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Biomedical subjects

F F Liu

Publications and source records attributed to F F Liu.

At least 73 records · Page 4Linked to original sources
PubMed1996

A case of achondrogenesis type IA with an occipital encephalocele.

We report on a case of achondrogenesis type IA (Houston-Harris) with an occipital encephalocele. Prenatal sonograms revealed polyhydramnios, subgaleal edema, microcephaly, a narrow thorax, pericardial effusion, and a severe short-limbed dwarfism with unossified tubular bones and vertebral bodies. Postmortem examination demonstrated additional findings of hydrops fetalis, a membranous calvarium with a defect, an occipital encephalocele, hypoplastic lungs, and wedge-like tubular bones. Whole body radiography revealed no ossification of the bones except some small identified foci of calcification in the base of the skull, clavicles, and pelvic bones. Histological examination of the growth plate showed hypercellularity and enlarged vacuolated chondrocytes with PAS-positive diastase-resistant cytoplasmic inclusions. Various abnormalities have been reported in association with achondrogenesis type IA, however, an associated neural tube defect has not previously been described in the literature. We report on an infant with both of these disorders.

Abnormalities, Multiple↗
PubMed1995

Prenatal diagnosis of omphalocele associated with umbilical cord cyst.

BACKGROUND: To study the cytogenetics, ultrasound findings, biochemical screening, perinatal outcome, and associated abnormalities in cases of omphaloceles associated with umbilical cord cysts. METHODS: From 1988 to 1994, three cases of omphaloceles with umbilical cord cysts were identified at Mackay Memorial Hospital. We compared the clinical data of our three cases with six other cases in the published literature. RESULTS: Two cases of omphaloceles with umbilical cord cysts were affected with trisomy 18. One had bilateral choroid plexus cyst, intrauterine growth retardation, low levels of maternal serum alpha-fetoprotein and free beta-human chorionic gonadotropin, and the other had cleft lip and palate, single umbilical artery and intrauterine growth retardation. An elevated level of maternal serum alpha-fetoprotein was found in the case with normal karyotype. Elevated levels of amniotic fluid alpha-fetoprotein were found in two cases. Rupture of the umbilical cord cyst and disruption of the umbilical cord occurred in one case at delivery. Based on the gross and microscopic examinations, the cord cysts we observed are likely to be pseudocysts. CONCLUSION: The umbilical cord cysts most commonly associated with omphaloceles are pseudocysts and allantoic cysts. Among our three cases and the six other cases published in the literature, four out of these nine cases were trisomy 18. Prenatal diagnosis of omphaloceles or umbilical cord cysts by ultrasound warrants cytogenetic analysis and detailed sonogram to rule out the possible combination of both abnormalities and trisomy 18. If an omphalocele is associated with a large umbilical cord cyst and a normal karyotype, cesarean section is recommended to prevent the dilemma of intrauterine vascular compromise of umbilical blood flow during labor.

Abnormalities, Multiple↗
PubMed1994

Phylloides tumor of the breast: a report of 14 cases.

The objective of this retrospective study is to determine the role of radiation therapy in the management of benign phylloides tumors. Fourteen patients with a diagnosis of benign phylloides tumor (PT) and registered at the Princess Margaret Hospital are included in the study. Definitive surgery consisted of either lumpectomy in seven patients or mastectomy in the other seven patients. One patient died of her disease, and the remaining patients had no evidence of disease at last follow-up (median 38.4 months). Among these 13 patients, 4 had at least one recurrence and the recurrence rate was higher for the group who underwent lumpectomy (43% compared with 28%). One patient was treated by lumpectomy and adjuvant radiation therapy, and had no subsequent recurrence (follow-up time 35.5 months). The role for radiation therapy in the management of this disease remains unclear.

Adult↗
PubMed1994

Lentigo maligna of the head and neck. Results of treatment by radiotherapy.

