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Biomedical subjects

K C Westbrook

Publications and source records attributed to K C Westbrook.

At least 19 recordsLinked to original sources
PubMed2001

Magnetic resonance imaging-guided core needle biopsy and needle localized excision of occult breast lesions.

BACKGROUND: Breast magnetic resonance imaging (MRI) has been reported to be twice as sensitive and three times more specific in detecting breast cancer. We report a series of MRI-guided stereotactic breast biopsies (SCNBB) and needle localized breast biopsies (NLBB) to evaluate MRI as a localization tool. METHODS: Forty-one breast lesions were identified in 39 patients who subsequently had SCNBB or NLBB. Suspicious areas of enhancement were stereotactically biopsied with 16-G core biopsy needles or localized with 22-G wires for excision under laser guidance. RESULTS: Forty-one breast lesions were identified from 1,292 breast MRIs. SCNBB identified three malignancies and two areas of atypia. Two additional cancers were found after NLBB. In patients having NLBB alone, five cancers and two areas of atypia were identified. CONCLUSIONS: In this initial series, breast MRI-guided SCNBB and NLBB were valuable tools in the management of patients with suspicious abnormalities seen only on MRI.

Adult↗
PubMed2001

Hematoma-directed ultrasound-guided breast biopsy.

OBJECTIVE AND SUMMARY BACKGROUND DATA: The standard technique for removal of nonpalpable breast lesions is needle localization breast biopsy. Because traumatic hematomas can often be seen with ultrasound, the authors hypothesized that iatrogenically induced hematomas could be used to guide the excision of nonpalpable lesions using ultrasound. METHODS: Twenty patients with nonpalpable breast lesions detected by magnetic resonance imaging only were enrolled in this single-institution trial, approved by the institutional review board. A hematoma consisting of 2 to 5 mL of the patient's own blood was injected into the breast to target the nonpalpable lesion. Intraoperative ultrasound of the hematoma was used to direct the excisional biopsy. RESULTS: The average age of women was 53.8 +/- 10 years. Ninety-five percent of lesions detected by magnetic resonance imaging were localized by hematoma injection. All the hematomas used to recognize targeted lesions were identified at surgery by ultrasound and removed without complication. Eight (40%) of the lesions were malignant, with an average tumor size of 12 +/- 6 mm (range 4-25). The remaining 12 lesions (60%) comprised papillomas, sclerosing adenosis, radial scar, fibroadenoma, and areas of atypical ductal hyperplasia. CONCLUSION: The results of this pilot study show the effectiveness of hematoma-directed ultrasound-guided breast biopsy for nonpalpable lesions seen by magnetic resonance imaging. This new procedure is potentially more comfortable for the patient because no wire or needle is left in the breast. It is technically faster and easier because ultrasound is used to visualize directly the location of the hematoma at surgery and to confirm lesion removal in the operating room by specimen ultrasound. The hematoma can be placed several days before biopsy, easing scheduling, and without fear of the migration that may occur with needle localization. This method may have ready application to mammographically detected lesions.

Adult↗
PubMed2000

Central venous catheter placement in patients with disorders of hemostasis.

BACKGROUND: Patients requiring central venous access frequently have disorders of hemostasis. The aim of this study was to identify factors predictive of bleeding complications after central venous catheterization in this group of patients. METHODS: A retrospective analysis of all central venous catheters placed over a 2-year period (1997 to 1999) at our institution were performed. The age, sex, clinical diagnosis, most recent platelet count, prothrombin international normalized ratio (INR), activated partial thromboplastin time (aPTT), catheter type, the number of passes to complete the procedure, and bleeding complications were retrieved from the medical records. RESULTS: In a 2-year period, 2,010 central venous catheters were placed in 1,825 patients. Three hundred and thirty placements were in patients with disorders of hemostasis. In 88 of the 330 patients, the underlying coagulopathy was not corrected before catheter placement. In these patients, there were 3 bleeding complications requiring placement of a purse string suture at the catheter entry site. In the remaining 242 patients, there was 1 bleeding complication. Of the variables analyzed, only a low platelet count (<50 x 10(9)/L) was significantly associated with bleeding complications. CONCLUSION: Central venous access procedures can be safely performed in patients with underlying disorders of hemostasis. Even patients with low platelet counts have infrequent (3 of 88) bleeding complications, and these problems are easily managed.

Blood Coagulation Disorders↗
PubMed1999

Role of breast magnetic resonance imaging in determining breast as a source of unknown metastatic lymphadenopathy.

