The Cambridge Prognostic Groups for improved prediction of disease mortality at diagnosis in primary non-metastatic prostate cancer: a validation study.

BACKGROUND: The purpose of this study is to validate a new five-tiered prognostic classification system to better discriminate cancer-specific mortality in men diagnosed with primary non-metastatic prostate cancer. METHODS: We applied a recently described five-strata model, the Cambridge Prognostic Groups (CPGs 1-5), in two international cohorts and tested prognostic performance against the current standard three-strata classification of low-, intermediate- or high-risk disease. Diagnostic clinico-pathological data for men obtained from the Prostate Cancer data Base Sweden (PCBaSe) and the Singapore Health Study were used. The main outcome measure was prostate cancer mortality (PCM) stratified by age group and treatment modality. RESULTS: The PCBaSe cohort included 72,337 men, of whom 7162 died of prostate cancer. The CPG model successfully classified men with different risks of PCM with competing risk regression confirming significant intergroup distinction (p < 0.0001). The CPGs were significantly better at stratified prediction of PCM compared to the current three-tiered system (concordance index (C-index) 0.81 vs. 0.77, p < 0.0001). This superiority was maintained for every age group division (p < 0.0001). Also in the ethnically different Singapore cohort of 2550 men with 142 prostate cancer deaths, the CPG model outperformed the three strata categories (C-index 0.79 vs. 0.76, p < 0.0001). The model also retained superior prognostic discrimination in the treatment sub-groups: radical prostatectomy (n = 20,586), C-index 0.77 vs. 074; radiotherapy (n = 11,872), C-index 0.73 vs. 0.69; and conservative management (n = 14,950), C-index 0.74 vs. 0.73. The CPG groups that sub-divided the old intermediate-risk (CPG2 vs. CPG3) and high-risk categories (CPG4 vs. CPG5) significantly discriminated PCM outcomes after radical therapy or conservative management (p < 0.0001). CONCLUSIONS: This validation study of nearly 75,000 men confirms that the CPG five-tiered prognostic model has superior discrimination compared to the three-tiered model in predicting prostate cancer death across different age and treatment groups. Crucially, it identifies distinct sub-groups of men within the old intermediate-risk and high-risk criteria who have very different prognostic outcomes. We therefore propose adoption of the CPG model as a simple-to-use but more accurate prognostic stratification tool to help guide management for men with newly diagnosed prostate cancer.

Gastrocolic fistula: a rare complication of gastric carcinoma.

Malignant gastrocolic fistula formation is a rare complication of gastric carcinoma. We report a cachectic 82-year-old woman who presented with upper abdominal pain, diarrhoea, loss of weight and loss of appetite. Further investigation of her symptoms revealed a gastrocolic fistula connecting the ulcerated tumour of the body of the stomach to the splenic flexure of the colon.

Molecular and pharmacodynamic properties of estrogenic extracts from the traditional Chinese medicinal herb, Epimedium.

The Chinese medicinal herb, Epimedium, used traditionally for bone health exerts estrogenic activity (EA) in vitro. A genetically characterized Epimedium brevicornum (EB) extract induced biphasic responses in the mRNA and protein expression of the estrogen-regulated progesterone receptor gene in breast cancer (MCF-7) cells. These changes were mirrored changes in estrogenic receptor (ERalpha) content. In male Sprague-Dawley rats, administration of the estrogenic prodrug, estradiol valerate increased area-under-curve of serum effects for ERalpha (AUC difference: 18,900EA(ERalpha) min; 95% CI: 0-37,800; p = 0.05) and breast cancer cell (MCF-7) growth (AUC difference: 30,200EA(MCF-7) min; 95% CI: 24,200-36,200; p<0.001), compared to placebo. Oral administration of Epimedium brevicornum increased ERalpha activity (1320EA(ERalpha) min, p<0.01). Our data indicate that estrogen-responsive bioassays can measure the pharmacokinetic/pharmacodynamics of estrogenic activity in serum. Epimedium brevicornum extract increases estrogenic activity in serum and human studies are required to evaluate whether Epimedium extracts have utility for estrogen replacement therapy.