BACKGROUND AND DESIGN: Although surgical excision is considered the treatment of choice for lentigo maligna, some elderly patients presenting with large lesions in the head and neck region may not be suitable candidates for surgical management. Radiotherapy has been used for this tumor at the Princess Margaret Hospital, Toronto, Ontario, for over the past 20 years with encouraging results. Fifty-four patients treated between 1968 and 1988 were identified, and their records were reviewed to determine treatment outcome. RESULTS: Younger patients with smaller lesions were treated with surgical excision (n = 18) and achieved an actuarial tumor control rate of 94% at 3 years. Older patients with larger lesions located in the head and neck area were treated by radiotherapy (n = 36), with an actuarial tumor control rate of 86% at 5 years. Three of the four patients not achieving tumor control by radiation were successfully treated with surgical excision, and two of them proved to have malignant melanomas (both Clark's level II) when examined histologically. One patient with residual pigmentation 4 months after treatment was unavailable for follow-up. No patients developed metastatic melanoma. The late cosmetic appearance was acceptable in the majority of irradiated patients, with 11% showing poor cosmesis due to progressive skin pallor, atrophy, and telangiectasia in the treated area. CONCLUSION: Conventional fractionated radiation therapy with superficial x-rays is a simple and effective method of management for lentigo maligna of the head and neck region. It is an excellent alternative treatment to surgical excision, with low morbidity and acceptable long-term cosmetic results.

Adult↗
PubMed1993

Beam shaping for microwave waveguide hyperthermia applicators.

PURPOSE: Hyperthermia treatments commonly use single element microwave waveguide applicators. The microwave beam patterns produced by these applicators are often non-uniform. As a result, hot spots are formed in the heated tissue and therapeutic temperatures are reached in only small areas of the treatment field. We have constructed new coupling boluses that improve the heating patterns of external microwave applicators. METHODS: The microwave beam transmitted through the bolus is modified by microwave absorbing saline/gelatin pads. The pads can be designed to result in a uniform heating pattern over a large area or alternatively, complex heating patterns can be generated for specific clinical applications. An analysis of the effect of bolus design parameters on microwave absorption patterns is presented. The heating patterns of the MA-100 and MA-120 microwave waveguide applicators have been measured in muscle and fat phantom materials with both the manufacturer's boluses and the new boluses. RESULTS: In the case of the MA-100, the area above the 70% heating level measured in a muscle phantom was increased by a factor of 2.3 by an absorbing pad bolus. Similarly, the heating area of the MA-120 was increased by a factor of 2.6 by an absorbing pad bolus. The boluses were tested in a clinical setting by measuring tissue temperature profiles in patients under different bolus arrangements. The area over which therapeutic temperature was achieved was increased considerably when the absorbing bolus was used. A second bolus was designed for the MA-120 to produce a ring heating pattern for the treatment of a breast cancer patient who had developed recurrences at the periphery of a skin graft. The heating pattern produced in a muscle phantom is compared with tissue temperature profiles measured during the hyperthermia treatment of this patient. CONCLUSIONS: Microwave absorbing filters using saline pads significantly improve the heating patterns of microwave waveguide hyperthermia applicators. This improvement was confirmed in clinical application where much greater areas of homogeneous heating were observed. The technology was extended to produce complex heating patterns for special clinical applications.

Breast Neoplasms↗
PubMed1993

Squamous cell carcinoma of the lip: analysis of the Princess Margaret Hospital experience.

We reviewed 117 patients with squamous cell carcinoma of the lip who were treated at the Princess Margaret Hospital between 1976 and 1985. Ninety-eight cancers arose from the lower lip, 18 from the upper lip and 1 from the commissure. Two patients had lymph node metastases at presentation. Sixty-one patients were treated with radiation therapy following a biopsy, 28 underwent surgery followed by post-operative radiation, and 28 had surgery alone. With a median follow-up time of 5.4 years, the 5-year actuarial overall and cause-specific survival rates were 81% and 99%, respectively. Local failure developed in 4 patients after radiation treatment, 3 of whom were salvaged by surgery. Six patients developed regional metastases after initial treatment, 4 of whom were salvaged with surgery and/or radiotherapy. Two patients died from lip cancer. After a univariate analysis, the only factor which predicted for nodal failure was T stage of the primary lesion, with a 4% risk of nodal failure for T1 lesions vs. 20% for T2/3 lesions (p = 0.03). No other patient, tumour or treatment variables influenced loco-regional control or survival in a statistically significant manner. Cosmetic and functional outcome were evaluated in 8 patients whose radiation treatments were administered 13 years ago. No patients had compromised lip function, and the majority had minimal cosmetic sequelae from their radiation therapy. Based on the excellent results of this review, we would continue to recommend radiation therapy as an effective treatment modality for patients with lip cancer because of the ease by which the entire tumour can be encompassed whilst maintaining excellent cosmetic and functional outcome.

