MR-Eye: High-Resolution Microscopy Coil MRI for the Assessment of the Orbit and Periorbital Structures, Part 2: Clinical Applications.

In the first part of this 2-part series, we described how to implement microscopy coil MR imaging of the orbits. Beyond being a useful anatomic educational tool, microscopy coil MR imaging has valuable applications in clinical practice. By depicting deep tissue tumor extension, which cannot be evaluated clinically, ophthalmic surgeons can minimize the surgical field, preserve normal anatomy when possible, and maximize the accuracy of resection margins. Here we demonstrate common and uncommon pathologies that may be encountered in orbital microscopy coil MR imaging practice and discuss the imaging appearance, the underlying pathologic processes, and the clinical relevance of the microscopy coil MR imaging findings.

MR-Eye: High-Resolution Microscopy Coil MRI for the Assessment of the Orbit and Periorbital Structures, Part 1: Technique and Anatomy.

Microscopy coil MR imaging of the orbits has been described previously as a technique for anatomic depiction. In the first part of this 2-part series, the improvement in spatial resolution that the technique offers compared with conventional MR imaging of the orbits is demonstrated. We provide a guide to implementing the technique, sharing pearls and pitfalls gleaned from our own practice to make implementation of microscopy coil MR imaging at your own center easy. As a quick reference guide to the small-scale structures encountered when reading the studies, a short anatomy section is included, which doubles as a showcase for the high-quality imaging that can be obtained. In the second part, our experience of microscopy coil MR imaging in day-to-day clinical practice takes it far beyond being a useful anatomic educational tool. Through a series of interesting cases, we highlight the added benefit of microscopy coil MR imaging compared with standard orbital MR imaging.

Acute pancreatitis: a comparison of intervention rates precipitated by early vs guideline CT scan timing.

AIM: To assess whether computed tomography (CT) examination earlier in acute pancreatitis (AP) precipitates any surgical or radiological intervention. MATERIALS AND METHODS: A single-centre retrospective cohort study comparing intervention rates in AP precipitated by early (<6 day of admission, n=100) and UK guideline (≥6 day of admission, n=103) CT examinations. RESULTS: No intervention was precipitated by performing CT before the sixth day of admission in AP. A statistically significant larger number of interventions were precipitated when CT was performed on the sixth day or later (p<0.05). Of note, this study was conducted using day of admission, rather than day of symptom onset. Six patients underwent repeat CT examination in the same admission after an early CT examination. CONCLUSION: Performing CT before the sixth day of admission does not lead to earlier intervention. Such early examinations waste resources and may offer false reassurance to clinicians.

Phase II studies of BBR3464, a novel tri-nuclear platinum complex, in patients with gastric or gastro-oesophageal adenocarcinoma.

BBR3464, a novel tri-nuclear platinum complex, forms long-range DNA adducts and is highly potent when compared with cisplatin in vitro. Preclinical studies demonstrated activity in cisplatin-resistant tumours and tumours with mutated p53 status. Phase I & II clinical studies gave preliminary indications of activity in melanoma, pancreatic, lung and ovarian cancers. The aim of this study was to determine the efficacy and confirm the toxicity of BBR3464 when given either as first- or second-line treatment for advanced disease in patients with gastric and gastro-oesphageal adenocarcinoma. Two multicentre, open label, Gehan design studies were conducted; one study used BBR3464 as first-line and the other as second-line treatment for metastatic or locally advanced disease. Nineteen first-line and 26 second-line patients were enrolled receiving a total of 74 and 53 infusions, respectively. Initially, seven patients in the second-line study received BBR3464 using the planned schedule of 1.1 mg/m2 every 4 weeks; however, 5 of these patients experienced dose-limiting grade 3 or 4 febrile neutropenia; subsequent patients in both studies were treated using the modified schedule of 0.9 mg/m2, every 21 days. In 1 of 17 evaluable, previously untreated patients, regression of multiple skin lesions was noted with stabilisation of lung metastases and maxillary sinus mass, lasting 155 days. In the first-line study, the median time to progression was 85 days [95% Confidence Interval (CI): 42, 127] (2.8 months) and in the second-line study, the median time to progression was 71 days [95% CI: 42, 109] and 38 days [95% CI: 32, 73] in the 1.1 and 0.9 mg/m2 dose level groups, respectively. Toxicity data were available for 45 patients. Neutropenia was the main toxicity seen (G3: 40%, G4: 40%). Febrile neutropenia was observed in six patients (15%) treated with 0.9 mg/m2 compared with five patients (71%) treated with 1.1 mg/m2 BBR3464. Other drug-related toxicities (G3/4) included: anaemia, thrombocytopenia, nausea, vomiting, diarrhoea, mucositis and fatigue. Diarrhoea and nausea/ vomiting were adequately controlled by the use of loperamide and antiemetics, respectively. Recruitment to the second-line study was closed early due to the poor response rate (1/17 evaluable, 6%; 95% CI: 1%, 27%) and short time to progression noted in the first-line study. Further studies with BBR3464 in this tumour type are not recommended.

