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Biomedical subjects

K T Brown

Publications and source records attributed to K T Brown.

At least 19 recordsLinked to original sources
PubMed2005

Upper urinary tract metastases from adenocarcinoma of the colon.

An unusual presentation of colorectal metastasis to the upper urinary tract is reported. The metastasis manifested as a filling defect seen during antegrade pyelography. Cytologic evaluation of aspirated material demonstrated metastatic colonic adenocarcinoma. A dilated collecting system may be caused by intraluminal material including tumor and blood clots. Whenever fixed filling defects are encountered, urine cytology should be sent even in the absence of renal parenchymal involvement by tumor. The cytological evaluation may allow for prompt diagnosis and treatment.

Acute Kidney Injury↗
PubMed2001

Portal vein embolization with use of polyvinyl alcohol particles.

Preoperative portal vein embolization has been used as method of inducing compensatory hypertrophy in the future remnant liver since it was first described in the late 1980s. Many different vascular embolic agents have been successfully used for this procedure, and there is no general consensus regarding which is the best agent. Polyvinyl alcohol (PVA) particles commonly used for arterial embolization come in many sizes, are readily available, and are easy to administer via conventional catheters. We describe an easy, safe, and effective method of the use of PVA particles for portal vein embolization.

Embolization, Therapeutic↗
PubMed2000

Hepatic neuroendocrine metastases: does intervention alter outcomes?

BACKGROUND: In most instances, advanced neuroendocrine tumors follow an indolent course. Hepatic metastases are common, and although they can cause significant pain, incapacitating endocrinopathy, and even death, they are usually asymptomatic. The appropriate timing and efficacy of interventions, such as hepatic artery embolization (HAE) and operation, remain controversial. STUDY DESIGN: The records of 85 selected patients referred for treatment of hepatic neuroendocrine tumor metastases between 1992 and 1998 were reviewed from a prospective database. A multidisciplinary group of surgeons, radiologists, and oncologists managed all patients. Overall survival among this cohort is reported and prognostic variables, which may be predictive of survival, are analyzed. RESULTS: There were 37 men and 48 women, with a median age of 52 years. There were 41 carcinoid tumors, 26 nonfunctional islet cell tumors, and 18 functional islet cell tumors. Thirty-eight patients had extrahepatic metastases, and in 84% of patients, the liver metastases were bilobar. Eighteen patients were treated with medical therapy or best supportive care, 33 patients underwent HAE, and 34 patients underwent hepatic resection. Both the HAE-related mortality and the 30-day operative mortality rates were 6%. By univariate analysis, earlier resection of the primary tumor, curative intent of treatment, and initial surgical treatment were associated with prolonged survival (p < 0.05). On multivariate analysis, only curative intent to treat remained significant (p < 0.04). Patients with bilobar or more than 75% liver involvement by tumor were least likely to benefit from surgical resection. One-, 3-, and 5-year survival rates for the entire group were 83%, 61%, and 53%, respectively. The 1-, 3-, and 5-year survivals for patients treated with medical therapy, HAE, and operation were 76%, 39%, and not available; 94%, 83%, and 50%; and 94%, 83%, and 76%, respectively. CONCLUSIONS: Hepatic metastases from neuroendocrine tumors are best managed with a multidisciplinary approach. Both HAE and surgical resection provide excellent palliation of hormonal and pain symptoms. In select patients, surgical resection of hepatic metastases may prolong survival, but is rarely curative.

Adult↗
PubMed2000

Recognition of intrabiliary hepatic metastases from colorectal adenocarcinoma.

