Search PubMed⌕ Search

Biomedical subjects

K W Fong

Publications and source records attributed to K W Fong.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prediction of perinatal outcome in fetuses suspected to have intrauterine growth restriction: Doppler US study of fetal cerebral, renal, and umbilical arteries.

PURPOSE: To determine and compare the diagnostic performance of fetal middle cerebral (MCA), renal (RA), and umbilical (UA) arterial Doppler ultrasonography (US) for prediction of adverse perinatal outcome in suspected intrauterine growth restriction (IUGR). MATERIALS AND METHODS: Two hundred ninety-three small-for-gestational age fetuses (24-39 weeks at recruitment and US-estimated weight or abdominal circumference below 10th percentile) were prospectively examined with Doppler US of the UA, MCA, and RA. Clinicians were blinded to MCA and RA Doppler measurements. RESULTS: Seventy-six fetuses (25.9%) had at least one major or minor adverse perinatal outcome. Major outcomes included stillbirth, neonatal death, neurologic complication, and necrotizing enterocolitis. The MCA pulsatility index (PI), compared with the UA PI and RA PI, was more sensitive (72.4% vs 44.7% and 8.3%) but less specific (58.1% vs 86.6% and 92.6%) in predicting adverse outcome. The UA PI had the highest positive likelihood ratio (ratio, 3.3); the MCA PI had the lowest negative likelihood ratio (ratio, 0.48). When gestational age at the first Doppler US examination was less than 32 weeks, the MCA PI had a sensitivity of 95.5% and negative predictive value of 97.7% for major adverse outcome (negative likelihood ratio, 0.10). CONCLUSION: In suspected IUGR, while an abnormal UA PI is a better predictor of adverse perinatal outcome than an abnormal MCA or RA PI, a normal MCA PI may help to identify fetuses without major adverse perinatal outcome, especially before 32 weeks gestational age.

Brain↗
PubMed1999

Concurrent chemoradiotherapy in patients with locally advanced nasopharyngeal carcinoma of the undifferentiated type.

The result with radiotherapy alone in patients with locally advanced nasopharyngeal carcinoma (NPC) was disappointing. Encouraging results have been reported with the use of concurrent chemoradiotherapy in patients with locally advanced squamous cell carcinoma of the head and neck. Hence, we decided to explore the use of this treatment schedule in patients who presented with locally advanced disease (UICC/AJCC classification system). Between July 1995 and March 1996, 14 patients with locally advanced NPC were treated with the following schedule: radiation therapy was given conventionally to a total of 66 to 70 Gy to both the nasopharynx and neck with or without parapharyngeal/intracavitary boost; chemotherapy consisted of intravenous cisplatin at 20 mg/m2/day and intravenous 5-flurouracil 1000 mg/m2/day, infused over 8 hours on days 1 to 4 during the first and fifth week of radiation therapy. Depending on the patient's tolerability and clinical assessment of toxicity, a third cycle of chemotherapy was planned 4 to 5 weeks after the second cycle, upon the completion of the radiotherapy. Twelve patients completed all intended treatment. Two patients failed to do so due to treatment-related mortality. The median follow-up duration was 30 months. Limiting toxicities were myelosuppression and oropharyngeal mucositis. The overall response rate was a 100% at both the primary and nodal sites of disease. The median disease-free survival was 21 months. Forty per cent of the patients were alive at 3 years. This treatment schedule was associated with an unacceptable treatment-related death rate. As a result, this protocol was terminated.

Adult↗
PubMed1998

Long-term hearing status after radiotherapy for nasopharyngeal carcinoma.

This paper evaluates the hearing status in the long-term, of patients who have had radiotherapy for nasopharyngeal carcinoma (NPC) and also discusses the hearing losses from a disability point of view, which takes into account binaural hearing. Forty patients who have had NPC successfully treated by a single radical course of radiotherapy of 70-80 Gy were studied at 2-12 years (mean 6.2 years) after radiotherapy. Each patient was examined clinically and with a pure-tone audiogram. Averaged hearing thresholds over 0.5, 1.0, 2.0 and 4.0 kHz were evaluated and a value > 30 dB was considered abnormal. The findings were compared with age-matched controls. The median hearing threshold for each ear in NPC patients was found to be 31.9 dB (range 10.0-86.3 dB) and that for controls 17.5 dB (7.5-38.8 dB) (P < 0.0005, Wilcoxon's matched pairs test). In NPC patients, 44 ears (55.0%) had abnormal hearing, of which 17 (21.3%), 5 (6.3%) and 22 (27.5%) ears had predominantly sensori-neural, conductive and mixed hearing losses, respectively. Nineteen ears had middle ear effusions, accounting for the majority of mixed and conductive hearing losses. In terms of individual patients, 8 (20.0%) and 18 (45.0%) patients had abnormal hearing in one year (monaural hearing disability) and both ears (binaural hearing disability), respectively. In conclusion, a substantial proportion of patients who have had radiotherapy for NPC, have hearing disability in the long-term, as compared to normal controls.

Adult↗
PubMed1998

Long-term post-irradiation middle ear effusion in nasopharyngeal carcinoma.