Combination antiangiogenesis therapy with marimastat, captopril and fragmin in patients with advanced cancer.

Marimastat, low molecular weight heparins and captopril have antiangiogenic activity in vitro and in animal models. We studied the safety and efficacy of the combination of these drugs in patients with advanced cancer. In all, 50 patients were enrolled. Captopril was given orally at a dose of 50 mg bd daily. Fragmin was administered as a daily subcutaneous injection of 200 units kg(-1) for the first 28 days and 5000 units thereafter. Marimastat was given at 10 mg bd orally. Serum, plasma and urinary angiogenic factors were measured at baseline and after 1 month of treatment. Inhibition of release of tumour necrosis factor alpha (TNF-alpha) from peripheral lymphocytes was used as a surrogate pharmacodynamic end point. There was one case of haemorrhagic stroke and one upper gastrointestinal haemorrhage. The commonest toxicity was myalgia. One of 10 patients with renal cancer had a partial response, and three patients had a prolonged period of stable disease. The treatment significantly inhibited phytohaemagglutinin (PHA)-stimulated TNF-alpha release from patient's lymphocytes. The combination of marimastat, fragmin and captopril is well tolerated and has in vivo activity. Inhibition of PHA-stimulated TNF-alpha release from lymphocytes is a surrogate pharmacodynamic marker of metalloprotease inhibition.

Phase I and pharmacokinetic study of the topoisomerase I inhibitor, exatecan mesylate (DX-8951f), using a weekly 30-minute intravenous infusion, in patients with advanced solid malignancies.

BACKGROUND: The topoisomerase I inhibitor exatecan mesylate (DX-8951f ) is a water-soluble hexacyclic analogue of camptothecin that does not require enzymatic activation. This study determined the toxicity, maximum tolerated dose (MTD), pharmacokinetics and pharmacodynamics of a weekly intravenous (i.v.) schedule of DX-8951f. PATIENTS AND METHODS: Thirty-five patients with advanced solid malignancies, stratified as minimally (MP) or heavily (HP) pre-treated, received escalating doses of DX-8951f as 30-min i.v. infusions for three out of every 4 weeks. Pharmacokinetics were described after the first infusion of DX-8951f. RESULTS: Infusions (244) of DX-8951f were administered with a median of two cycles (range 1-10). The main toxicity observed was haematological. There was no significant gastrointestinal toxicity. Two patients (6%) had confirmed partial responses. Twelve patients (39%) had stable disease. DX-8951f had a terminal elimination half-life of approximately 8 h and a clearance of 2 l/h/m(2). The area under the plasma concentration versus time curve (AUC( infinity )) and the maximum plasma concentration (C(max)) increased linearly with the dose. A linear relationship was present for the percentage decrease in neutrophil counts or platelet counts and AUC( infinity ) as well as C(max). CONCLUSIONS: The dose-limiting toxicity of DX-8951f is neutropenia for MP patients and neutropenia and thrombocytopenia for HP patients. Evidence for clinical activity was seen, suggesting phase II study of the drug is indicated. Using this schedule the recommended dose is 2.75 mg/m(2)/week for MP patients and 2.10 mg/m(2)/week for HP patients.