Intrinsic involvement of bile ducts, by metastatic colorectal adenocarcinoma growing from within or invading the lumen of bile ducts, is not a well recognized pattern of tumor growth. Clinical, radiographic, operative, and histopathologic aspects of 15 patients with intrabiliary colorectal metastases were described. Fourteen patients were explored for possible hepatic resection. Two had jaundice, two radiographic evidence of an intrabiliary filling defect, 10 intraoperative evidence of intrabiliary tumor, and six microscopic evidence of intrabiliary tumor. Eleven patients underwent hepatic resection. Five of the resected patients developed hepatic recurrence. Four patients were explored for possible repeat resection. One had jaundice, one radiographic evidence of an intrabiliary filling defect, all had intraoperative evidence of intrabiliary tumor, and three microscopic evidence of intrabiliary tumor. Three patients underwent repeat hepatic resection. All patients with preoperative jaundice and radiographic evidence of an intrabiliary filling defect were unresectable. Overall, actuarial five-year survival is 33% for those patients resected versus 0% for those not resected. Intraoperative recognition of intrabiliary tumor at exploration for hepatic resection was more common than clinical, radiographic, or histopathologic recognition. More diligent examination of resected liver tissue by the surgeon and pathologist may increase identification of bile duct involvement and aid in achieving adequate tumor clearance.

Adenocarcinoma↗
PubMed1999

Particle embolization of hepatic neuroendocrine metastases for control of pain and hormonal symptoms.

PURPOSE: To evaluate treatment outcome with respect to the indication for treatment in patients with neuroendocrine tumors metastatic to the liver undergoing hepatic artery embolization with polyvinyl alcohol (PVA) particles. MATERIALS AND METHODS: Charts and radiographs were reviewed of 35 patients undergoing 63 separate sessions of embolotherapy between January 1993 and July 1997. Patient demographics, tumor type, indication for embolization, and complications were recorded. Symptomatic and morphologic responses to therapy were noted, as well as duration of response. RESULTS: Fourteen men and 21 women underwent embolization of 21 carcinoid and 14 islet cell tumors metastatic to the liver. These patients underwent 63 separate episodes of embolotherapy. Of 48 episodes that could be evaluated, response to treatment was noted following 46 episodes (96%). The duration of response was longest in patients treated for hormonal symptoms with (17.5 months) or without (16 months) pain, and was shortest (6.2 months) when the indication was pain alone. Complications occurred after 11 of the 63 embolizations (17%), including four (6%) deaths. Cumulative 5-year survival following embolotherapy was 54%. CONCLUSION: Hepatic artery embolization with PVA particles is beneficial for patients with neuroendocrine tumors metastatic to the liver and may be used for control of pain as well as hormonal symptoms. This therapy should be used cautiously when more than 75% of the hepatic parenchyma is replaced by tumor.

Adenoma, Islet Cell↗
PubMed1999

Up-regulation of retinoic acid receptor beta expression in renal cancers in vivo correlates with response to 13-cis-retinoic acid and interferon-alpha-2a.

Retinoic acid receptor-beta (RAR-beta) mRNA is not expressed by retinoid-resistant renal cancer cell lines but is present in retinoid-sensitive SK-RC-06 renal cancer cells and increases following incubation with retinoic acid (RA), suggesting that the antitumor action of RA is mediated through RAR-beta (A. D. Hoffman et al., Clin. Cancer Res., 2: 1077-1082, 2996). To determine whether RAR-beta expression correlates in vivo with major clinical response to patients with renal cell carcinoma (RCC) who were treated with retinoid-based therapy, we used in situ hybridization to analyze RAR-beta expression in tumor specimens obtained from patients who were treated on a clinical trial with 13-cis-RA and IFN-alpha. Thirty-three tissue specimens were analyzed (23 pretreatment and 10 on-treatment). mRNA expression was based on staining intensity, with scores within tumor cells ranging from 0 to 2, where a score of 0 indicated absence of staining, a score of 1 indicated weak staining, and a score of 2 indicated strong staining. RAR-beta expression was present in 22 of 23 (96%) pretreatment and 9 of 10 (90%) on-treatment specimens. Pretreatment levels of expression did not associate with the site of biopsy and did not predict for major clinical response to RA plus IFN-alpha therapy (two-sided Fisher's exact test, P = 0.826). However, an increase in the intensity of RAR-beta mRNA expression was detected in four of five (80%) patients who achieved a major response but in none of the five patients with progressive disease in whom sequential biopsies were available (two-sided Fisher's exact test, P = 0.048). These data show that RAR-beta transcripts increase in tumor cells of RCC patients who clinically respond to retinoid-based therapy. Retinoids that potently induce RAR-beta expression should be evaluated in the treatment of advanced RCC.