Induction of stanniocalcin-1 expression in apoptotic human nasopharyngeal cancer cells by p53.

There is growing evidence to suggest that altered patterns of STC1 gene expression relate to the process of human cancer development. Our previous study has demonstrated the involvement of HIF-1 in the regulation of STC1 expression in human cancer cells. Recently, STC1 has been implicated as a putative pro-apoptotic factor in regulating the cell-death mechanism. Thus it would be of interest to know if STC1 is regulated by a tumor suppressor protein, p53. In this study, we provide evidence to demonstrate that the induction of STC1 expression in apoptotic human nasopharyngeal cancer cells (CNE2) is mediated by the activation of p53. Our study indicated that the activation of STC1 and heat-shock protein (hsp70) accompanied iodoacetamide (IDAM)-induced apoptosis in CNE-2. In addition, cellular events such as GSH depletion, mitochondrial membrane depolarization, reduction of pAkt and procaspase-3, and the induction of total p53 protein, acetylated p53, and annexin V positive cells were observed. The activation of STC1 was found to be at the transcriptional level and was independent of prior protein synthesis. Co-treatment of IDAM exposed cells with N-acetyl cysteine (NAC) prevented cell death by restoring mitochondrial membrane potential and cellular levels of GSH. NAC co-treatment also suppressed STC1 expression but had no effect on IDAM-induced hsp70 expression. RNA interference studies demonstrated that endogenous p53 was involved in activating STC1 gene expression. Collectively, the present findings provide the first evidence of p53 regulation of STC1 expression in human cancer cells.

Prospective study of the effectiveness of percutaneous transhepatic photodynamic therapy for advanced bile duct cancer and the role of intraductal ultrasonography in response assessment.

BACKGROUND AND STUDY AIMS: We evaluated the therapeutic effects of percutaneous transhepatic photodynamic therapy (PDT) in patients with advanced bile duct cancer. The utility of intraductal ultrasonography (IDUS) for the assessment of responses and for regular follow up after PDT was also examined. METHODS: Percutaneous transhepatic biliary drainage (PTBD) was initiated before PDT. Following dilation and maturation of the PTBD tract, percutaneous PDT was performed. Intraluminal photoactivation was carried out using percutaneous cholangioscopy 2 days after intravenous application of a hematoporphyrin derivative. All patients were additionally provided with percutaneous bile duct drainage catheters after PDT. IDUS was conducted monthly to measure the thickness of the tumor mass before and after PDT. RESULTS: 24 patients with advanced cholangiocarcinomas (Bismuth IIIa, n = 4; IIIb, n = 10; IV, n = 10) were treated with PDT. At 3 months after PDT, the mean thickness of the tumor mass had decreased from 8.7 +/- 3.7 mm to 5.8 +/- 2.0 mm (P < 0.01). At 4 months after PDT, the thickness of the mass had increased to 7.0 +/- 3.7 mm. Quality of life indices improved dramatically and remained stable 1 month after PDT; the Karnofsky index increased from 39.1 +/- 11.36 to 58.2 +/- 22.72 points (P = 0.003). The 30-day mortality rate was 0 %, and the median survival time was 558 +/- 178.8 days (current range 62 - 810 days). CONCLUSIONS: PDT using percutaneous cholangioscopy is safe and effective for advanced hilar cholangiocarcinoma, and seems to prolong survival. IDUS is useful for evaluating changes in the thickness of the tumor mass after PDT.

Endoluminal gastroplication for treatment of patients with classic gastroesophageal reflux symptoms and borderline 24-h pH studies.

