MRI treatment planning for CNS neoplasm: graphic display of target volume using boxed cursor.

Treatment planning systems are now capable of interfacing with MRI units, however, reconstructing images in multiple planes remains a laborious process. We have described the construction of contrast markers used with MRI imaging to determine the isocenter coordinates of preplanned CNS treatment fields. Currently existing software was then used to reconstruct the patients target volume by centering a box cursor of appropriate size over the predetermined coordinate representing isocenter. Off axis views of the target volume were easily reconstructed, as were images in the coronal and axial planes. The box cursor technique was useful in making modifications to field placement and field size.

Preoperative radiation therapy for rectal cancer. An effective therapy in need of a clinical trial.

Sixty patients with locally advanced adenocarcinoma of the rectum have been treated with preoperative high-dose pelvic irradiation in an attempt to improve operability and increase local control. Fifty-six patients showed no evidence of distant metastases at surgery and their records have been analyzed with respect to recurrence patterns, survival, and complications. The results have been compared with those of a similar analysis of 106 patients treated with curative surgery alone. There was a statistically significant improvement in local control between groups, with 16% of patients in the radiotherapy group having a component of local failure compared with 40% in the surgery group. A dose response was observed, with 67% local control at 4000 rad (4000 cGy) and 91% local control at 5000 rad (5000 cGy). Despite the more advanced clinical stage of the irradiated patients, no significant difference in survival was seen between groups, with a five-year survival rate of 52% in the irradiated patients and 48% in patients treated by surgery alone. Preoperative high-dose radiotherapy was well tolerated, with a 5% incidence of major complications in both groups.

Dose response to preoperative irradiation in rectal cancer: implications for local control and complications associated with sphincter sparing surgery and abdominoperineal resection.

Sixty patients with locally advanced adenocarcinoma of the rectum have been treated with preoperative high dose pelvic irradiation at the University of Virginia and Rockingham Memorial Hospital. Fifty-six patients showed no evidence of distant metastases at surgery. A dose response was observed with a 67% incidence of local control with 4000 cGy vs. 91% incidence with 5000 cGy. For the 52 patients who received curative surgery, there has been no local failure alone; 6 of these patients have had local plus distant failure and 16 have had distant failure only. Forty-three percent had anterior resection (AR) and 57% had abdominoperineal resections (APR). The major complication rate was 5% and the minor 14%. No increase in complications or decrease in local control was found between APR and AR. Five-year actuarial survival was 64% for lesions limited to the bowel wall, 59% for node negative lesions with disease extending through the wall, and 23% for node positive patients.

Enzymatic assay for creatinine with fixed-time kinetics on a centrifugal analyzer.

A method is described for enzymatic measurement of serum creatinine using a centrifugal analyzer. The method employs fixed-time kinetics and a true serum blank. The method required 100 microliters of serum and is linear to 90 mg per L. Day-to-day precision studies revealed a standard deviation (coefficient of variation) of less than +/- 0.5 mg per L (7.4 percent) at a mean creatinine concentration of 6 mg per L and +/- 0.5 mg per L (1.8 percent) at a mean value of 28 mg per L. The method was free of interferences from acetoacetic acid, ascorbic acid, bilirubin, and hemoglobin. The speed, precision, and accuracy of the method suggest that it represents a useful alternative to methods using the alkaline picrate procedure.

Measurement of glycosylated hemoglobins using boronate affinity chromatography.

A boronate affinity column method for the measurement of glycosylated hemoglobins was evaluated. In the procedure the glycosylated hemoglobins were bound by immobilized boronic acid to separate them from nonglycosylated hemoglobins. Elution of bound glycosylated hemoglobins was carried out with sorbitol buffer, and the absorbance was read at 414 nm. The method was linear to a glycosylated hemoglobin concentration of at least 20 percent. The precision of the method ranged from 1.2 to 2.8 percent (C.V.) within-run, and 3.4 to 5.3 percent day-to-day. The reference interval was 4.8 to 6.4 percent. The method correlated with a cation exchange resin mini-column method (r = 0.94) and a colorimetric method (r = 0.93) but results from the boronate affinity method were higher in diabetic patients. The measured glycosylated hemoglobin was significantly correlated with estimated one-day-mean plasma glucose in diabetic patients (r = 0.54, n = 52, p less than 0.002). The affinity method provides an attractive alternative to earlier methods for measuring glycosylated hemoglobins.