Biopsy↗
PubMed1998

MRI as an alternative to CT-guided biopsy of adrenal masses in patients with lung cancer.

BACKGROUND: This study was performed to assess chemical shift magnetic resonance imaging (CSMRI) for characterizing adrenal masses in patients with lung cancer, and to compare charges associated with two algorithms for assessing adrenal masses in these patients. METHODS: Forty-two patients with lung cancer underwent both CSMRI (using in-phase and opposed-phase gradient echo images) and computed tomography-guided percutaneous biopsy of adrenal masses. Adrenal-to-spleen signal intensity ratios on the opposed-phase images were correlated with histopathologic results. The normalized charges for two algorithms were compared. In algorithm A, computed tomography-guided biopsy is used first to evaluate an adrenal mass; in algorithm B, CSMRI is used first, followed by computed tomography-guided biopsy only if CSMRI findings are not diagnostic of adenoma. RESULTS: Biopsy showed 24 (57%) adrenal adenomas and 18 (43%) metastases. Chemical shift magnetic resonance imaging was 96% sensitive for adenoma and 100% specific. The average normalized charges associated with algorithm A were $1,905 per patient versus $1,890 with algorithm B. CONCLUSIONS: Initial use of CSMRI in evaluating an adrenal mass in lung cancer patients can obviate biopsy in 55% of patients, and its charges are similar to those for performing computed tomography-guided biopsy in all patients.

Adenocarcinoma↗
PubMed1997

Outpatient treatment of iatrogenic pneumothorax after needle biopsy.

PURPOSE: To evaluate prospectively the feasibility of treating iatrogenic pneumothorax after fine-needle aspiration biopsy (FNAB) of the lung with short-term placement of a small-caliber chest tube and to determine whether a 1-hour clamping trial is adequate to identify patients with persistent air leak. MATERIALS AND METHODS: All patients undergoing FNAB of lung masses over a 28-month period were entered into the study. Patients with symptomatic, enlarging, or greater than 30% pneumothorax were treated with an 8-F chest tube. After 2 hours, the chest tube was clamped, and if the lung remained expanded for an additional hour, the chest tube was removed and the patients were discharged after a brief observation period. Patients were followed up by telephone after 24 hours. RESULTS: Three hundred fifteen patients underwent FNAB of the lung. Sixty-eight patients (22%) developed a pneumothorax. Chest tubes were placed in 14 patients (4%): Six patients (2%) required admission to the hospital (four for air leaks), and the other eight patients were treated successfully as outpatients, with removal of the chest tube before discharge the day of FNAB. CONCLUSION: Patients who develop clinically important pneumothorax after FNAB can be safely treated with short-term, small-caliber chest tubes and require hospital admission only if they demonstrate evidence of continued air leak.

Adolescent↗
PubMed1997

Comparison of two algorithms and their associated charges when evaluating adrenal masses in patients with malignancies.

OBJECTIVE: This study was performed to compare two proposed algorithms used when evaluating an adrenal mass discovered during staging evaluation of a patient with a known malignancy. Such evaluation was meant to lead to determination of the relative charges associated with each algorithm. SUBJECTS AND METHODS: Fifty-four patients with known malignancies who required evaluation of an adrenal mass underwent both chemical shift imaging (CSI) and CT-guided for CSI. The hospital charges incurred for each procedure and any associated complications were normalized using national relative-value scale charges and conversion factors. A decision analysis was performed to compare the relative charges that would have been incurred if adrenal MR imaging had been performed in all patients, followed by CT-guided biopsy only in those patients with MR findings not diagnostic of adrenocortical adenoma, and the relative charges incurred if only CT-guided adrenal biopsy had been performed in every patient. RESULTS: Twenty-three (43%) of 54 adrenal masses were shown to be metastases by CT-guided biopsy. The sensitivity and specificity of CSI for the diagnosis of adrenocortical adenoma were 94% and 100%, respectively. The charges incurred by performing MR imaging as the initial examination with subsequent CT-guided biopsy only in those patients with CSI findings not diagnostic of adenoma would have been similar to those incurred by first performing CT-guided adrenal biopsy in every patient. CONCLUSION: CSI is an accurate, noninvasive technique for evaluating adrenal masses in patients with cancer. If CT-guided biopsy is used only when CSI is not diagnostic of adrenocortical adenoma, the associated charges would be virtually the same as when CT-guided biopsy is performed as the first test in every patient. Moreover, biopsies could have been avoided in 54% of these patients.