BACKGROUND: Patients with classic gastroesophageal reflux disease (GERD) symptoms and borderline 24-h pH studies are not considered to be good candidates for surgical fundoplication. Endoluminal gastroplication (ELGP) is a new endoscopic treatment for patients with GERD. The aim of this study was to evaluate the efficacy of ELGP in these patients. METHODS: Patients with heartburn, regurgitation symptoms and a DeMeester score of less than 30 were studied. ELGP involved placement of two or three plications within 2 cm of the gastroesophageal junction. Clinical outcomes measured were heartburn symptom score (HSS), regurgitation frequency score (RFS) and medication use. RESULTS: Twenty-five patients (11 M, 14 F, mean age of 51 years) had a medication use of 11.5 doses of proton-pump inhibitors per week prior to ELGP. Average lower esophageal sphincter pressure measured 15 +/- 8 mmHg, and average DeMeester score was 18 +/- 8. Nine patients had hiatal hernias and 11 had esophagitis. Twenty-four patients were available for a mean follow-up of 12 months. HSS significantly decreased from 48 to 17 (P < 0.01) and RFS was reduced from 1.8 to 0.7 (P < 0.01). Proton-pump inhibitor use was 5.3 doses per week (P < 0.01) post-ELGP; 12 patients (50%) were off medications, 3 (13%) had a 50% reduction in medication use, and in 9 (37%) there was no change. Complications were bleeding in one patient and aspiration pneumonia in another patient. CONCLUSIONS: Endoluminal gastroplication provides symptomatic relief for patients with classic GERD symptoms despite medical therapy and borderline 24-h pH studies.

Sorption and degradation of steroid hormones in soils during transport: column studies and model evaluation.

Natural and synthetic analogues of steroid hormones and their metabolites have emerged as contaminants of concern. Characterizing sorption and degradation processes is essential to assess the environmental distribution, persistence, and ecological significance of steroid hormones in terrestrial and aquatic systems. We examined the fate and transport of testosterone and 17beta-estradiol by conducting a series of fast-flow-velocity transport experiments under pulse-type and flow-interruption boundary conditions in columns packed with a surface soil, freshwater sediment, and two sands. Flow-interruption experiments provided independent estimates of degradation coefficients for the parent hormones and their metabolites, while pulse-input type experiments were used to identify transport mechanisms for hormones by employing forward modeling approaches. Estimated degradation rate coefficients (k) for the hormones from flow-interruption experiments ranged from 0.003 to 0.015 h(-1) for testosterone and from 0.0003 to 0.075 h(-1) for estradiol, similar to those observed in batch studies. Degradation rate coefficients for the two primary metabolites were 1-2 orders of magnitude larger than those for the parent chemicals. Estimated k values decreased with column life as a result of nutrient depletion. Large sorption by soils of the parent and metabolites (log Koc approximately 2.77-3.69) did not appear to hinder degradation; k values were an order of magnitude smaller than the estimated sorption mass-transfer constants. Differences in hormone breakthrough curves from a single-pulse displacement and those predicted using independently estimated parameters suggest that modeling hormone degradation as a simple first-order kinetic process may be sufficient, but not accurate.

A survey on anesthesia for thoracoscopic sympathetic surgery in treatment of hyperhidrosis palmaris in Taiwan.

Thoracoscopic approach to sympathetic surgery has gained its popularity and emerged as the main stream in the treatment of hyperhidrosis palmaris in Taiwan. Different kinds of anesthesia have been practiced and reported in these surgeries. We made a survey of anesthetic methods in twelve medical centers and regional hospitals of the island. It was found out that the choice of the anesthesia was mainly dependent on the mutual trust and the full communication between the anesthesiologist and the surgeon, both based on their skills and the operative methods chosen by the surgeon. Single-lumen endotracheal tube with general inhalation anesthesia is practiced in most of the hospitals surveyed. Sevoflurane and desflurane are the choices of the inhalational anesthetic agents. In short, the anesthesiologists tend to practice the type of anesthesia that is simple but safe enough to secure the airway of the patient throughout the thoracoscopic sympathetic surgery.

