The use of the Australian Basic Treatment Equivalent (BTE) workload measure for linear accelerators in Canada.

The Inter Society of Radiation Oncologists of North America (ISRON) workload standard for linear accelerators is the one most widely used; it regards the treatment of 250 or more patients per year as an acceptable limit. Nevertheless, there is concern that this standard does not represent the current workload of linear accelerators, given that the complexity of techniques and equipment has increased significantly since the ISRON model was developed in the late 1980s. Delaney et al. recently validated a workload indicator for Australian (AUS) centres, known as the basic treatment equivalent (BTE). They showed that this was a better predictor of workload and that there was less variation between centres using this model than there would have been by using fields/hour. This centre attempted to validate this model for use in a Canadian centre, by collecting treatment data on all linear accelerator-treated patients during February 1998. The linear accelerators at this centre delivered 2,295 fractions (6,928 fields) in 662 hours during February 1998. When 15 minutes was used as a denominator, the BTE model functioned as a better workload indicator than simple measures such as fields/hour. It also had better performance in reducing variability between machines. A BTE of 3,403 was calculated for these machines. The mean value for fields/hour, BTE/hour and BTE/fraction for this centre fell within the range of values quoted by AUS centres. The BTE/fraction value for this centre was relatively high compared with the AUS mean, indicating this centre's reliance on the use of a high number of complex techniques. We recommend that the model should be further refined for the Canadian context by developing BTE values with the use of local time and motion studies, including factors such as multileaf collimators and enhanced dynamic wedges.

A phase II study of regional 2-weekly 5-fluorouracil infusion with intravenous folinic acid in the treatment of colorectal liver metastases.

Forty patients with unresectable colorectal metastases confined to the liver were evaluated in a phase II study. 5-Fluorouracil (5-FU) was delivered via a surgically placed hepatic artery catheter. Patients received folinic acid (200 mg m-2) intravenously over 2 h followed by a loading dose of intra-arterial 5-FU (400 mg m-2) over 15 min, then 5-FU (1600 mg m-2) by intra-arterial infusion over the following 22 h. This was repeated on day 2 and the whole schedule was repeated every 2 weeks. Response was assessed after six treatments. The median follow-up was 17 months. Overall response rate was 46% with 8% complete response. Estimated median survival is 19 months. Site of progression was the liver alone in 55%, liver and lung in another 16% and 29% in other sites. Eight patients experienced grade 3 or 4 toxicity. The response rate of this regimen compares favourably with reported trials of intra-arterial FUDR, and our schedule is currently being compared with a similar schedule of intravenous 5-FU and folinic acid in a randomized Medical Research Council trial (CR05).

Intraperitoneal chemotherapy: a prolonged infusion of 5-fluorouracil using a novel carrier solution.

A novel carrier solution, icodextrin 20 (7.5%) has allowed exploration of prolonged intraperitoneal (IP) infusion of the cytotoxic drug, 5-fluorouracil. Eighteen patients with intraperitoneal carcinomatosis were entered into a feasibility and pharmacokinetic study of prolonged regional (IP) chemotherapy.. Specialist nurses trained the patients to self-administer their own treatment via a permanent i.p. catheter. A twin bag delivery system was used to perform one exchange daily. It proved possible to deliver continuous (5 days per week) i.p. 5-fluorouracil at doses of 200 mg/m2 and 300 mg/m2 for up to 12 weeks. The toxicities seen were infective peritonitis, nausea and vomiting, lethargy and anorexia. This was a nurse-led study and the home-based therapy holds promise for patients with malignant peritoneal disease.

Phase I clinical and pharmacokinetic study of leucovorin and infusional hepatic arterial fluorouracil.

