Immunosuppression in liver transplantation: monitoring, dose adjustment, reduction, and withdrawal.
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Dose-Response Relationship, Drug↗
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Reirradiation alternating with docetaxel and cisplatin in inoperable recurrence of head-and-neck cancer: a prospective phase I/II trial.
PURPOSE: Inoperable locoregional recurrences of head-and-neck cancer in a previously irradiated volume represent a therapeutic dilemma. Chemotherapy alone has no curative potential, whereas reirradiation and concurrent chemoradiation can salvage a small fraction of patients. Mucosal toxicity of concurrent chemoradiation requires substantial dose reduction of chemotherapy. Alternating chemoradiation offers the chance to give both full-dose chemotherapy and radiotherapy. The latter may provide a particular advantage for recurrent, potentially radiation resistant tumors. The feasibility and efficacy of a full-dose docetaxel containing alternating chemoradiation schedule was tested. PATIENTS AND METHODS: Twenty-seven patients (Karnofsky performance status score >/=70%) with histologically proven recurrent squamous cell cancer that occurred >/= 6 months in a previously irradiated area (>/= 60 Gy) were considered unresectable and unsuitable for brachytherapy. Alternating chemoradiation consisted of 3 cycles of docetaxel 60 mg/m(2) d1 and cisplatin 15 mg/m(2) d2-5, q d22, and involved field radiotherapy 2.0 Gy every day d8-12, d15-19, d29-33, and d36-40 (40.0 Gy total dose). Dose reduction of docetaxel to 50 mg/m(2) was necessary, because of hematologic toxicity in the first 12 patients. RESULTS: Alternating chemoreirradiation was applied as planned in 12 of 27 patients, with reirradiation completed per protocol in 81%. Overall, patients received 83% of the intended dose of docetaxel and 73% of cisplatin. Third-degree common toxicity criteria mucositis occurred in 15%, leukopenia of >/= third degree by common toxicity criteria in 37%, and 3 early deaths were observed. Median time to follow-up, time to local progression, median survival, and 3-year survival rates were 42 months, 10 months, 10 months, and 18%, respectively. CONCLUSIONS: Alternating chemoreirradiation in recurrences of head-and-neck cancer resulted in 80% overall response with acceptable toxicity. A significant minority of patients had durable tumor control with a chance of long-term survival.
Adult↗
Pharmacotherapy of impaired affect in recovering schizophrenic patients.
BACKGROUND: Prominent and persistent anxiety, depression, and/or negative features characterize a substantial minority of recovered or residually psychotic schizophrenic outpatients and contribute to poor outcome. Because extrapyramidal side effects of typical neuroleptic medications often resemble such features, we first systematically studied the contribution of extrapyramidal side effects to these problems and their treatment. For patients who remained distressed, controlled trials of supplemental thymoleptics were undertaken. METHODS: In trial 1, 92 distressed (depressed and/or anxious) patients and 36 patients in a defect state (patients with negative symptoms) participated in a double-blind, intramuscular challenge that compared centrally acting benztropine mesylate with peripherally acting glycopyrrolate. In trial 2, 57 distressed patients and 22 patients in a defect state were randomly assigned to a double-blind, neuroleptic medication dose-reduction group. In trial 3, 57 chronically distressed patients who were maintained on a low dose of fluphenazine decanoate were randomly assigned to a supplemental desipramine hydrochloride, lithium carbonate, or placebo group under double-blind conditions for 12 weeks. RESULTS: For patients who were already maintained on antiparkinsonian medication, impaired affect was not resolved by additional benztropine. Only distressed patients with a family history of severe mental disorder (often affective) showed improvement with neuroleptic medication dose reduction. Patients in the defect-state group reported less dysphoria on a reduced neuroleptic medication dose, but negative symptoms persisted. Desipramine improved diverse aspects of mood and residual psychoticism, possibly as a prophylaxis against minor affective exacerbations. Depression improved in women only. Lithium positively affected multiple indexes of anxiety and anxious depression. CONCLUSION: Most often, persistent affective impairments are neither resistant extrapyramidal side effects nor characterological traits. Thymoleptics improve the nonphasic, chronic types of anxiety and depression in contrast to the acute, episodic forms, for which little support can be found in the literature.