A metastatic pituitary carcinoid tumor successfully treated with gamma knife radiosurgery.

Intracranial metastasis occurs in a certain number of patients with carcinoid tumor. However, carcinoid tumor with metastasis to the pituitary gland is extremely rare. Up to the present, no effective treatment for either a metastatic intracranial carcinoid tumor or a metastatic pituitary lesion of any origin has been documented. We have treated a case of metastatic carcinoid tumor of the pituitary gland with transsphenoidal tumor resection followed by gamma knife radiosurgery. A 59-year-old man presented with headache and left oculomotor palsy. He was treated at the same hospital for bronchial atypical carcinoid tumor one and a half years ago. Magnetic resonance image of the brain showed a pituitary tumor. There were no signs of recurrent or metastatic lesion elsewhere despite thorough investigation. Transsphenoidal approach for removal of tumor was done and the pathology turned out to be a metastatic carcinoid tumor. Subsequent gamma knife radiosurgery was given for residual tumor. The oculomotor palsy improved after radiosurgery. No neurological deficit occurred. Follow-up CT scan of the brain showed complete resolution of the tumor. We concluded that gamma knife radiosurgery could be used to treat a metastatic intracranial carcinoid tumor. It can also be used to treat a metastatic lesion of the pituitary gland without causing neurological deficit.

Role of pH in partitioning and cation exchange of aromatic amines on water-saturated soils.

Predicting the reversible interactions between aromatic amines and soil is essential for assessing the mobility, bioavailability and exposure from contaminated sites. Reversible sorption mechanisms of aniline and alpha-naphthylamine were investigated by using single and binary solute sorption to five soils at several pH values, and by applying a distributed parameter (DP) model. The DP model assumes linear partitioning of the neutral species into soil organic matter domains and organic cation binding on negative-charged sites with the exchange coefficients represented by a Gaussian probability distribution. Sorption nonlinearity was attributed to cation exchange with varying site affinities, which was adequately simulated using the DP model. Greater uptake by hydrophobic partitioning and selectivity for cation exchange sites was observed for alpha-naphthylamine compared to aniline. Sorption of alpha-naphthylamine was not impacted quantitatively by aniline under those conditions examined; however, aniline sorption was reduced by alpha-naphthylamine with the largest reduction occurring in the soil with the lowest pH. DP model simulations showed that although hydrophobic partitioning increases with soil-solution pH, cation exchange still contributes significantly to the total sorption even at soil-solution pH values greater than pKa + 2.

Modeling competitive cation exchange of aromatic amines in water-saturated soils.

Competitive association to several components of soil through ion exchange processes influences the fate of organic cations in the environment. To examine these processes, the distributions of aniline and 1-aminonaphthalene between aqueous 5 mM CaCl2 solutions and three different Indiana soils were evaluated. Solute ratios (Sr) of aniline to 1-aminonaphthalene of 0.4-4.7 were employed, and the soil solutions ranged in pH from 2.7 to 7.5, with all measurements made 24 h after the introduction of the chemicals to the soils. Two previously proposed equilibrium models--the two-site (TS) and distributed parameter (DP) models--were modified to predict competition. These models assume instantaneous equilibrium of the following reversible processes: (i) acid dissociation of the protonated organic base (BHaq+) in the aqueous phase; (ii) ion exchange on the soil between the protonated organic base and inorganic divalent cations (Daq2+ = Caaq2+ + Mgaq2+); and (iii) partitioning of the nonionic species of aniline (Baq) to soil organic carbon. The TS model is a general mass action model that does not take into consideration cation exchange site heterogeneity, whereas the DP model considers association constants to these sites to be distributed in a log-normal fashion. To describe competition for cation exchange sites within the DP model, it was necessary to add a correlation coefficient (rho) that relates the ion-exchange association constant (KBH) probability density distribution functions of the two compounds. The value of rho is characteristic of each soil. Results indicate that competition has a greater effect at low pH values, where ion exchange is the predominant process. For all cases, these models capture the general trends in the soil-water distribution data of both amines. The DP model also captures the nonlinearity of the 1-aminonaphthalene isotherms at low pH while at the same time capturing the nearly linear isotherms of aniline as a competing organic base.

