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PubMedDate not supplied

Quinolone disposition in the elderly. Practical implications.

The fluoroquinolones are antibiotics frequently used in infections that affect elderly individuals. The physiological aging process can profoundly affect the pharmacokinetics of drugs, necessitating adjustment of dosage regimens in the elderly. Changes in pharmacokinetics with age are mainly due to the progressive deterioration of renal function, with resultant lower clearance of drugs which are eliminated by the kidneys. Ofloxacin is almost totally renally excreted and elimination is slower in older age groups; a dose reduction is therefore recommended for this quinolone. Unexpected alterations in pharmacokinetics may occur, as exemplified by the increased bioavailability of oral ciprofloxacin in elderly subjects. This is a well-documented phenomenon of such significance that lower oral doses are advisable for the elderly. Renal clearance of ciprofloxacin decreases in old age, but because of substantial nonrenal elimination the total clearance is affected less. Studies of the pharmacokinetics of the other quinolones in old age are scarce. No data exist on the absolute oral bioavailability of norfloxacin, enoxacin and pefloxacin. Renal clearance seems to be reduced, but since no intravenous studies have been reported, the total and nonrenal clearances are unknown in the elderly. No safe conclusions can be drawn regarding the necessity of dose reductions from a pharmacokinetic point of view. However, reports of adverse reactions to quinolones in the elderly, especially concentration-dependent symptoms from the central nervous system, and the risk of interaction with other drugs, suggest the need for caution in determining dosages of all of these compounds in elderly subjects.

4-Quinolones↗
PubMedDate not supplied

Optimization of Z-axis automatic exposure control for multidetector row CT evaluation of neck and comparison with fixed tube current technique for image quality and radiation dose.

BACKGROUND AND PURPOSE: Z-axis automatic exposure control (AEC) technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare diagnostic acceptability, noise, and radiation exposure of multidetector row CT (MDCT) of neck performed with z-axis AEC and with fixed current. MATERIALS AND METHODS: Two study groups of 26 patients each underwent MDCT of neck using z-axis AEC with 8 noise index (NI), 150-440 mA, and 10 NI, 75-440 mA, respectively. A control group consisting of another 26 patients underwent MDCT of neck with fixed-current technique (300 mA). Objective noise and mean tube current-time products (mA . s) were recorded. Two radiologists evaluated images for diagnostic acceptability and subjective noise on a 5-point scale. RESULTS: All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with z-axis AEC (shoulder: NI 8, 20.6 +/- 6.2 HU; NI 10, 22.2 +/- 4.6 HU) than with fixed current (16.2 +/- 6 HU) (P = .01). There was no significant difference between AEC and fixed current in diagnostic acceptability and subjective noise (P = .22-.42). AEC resulted in significant radiation dose reduction (NI 8, 186.3 +/- 20.5 mA . s; NI 10, 158.1 +/- 21.2 mA x s), compared with fixed current (235 +/- 21.8 mA x s). CONCLUSION: Z-axis AEC resulted in similar subjective noise and diagnostic acceptability, with radiation dose reduction of 21% for NI of 8 and 33% for NI of 10, respectively, for MDCT evaluation of neck, compared with those of fixed current technique.

Adult↗
PubMed1998

Modeling the cost-effectiveness of granulocyte colony-stimulating factor use in early-stage breast cancer.

