Scintigraphy in prediction of the salivary gland function after gland-sparing intensity modulated radiation therapy for head and neck cancer

BACKGROUND AND PURPOSE: To evaluate salivary gland scintigraphy in prediction of salivary flow following radiation therapy. PATIENTS AND METHODS: Twenty patients diagnosed with head and neck cancer were treated with intensity modulated radiation therapy with an intention to spare the salivary gland function. The total quantitative saliva secretion was measured prior to and 6 and 12 months after therapy, and the function of the major salivary glands was monitored using Tc-99m-pertechnetate scintigraphy. Two models were designed for prediction of the post-treatment salivary flow: an average model, based on the average proportions of saliva produced by each of the four major glands in healthy subjects, and an individual model, based on saliva produced by each gland as measured by scintigraphy prior to therapy. These models were compared with volume-based (Lyman) normal tissue complication probability models using two published sets of model parameters. RESULTS: The D(50) for the parotid and the submandibular gland function assessed at 6 and 12 months after radiotherapy was approximately 39Gy. The scintigraphy-based individual model predicted well the measured post-treatment saliva flow rates. The correlation coefficient between the predicted stimulated and the measured saliva flow rate was 0.77 (p<0.0001) at 6 months and 0.55 (p=0.034) at 12 months after completion of radiotherapy. The relative changes in unstimulated and stimulated salivary flow rates showed similar dependency on the cumulative radiation dose. CONCLUSIONS: Salivary gland function assessed by scintigraphy prior to radiotherapy is useful in prediction of the residual salivary flow after radiotherapy.     

Immunohistochemical profile of cystosarcoma phyllodes of the breast: a study of 23 cases

Cystosarcoma phyllodes (CP) of the breast is a rare biphasic tumor composed of benign epithelium and a spindle cell stroma. Biologic behavior of CP cannot be predicted with certainty on the basis of morphologic criteria only. We studied immunohistochemical expression of basic fibroblastic growth factor (bFGF), urokinase, Ki67, p53 protein, and microvessel density in stromal and epithelial components of 14 low-grade CP (LCP) and 9 high-grade CP (HCP). bFGF was more often positive in LCP than in HCP. The stroma was positive for bFGF in 86% of LCP and 67% of HCP, and the epithelium was positive in 64% of LCP and 14% of HCP. Urokinase was positive in stromal cells of 86% of LCP and 93% of HCP. The epithelial positivity for urokinase in both groups resembled closely that of the stroma. p53 protein was more often positive in stromal cells of HCP (67%) than in LCP (50%). Ki67 was positive in the stroma of 43% of LCP and 89% of HCP and in the epithelium of 14% of LCP and 33% of HCP. There was no significant difference in microvessel density (MVD) in low- and high-grade lesions. Our study demonstrates that stromal Ki67 and p53 immunohistochemical positivity are more often associated with high-grade tumors. The positive immunostaining for bFGF, urokinase, Ki67, and p53 in stroma and epithelium of the majority of CP supports the existence of epithelial-stromal interactions and recognizes epithelium as an integral part of this tumor.     

Reference intervals for cystatin C in pre- and full-term infants and children

Cystatin C is a non-glycated, 13-kDa basic protein produced by all nucleated cells. Recent studies have indicated that the plasma concentration of cystatin C is a better marker for glomerular filtration rate (GFR) than plasma creatinine, which is most commonly used for this purpose. We established reference values for plasma cystatin C in pre- or full-term infants and children. For comparison we also measured the creatinine concentration in the same samples. Cystatin C was measured by a commercially available immunoturbidimetric method with a Hitachi 704 analyzer in sera obtained from 58 pre-term infants, 50 full-term infants and 299 older children (132 girls, 167 boys, median age 4.17 years, range 8 days to 16 years). No sex differences were found. The pre-term infants had higher cystatin C concentrations (mean 1.88 mg/l, SD 0.36 mg/l) than the full-term (mean 1.70 mg/l, SD 0.26 mg/l, P=0.0145). The reference interval for pre-term infants calculated non-parametrically was 1.34–2.57 mg/l and for full-term infants 1.36–2.23 mg/l. The cystatin C concentration decreased rapidly after birth, and above 3 years of age did not depend on age. The reference interval for children 3–16 years of age calculated non-parametrically was 0.51–1.31 mg/l. Younger children (<1 year: 0.75–1.87 mg/l; 1–3 years: 0.68 –1.60 mg/l) had slightly, but significantly, higher plasma cystatin C levels. Received: 26 January 2000 / Revised: 12 April 2000 / Accepted: 17 April 2000     

Malacoplakia of the urethra: a case of unique localization with followup.

A case of malacoplakia of the urethral meatus, without any association of vesical involvement, or any other synchronous or metachronous localization is presented. To our knowledge this is the fourth case in the literature at this site. The patient was free of disease 9 years after excision.     

3-methylcholanthrene-induced monooxygenase (O-deethylation) activity of human lymphocytes.

With a direct fluorescence assay, the levels of mixed-function oxidase activity were determined in mitogen-activated human lymphocytes. The O-deethylation of ethoxyresorufin to resorufin was used to quantitate mixed-function oxidase activity. Ethoxyresorufin O-deethylase activity was low to nondetectable in noninduced, mitogen-activated cells, but it was readily detected in 3-methylcholanthrene, mitogen-activated lymphocytes. The activity was: (a) dependent on assay time and number of lymphocytes; (b) dependent on the presence of reduced nicotinamide adenine dinucleotide phosphate; (c) stable to freezing at -80 degrees for at least 2 weeks; (d) reproducibly detected in duplicate samples of blood from one individual when cultured and assayed at the same time; but (e) quite variable in samples of blood from one individual at different times. Since in hepatic and pulmonary tissue of model animal systems ethoxyresorufin is a specific substrate for cytochrome P-448-associated monooxygenases, the use of this chemical could proffer an assay that specifically measures human cytochrome P-448-associated activity.     

1H MRS studies in the Finnish boron neutron capture therapy project: detection of 10B-carrier, L-p-boronophenylalanine-fructose

This article summarizes the current status of 1H MRS in detecting and quantifying a boron neutron capture therapy (BNCT) boron carrier, L-p-boronophenylalanine-fructose (BPA-F) in vivo in the Finnish BNCT project. The applicability of 1H MRS to detect BPA-F is evaluated and discussed in a typical situation with a blood containing resection cavity within the gross tumour volume (GTV). 1H MRS is not an ideal method to study BPA concentration in GTV with blood in recent resection cavity. For an optimal identification of BPA signals in the in vivo 1H MR spectrum, both pre- and post-infusion 1H MRS should be performed. The post-infusion spectroscopy studies should be scheduled either prior to or, less optimally, immediately after the BNCT. The pre-BNCT MRS is necessary in order to utilise the MRS results in the actual dose planning.