PURPOSE: A phase I and pharmacokinetic trial was performed between October 1993 and June 1994 to determine the maximum-tolerated dose of hepatic arterial infusion (HAI) of fluorouracil (5-FU) and intravenous (IV) leucovorin (folinic acid; FA) in patients with hepatic metastases from colorectal cancer. PATIENTS AND METHODS: Forty-three patients received 310 courses of HAI chemotherapy administered over 48 hours every 2 weeks. The regimen consisted of FA 200 mg/m2 by IV infusion over 2 hours, followed by a loading dose of 5-FU 400 mg/m2 by HAI over 15 minutes, followed by a 22-hour infusion of 5-FU at doses ranging from 0.8 to 1.84 g/m2, with identical chemotherapy on day 2. Pharmacokinetic studies were performed to determine peak and steady-state plasma concentrations (Css) of 5-FU. RESULTS: Severe diarrhea and cardiac and neurologic toxicity were dose-limiting at 1.84 g/m2. The recommended dose for the 22-hour component of the schedule was 1.6 g/m2 and was associated with tolerable toxicity. A Css of 2.2 +/- 0.8 mumol/L for 5-FU was achieved on the recommended schedule, which compares favorably with conventional IV 5-FU regimens. Among 30 patients assessable for response, there were four complete responses and seven partial responses, and 12 patients with stable disease and seven with progressive disease, reported after 3 months (ie, six cycles) of therapy. CONCLUSION: A regimen that combines 5-FU and FA has been identified for regional chemotherapy in patients with hepatic metastases from colorectal cancer. The systemic levels of 5-FU achieved are similar to the conventional IV de Gramont regimen using an identical schedule of 5-FU and FA, which implies that this chemotherapy has the best of both worlds, ie, a regional advantage in delivering high drug concentrations to the target organ with adequate systemic cover for extrahepatic micrometastases.

The West Midlands epithelial ovarian cancer adjuvant therapy trial.

In a multicentre prospective randomized controlled trial, single agent cisplatinum was compared with whole abdomino-pelvic moving strip radiotherapy in the management of Stage IC-III epithelial ovarian cancer patients who had no macroscopic residual disease after primary surgery. Over a 6-year period 40 eligible patients were recruited, 15 of whom had Stage III disease. The overall 5-year survival was 60% with no significant survival difference between the treatment groups. Acute toxicity was common in both arms and six (11%) patients experienced significant long term disability.

Treatment of multiple pterygium syndrome.

Multiple pterygium syndrome is a rare, inherited disorder manifested by growth retardation, facial or genital anomalies, and widespread musculoskeletal deformities. Pterygia are the predominant hallmark of the syndrome. Five children with multiple pterygium syndrome were treated from 1978 to 1987. Treatment involved both upper and lower pterygia and contractures. The results of treatment and modalities used are discussed and a protocol suggested.

Management of aneurysms that involve the juxtarenal or suprarenal aorta.

Juxtarenal and suprarenal aneurysms are being seen with increasing frequency as CT and magnetic resonance imaging expand the examination of the aorta. Careful exposure of the suprarenal aorta, either by a direct anterior transperitoneal or an extraperitoneal approach, facilitates repair of the aneurysms. Direct graft replacement can then be performed with low morbidity and mortality rates.

Adhesion of clinical and environmental Aeromonas isolates to HEp-2 cells.

A total of 63 Aeromonas strains isolated from diarrhoeal faeces or water samples were tested for adhesion to HEp-2 cells. An association between diarrhoea and high level adhesion was observed in that 12 of the 34 faecal isolates and none of the 29 environmental isolates yielded greater than 20 bacteria per HEp-2 cell in the adhesion assay. The proportion of high adherers was significantly greater for A. sobria (57%) than for A. hydrophila isolates (19%). Three of the eight faecal A. caviae isolates were also found to be high adherers. All of the environmental isolates were heavily pilated with pili having a mean diameter of 5 nm and a mean length of 420 nm; these were termed type-S pili. Of the 34 faecal isolates, 32% possessed S pili, and 68% were lightly pilated with up to 15 thin, flexible type-L pili, of mean diameter 2.5 nm and mean length 960 nm. Type-L pilation was associated with a high level of HEp-2 cell adhesion, and was more common in A. sobria and A. caviae than in A. hydrophila isolates. These results suggest that adherence to HEp-2 cells is a useful model for the investigation of Aeromonas enteropathogenicity, and that adhesion may be pilus-mediated in this organism.

Finite purification of Anaplasma marginale: serologic inactivity of the anaplasma body.

Anaplasma bodies finitely purified by affinity chromatography to eliminate all traces of erythrocytic stromata were not agglutinated by serum from calves having acute anaplasmosis. The stromata which were associated with the anaplasma bodies were also finitely purified and agglutinated with such serum. The evidence indicates that the antibody in anaplasmosis that is detected by agglutination tests is directed against the erythrocytic stromata and not against the finitely purified anaplasma bodies.