PURPOSE: To model the cost-effectiveness (CE) of granulocyte colony-stimulating factor (G-CSF) in early-stage breast cancer when its use is directed to those most in need of the medication. METHODS: A conditional CE model was developed for the use of G-CSF based on a ranking of patient need as determined by patient blood counts during the first cycle of chemotherapy. In the base case, no G-CSF was used. In the alternative case, G-CSF was used in the following manner. If the risk of a neutropenic event (as defined by a predictive model based on nadir absolute neutrophil count [ANC] and hemoglobin decrease in cycle 1) was equal to or exceeded a predetermined critical value "T," then patients would receive G-CSF in cycles 2 through 6 of chemotherapy. If the risk of an event was less than T, patients would not use G-CSF unless an event occurred, at which time G-CSF would be administered with every subsequent cycle. RESULTS: A decision rule (T) that would allow the most needy 50% of early-stage breast cancer patients to receive G-CSF after the first cycle of chemotherapy resulted in a CE ratio of $34,297 dollars per life-year saved (LYS). If only the most needy 10% of patients received G-CSF, then the associated CE ratio was $23,748/LYS; if 90% of patients could receive the medication, the CE ratio would be $76,487/LYS. These estimates were relatively insensitive to inpatient hospital cost estimates (inpatient costs for fever and neutropenia of $3,090 to $7,726 per admission produced dollar per LYS figures of $34,297 to $32,415, respectively). However, the model was sensitive to assumptions about the shape of the relationship between dose reduction and disease-free survival (DFS) at 3 years. CONCLUSION: Providing G-CSF to the neediest 50% of early-stage breast cancer patients (as defined by first-cycle blood counts) starting after the first cycle of chemotherapy is associated with a CE ratio of $34,297/LYS, which is well in the range of CE ratios for treatment of other common medical conditions. Furthermore, conditional CE studies, based on predictive models that incorporate individual patient risk, allow one to define populations for which therapy is, or is not, cost-effective. Limitations of our present understanding of the shape of the chemotherapy dose-response curve, especially at low levels of dose reductions, affect these results. Further work is required to define the shape of the dose-response curve in early-stage breast cancer.

Breast Neoplasms↗
PubMed2004

Phase II study of R115777, a farnesyl transferase inhibitor, in myelodysplastic syndrome.

PURPOSE: To perform a phase II study of the farnesyl transferase inhibitor R115777 (Zarnestra; Johnson and Johnson Pharmaceutical Research and Development, Raritan, NJ) in patients with myelodysplastic syndrome (MDS), using doses recommended in a phase I study in relapsed/refractory leukemia. PATIENTS AND METHODS: Patients with MDS were treated with R115777 at doses of 600 mg orally (PO) bid in cycles of 4 weeks of therapy followed by a 2-week rest period. Dose reduction rules for toxicity were applied. RESULTS: Twenty-seven of the 28 patients treated were assessable. Three patients responded (complete remission, n = 2; partial remission, n = 1). Responders included two patients with refractory anemia with excess blasts and one patient with refractory anemia with excess blasts in transformation. Two of the responders had a diploid karyotype and one had multiple cytogenetic abnormalities including monosomy 5 and 7. The starting dose of 600 mg PO bid resulted in side effects (myelosuppression, fatigue, neurotoxicity, rash, or leg pain) necessitating dose reduction (n = 4) or discontinuation of therapy (n = 7) in 11 (41%) of 27 patients during the induction period (12 weeks). Lower doses of 300 mg PO bid were well tolerated. All responses occurred in patients who had been reduced to this dose level during the initial two cycles. CONCLUSION: This study suggests that R115777 has modest activity in MDS patients, but that, in this patient population, 4 weeks of daily doses of 600 mg PO bid is not tolerated. Further exploration of the optimal dose/schedule and correlation with biologic end points are warranted.

Aged↗
PubMed1997

Post-transplantation diabetes is better controlled after conversion from prednisone to deflazacort: a prospective trial in renal transplants.

It is well known that long-term use of steroids plays a decisive role in the development of glucose intolerance and diabetes mellitus (DM). Deflazacort, an oxazoline derivative of prednisolone, has been introduced as a potential substitute for conventional steroids in order to ameliorate glucose intolerance. We initiated a randomized study of conversion from prednisone to deflazacort in kidney transplantation (Tx) recipients presenting with pre-Tx or post-Tx DM to ascertain whether or not the switch to deflazacort would ameliorate the diabetic state. Forty-two recipients in the conversion group were compared with 40 patients on prednisone (the control group) in a prospective manner. The dose reduction of insulin or oral blood glucose-lowering agents, the adequacy of glucose control, and the development of side effects were the criteria for evaluating outcome. In the conversion group, patients were switched to a deflazacort at a dose ratio of 6 mg deflazacort to 5 mg prednisone. During the mean follow-up period of 13.2 months, neither graft dysfunction nor acute rejection developed in the conversion group. Improvement in blood glucose control in the conversion group was noted. When the conversion group was stratified into pre- or post-Tx DM, promising effects were clearly evident in the post-Tx DM patients. More than 50% dose reduction of blood glucose-lowering agents was possible in 42.3% of post-Tx DM patients. In conclusion, it was readily possible to control blood glucose better in post-Tx DM recipients without seriously affecting the immunosuppressive activity after conversion to deflazacort.