This study aimed to find out if there were factors which influenced the development of long-term middle ear effusion (MEE) in patients irradiated for nasopharyngeal carcinoma. Thirty-five patients (70 ears) were studied for 2-8 years (mean 5.5 years) post-radiotherapy. The factors studied were (a) sex (b) age (c) tumour size and (d) presence of pre-radiotherapy MEE. Only the presence of pre-radiotherapy MEE was found to be statistically significant (P = 0.004, Fisher's exact test). Stepwise multiple regression analysis showed the presence of pre-radiotherapy MEE was a predictor of post-radiotherapy MEE with an odds ratio of 0.67. It is postulated that irreversible Eustachian tube dysfunction occurs when the tube which has been damaged by tumour is further damaged by irradiation. This may explain the frequent persistent otorrhea when ventilation tubes are used to treat post-radiotherapy MEE in patients with nasopharyngeal carcinoma. In conclusion, an ear with pre-irradiation MEE was almost seven times more likely to have long-term post-irradiation MEE than an ear without pre-irradiation MEE.

Ear, Middle↗
PubMed1997

Intrathecal methotrexate overdose.

We report two cases of intrathecal methotrexate overdose. A 3-y-old girl with acute lymphoblastic leukaemia and a 4-y-old boy with Burkitt's lymphoma were to receive an intrathecal injection of methotrexate after completion of intravenous methotrexate infusion. Instead of 12.5 mg, they both received a dose of 125 mg. Both children developed generalized convulsion 3 h after the overdose, but afterwards recovered completely. Intravenous folinic acid and dexamethasone rescue were employed, but no attempt was made to exchange the cerebrospinal fluid. In addition to the staff's failure to check the drug label carefully, the marked resemblance of the two dose preparations of methotrexate (50 mg/5 ml and 500 mg/5 ml) may have been contributory.

Antimetabolites, Antineoplastic↗
PubMed1996

Hearing disability before and after radiotherapy for nasopharyngeal carcinoma.

This paper evaluates post-irradiation hearing changes in patients with nasopharyngeal carcinoma (NPC) from a disability orientated approach, which takes into account binaural hearing. Newly diagnosed patients with NPC were studied before radiotherapy, and at four to 12 months (mean 9.2 months) after radiotherapy, provided they remained disease-free. Each patient was examined clinically and with pure tone audiograms. Tympanometry was used to confirm middle ear effusion. Averaged hearing thresholds over 0.5, 1 and 2 kHz were evaluated. If abnormal (> 30 dB), the resultant hearing disability was illustrated by a modified Glasgow Plot. Twenty-three males and 10 females completed the study. Middle ear effusions resulted in 39.3 per cent (binaural in two patients) and 33.3 per cent (binaural in five patients) of patients having hearing disability pre- and post-irradiation respectively. No patient had hearing disability as a result of a sensorineural loss. It is recommended that future reporting of post-irradiation hearing changes in patients with NPC, as in middle ear surgery, be considered from a disability-orientated approach.

Adult↗
PubMed1996

Patient profile and survival in 270 computer tomography-staged patients with nasopharyngeal cancer treated at the Singapore General Hospital.

This is a report analysing the patient profile and survival results in 270 patients with nasopharyngeal carcinoma treated with radiation therapy between July 1987 and December 1988. The patients had a median age of 52.6 months, and a male-female ratio of 2.5:1. Ninety-four percent of patients were Chinese. The commonest presentation was that of a neck mass (found in approximately 65% of patients). Approximately two-thirds presented with disease more advanced than Ho's stage II. At a median follow-up of 52.6 months, the 5-year actuarial survival rate was 53% and the freedom from relapse rate was 57%. One hundred and seven patients died within the observation period. Of these, 46 patients had disease in the post nasal space, 41 in the neck and 60 in sites outside the head and neck.

Actuarial Analysis↗
PubMed1996

Localised nodal non-Hodgkin's lymphoma--a study of 42 cases treated by radiotherapy.

The records of 42 patients with stage I and II nodal non-Hodgkin's lymphoma treated by radiotherapy with and without chemotherapy were analysed with regards to clinical presentation, investigations, treatment, radiotherapy techniques and results. The 5-year overall survival rates for all, low grade, intermediate grade and high grade histology types are 69.5%, 100%, 64.4% and 46.9% respectively. The 5-year relapse-free survival rates of those treated by initial radiotherapy alone for all, low grade and intermediate-high grade histology types are 54.8%, 46.9% and 59.4% respectively.

Adolescent↗
PubMed1990

Lip and intraoral tumours: a local perspective.

Lip and intra-oral cancer is an uncommon disease in Singapore among the local population. The incidence is less than 1.5% of all cancers reported to the Singapore Cancer Registry which recorded a total of 18,049 cases of all types of cancer in a 5-year period from 1978 to 1982. The Department of Plastic Surgery at Singapore General Hospital has been conducting a multidisciplinary clinic for the management of head and neck tumours since 1984. The results of the distribution, age, sex and racial differences, risk factors and modalities of treatment of the various types of cancer affecting the lip and intraoral region were analysed in a prospective study. A total of 69 cases were analysed and of these 59 (85.5%) were squamous cell carcinoma (SCC) of varying grades of malignancy, the remaining comprising adenoidcystic and mucoepidermoid carcinoma, malignant melanoma and a single case of ameloblastoma. A number of predisposing factors such as smoking, alcohol and the chewing of betel nuts could be identified in the history of patients suffering from cancers involving the buccal mucosa and tongue. As the numbers involved in non-SCC are small in this study, the discussion will be confined to patients presenting with squamous cell carcinoma only.