Adrenal Cortex Neoplasms↗
PubMed1996

Portal vein evaluation with US: comparison to angiography combined with CT arterial portography.

PURPOSE: To compare ultrasound (US) to angiography combined with computed tomography during arterial portography (CTAP) in the preoperative evaluation of the portal vein. MATERIALS AND METHODS: Sixty-three consecutive patients being considered for hepatic resection underwent color and spectral Doppler US and angiography with CTAP before surgery. The main, right, and left portal veins were evaluated separately. A total of 187 veins were assessed for encasement, occlusion, or thrombosis. RESULTS: At surgery, 41 portal veins were abnormal. US allowed detection of 38 of 41 (93%) involved portal veins with 93% sensitivity, 99% specificity, 97% positive predictive value, and 98% negative predictive value. Angiography with CTAP allowed diagnosis of 37 of 41 (90%) involved portal veins with 90% sensitivity, 99% specificity, 95% positive predictive value, and 97% negative predictive value. CONCLUSION: US is comparable to angiography combined with CTAP in evaluation of the portal vein.

Constriction, Pathologic↗
PubMed1996

Hepatic lobar atrophy: association with ipsilateral portal vein obstruction.

OBJECTIVE: This study was performed to evaluate the association between hepatic lobar atrophy, bile duct obstruction, and portal vein obstruction. MATERIALS AND METHODS: Thirty cases of hepatic lobar atrophy identified on angiography with CT during arterial portography from August 1992 to March 1995 were retrospectively reviewed by two independent observers. Cases were evaluated for vascular patency and bile duct obstruction. Malignant diagnoses were present in 28 of 30 patients. RESULTS: Twenty-two patients (73%) had atrophy in the left lobe and eight patients (27%) had right lobar atrophy. Portal vein obstruction was unilateral and confined to the atrophic lobe in 26 patients (87%). In contrast, bile duct obstruction was bilateral in 23 patients (77%) and in only four patients (13%) was it isolated to the atrophic lobe. The correlation between atrophy and portal vein obstruction was significant, with 90% sensitivity, 97% specificity, and 96% positive predictive value (p < .00001). For the correlation between atrophy and biliary obstruction, the sensitivity of angiography with CT during arterial portography was 90%, specificity was 23%, and positive predictive value was 54% (p = .17). CONCLUSION: Hepatic lobar atrophy usually occurs in the setting of combined biliary and portal vein obstruction. A significant correlation exists between hepatic lobar atrophy and ipsilateral portal vein obstruction.

Adult↗
PubMed1996

Malignant hepatic hilar tumors: can ultrasonography be used as an alternative to angiography with CT arterial portography for determination of resectability?

Nineteen consecutive patients with malignant hilar obstruction were imaged with angiography, CT portography, and ultrasonography with color and spectral Doppler technique; all had surgical pathologic correlation. At surgery, 12 of 19 patients (63%) were found to have portal vein involvement; 15 of 19 (79%) had parenchymal invasion; and 11 of 19 (58%) had lobar atrophy. Level of biliary obstruction was determined in seven of 19 patients (37%) without drainage catheters. No difference was found between ultrasonography and angiography with CT portography for diagnosis of atrophy, level of bile duct obstruction, hepatic involvement, or venous invasion. Extrahepatic metastases in nine of 19 patients (47%) were poorly predicted by both CT portography and ultrasonography.