BACKGROUND: Occult primary breast cancer (OPBC) represents less than 1% of breast cancer. In only a third of cases, mammography identifies a primary tumor. We hypothesized that rotating delivery of excitation off-resonance breast magnetic resonance imaging (MRI) would identify or exclude the breast as a primary site in patients with OPBC. METHODS: In a retrospective review, 10 patients were identified with OPBC in which MRI was performed. Malignant appearing lesions were correlated with histopathologic findings at biopsy or surgery. RESULTS: MRI identified the primary site in 8 of 10 cases as breast (80%), and excluded it in 2 cases. The extent of disease and location was accurately predicted when compared with histopathologic specimen. CONCLUSIONS: As we continue to focus on a cure of early breast cancer, it is imperative that diagnostic images become more sensitive and specific. MRI accurately predicted OPBC in this subset of patients.

Adult↗
PubMed1998

Effect of glutamine on methotrexate efficacy and toxicity.

OBJECTIVE: To examine the effect of oral glutamine (GLN) on the efficacy and toxicity of methotrexate (MTX). SUMMARY BACKGROUND DATA: The use of high-dose chemotherapy regimens is limited by the severity of their toxicities. Oral GLN has been shown to decrease the gut toxicity seen with MTX treatment while enhancing its tumoricidal effect. METHODS AND RESULTS: Studies were done in laboratory rats and in breast cancer outpatients. Fischer 344 rats were randomized to 48 hours of prefeeding with GLN (1 g/kg/day) or an isonitrogenous amount of glycine. Rats were killed 24 hours after receiving a 20-mg/kg intraperitoneal dose of MTX. In the GLN group, there was a threefold increase in total MTX in the tumor as compared with the control group, and this increase was in both the diglutamated and pentaglutamated MTX. Inversely, there was a significant decrease in the total polyglutamated MTX in the gut in the GLN group. Given the results of this preclinical study, the authors performed a phase I trial. Nine patients diagnosed with inflammatory breast cancer received GLN (0.5 g/kg/day) during MTX neoadjuvant therapy, escalating from doses of 40 mg/m2 to 100 mg/m2 weekly for 3 weeks, followed by a doxorubicin-based regimen. No toxicity of oral GLN was detected. No patient showed any sign of chemotherapy-related toxicity. One patient had a grade I mucositis. Except for one, all patients responded to the chemotherapy regimen. Median survival was 35 months. CONCLUSIONS: These studies suggest that GLN supplementation is safe in its administration to the tumor-bearing host receiving MTX. By preferentially increasing tumor retention of MTX over that of normal host tissue, GLN may serve to increase the therapeutic window of this chemotherapeutic age.

Adult↗
PubMed1994

Prevention of chronic radiation enteropathy by dietary glutamine.

BACKGROUND: Nearly 50% of all cancer patients receive therapeutic radiation during the course of their disease. The risk of late complications is the main dose-limiting factor in the delivery of radiation therapy. The small intestine, the major site of chronic radiation enteropathy, is also the principal organ of glutamine consumption. We therefore hypothesized that the provision of supplemental glutamine may have a protective effect on the development of chronic radiation enteropathy. METHODS: This study evaluated the effects of supplemental oral glutamine on the development of chronic radiation (XRT) enteropathy. After scrotalization of a loop of small intestine, rats were randomized to receive 1 g/kg/day glutamine (GLN) or glycine (GLY) by gavage. After 2 days of prefeeding, rats were randomized to 1 of 4 groups: GLN + XRT (n = 10), GLY + XRT (n = 10), GLN only (n = 10), GLY only (n = 10). Twenty Gy was delivered to the scrotalized bowel in the GLN + XRT and GLY + XRT groups via a collimated beam. Gavage was continued for 10 days. Animals were then pair-fed chow. Rats were killed at 2 months postirradiation. Chronic radiation injury was assessed microscopically. RESULTS: Injury scores in GLN + XRT were similar to those of unirradiated bowel and significantly different from GLY + XRT (1.89 +/- 0.48 in XRT + GLN vs. 6.42 +/- 1.55 in the XRT + GLY, p < 0.01). Elevated Injury Scores in the XRT + GLY group correlated with gross thickening and fibrosis, a 10-fold decrease in gut GLN extraction (1.40 +/- 4.3% in GLY + XRT vs. 16.0 +/- 5.1% in GLN + XRT, p < 0.05), and a 30% decrease in glutathione content (2.46 +/- 0.19 and GLY + XRT vs. 3.17 +/- 0.17 GLN + XRT, p < 0.05). CONCLUSIONS: Provision of GLN during abdominal/pelvic XRT may prevent XRT injury and decrease the long-term complications of radiation enteropathy.

