubMed1992

[Characteristics and results of the determination of the doses of internal irradiation of the thyroid gland in the population of contaminated districts of the Byelorussian Republic].

The authors provide the results of studying the reconstruction of individual doses of thyroid radiation among the community living in polluted areas of the Byelorussian Republic according to radiation monitoring data and with regard to the nature of radioactive pollution of the land. Every individual result of estimating the degree of thyroid radiation was characterized by 3 magnitudes: the lower and upper limit of possible values and by the intermediate (basic) value. The authors hold that studies of the correlations between the values of individual doses of thyroid radiation and different parameters of the radiation situation in every region will promote further specification of individual doses of thyroid radiation.

Accidents↗

PubMed2003

[Clinical study of single-dose G-CSF in mobilization and reconstruction of allogeneic peripheral blood stem cell transplantation].

BACKGROUND & OBJECTIVE: Mobilization of hematopoietic stem cells from healthy donors by stimulators such as granulocyte colony stimulating factor (G-CSF) in allogeneic peripheral blood stem cell transplantation (allo- PBSCT) is increasingly used clinically; however, the mechanism, the dose, and the schedule are not fully understood. This study was designed to evaluate the effectiveness and safety of single daily dose of 250 microg G-CSF (Lenograstim) for stem cell mobilization and hematopoietic reconstitution after allo-PBSCT. METHODS: The study included a group of 38 consecutive patients with hematological malignancies (acute leukemia:21 cases; chronic myelogenous leukemia:14 cases; myelodysplastic syndrome:3 cases) from January 2000 to June 2002. For the 38 sibling or matched unrelated donors G-CSF was administered at single daily dose of 250 microg despite of their body weight. Leukapheresis was performed on the fifth day. The patients were conditioned with total body irradiation (TBI)+cyclophosphamide or busulfan+cyclophosphamide. G-CSF support was given from the third day after stem cell reinfusion, usually until neutrophil recovery. RESULTS: The average dosage of G-CSF administrated was 4.8 microg x (kg x d)(-1). An average of 1.7 times of apheresis were performed. The median CD34(+) cell and CD34(+)/CD38(-) cell yield were 6.09 x 10(6)/kg and 1.33 x 10(6)/kg, respectively. The CD4(+)/CD8(+) ratio of the leukapheresis products was 1.41+/-0.51,and (17.61+/-6.64)% of the leukapheresis products were CD3(-)/CD16(+)CD56(+) cells. G-CSF was used after reinfusion for the median time of 9 days. The median time for WBC >1 x 10(9)/L, ANC >0.5 x 10(9)/L,and PLT >20 x 10(9)/L were 11,11,and 12 days, respectively. One patient died of severe infection on the fifth day after transplantation, while all the other patients achieved hematopoietic reconstitution satisfyingly. CONCLUSION: The administration of G-CSF in the single dose fashion in allo-PBSCT has a good effect in the mobilization of PBSC with minor side effects, and it can markedly promote hematopoietic reconstitution after transplantation.

Adjuvants, Immunologic↗

PubMed2005

Improvement of image quality in chest MDCT using nonlinear wavelet shrinkage with trimmed-thresholding.

Multidetector-row computed tomography (MDCT) has dramatically increased the speed of scanning, and allows high-resolution imaging compared with conventional single detector-row CT (SDCT). However, the use MDCT makes use of an increase in volume scanning, and causes a simultaneous increase in radiation dose to the patient. Thus, the radiation dose from the X-ray CT has become a problem in recent years. In this study, nonlinear wavelet-based edge preservation de-noising using trimmed-thresholding was applied to reconstructed low-dose chest MDCT images, and optimal wavelet processing including wavelet functions and thresholding methods was examined. Moreover, the usefulness of the de-noising for reducing radiation dose was examined. As a result of optimized edge preservation de-noising, noise reduction was achieved with little deterioration in image quality, and the wavelet function used at that time was Coiflet's with shorter support. As a result, almost the same quality of reconstructed image of the chest phantom was obtained for conventional scanning and low-dose scanning with the wavelet de-noising method using trimmed- thresholding. That is, the radiation dose from MDCT could be reduced using this wavelet-based de-noising method.

Humans↗