Adult↗
PubMed2004

Multicenter phase II study of erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with recurrent or metastatic squamous cell cancer of the head and neck.

PURPOSE: To determine the efficacy and safety profiles of erlotinib in patients with advanced recurrent and/or metastatic squamous cell cancer of the head and neck (HNSCC). PATIENTS AND METHODS: Patients with locally recurrent and/or metastatic HNSCC, regardless of their HER1/EGFR status, were treated with erlotinib at an initial dose of 150 mg daily. Dose reductions or escalations were allowed based on tolerability of erlotinib. RESULTS: One-hundred fifteen patients were enrolled onto this study. Forty-seven percent of patients received erlotinib at 150 mg daily throughout the entire study, 6% had dose escalations, and 46% required dose reductions and/or interruptions. Five patients achieved partial responses on study, for an overall objective response rate of 4.3% (95% CI, 1.4% to 9.9%). Disease stabilization was maintained in 44 patients (38.3%) for a median duration of 16.1 weeks. The median progression-free survival was 9.6 weeks (95% CI, 8.1 to 12.1 weeks), and the median overall survival was 6.0 months (95% CI, 4.8 to 7.0 months). Subgroup analyses revealed a significant difference in overall survival favoring patients who developed at least grade 2 skin rashes versus those who did not (P =.045), whereas no difference was detected based on HER1/EGFR expression. Rash and diarrhea were the most common drug-related toxicities, encountered in 79% and 37% of patients, respectively, though the severity was mild to moderate in most cases. CONCLUSION: Erlotinib was well tolerated in this heavily pretreated HNSCC population and produced prolonged disease stabilization; hence, further evaluation of its role in this tumor type is warranted.

Administration, Oral↗
PubMed1984

Contingency management interventions: effects on treatment outcome during methadone detoxification.

We examined the effectiveness of a contingency management program in preventing relapse to illicit opiate use and increasing treatment retention during outpatient methadone detoxification treatment. Twenty male opiate addicts were randomly assigned to an experimental or control group. Following a 3-week methadone stabilization period, men in both groups received identical gradual methadone dose reductions during Weeks 4 through 9 and were maintained on placebo during Weeks 10 through 13. Beginning in Week 4, control patients received $5.00 for providing a specimen twice weekly. Experimental patients received $10.00 and a take home methadone dose for each opiate-free urine specimen but forfeited the incentives and participated in more intensive clinic procedures when specimens were opiate positive. The contingency management procedure slowed the rate of relapse to illicit opiate use. Experimental patients provided significantly more opiate-free urines during the methadone dose reduction in Weeks 4 through 9 than control patients, although the difference between groups was no longer significant during placebo administration in Weeks 10 through 13. In addition, the contingency management program improved treatment retention and reduced symptom complaints during the detoxification. The usefulness and limitations of contingency management procedures for outpatient methadone detoxification are discussed.

Adult↗
PubMed2004

Optimization of the schedule of gemcitabine-cisplatin combination as induction regimen for patients with biopsy-proven stage IIIa N2 - stage IIIb non-small-cell lung cancer: a prospective phase-II study.