Adolescent↗
Clinical efficacy of budesonide Turbuhaler compared with that of beclomethasone dipropionate pMDI with volumatic spacer. A 2-year randomized study in 102 asthma patients.
A total of 102 patients had their asthma treatment with beclomethasone dipropionate (BDP) optimized in order to achieve the best possible control of symptoms. Thereafter, the BDP doses were gradually reduced over a 2-year period (1988-90) to the lowest possible without deterioration of their asthmatic condition. In the beginning of 1990, treatment was changed in 76 patients (group A) to the nearest possible dose of budesonide delivered via Turbuhaler. Twenty-six randomly selected patients (25% of the study population; group B) continued treatment with BDP. In both groups, dose reductions were tried during 1990-2 every third month as long as the patients remained symptom-free and without significant decreases in FEV1 or PEF. In group A, the maintenance dose could be reduced from 1003.9 +/- 325.4 micrograms BDP (mean +/- SD) to 602.9 +/- 454.4 micrograms budesonide Turbuhaler (P < 0.001). In group B, no significant dose reduction was possible; the mean dose was +/- SD 1067.3 +/- 36.6 micrograms in 1990, and 1019.2 +/- 324.7 micrograms in 1992. The results indicate that, in efficacy, 0.6 mg budesonide Turbuhaler corresponds to approximately 1.0 mg BDP with volumatic spacer. This difference is probably due to an improved pulmonary delivery of budesonide with Turbuhaler.
Adrenergic beta-Agonists↗
Precision in quantitative CT: impact of x-ray dose and matrix size.
A study was performed to determine whether recommended technique factors for postprocessing dual-energy (DE) quantitative computed tomography are optimum in terms of precision and x-ray dose. In particular, possible dose reduction as a result of an upgrade of the CT scanner to more efficient detectors was explored. Series of images of an anthropomorphic phantom containing a human vertebra, a tissue-simulating lumbar simulator with various marrow inserts, and a polyethylene cylinder were generated. Recommended DE x-ray technique factors as well as factors resulting in about two times, one-half, and one-fourth the x-ray dose were employed. The effects of reconstruction with different matrix sizes was studied. Standard deviations of the CT numbers within regions of interest in individual images (noise) and standard deviations of mean CT numbers, single-energy (SE), and DE measurements for series of images (reproducibilities) were computed. It was found that the low-energy component of the DE technique was optimum, but the high-energy component could be reduced by a factor of 2 with negligible loss in precision. This translates into a dose reduction of 36% relative to the recommended DE technique. Vertebral inhomogeneities were responsible for more than 65% of the standard deviations in individual images of the vertebra even at the lowest doses. For all of the techniques, the noise in images of all objects decreased as the x-ray dose increased and as the matrix size decreased. Reproducibility of mean values, however, did not necessarily improve, and aberrant results such as improvement in reproducibility with a reduction in dose were sometimes observed. It is hypothesized that this may be due to variations in the actual kVp for each image in a series.
Absorptiometry, Photon↗
Anemia in the treatment of hepatitis C virus infection.