Human Ca2+/calmodulin-dependent protein kinase kinase beta gene encodes multiple isoforms that display distinct kinase activity.

Ca(+2)/calmodulin-dependent protein kinases (CaMKs) are activated upon binding of Ca(+2)/calmodulin. To gain maximal activity, CaMK I and CaMK IV can be further phosphorylated by an upstream kinase, CaMK kinase (CaMKK). We previously isolated cDNA clones encoding human CaMKK beta isoforms that are heterogeneous in their 3'-sequences (Hsu, L.-S., Tsou, A.-P., Chi, C.-W., Lee, C.-H., and Chen, J.-Y. (1998) J. Biomed. Sci. 5, 141-149). In the present study, we examined the genomic organization and transcription of the human CaMKK beta gene. The human CaMKK beta locus spans more than 40 kilobase pairs and maps to chromosome 12q24.2. It is organized into 18 exons and 17 introns that are flanked by typical splice donor and acceptor sequences. Two major species of transcripts, namely the beta1 (5.6 kilobase pairs) and beta2 (2.9 kilobase pairs), are generated through differential usage of polyadenylation sites located in the last and penultimate exons. Additional forms of CaMKK beta transcripts were also identified that resulted from alternative splicing of the internal exons 14 and/or 16. These isoforms display differential expression patterns in human tissues and tumor-derived cell lines. They also exhibit a distinct ability to undergo autophosphorylation and to phosphorylate the downstream kinases CaMK I and CaMK IV. The differential expression of CaMKK beta isoforms with distinct activity further suggests the complexity of the regulation of the CaMKK/CaMK cascade and an important role for CaMKK in the action of Ca(+2)-mediated cellular responses.

Microsurgical treatment of deep arteriovenous malformations--basal ganglia and thalamus.

BACKGROUND: Surgery for deep nuclei arteriovenous malformations (AVMs) is controversial after the introduction of stereotactic irradiation and embolization. However, rupture of an AVM in this location can lead to catastrophic parenchymal or intraventricular hemorrhage. Thus, microsurgery still has its place in treatment of such lesions to prevent the untreated AVM bleeding or rebleeding. We present a series of 16 AVMs located in the deep nuclei treated by direct microsurgery before radiosurgery was available in 1993. METHODS: We reviewed the clinical and angiographic characteristic of 16 patients with deep-seated AVMs (three in caudate nucleus, three in lentiform nucleus and ten in thalamus). The surgical approach was described separately depending upon the location of the AVMs. The surgical outcomes were classified as excellent (symptoms improved), good (no additional neurological deficit), fair (minor neurological deficit), bad (major neurological deficit) and dead. RESULTS: Complete AVM elimination was achieved in 16 patients (100%) in one-stage operation. Eleven patients had excellent or good outcomes, three had fair outcomes and two had bad outcomes. There were no deaths in this series. Two patients had permanent hemiparesis to make a late morbidity rate of 12.5%. CONCLUSIONS: With improving microsurgical techniques, neuroimaging and neuroanesthesia, difficult and deeply hidden AVMs can be successfully resected under microsurgery with an acceptably low morbidity and mortality rate.

Membranous occlusion of the foramen of Monro following ventriculoperitoneal shunt insertion: a role for endoscopic foraminoplasty.