Aim of this study was to define the optimal schedule of gemcitabine (GCB)\cisplatin (CDDP) combination as induction chemotherapy (CHT) in patients with stage IIIa pN2-IIIb non - small-cell lung cancer (NSCLC). Fifty patients with mediastinoscopically-proven stage-IIIa pN2 -IIIb NSCLC were treated with 3 cycles of induction CHT followed by surgery (if staged IIIa) and three-time-daily accelerated radiotherapy. Chemotherapy initially consisted of 3 courses of CDDP 100 mg\m(2) d1 plus GCB 1000 mg\m(2) dd 1,8,15 repeated every 4 weeks, than was modified in CDDP 80 mg\m(2) d1 plus GCB 1250 mg\m(2) dd 1,8 repeated every 3 weeks. Twenty-nine four-week scheduled treatment cycles were firstly administered to 10 patients (pts): treatment-related toxicity, mainly hematological, caused a dose-reduction or treatment omission on day 15 in 65% of cycles. After the protocol was amended, 119 three-week scheduled treatment cycles were administered to 40 pts. Treatment-related toxicity of the new schedule caused a dose-reduction or treatment omission in only 10% of cycles, no patients requiring chemotherapy discontinuation. Thirty-seven out of fifty patients (74%, 95% CI: 60-85%) achieved a partial response, 7 had stable disease and 6 had disease progression. Similar activity was seen with both schedules. One nodal pathological complete remission was observed among the 24 pts who underwent surgery. At present, with a median follow-up of 13 months (mos), 2-year (y) survival of all the 50 pts and of the 24 pts staged IIIa who underwent surgery is estimated as 37% (95% CI: 24-58%) and 47% (95%CI: 27-80%), respectively. When given as induction chemotherapy, a three-week schedule of CDDP plus GCB combination appeared to be effective, with lower toxicity and better compliance than a four-week schedule.

Adult↗
PubMedDate not supplied

A pilot study of ChlOPhEPP-B--a weekly regimen for patients with untreated advanced or recurrent Hodgkin's disease.

Twenty-five patients with either previously untreated advanced Hodgkin's disease (HD) or with relapsed disease were treated with an intensive weekly chemotherapy regimen (ChlOPhEPP-B) in which the myelosuppressive combinations of epirubicin and chlorambucil, and procarbazine and etoposide alternated at two-week intervals, interspersed with vincristine and prednisolone and then vincristine, prednisolone and bleomycin in a four-week cycle. Of the previously untreated patients (n = 14), 12 (86 per cent) showed a complete response (CR); in the previously treated patients (n = 11), CR was achieved in five (46 per cent). Toxicity was predictable and not evidently more severe than with more standard regimens. Neutropenia leading to treatment delay and/or dose reduction was seen in 11 patients (44 per cent) but severe neutropenia (WHO grade 4) was documented in only six patients (24 per cent) for a cumulative total of nine treatment weeks (1.8 per cent of the total treatment time). Dose reductions for neutropenia were applied in relation to 11 of the 379 weekly treatment points (2.9 per cent). Delays in treatment, for any reason, averaged 3.65 weeks per patient. The study demonstrated the feasibility of a more intensive weekly multidrug schedule. This approach may be applicable in the treatment of advanced HD and represents a further option in the strategy of treating relapsed disease.

Adult↗
PubMed1969

Simultaneous reactivation of ultraviolet damage in xanthium leaves.

Experiments on Xanthium leaf discs were carried out to determine whether concomitant photoreactivation could be detected and if so, to compare its effects with photoreactivation due to post-irradiation treatments. Attempts mere made to simulate certain intensities of unfiltered solar radiation. A small but definite amount of simultaneous reactivation was observed. The dose reduction factor averaged 0.57. It was not clear whether the reactivation was due mainly to direct photoreactivation, photoprotection, or to heating effects. A much larger amount of reactivation due to post-irradiation treatments (direct photoreactivation) was noted with the dose reduction factor averaging 0.30.

Journal Article↗
PubMedDate not supplied

Putative role of dihydropyrimidine dehydrogenase in the toxic side effect of 5-fluorouracil in colorectal cancer patients.