Epirubicin in patients with liver dysfunction: development and evaluation of a novel dose modification scheme.

This study aimed to develop an epirubicin dose modification scheme in women with breast cancer and liver dysfunction. We first identified target areas under the concentration-time curve (AUCs) of 2400 and 1600 ng/ml.h from pharmacokinetic studies in 15 women with normal liver tests. In a second group of 16 women with abnormal liver biochemistry, the relationship between raised asparate aminotransferase (AST) and epirubicin clearance was: dose=AUC (97.5-34.2xlog AST). Adaptive dosing was evaluated prospectively in a third group of 41 women with serum AST > or =2xnormal+/-raised bilirubin. The median AUCs were 2444 and 1608 ng/ml.h, close to the high and low target AUCs, respectively. Variability in AUC was lower with adaptive dosing than in a fourth group given an unadjusted dose of epirubicin (coefficient of variation=25.8, 30.0 and 46.5%, respectively; P=0.06). Epirubicin dosing based on AST is safe and may reduce pharmacokinetic variability.

Soluble Tie2 and Flt1 extracellular domains in serum of patients with renal cancer and response to antiangiogenic therapy.

Antiangiogenesis drugs can be difficult to evaluate because they produce disease stabilization rather than tumor regression. Markers of endothelial mass in tumors may be of value to monitor therapy and evaluate such drugs. Soluble domains of the endothelial receptor tyrosine kinases, sTie2 (angiopoietin receptor) and sFlt1 (vascular endothelial growth factor receptor-1) were analyzed by sandwich ELISA in serum samples from 43 patients with advanced renal cancer before and 1 month after antiangiogenic therapy with razoxane. Pretreatment sFlt1 levels were 0.77 ng/ml +/- 0.48 (SD) and sTie2 74.3 ng/ml +/- 15 (SD). Pretreatment sFlt1 levels above the median were associated with a lesser chance of stable disease (P = 0.04) and poorer survival (P = 0.01). Fall of sTie2 on treatment was associated with stable disease (P = 0.05) and improved survival (P = 0.04). The soluble receptors measured weeks before response were assessed and correlated with response and survival, showing they may be useful to monitor and develop antiangiogenic therapy.

A phase II study of razoxane, an antiangiogenic topoisomerase II inhibitor, in renal cell cancer with assessment of potential surrogate markers of angiogenesis.

Renal cell carcinoma (RCC) is an angiogenic tumor resistant to standard cytotoxic chemotherapeutic agents. Although often responsive to immunomodulatory agents including interleukin 2 and IFN-alpha, the overall results in randomized Phase III studies are disappointing with only modest improvements in overall survival. This Phase II study evaluated the efficacy and tolerability of razoxane, an antiangiogenic topoisomerase II inhibitor, in 40 patients (32 men, 8 women; age: range, 31-76 years; median, 58 years) with inoperable RCC. Twenty patients received razoxane 125 mg p.o., twice a day for 5 days each week for 8 weeks (one cycle). This was repeated in patients with stable disease (StD), but was discontinued after 16 weeks if there was no evidence of an objective response. Because minimal toxicity was seen, subsequent patients (n = 20) were treated until progressive disease (PD) was documented. Of 38 evaluable patients, 11 (29%) had StD for a minimum of 4 months, and the remainder had PD. Median overall survival was 7.3 months. Duration of survival was significantly better in patients with StD compared with those with PD (P = 0.003). The effect of treatment on six potential surrogate serum/plasma (vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), urokinase plasminogen activator soluble receptor (uPAsr), E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand's factor (vWF) and two urinary (VEGF and bFGF) markers of angiogenesis was evaluated before and after 1 cycle of treatment. Pretreatment serum VEGF and E-selectin levels above the median value were associated with a poor prognosis. Serum VCAM-1 levels and urinary VEGF levels rose significantly after one cycle in patients with PD but not in those with StD. Serum VEGF, bFGF, VCAM-1 and vWF, plasma uPAsr and urinary bFGF levels were significantly higher in PD patients compared with StD patients before and/or after 1 cycle of treatment. In conclusion, razoxane is an antiangiogenic agent that has minimal toxicity and that requires further evaluation in combination with other active agents in the treatment of RCC. Surrogate serum and urinary markers of angiogenesis may have a role to play in predicting disease response and overall survival in RCC.