Hepatitis C virus (HCV) infection is a significant worldwide health care problem. Nearly one-third of all patients infected with human immunodeficiency virus (HIV) are coinfected with HCV. Compared with HIV-monoinfected persons, coinfected individuals experience more rapid progression of fibrosis and higher incidence of cirrhosis and death as a result of liver disease. Treatment for HCV infection includes ribavirin (RBV) plus interferon alfa (IFN-alpha) or pegylated IFN, a combination treatment associated with anemia that may require RBV dose reduction or discontinuation. IFN-RBV-associated anemia is more profound among coinfected patients, who have a high prevalence of pretreatment anemia and may also be taking other medications causing anemia. Epoetin alfa administration to HCV-infected patients with IFN-RBV-related anemia can significantly increase hemoglobin levels and maintain significantly higher RBV doses compared with patients treated with RBV dose reduction alone. Higher RBV doses and adherence to HCV therapy have been associated with higher sustained virologic response (SVR) rates. Maintenance of RBV dose with epoetin alfa may improve adherence, thereby affecting SVR.
Anemia↗
Effective techniques for reduction of radiation dosage to patients undergoing invasive cardiac procedures.
The goal of this study was to improve radiation dose reduction techniques in invasive cardiology and after patients' radiation data had approached minimal levels, to evaluate predictors of their radiation exposure resulting from invasive cardiac procedures. Over the course of 1 year (and 1996 procedures) we minimized cinegraphic frames and runs, as well as fluoroscopy time, and trained ourselves to achieve effective fluoroscopy-saving positioning of blinds and filters toward the regions of interest. We were consequently able to reduce the mean dose-area products (DAP) for coronary angiography and angioplasty, combined interventions, high-frequency rotational atherectomy, and excimer laser angioplasty: from levels of 53.9 Gy cm(2), 79.6 Gy cm(2), 112.3 Gy cm(2), 119.4 Gy cm(2), and 168.0 Gy cm(2) as currently reported in the literature, to 12.9 Gy cm(2), 13.3 Gy cm(2), 25.9 Gy cm(2), 33.0 Gy cm(2), and 27.1 Gy cm(2), respectively. The mean DAP due to interventions in acute myocardial infarction was 38.3 Gy cm(2). DAP was influenced by body mass index, complexity of coronary artery disease, tube angulation, documented structure, coronary recanalization, emergency circumstances, and the percutaneous transluminal coronary angioplasty (PTCA) target vessel involved, but not by stent implantation. By favouring radiation-reducing cranial posteroanterior views over standard left anterior oblique views for visualization of the left anterior descending and the diagonal artery, we consequently achieved mean PTCA-DAPs of 10.4 Gy cm(2) and 8.6 Gy cm(2), respectively: levels significantly lower than those for PTCA of the right coronary artery (13.3 Gy cm(2)), left circumflex artery (13.7 Gy cm(2)), and obtuse marginal branch (16.9 Gy cm(2)). In conclusion, enhanced knowledge of radiation dose-reduction techniques significantly reduces patient radiation hazards in invasive cardiology.
Angioplasty, Balloon, Coronary↗
Design and dosimetric considerations of a modified COMS plaque: the reusable "seed-guide" insert.
The Collaborative Ocular Melanoma Study (COMS) developed a standardized set of eye plaques that consist of a 0.5 mm thick bowl-like gold alloy backing with a cylindrical collimating lip. A Silastic seed carrier into which 125I seeds are loaded was designed to fit within the backing. The carrier provides a standardized seed pattern and functions to offset the seeds by 1.0 mm from the concave (front) surface of the carrier. These Silastic carriers have been found to be difficult to load, preclude flash sterilization, and are a source of dosimetric uncertainty because the effective atomic number of Silastic is significantly higher than that of water. The main dosimetric effect of the Silastic carrier is a dose-reduction (compared to homogeneous water) of approximately 10%-15% for 125I radiation. The dose reduction is expected to be even greater for 103Pd radiation. In an attempt to improve upon, yet retain as much of the familiar COMS design as possible, we have developed a thin "seed-guide" insert made of gold alloy. This new insert has cutouts which match the seed pattern of the Silastic carrier, but allows the seeds to be glued directly to the inner surface of the gold backing using either dental acrylic or a cyanoacrylate adhesive. When glued directly to the gold backing the seeds are offset a few tenths of a millimeter further away from the scleral surface compared to using the Silastic carrier. From