We report two cases of lateral ventricle dilatation due to membranous occlusion of the foramen of Monro following ventriculoperitoneal shunt insertion. Both cases were treated successfully by endoscopic foraminoplasty of the obstructed foramen of Monro and III ventriculostomy. One child had meningomyelocele and hydrocephalus. She had CSF infection after repair of the back lesion. Isolated left lateral ventricle occurred after insertion of a right ventriculoperitoneal shunt for hydrocephalus when the girl was 2 months old. A right ventriculoperitoneal shunt was then inserted. Chronic shunt infection with abdominal pseudocyst was found 8 years later. The shunts were exteriorized. Membranous obstruction of the foramen of Monro was found endoscopically. Fenestration of the membranous obstruction along with a III ventriculostomy was performed. After the endoscopic procedure, the exteriorized ventriculoperitoneal shunt was removed 2 weeks later. The patient was still symptom free without shunting 14 months after the operation. The other child had hydrocephalus after a premature birth and hemorrhage. Repeated ventriculoperitoneal shunt infections contributed to membranous obstruction of bilateral foramen of Monro. After the shunt infection was treated this patient's shunting procedure was simplified by endoscopic foraminoplasty of the left and right foramen of Monro along with a III ventriculostomy. He was symptom free with a new ventriculoperitoneal shunt 9 months after the operation.

Elevated levels of urine angiostatin and plasminogen/plasmin in cancer patients.

Previously, a specific angiogenesis inhibitor, angiostatin, discovered in urine and serum of tumor-bearing mice, was reported to potently block tumor growth and metastasis in animal models. Detection of angiostatin and its precursor proteins in urine from cancer patients has not been reported. Now, we report the development of an antibody-based analysis system that allows us to detect angiostatin and plasminogen/plasmin (Pgn/plasmin) in the urine of cancer patients. The detection system is a combination of a novel lysine-ELISA assay and Western immunoblot analysis using a specific antibody to human angiostatin and Pgn/plasmin. High levels of Pgn/plasmin were detected in the urine from various cancer patients, whereas healthy individuals showed relatively low levels of urine Pgn/plasmin. Of interest, angiostatin is detectable in urine samples of patients with various cancers, including acute lymphoblastic leukemia, suggesting that angiogenesis may play an important role in the development and progression of leukemia. Our data for the first time show that angiostatin and Pgn/plasmin are present at relatively high levels in the urine of human cancer patients. Detection of urine angiostatin in cancer patients helps us not only to understand the role of this angiogenesis inhibitor in cancer development and progression but also allows us to develop tools of cancer diagnosis and prognosis. Thus angiostatin has both therapeutic and diagnostic implications in cancer disease.

Prolonged circulating lives of single-chain Fv proteins conjugated with polyethylene glycol: a comparison of conjugation chemistries and compounds.

The utility of single-chain Fv proteins as therapeutic agents would be substantially broadened if the circulating lives of these minimal antigen-binding polypeptides were both prolonged and adjustable. Poly(ethylene glycol) (PEG) bioconjugate derivatives of the model single-chain Fv, CC49/218 sFv, were constructed using six different linker chemistries that selectively conjugate either primary amines or carboxylic acid groups. Activated PEG polymers with molecular weights of 2000, 5000, 10 000, 12 000, and 20 000 were included in the sFv bioconjugate evaluation. Additionally, the influence of PEG conjugate geometry in branched PEG strands (U-PEG) and the effect of multimeric PEG-sFv bioconjugates on circulating life and affinity were examined. Although random and extensive PEG polymer conjugations have been achievable in highly active derivatives of the prototypical PEG-enzymes, PEGylation of CC49/218 sFv required stringent adjustment of reaction conditions in order to preserve antigen-binding affinity as measured in either mucin-specific or whole cell immunoassays. Purified bioconjugates with PEG:sFv ratios of 1:1 through 2:1 were identified as promising candidates which exhibit sFv affinity (K(d)) values within 2-fold of the unmodified sFv protein. Interestingly, PEG conjugation to carboxylic acid moieties, using a PEG-hydrazide chemistry, achieved significant activity retention in bioconjugates at a higher PEG:sFv ratio (5:1) than with any of the amine-reactive activated PEG polymers. Prolonged circulating life in mice was demonstrated for each of the PEG conjugates. An increase in PEG polymer length was found to be more effective for serum half-life extension than a corresponding increase in total PEG mass. For example, CC49/218 sFv conjugated to either one strand of PEG-20000, or four strands of PEG-5000, displayed about 20- or 14-fold increased serum half-life, respectively, relative to the unmodified sFv. The demonstrated suitability of established random conjugation chemistries for PEGylation of sFv proteins, in conjunction with innovative site-specific conjugation methods, indicates that production of a panoply of sFv proteins with both engineered affinity and tailored circulating life may now be achievable.