The protein kinase C inhibitor CGP41251 suppresses cytokine release and extracellular signal-regulated kinase 2 expression in cancer patients.

Components of cell signaling pathways provide important targets for anticancer drugs. Protein kinase C (PKC) is a serine/threonine-specific kinase that regulates cell growth and differentiation. It is also implicated in tumor promotion. The staurosporine analogue CGP41251 is a PKC inhibitor, and it is currently in a Phase I clinical trial for treatment of advanced cancer. However, it is difficult to define its biological activity. We have used two approaches to measure the in vivo biological response to CGP41251: (a) sequential whole blood samples were taken from 27 patients before and during treatment and incubated with mitogen (PHA), and cytokine [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6] release was measured ex vivo; and (b) peripheral blood lymphocytes were isolated from seven of these patients, and the levels of extracellular signal-regulated kinase 2 were measured by Western blotting. Response to PHA was significantly lowered during treatment (P < 0.001 for TNF-alpha production; P < 0.03 for IL-6). This was most evident at 7 and 28 days after the start of treatment in patients receiving higher doses (150-300 mg/day; P = 0.002 and P = 0.02, respectively, for TNF-alpha and P = 0.001 and P = 0.003, respectively, for IL-6 release). Whole blood cytokine production returned to pretreatment levels after drug administration ceased. The levels of extracellular signal-regulated kinase 2 were reduced by 50-97% during treatment in all seven patients tested. These results show for the first time that a PKC inhibitor can block in vivo signaling pathways in cancer patients. The assays we describe complement toxicity studies in selecting relevant doses for Phase II trial of novel agents, particularly when biological activity occurs at doses below those that cause obvious side effects.

Phase II study of RC-160 (vapreotide), an octapeptide analogue of somatostatin, in the treatment of metastatic breast cancer.

RC-160 (octastatin/vapreotide) is a potent octapeptide analogue of somatostatin with growth inhibitory activity in experimental tumours in vitro and in vivo, including breast cancer. We evaluated the efficacy and tolerability of high-dose RC-160, 3 mg day(-1) on week 1 increased to 4.5 mg day(-1) for weeks 2-4 and subsequently 6 mg day(-1) until the end of treatment, administered by continuous subcutaneous infusion in the management of 14 women with previously treated metastatic breast cancer. The age range was 37-80 years (median 58.5 years) and performance status 0-2. The treatment was well tolerated with no dose reductions being required. No grade 3 or 4 toxicities were seen. Abscess formation developed at the infusion site in eight patients and erythema and discomfort was seen in a further three patients. A significant reduction in IGF-I levels occurred by day 7 and was maintained throughout the treatment. The lowest dose of RC-160 produced the maximal IGF-I response. Although there was no reduction in prolactin levels in patients whose baseline levels were normal, elevated prolactin levels found in three patients fell to within the normal range 7 days after commencing RC-160 treatment. A small but significant rise in fasting blood glucose levels was also recorded, the highest level on treatment being 7.6 mmol l(-1). No objective tumour responses were observed, all patients showing disease progression within 3 months of commencing treatment. These findings demonstrate that high-dose RC-160, administered as a continuous subcutaneous infusion, can reduce serum levels of the breast growth factors IGF-I and prolactin but is ineffective in the management of metastatic breast cancer. Encouraging preclinical anti-tumour activity and the favourable toxicity profile in patients suggest the merit of future studies combining RC-160 with anti-oestrogen, cytotoxic and anti-angiogenic agents.

What is the effect of adjusting epirubicin doses for body surface area?