a dosimetric perspective, the space formerly occupied by the Silastic carrier is now assumed to be water equivalent. Water equivalency is a desirable attribute for this space because it eliminates the dosimetric uncertainties related to the atomic composition of Silastic and thereby facilitates the use of either 125I and/or 103Pd seeds. The caveat is that a new source of dosimetric uncertainty would be introduced were an air bubble to become trapped in this space during or after the surgical insertion. The presence of air in this space is modeled and the dosimetric impact discussed. Another unintended consequence of water equivalency is that some fluorescent x rays emitted from the gold backing can now reach the eye. These very low energy x rays were virtually eliminated by absorption in Silastic. When loaded with 125I seeds the modified plaque appears to produce dose distributions that are almost the same as those of the original COMS plaque and the maximum dosimetric uncertainty introduced by an air bubble is about 2%. Dose distributions calculated for a modified plaque loaded with 103Pd seeds show that dose to healthy ocular structures distal to the tumor apex can be reduced compared to 125I. Clearly, it is faster and easier to glue seeds into the reusable gold seed-guide insert than it is to load the COMS-Silastic carrier.
Brachytherapy↗
Double-blind comparison of half-dose and standard-dose flupenthixol decanoate in the maintenance treatment of stabilised out-patients with schizophrenia.
A double-blind controlled trial of 50% dose reduction in maintenance treatment in stable out-patients with low BPRS scores and good social function shows a significantly higher relapse rate in the low-dose group at 12 months (P less than 0.05). After an interval of 24-36 months from dose reduction, 56-76% had experienced a relapse and 76-79% had resumed their former dosage. No clear advantage was shown for the lower dose in either a reduction of side-effects or improved social function, but a reduced prevalence or lower rate of symptom emergence for tardive dyskinesia was suggested.
Adult↗
Neoadjuvant chemotherapy for advanced ovarian cancer.
The purpose of this study was to compare the survival of women with clinical, radiologic, and histologic findings compatible with advanced ovarian cancer who were treated with neoadjuvant chemotherapy to that of a group of women with FIGO stage IIIC (suboptimal debulking) and stage IV epithelial ovarian cancers treated with the same chemotherapy. Eleven women with physical, radiologic, and histologic findings compatible with advanced ovarian cancer (median age, 73 years) treated with neoadjuvant carboplatin and cyclophosphamide chemotherapy were compared to 18 women (median age, 60 years) who had stage III and suboptimal surgical cytoreduction (> 2 cm residual tumor, 13 patients) or stage IV (5 patients) ovarian cancer followed by the same chemotherapy. The progression-free survival for the 11 women receiving neoadjuvant chemotherapy was 9.1 months which was not statistically different from the 8.5 months progression-free survival for the 18 women with suboptimally debulked stage IIIC or stage IV disease (P = 0.98). The overall survival was not significantly different (P = 0.26). Neoadjuvant-treated patients tended to tolerate chemotherapy better as none required dose reduction for bone marrow suppression, while 6 of 18 conventionally treated patient required dose reductions. In conclusion, neoadjuvant chemotherapy appears to be an effective means of palliating women with clinical, radiological, and histologic findings compatible with advanced ovarian cancer. A prospective study is necessary in which women with findings compatible with advanced ovarian cancer that is not likely to be effectively cytoreduced surgically are randomized to either undergo cytoreductive surgery followed by chemotherapy or receive neoadjuvant chemotherapy.
Adult↗
Retention in ambulatory detoxification.
The background characteristics and mean levels of neuroticism were compared for three groups of 20 male addicts, each, who (1) completed 21 d of ambulatory detoxification, (2) transferred to methadone maintenance before completing detoxification, and (3) dropped out of detoxification. The patients who completed treatment or dropped out were more likely to be Black and less neurotic than those who transferred to methadone maintenance. In addition, it was found that patients dropped out near the time of the first methadone dose reduction, whereas those who transferred to methadone maintenance did so near the final dose reduction in the 21-d detoxification schedule. The clinical implications for retaining patients until completion of ambulatory detoxification treatment are discussed.