Adult↗
PubMed1988

Prenatal sonographic diagnosis of Pena-Shokeir syndrome type I, or fetal akinesia deformation sequence.

We report on a familial case of Pena-Shokeir syndrome type I (fetal akinesia deformation sequence) born to healthy parents. The antenatal ultrasound diagnosis was based on hydramnios, restricted limb movements, decreased fetal chest movements, small chest, arthrogryposis, clubfoot, fixed extension of knees, fixed flexion of elbows, camptodactyly, kyphosis of thoracic spine, cryptorchidism, and small muscle bulk. Thymic hyperplasia was noted at autopsy.

Abnormalities, Multiple↗
PubMed1987

Etiological factors associated with the development of periventricular leukomalacia.

Prenatal, intrapartum and postnatal factors are compared between 15 preterm infants, known to have periventricular leukomalacia (PVL) on ultrasound and 15 infants of similar birthweight and gestation who ultrasonographically showed no evidence of cystic lesions, and who are known to be neurologically normal at follow up. Prenatally, the incidence of antepartum haemorrhage was significantly higher in the PVL group. Intrapartum factors were similar between the two groups but postnatally, the PVL group had significantly lower PaCO2 readings during the first 72 h of life. It is postulated that a severe maternal bleed in late pregnancy and neonatal hypocarbia could significantly decrease cerebral perfusion and cause areas of ischaemia and infarction resulting in periventricular leukomalacia.

Encephalomalacia↗
PubMed1986

Periventricular leukomalacia: ultrasonic diagnosis and neurological outcome.

The ultrasonographic findings and neurological development of 15 preterm infants, born between August 1981 and July 1984, who developed periventricular leukomalacia (P.V.L.) are described. The incidence of P.V.L. in infants with a birth weight less than 1 500 g was 2.3%. Nine of the 15 infants demonstrated areas of increased echogenicity in the periventricular regions prior to the development of cystic changes. The mean age for the appearance of cysts was 26 days. At follow-up 14 infants showed evidence of abnormal motor development and 8 infants had visual defects. All infants appear to have normal hearing, but 3 infants show signs of delayed speech. To date, only 2 infants demonstrate signs of mental retardation, but many of the infants are too young to assess intelligence accurately.

Brain Diseases↗
PubMed1986

Fetal renal cystic disease: sonographic-pathologic correlation.

Renal cystic disease encompasses a complex group of pathologic and clinical entities, with varied yet distinctive sonographic features. An accurate assessment of the fetal genitourinary tract and the amniotic fluid volume by sonography can lead to a specific prenatal diagnosis in most cases. This article emphasizes the usefulness of sonographic-pathologic correlation in understanding renal cystic disease. The entities discussed are infantile polycystic kidney disease (Osathanondh and Potter type I), multi-cystic renal dysplasia (type II), adult polycystic kidney disease (type III) and renal cystic dysplasia associated with obstructive uropathy (type IV). Sonograms of six correctly diagnosed cases between November 1982 and November 1984 were retrospectively reviewed and correlated with their pathologic findings. The differential diagnosis and possible pitfalls are discussed. In addition, the impact on perinatal management and the role of genetic counselling will be emphasized.

Female↗
PubMed1985

Reliability of amniotic fluid volume estimation from ultrasonograms: intraobserver and interobserver variation before and after the establishment of criteria.

This study assesses levels of intraobserver and interobserver agreement for the determination of decreased and normal amniotic fluid volumes, both before and after the development of criteria. Good to excellent levels of agreement were obtained. Agreement may be higher after the development of criteria and may be higher for more experienced ultrasonographers.

Amniotic Fluid↗
PubMed1984

Diagnosis and evolution of periventricular leukomalacia: a study with real-time ultrasound.

Periventricular leukomalacia is an ischemic lesion in periventricular white matter of premature infants. Hemorrhage into the ischemic area occurs in up to 25% of cases. We report two cases in which the diagnosis of periventricular leukomalacia was made during life with real-time ultrasound scanning. In one case, serial scans demonstrated the evolution of echodense regions, observed in the first 3 days of life, to cystic echolucent areas at 4 weeks. In the second case, periventricular echodense areas did not precede the occurrence of cystic echolucent lesions. This may reflect a more chronic ischemic cerebral insult (consistent with recurrent apnea and bradycardia) rather than a presumed acute episode of cerebral ischemia (with or without secondary hemorrhage) sustained by the first case. Real-time ultrasound scanning is a simple, non-invasive technique with which to document the evolution of periventricular leukomalacia, and thus to define the clinical neurological correlates in the neonatal period.

Brain Ischemia↗