Doses of cytotoxic drugs are routinely adjusted according to body surface area. We have evaluated this practice in 32 women with advanced breast cancer treated with single-agent epirubicin 12.5-120 mg m(-2). Epirubicin and its metabolites were measured by high-performance liquid chromatography (HPLC). Unadjusted plasma clearance was calculated from dose in mg, and adjusted clearance from dose in mg m(-2). Unadjusted clearance did not correlate with surface area, height, weight, per cent ideal body weight or body mass index. There was no difference in the coefficient of variation (CV) of adjusted and unadjusted clearance (39.4% and 37.7% respectively). The AUC that would have resulted from giving an unadjusted dose was calculated. This predicted AUC was accurate, unbiased and had the same CV as the actual AUC. Similarly, in 11 patients an analysis of actual and predicted neutropenia confirmed that unadjusted dosing would have had no significant effect on the pattern of myelosuppression. Normalization of epirubicin dosage according to surface area appears not to reduce either pharmacokinetic or pharmacodynamic variability.

Doxorubicin pharmacokinetics: the effect of abnormal liver biochemistry tests.

We studied variability in doxorubicin pharmacokinetics in 24 patients with abnormal liver biochemistry tests. Blood samples were collected after the first cycle of single-agent doxorubicin given as an i.v. bolus and plasma levels were measured by high-performance liquid chromatography. The relationship between doxorubicin clearance (dose/AUC) and liver biochemistry tests (AST, bilirubin, albumin, alkaline phosphatase and indocyanine green clearance) was investigated. Patients with a raised bilirubin level had reduced doxorubicin clearance, but there was no clear relationship between the extent of this elevation and the reduction in doxorubicin clearance. Doxorubicin clearance was lower in patients with an isolated increase in AST than in those with normal liver biochemistry, but this difference was not statistically significant. Nevertheless, there was a significant correlation between reduced doxorubicin clearance and both raised serum AST levels and low indocyanine green clearance. These pharmacokinetic data suggest that current dose reductions based solely on the extent to which bilirubin is elevated may not be optimal.

Anthracycline doses in patients with liver dysfunction: do UK oncologists follow current recommendations?

The question of whether UK oncologists follow current anthracycline dose modifications when treating patients with liver dysfunction was addressed through a questionnaire. Oncologists were asked the dose of doxorubicin or epirubicin they would prescribe for a woman with breast cancer and liver metastases who had one of four different patterns of abnormal liver chemistry. In each case, the median dose of anthracycline that would have been prescribed was close to that currently recommended. There was, however, wide variation in the dose that oncologists said they would prescribe, some avoiding an anthracycline altogether, whereas others would give full-dose treatment. Medical oncologists would prescribe a significantly lower dose of anthracycline than clinical oncologists for a patient with the most severely disturbed liver tests. Overall, medical oncologists were also significantly more likely to prescribe epirubicin. These results show the need for new, widely accepted anthracycline dose modifications for patients with liver dysfunction.

Gender affects doxorubicin pharmacokinetics in patients with normal liver biochemistry.

We studied the variability in doxorubicin pharmacokinetics in 27 patients, all of whom had normal liver biochemistry tests. Blood samples were collected after the first cycle of single-agent doxorubicin given as an i.v. bolus and plasma levels were measured by high-performance liquid chromatography (HPLC). The relationship of doxorubicin clearance (dose/AUC) with biochemical tests (AST, bilirubin, alkaline phosphatase, albumin, creatinine) and physical characteristics (age, gender, height, weight, tumour type) was investigated. The 6 men had a significantly higher doxorubicin clearance than did the 21 women (median values, 59 and 27 lh-1 m-2, respectively; P = 0.002). Doxorubicin clearance was significantly lower in patients with breast cancer than in those with other tumours (median values, 26 and 53 lh-1 m-2, respectively; P = 0.0008). The other biochemical and physical parameters did not correlate with doxorubicin clearance. However, in multivariate analysis, gender was the only factor predicting doxorubicin clearance (r2 = 40%). The ratio of the AUCs for doxorubicinol and doxorubicin (R) was higher in the men than in the women (median values, 0.62 and 0.36, respectively; P = 0.03). We conclude that gender may be an important determinant of doxorubicin clearance in patients with normal liver biochemistry.