Black or African American↗
[Internistic therapy possibilities in therapy-resistant Crohn disease].
About 20% of patients with active Crohn's disease do not respond to acute-phase-therapy with glucocorticoids at an initial dose of 60 mg prednisolone-equivalent and stepwise dose reduction every week. In case of primary failure of this therapeutic scheme the dose of glucocorticoids has to be enhanced. If necessary a combination with total parenteral nutrition or tube feeding should be used. In case of early recurrence of inflammation during dose reduction or chronic steroid-dependent disease activity a combination of glucocorticoids with Azathioprine will be successful in about 75% of patients. In addition a combination of glucocorticoids with tube feeding (elemental or polymeric diet) will lead to remission of inflammatory activity in about 60 to 70% of these patients. In patients, who are still refractory to these therapeutic procedures, operation should be discussed.
Anti-Bacterial Agents↗
Planning of radiotherapy for patients with hip prosthesis.
The effects of a hip prosthesis on the dose distribution when treating pelvic cancer have been evaluated. A prosthesis of titanium alloy in a water phantom was used as a model. Photon radiation beams with energies of 6, 20, and 50 MV and with a focus phantom distance of 100 cm were directed against the prosthesis. The dose profiles at different depths were measured with the RFA-7 system. The sphere of the prosthesis was inhomogeneous. The dose in a beam behind the prosthesis was reduced with the order of 10-40% and the largest distortion was behind the shaft. Using an opposed four-field technique with the same weight on all the fields, the dose reduction was as large as 7-12% in a string across the target behind the end of the shaft. With 50% weight on the lateral fields, the dose reduction was 4-8% of the average dose. Such an uneven dose distribution may decrease the curability, and a treatment technique not including the prosthesis should be preferred. Finally, a local increase of the dose close to the prosthesis seems to be of limited practical concern even at the highest energies.
Hip Prosthesis↗
Evaluation of interferon treatment in cirrhotic patients with hepatitis C.
The aim of this study was to examine the effects of interferon on cirrhotic patients with hepatitis C and the incidence of adverse reactions. The subjects were 35 cirrhotic patients, and 29 chronic active hepatitis patients without cirrhosis (CAH) served as controls. The cirrhotic patients received 3 or 6 million units of human lymphoblastoid interferon daily for one or two weeks and then three times a week for 22 or 23 weeks, while the CAH patients received 6 million units daily for 2 weeks and then three times a week for 14 or 16 weeks. Discontinuation of interferon treatment or dose reduction was required in the 7 cirrhotic patients. The most frequent reason was thrombocytopenia. Dose reduction alone was necessary in two CAH patients. Five cirrhotic patients (14.3%) and nine CAH patients (31.0%) were classified as complete responders to interferon treatment. In all five complete responders with cirrhosis, the hepatitis C virus RNA level before treatment was less than 5 log copies/50 microliters. The results of this study confirm the beneficial effect of interferon in selected patients with cirrhosis on basis of pre-treatment virus levels and platelet count.
Base Sequence↗
Scattering effects on the dosimetry of iridium-192.
Dosimetry calculations for iridium-192 sources generally assume that a sufficient medium surrounds both the iridium source(s) and the point of calculation so that full scattering conditions exist. In several clinical applications the iridium sources may be anatomically located so that the full scattering requirement is not satisfied. To assess the magnitude of this problem, relative measurements were made with a small ionization chamber in phantoms near air and lung-equivalent interfaces. Dose reduction caused by decreasing the volume of scattering material near these interfaces was then evaluated for a few clinical applications. The results show that reductions on the order of 8% may be expected at the interface with minimal dose reduction within the volume of the implant itself. In addition, the results indicate the verification of source strength of iridium sources in phantom require phantom dimensions determined by the source-chamber separation distance.