Administration, Oral↗
PubMed1992

Effect of supplemental dietary glutamine on methotrexate concentrations in tumors.

This study evaluated the effects of supplemental dietary glutamine (GLN) on methotrexate sodium concentrations in tumors and serum of sarcoma-bearing rats following the initiation of methotrexate. After randomization to a GLN diet (+GLN) or GLN-free diet (-GLN), tumor-bearing rats received 20 mg/kg of methotrexate sodium by intraperitoneal injection. The provision of supplemental GLN in the diet increased methotrexate concentrations in tumor tissues at 24 and 48 hours (38.0 +/- 0.20 nmol/g for the +GLN group vs 28.8 +/- 0.10 nmol/g for the -GLN group and 35.6 +/- 0.18 nmol/g for the +GLN group vs 32.5 +/- 0.16 nmol/g for the -GLN group, respectively). Arterial methotrexate levels were elevated only at 48 hours (0.147 +/- 0.007 microns/L for the +GLN group vs 0.120 +/- 0.006 microns/L for the -GLN group). Tumor morphometrics were not different between the groups but significantly greater tumor volume loss was seen even at 24 hours (-2.41 +/- 1.3 cm3 for the +GLN group vs -0.016 +/- 0.9 cm3 for the -GLN group). Tumor glutaminase activity was suppressed in both groups at 48 hours, but more so in the +GLN group (0.94 +/- 0.13 mumol/g per hour for the +GLN group vs 1.47 +/- 0.22 mumol/g per hour for the -GLN group). This study suggests that GLN may have therapeutic as well as nutritional benefit in oncology patients.

Animals↗
PubMed1992

Advantages of the Papillon protocol in the preoperative treatment of rectal carcinoma.

Standard treatment for advanced rectal carcinoma currently includes surgery, radiotherapy, and chemotherapy. Although there are theoretic advantages to preoperative irradiation, it is often not performed because of the prolonged delay of surgery and the purported increase in perioperative complications. A pilot study was undertaken at our institution to evaluate a treatment protocol advocated by Dr. Papillon that offers a shorter treatment time and less patient morbidity than conventional preoperative therapy for rectal carcinoma. Twenty patients with rectal cancer underwent the preoperative regimen that consisted of 3,000 cGy delivered in 10 fractions over 12 days with concomitant 5-fluorouracil and mitomycin-C. Complications were acceptable. Local recurrence was lower than in most reported trials, and survival rates were comparable. Additional benefits of the protocol include lower radiation morbidity to the patient and a decreased delay between diagnosis and surgery.

Adenocarcinoma↗
PubMed1991

Prognostic significance of carcinoembryonic antigen in colorectal carcinoma. Serum levels before and after resection and before recurrence.

The use of carcinoembryonic antigen was evaluated in 425 patients with a mean follow-up of 48 months. The preoperative and postoperative carcinoembryonic antigen levels were predictive of recurrence and survival independent of the tumor stage. In a multivariate regression analysis of age, location, tumor stage, and preoperative and postoperative carcinoembryonic antigen levels, the latter three factors were significant prognostic variables with respect to the adjusted survival. Recurrent disease was found in 42% of patients, excluding patients with stage IV disease. The carcinoembryonic antigen level at recurrence was greater than 5 ng/mL in 79% of the patients and in 89% of the intra-abdominal recurrences. Carcinoembryonic antigen level at recurrence was not predictive of postrecurrence survival except in the subgroup of locoregional disease. The life span in patients with liver and lung metastases was not influenced by carcinoembryonic antigen level at recurrence. Preoperative and postoperative carcinoembryonic antigen levels can indicate a poorer prognostic group of patients with colorectal cancer who may benefit from adjuvant treatment. The carcinoembryonic antigen at recurrence can be used effectively to diagnose intra-abdominal recurrences and project survival after development of local/regional disease.

Aged↗
PubMed1990

Breast cancer.