Dihydropyrimidine dehydrogenase (DPD) is the first and rate limiting enzyme in the catabolism of 5-fluorouracil (5-FU). It has been reported from various laboratories that the plasma concentration of 5-FU was influenced by DPD activities in various normal human organs (e.g. liver or lymphocytes). Since the congenital deficiency in DPD caused severe, in some cases lethal, FU-related toxicity, it was decided to collect data about the DPD activity in colorectal cancer patients in order to investigate the possible correlation between the enzyme activity and appearance of the side effects of 5-FU. Assuming that DPD activity in lymphocytes represents the 5-FU catabolic capacity of the organism, DPD activity was determined in the lymphocytes of 48 patients with colorectal cancer after surgery during the therapeutic course with 5-FU and folinic acid. On the basis of the enzyme activity, patients were divided into three categories: low (DPD <5.03 pmol/min/10(6) lymphocytes); medium (DPD = 5.04-13.25 pmol/min/10(6) lymphocytes), and high (DPD > 13.26 pmol/min/10(6) lymphocytes) activity groups. By evaluating the toxic side effects during the 5-FU + folinic acid treatment, the following results were obtained. In the low DPD activity group, 9 of 11 patients had 5-FU-related side effects (mucositis, diarrhea, myelotoxicity, angina pectoris, hypertension). In 3 patients, no change of the therapy was needed, in 3 patients symptoms could be reversed by dose reduction of 5-FU while in 3 patients interruption of 5-FU therapy was needed. In the medium DPD activity group, mild toxicity (diarrhea, transitory hypertension) occurred in 5 of 29 and in the high activity group (diarrhea) in 1 of 8 patients, respectively. In these last two groups, no dose reduction of 5-FU was necessary. The present study furnished further evidence for the possible correlation between the 5-FU side effects and DPD function. Consequently, it is recommended to measure DPD activity prior to 5-FU based chemotherapy, which might be helpful in avoiding drug-related toxicity by adjusting the dose of 5-FU individually.

Adult↗
PubMed1981

[Prospective examinations of digitalis poisoning].

Despite many years of using digitalis to treat congestive heart failure, the problem of intoxication has remained unchanged. In nine prospective studies on patients under a maintenance treatment with digoxin the intoxication rate ranged from 15.2% to 27.5%. Other studies have also shown that renal insufficiency was present in 70% of intoxicated patients. In contrast the digitoxin toxicity rate, as shown in two prospective studies from Norway and France on 649 and 2120 patients respectively, resulted in an intoxication rate of 5.8% and 3.2% respectively. The explanation for the discrepancy between the two glycosides seems to be predominantly the influence of renal function on drug elimination. Digoxin is mainly excreted through the kidneys; an impairment of the renal function will therefore lead to a reduced elimination of this drug. In these cases a dose reduction of digoxin is necessary. Digitoxin on the other hand is excreted both through the kidneys and the bile. Impairment of the renal function does, therefore, not lead to any decrease in digitoxin elimination whether in renal disease, during heart failure or in old age. In contrast to digoxin, no dose reduction is necessary with digitoxin when renal function is reduced. Digitoxin is therefore easier to handle in the long term management of cardiac patients with and without renal impairment.

Digitalis Glycosides↗
PubMed1994

[Phase II study of a continuous five-day intravenous infusion of cisplatin and etoposide with concurrent chest radiation therapy in limited stage small cell lung cancer].

The efficacy of continuous five-day intravenous infusion of cisplatin (CDDP) and etoposide with concurrent chest radiation therapy was evaluated in patients with limited stage small cell lung cancer. The first group of patients registered from February 1989 to September 1990 received three courses of chemotherapy (CDDP 20 mg/m2/day x 5 days, etoposide 40 mg/m2/day x 5 days) and concurrent chest radiation therapy on the third course with dose reduction of etoposide. The second group of patients registered after February 1991 received four courses of chemotherapy (CDDP 20 mg/m2/day x 5 days, etoposide 50 mg/m2/day x 5 days) and concurrent chest radiation therapy on the first and second courses with dose reduction of etoposide. The response rates were 91.7% and 93.3%, respectively. The median duration of survival was 32.0 months and 20.1 months, respectively. Major toxicity was leukocytopenia and 64% and 80% of patients encountered leukocytopenia of Grade 3 or 4. In conclusion, these regimens show remarkable efficacy with acceptable toxicity.

Aged↗
PubMed2005

Predictors of recurrent ischemic optic neuropathy in giant cell arteritis.