Adult↗
PubMed1995

Adrenal masses in patients with malignancy: prospective comparison of echo-planar, fast spin-echo, and chemical shift MR imaging.

PURPOSE: To assess echo-planar, fast spin-echo (SE), and chemical shift magnetic resonance (MR) imaging in differentiation of adrenal adenomas from malignant adrenal masses in patients with known malignancy. MATERIALS AND METHODS: Sixty-eight adrenal masses (23 malignant, 45 benign) in 68 patients with known malignancy were examined with echo-planar, fast SE with and without fat suppression, and chemical shift pulse sequences. RESULTS: With a cutoff T2 value of 75 msec, the sensitivity of echo-planar imaging for benign lesions was 82%, and specificity was 96%. With a cutoff adrenal mass-to-spleen signal intensity ratio of 0.80, the sensitivity of fast SE imaging for benign lesions was 53%, and specificity was 96%. With a cutoff adrenal mass-to-spleen ratio of 0.55, the sensitivity of chemical shift imaging for benign lesions was 80], and specificity was 100%. CONCLUSION: Chemical shift imaging and calculated T2 values from echo-planar imaging are promising techniques for differentiation of adrenal adenomas from malignant adrenal masses and can obviate biopsy.

Adenoma↗
PubMed1993

Cytologic analysis in fine-needle aspiration biopsy: smears vs cell blocks.

OBJECTIVE: Imaging-directed fine-needle aspiration biopsy can be performed with or without immediate cytologic assessment (smears). We compared the results obtained immediately from cytologic smears with the results of cell-block analysis. We wished to determine the frequency of false-negative findings on cytologic smears in patients subsequently found to have malignant tumors by cell-block analysis. MATERIALS AND METHODS: We retrospectively reviewed the records for 100 consecutive biopsies performed between January 1986 and August 1987. In each case, specimens were obtained from both a 22-gauge and a 20-gauge notched needle placed in tandem. The study group consisted of 84 patients who had results of analyses of both cytologic smears and cell blocks available for review and who had clinical or surgical correlation. RESULTS: Sixty-four (76%) of the 84 biopsies yielded malignant tumor cells, 11 yielded evidence of a benign process, and nine were not diagnostic. Malignant tumor cells were seen on the cytologic smears in 55 (86%) of the 64 patients who had malignant tumors; in the other nine patients, the malignant tumors were indicated by the cell-block analysis only. Within the group of benign disorders, in only one case (9%) was the cell block diagnostic when the cytologic smear was not. CONCLUSION: Operators performing fine-needle aspiration biopsy should be aware of the limitations of immediate cytologic evaluation. Cell-block analysis of the aspirate remaining after the smears are made can be expected to increase the diagnostic accuracy in up to 14% of patients.

Aged↗
PubMed1992

Paucity of angiographic findings despite extensive organized thrombus in chronic thromboembolic pulmonary hypertension.

The authors describe a patient with chronic thromboembolic pulmonary hypertension. At pulmonary angiography, only severe hypertension with pruning of peripheral vessels was seen; the right pulmonary artery appeared normal. Despite the limited use of a nonionic contrast material, the patient died 11 hours after the study. At autopsy, a laminated well-organized thrombus that occupied virtually all of the right pulmonary artery and adhered to the vessel wall was seen. Other modalities should be investigated to help establish the diagnosis of chronic thromboembolic pulmonary hypertension.

Adult↗
PubMed1989

Gastric and hepatic infarction following embolization of the left gastric artery: case report.

The authors report an initially successful left gastric artery embolization performed because of massive upper gastrointestinal bleeding; the procedure was complicated by focal gastric and hepatic infarctions. These complications occurred in the absence of underlying factors known to predispose to ischemia. Low-grade gastric bleeding persisting after seemingly successful embolization of the left gastric artery may indicate ischemic gastritis and is an indication for endoscopy. In addition, the presence of a left hepatic artery completely replaced to the left gastric artery should alert one to the potential for hepatic necrosis.

Aged↗