Breast cancer will affect 1 out of 10 women in the United States and cause 27 deaths per 100,000 women per year. The etiology remains unknown, but the incidence correlates with genetic as well as environmental factors. Screening programs have been shown to prolong the survival by early detection compared with control populations but remain underutilized by physicians and patients. Breast disease can be evaluated by physical examination and mammography and a definitive diagnosis made by needle aspiration, needle biopsy, or excisional biopsy. This allows the patient to participate in the decision regarding mastectomy vs. conservative surgery plus radiation therapy. These two approaches have equivalent survival in selected patients. Patients with locally advanced, nonmetastatic disease benefit from a multidisciplinary approach using preoperative chemotherapy and postoperative radiation therapy. This approach has allowed less disfiguring surgery and improved survival. Preinvasive carcinoma is diagnosed more frequently with the increased use of screening mammography. Local therapy options include simple mastectomy, local excision plus radiation, or local excision alone. The natural history and results of therapy in preinvasive disease are evolving as more data are accumulated. Systemic adjuvant therapy is recommended for all node-positive patients and most node-negative patients with invasive cancer. The specific modality (hormonal or cytotoxic) varies with the subgroup involved. Treatment of metastatic disease to palliate symptoms and prolong survival includes the use of local therapies (surgery and radiation) and hormonal and cytotoxic agents. Most patients benefit, but cure has been unobtainable. Newer approaches utilizing high-dose chemotherapy and bone marrow support with growth factors or autologous transplantation are currently being explored.

Breast Neoplasms↗
PubMed1989

Peritoneal carcinomatosis in nongynecologic malignancy. A prospective study of prognostic factors.

Regional recurrence of malignant tumors in the peritoneal cavity usually signifies a poor prognosis for the host and often results in gastrointestinal complications requiring surgical intervention. One hundred patients with nongynecological malignancies found with peritoneal carcinomatosis were followed prospectively. The most common primary tumors were colorectal (N = 45) and pancreatic (N = 20) carcinoma. When associated with pancreatic carcinoma, 65% of patients had liver metastases and 60% had ascites. The presence of ascites was associated with poor survival, with no patient surviving past 30 days. Ascites was also a sign of poor prognosis in patients with colorectal carcinoma. Among possible prognostic factors in colorectal carcinoma patients, only disease-free interval, presence of lung metastases, and ascites showed statistically significant correlations with survival. Peritoneal carcinomatosis in sarcoma (N = 7) and breast cancer (N = 6) patients had median survival of 12 and 7 months, respectively. Surgical intervention for gastrointestinal complications in peritoneal carcinomatosis can provide significant palliation, with a few exceptions such as in patients with pancreatic or gastric carcinoma, ascites, and poor performance status.

Adult↗
PubMed1987

The current evaluation of nonpalpable breast lesions.

To understand the suspected low yield of malignant neoplasms from biopsies guided by needle localization, we reviewed 122 biopsies performed from January 1985 to November 1986 at University Hospital and Arkansas Baptist Medical Center, Little Rock. The positive biopsy rates were 3.5% and 10.6%, respectively. After review of these cases, the following guidelines for biopsy were developed: (1) Do not perform a biopsy on a low-density mass less than 1 cm in diameter. (2) Do not perform a biopsy for asymmetric density or questionable mass. (3) Do not perform a biopsy for secondary signs of malignancy such as skin thickening or asymmetric vasculature. (4) Biopsy is indicated for clustered calcifications, a dominant mass greater than 1 cm in diameter, stellate lesions, or interval change from a previous mammogram. These changes resulted in a positive biopsy rate of 15% for the period from November 1986 through April 1987.

Biopsy, Needle↗
PubMed1986

Precise intraoperative location of gastrointestinal bleeding with a hand-held counter. Work in progress.

The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Müller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding.

Gastrointestinal Hemorrhage↗
PubMed1985

Clinical oncology assistantship program for medical students.

The Clinical Oncology Assistantship Program has been offered to approximately 16 sophomore medical students each year at the University of Arkansas for Medical Sciences since 1975. This is an elective, 10-week program given during the summer recess. In the first week of the program, core lectures are given by a multidisciplinary team of cancer educators affiliated with the University of Arkansas. Following this, students spend nine weeks rotating through medical, surgical, and pediatric oncology services of the University of Arkansas for Medical Sciences. In addition, they spend several hours during the program participating in self-directed learning activities at the university's Cancer Teaching Center. The program has been well received by the students, and each year all of the available positions have been filled. Responses on a follow-up questionnaire sent in July 1983 to past participants showed that they continued to rate the program highly. Moreover, 78 percent of the respondents felt the program had influenced positively their attitude toward cancer patients.

Arkansas↗
PubMed1985

Use of intraoperative radionuclide study and colonoscopy in gastrointestinal hemorrhage.

Tc-99m labeled red cell imaging is used in the diagnosis and localization of gastrointestinal hemorrhage. A patient in whom a preoperative scan was positive in the right paraumbilical region is discussed. Intraoperative Tc-99m labeled red cell imaging was used in conjunction with colonoscopy, and the site of active bleeding was found in the proximal transverse colon, which had been displaced downward because of adhesions.

Colonoscopy↗