BACKGROUND: The competing interests of preventing recurrent ischemic optic neuropathy (ION) and minimizing medication side effects make corticosteroid dose reduction in giant cell arteritis (GCA) a difficult problem. The authors sought to determine whether any factors were predictive of recurrent ION. METHODS: Retrospective review of the records of 100 consecutive patients with biopsy-proven giant cell arteritis diagnosed in two Australian hospitals between 1988 and 1998. Among 67 patients who met inclusion criteria for ION in GCA, seven patients had recurrent ION. We compared the seven patients with recurrent ION to the 60 patients with nonrecurrent ION in terms of age, gender, mode of corticosteroid delivery, initial visual acuity in the affected eye, prevalence of bilateral ION, initial erythrocyte sedimentation rate (ESR) level, and rate of corticosteroid dose reduction. In the recurrent ION group, we documented the timing of the recurrence in relation to corticosteroid dose, elevation in acute phase reactants, and relapse of systemic symptoms. RESULTS: We found recurrent ION in GCA in 10% of our cohort, higher than has been previously reported. Recurrences, all of which were ipsilateral, occurred from 3 to 36 months (median 8 months) after the initial ION. None of the clinical indicators the authors examined differed between the two groups. Six of seven patients with recurrent ION had elevations in ESR or C-reactive protein or a new headache at the time of ION recurrence, but in only one of these patients were these features recognized as preceding the recurrent ION. One patient had neither an elevation in acute phase reactants nor a relapse in systemic symptoms of GCA at the time of ION recurrence. CONCLUSIONS: Recurrent ION in GCA is difficult to predict. Although elevated acute phase reactants or new systemic symptoms consistent with GCA were present in six (83%) of our patients with ION recurrence, in only one patient (17%) did these events occur with enough lead time to allow caregivers to act preemptively. Thus, even very close monitoring of GCA patients with ION may not predict ION recurrence.

Adrenal Cortex Hormones↗
PubMed2006

Preliminary experience with mycophenolate mofetil for preservation of renal function in cardiac transplant patients with documented cyclosporine nephrotoxicity.

BACKGROUND: Cyclosporine (CyA) has positively impacted on the outcome of cardiac transplantation; however, the nephrotoxicity associated with CyA has been a major drawback. METHODS: In an effort to reduce exposure to CyA and possibly alleviate its nephrotoxic effects, we undertook a therapeutic strategy to switch cardiac transplant patients with biopsy-proven CyA nephrotoxicity from azathioprine (AZA) to mycophenolate mofetil (MMF) with subsequent CyA dose reduction or elimination. RESULTS: MMF was substituted for AZA in five cardiac transplant patients (four males; mean age, 60 +/- 6 years old; average time from transplant was 7 +/- 3 years) who had biopsy proven evidence of CyA nephrotoxicity, and in whom CyA dose was reduced (3/5) or discontinued (2/5). At the time of the therapeutic intervention, four patients had an average serum creatinine of 230 +/- 62 micromol/L and one patient had just been started on haemodialysis (HD). During an average follow-up period of 42 months, the slope of the inverse serum creatinine significantly improved in three patients and continued to deteriorate in one patient. The patient on HD could be transiently taken off HD. However, he developed a severe episode of cardiac rejection requiring antirejection therapy and increase in the dose of CyA. The patient was subsequently returned back on HD. CONCLUSION: In this preliminary report, we show that AZA to MMF switch with subsequent CyA dose reduction or discontinuation may slow down the progression of kidney disease in some patients. However, the patients should be followed closely for evidence of cardiac rejection.

Aged↗
PubMed2002

Radiation dose and image quality in diagnostic radiology. Optimization of the dose-image quality relationship with clinical experience from scoliosis radiography, coronary intervention and a flat-panel digital detector.