Intraoperative neurosurgical ultrasonography.

BACKGROUND: Ultrasound scanning is a well-established means of evaluating intracranial structures in infants and children with open fontanelles. However, it remains underutilized in neurosurgical operations. We present our experience with the intraoperative use of realtime ultrasonography during 36 neurosurgical procedures. METHODS: Thirty-six intraoperative ultrasonography (IOUS) procedures were performed over the past two years. Thirty-two patients had intracranial lesions and four had intraspinal tumors. A real-time scanner equipped with a 5 MHz and a 7.5 MHz transducer was used during surgery. RESULTS: IOUS worked well, regardless of the location of the craniotomy site. It was useful in localizing and characterizing intracranial and intraspinal masses, assuring the completeness of tumor removal (22 cases), proper positioning of ventricular shunt catheters (5 cases), guiding and confirming the decompression of cysts or abscesses (3 cases) and real time monitoring of surgical complications (36 cases). CONCLUSIONS: IOUS can be helpful in defining intracranial and intraspinal lesions as well as normal architecture. It shortens the operative time and decreases the surgical morbidity. The expertise of the physician with sonographic equipment facilitates its accurate and expedient intraoperative neurosurgical application.

Pilocytic astrocytoma of the posterior fossa: a follow-up study in 15 patients.

BACKGROUND: The extent of resection in pilocytic astrocytoma of the posterior fossa remains undefined, as the problem of hydrocephalus has not yet been solved. We retrospectively reviewed the data from 15 patients with a pilocytic astrocytoma of the posterior fossa to evaluate the impact of surgical technique, in terms of resection extent, by serial magnetic resonance imaging (MRI) examinations. In addition, the issue of hydrocephalus was considered and related to the different treatment modalities. METHODS: Macroscopic, gross, total resection of the tumor was performed in all 15 patients. Follow-up was obtained in 14 patients for a period ranging between 11 and 119 months (median, 41.5 months). The ages of patients ranged from two to 13 years (mean, 7 +/- 3 years). All patients underwent serial MRI examinations in the first month, every six months for the first two years and then yearly. RESULTS: Outcome was good in 12 patients who had no neurologic deficit and fair in two patients who were slightly handicapped but had an independent life. There were four patients with an abnormally persistent enhancement on MRI, with a median follow-up of 30 months. One of these patients had progressively increasing size of the enhancement. Three of them had the same size of enhancement during the follow-up period. The MRI findings showed residual tumors in four patients. One of them had tumor regrowth one year after surgery. There were 11 cases with pilocytic astrocytoma and hydrocephalus. Five patients were treated with tumor removal and external CSF drainage. Six patients underwent tumor removal only, without perioperative cerebrospinal fluid (CSF) drainage. Only one patient had a permanent ventriculoperitoneal shunt. CONCLUSIONS: Our study illustrated that the extent of tumor resection of pilocytic astrocytoma can be defined by postoperative serial MRI examinations. Long-term follow-up with MRI seems mandatory in cases with abnormal enhancement. Hydrocephalus is a common finding in patients with a pilocytic astrocytoma. A permanent ventriculoperitoneal shunt is required only in patients with postoperative hydrocephalus.