Brachytherapy↗
Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less.
BACKGROUND AND PURPOSE: Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods. PATIENTS AND METHODS: Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated. Dose volume histograms could then be constructed of planning target volumes for phases 1 and 2 (PTV 1 and 2, respectively), lung and spinal cord for the 2D plans and compared with the 3D plans. RESULTS: There was a significantly lower absolute dose to the isocentre with 2D compared to 3D planning with dose reductions of 3.9% for phase 1, 4.4% for phase 2 and 4.7% for those treated with a single phase. Maximum dose to spinal cord was greater in 17 of the 24 2D plans with a median dose reduction of 0.82 Gy for 3D (P=0.04). The percentage volume of whole lung receiving > or =20 Gy (V20) was greater in 16 of the 24 2D plans with a median reduction in V20 of 2.4% for 3D (P=0.03). CONCLUSIONS: A lower dose to tumour was obtained using 2D planning due to the method of dose calculation and spinal cord and lung doses were significantly higher.
Aged↗
Use of famotidine in adult patients with end-stage renal disease: assessment of dosing and mental status changes.
BACKGROUND: Famotidine dosage adjustment is required in patients with chronic kidney disease. Since recommendations on the degree of famotidine dose reduction vary between references, a chart review was conducted to evaluate the tolerability of varying famotidine doses in adults with end-stage renal disease (ESRD). METHODS: An assessment was made of famotidine doses prescribed to patients with ESRD over a 7-year period in a university hospital. Patient medical records were reviewed for evidence of mental status changes associated with famotidine. RESULTS: In 38 patients who met study criteria, 35 had no evidence of mental status change while receiving famotidine therapy. Among these 35 patients, the mean dose of famotidine was 24 mg/daily for 5.5 days. Three patients had mental status changes possibly associated with famotidine therapy. CONCLUSIONS: In this study, most ESRD patients seemed to tolerate famotidine 20 mg daily well, but larger prospective studies need to be done before final recommendations can be made. A small percentage of patients may require further dose reduction to minimize risk of mental status change.
Adult↗
Phase I and pharmacokinetic trial of gemcitabine in patients with hepatic or renal dysfunction: Cancer and Leukemia Group B 9565.
PURPOSE: To ascertain if hepatic or renal dysfunction leads to increased toxicity at a given dose of gemcitabine and to characterize the pharmacokinetics of gemcitabine and its major metabolite in patients with such dysfunction. PATIENTS AND METHODS: Adults with tumors appropriate for gemcitabine therapy and who had abnormal liver or renal function tests were eligible. Patients were assigned to one of three treatment cohorts: I-AST level less than or equal to two times normal and bilirubin level less than 1.6 mg/dL; II-bilirubin level 1.6 to 7.0 mg/dL; and III-creatinine level 1.6 to 5.0 mg/dL with normal liver function. Doses were explored in at least three patients within each cohort. Gemcitabine and its metabolite were to be measured in the blood in all patients. RESULTS: Forty patients were assessable for toxicity. Transient transaminase elevations were observed in many patients but were not dose limiting. Patients with AST elevations tolerated gemcitabine without increased toxicity, but patients with elevated bilirubin levels had significant deterioration in liver function after gemcitabine therapy. Patients with elevated creatinine levels had significant toxicity even at reduced doses of gemcitabine, including two instances of severe skin toxicity. There were no apparent pharmacokinetic differences among the three groups or compared with historical controls. CONCLUSION: If gemcitabine is used for patients with elevations in AST level, no dose reduction is necessary. Patients with elevated bilirubin levels have an increased risk of hepatic toxicity, and a dose reduction is recommended. Patients with elevated creatinine levels seem to have increased sensitivity to gemcitabine, but the data are not adequate to support a specific dosing recommendation.
Aged↗