UNLABELLED: X-rays are known to cause malignancies, skin damage and other side effects and they are thus potentially dangerous. Therefore, it is essential and in fact mandatory to reduce the radiation dose in diagnostic radiology as far as possible. This is also known as the ALARA (as low as reasonably achievable) principle. However, the dose is linked to image quality and the image quality may not be lowered so far that it jeopardizes the diagnostic outcome of a radiographic procedure. The process of reaching this balance between dose and image quality is called optimization. The aim of this thesis was to propose and evaluate methods for optimizing the radiation dose-image quality relationship in diagnostic radiography with a focus on clinical usefulness. The work was performed in three main parts. OPTIMIZATION OF SCOLIOSIS RADIOGRAPHY: In the first part, two recently developed methods for digital scoliosis radiography (digital exposure and pulse fluoroscopy) were evaluated and compared to the standard screen-film method. Radiation dose was measured as kerma area-product (KAP), entrance surface dose (ESD) and effective dose; image quality was assessed with a contrast-detail phantom and through visual grading analysis. Accuracy in angle measurements was also evaluated. The radiation dose for digital exposure was nearly twice as high as the screen-film method at a comparable image quality while the dose for pulsed fluoroscopy was very low but with a considerably lower image quality. The variability in angle measurements was sufficiently low for all methods. Then, the digital exposure protocol was optimized to a considerably lower dose with a slightly lower image quality compared to the baseline. FLAT-PANEL DETECTOR: In the second part, an amorphous-silicon direct digital flat-panel detector was evaluated using a contrast-detail phantom, measuring dose as entrance dose. The flat-panel detector yielded a superior image quality at a lower dose than both storage phosphor plates and screen-film. Equivalent image quality compared to storage phosphor plates was reached at about one-third of the dose. OPTIMIZATION OF PERCUTANEOUS CORONARY INTERVENTION (PCI): In the third part, influence of various settings on radiation dose and image quality in coronary catheterisation and PCI was investigated. Based on these findings, the dose rate for fluoroscopy was reduced to one-third. The dose reduction was evaluated in a clinical series of 154 PCI procedures before and 138 after the optimization. Through this optimization, the total KAP was significantly reduced to two-thirds of the original value. IN SUMMARY: This thesis indicates the possibility of dose reduction in diagnostic radiology through optimization of the radiographic process.

Coronary Angiography↗
PubMed2005

Survey of oxaliplatin-associated neurotoxicity using an interview-based questionnaire in patients with metastatic colorectal cancer.

BACKGROUND: New chemotherapy regimens for patients with colorectal cancer have improved survival, but at the cost of clinical toxicity. Oxaliplatin, an agent used in first-line therapy for metastatic colorectal cancer, causes acute and chronic neurotoxicity. This study was performed to carefully assess the incidence, type and duration of oxaliplatin neurotoxicity. METHODS: A detailed questionnaire was completed after each chemotherapy cycle for patients with metastatic colorectal cancer enrolled in a phase I trial of oxaliplatin and capecitabine. An oxaliplatin specific neurotoxicity scale was used to grade toxicity. RESULTS: Eighty-six adult patients with colorectal cancer were evaluated. Acute neuropathy symptoms included voice changes, visual alterations, pharyngo-laryngeal dysesthesia (lack of awareness of breathing); peri-oral or oral numbness, pain and symptoms due to muscle contraction (spasm, cramps, tremors). When the worst neurotoxicity per patient was considered, grade 1/2/3/4 dysesthesias and paresthesias were seen in 71/12/5/0 and 66/20/7/1 percent of patients. By cycles 3, 6, 9, and 12, oxaliplatin dose reduction or discontinuation was needed in 2.7%, 20%, 37.5% and 62.5% of patients. CONCLUSION: Oxaliplatin-associated acute neuropathy causes a variety of distressing, but transient, symptoms due to peripheral sensory and motor nerve hyperexcitability. Chronic neuropathy may be debilitating and often necessitates dose reductions or discontinuation of oxaliplatin. Patients should be warned of the possible spectrum of symptoms and re-assured about the transient nature of acute neurotoxicity. Ongoing studies are addressing the treatment and prophylaxis of oxaliplatin neurotoxicity.

Adult↗
PubMedDate not supplied

Digital radiography in pediatric orthopaedics: a prospective, controlled, and randomized trial.

A prospective, controlled, and randomized trial of digital radiography was conducted to evaluate its advantages in children. Matched pairs of radiographs of the feet were taken in 20 children, and pelvic radiographs were taken in another 20 children. Each pair comprised a digital and conventional film. Half of the digital films were made with a 50% radiation dose reduction. The films were scored for quality. Statistically significant advantages were seen for the digital radiographs as compared with the conventional technique. Visualization of soft tissue and bony detail was enhanced in both foot and pelvic radiographs. This was true even with a 50% dose reduction in many of the parameters scored. We conclude that digital radiography offers advantages over conventional radiography, and recommend its use.

Child↗