Adult↗
PubMed1991

Postradiation dental extractions without hyperbaric oxygen.

This study examined the incidence of osteoradionecrosis after tooth extraction with low-epinephrine or epinephrine-free, nonlidocaine local anesthetics and conservative surgical techniques. Estimates of the absorbed radiation dose on irradiated alveolar bone were made by reviewing radiotherapy records. This investigation included 72 patients ranging in age from 22 to 80 years (median 57.4 years). We removed 449 teeth. Analysis of radiotherapy check films revealed that only 196 teeth (44%) were included within the treatment volume. The median prescribed tumor dose was 50 Gy (range 25 to 84 Gy) in 20 fractions (range 10 to 37), with a median dose per fraction of 2.5 Gy (range 1.88 to 3.14 Gy). Follow-up time ranged from 68 days to 19.3 years (median 4.8 years). No instances of osteoradionecrosis occurred as a result of dental extraction with this conservative method.

Adult↗
PubMed1991

A management approach to incompletely excised basal cell carcinomas of skin.

There were 187 incompletely resected basal cell carcinomas (BCC) of skin referred to the Princess Margaret Hospital between 1970 and 1985. Median age at presentation was 62 years. The commonest location of these lesions was in the head and neck region (93%). One hundred twenty lesions were immediately treated: 119 were irradiated and 1 was excised. The remaining 67 lesions were managed expectantly. Follow-up time for the entire population ranged from 1 month to 17 years, with a median time of 2.7 years. The 5-year probability of remaining relapse-free in the group immediately treated was 91% versus 61% if managed expectantly (p = 0.0001). If only lateral margins were positive, the crude probability of local failure was 3/18 (17%), versus 9/27 (33%) if the deep margins were involved (p = 0.2). Once relapse occurred in the group of lesions treated expectantly, 17/20 (85%) of these relapses were salvaged by either radiation or surgery. The 10-year actuarial probability of local control for the lesions immediately treated and observed were similar: 92% and 90%, respectively (p = 0.5). An economic analysis revealed that immediate radiation treatment saved the health system only $223.00 per patient. Since there is no difference in the ultimate local control between these two approaches, and these elderly patients may be spared the morbidity of unnecessary treatments, it is suggested that a policy of observation may be adopted for basal cell carcinomas of skin which have been incompletely excised.

Actuarial Analysis↗
PubMed1990

Evaluating radiation in combination with hyperthermia trials: the importance of clinical and technical parameters.

A proper evaluation of hyperthermia and irradiation trials is necessary to correctly interpret clinical results and to define limitations and properties of this new therapeutic approach. A better understanding of the "weight" of different technologic and clinical parameters that influence clinical response is thus clearly needed, particularly if future advances in hyperthermia technology and clinical results are to be expected. Patient variables, tumor variables, and treatment characteristics have been analyzed, and the difficulties of properly evaluating the "weight" of single parameters have been stressed. At the current state of knowledge, the Karnofsky index, site of disease (for regional heating), tumor status (recurrent versus metastatic disease) and XRT dose per fraction (for melanomas) seem to correlate with response. Tumor dimension, XRT total dose and thermal parameters reflecting the lowest tumor temperatures appear to statistically influence complete response rates of heated and irradiated tumors. In addition, a critical method of presenting results should be followed to enable comparison of data from different trials.

Clinical Trials as Topic↗
PubMed1989

The surgical margin in soft-tissue sarcoma.

In a retrospective review of 231 patients who were referred to Princess Margaret Hospital because of a soft-tissue sarcoma in an extremity, 100 patients were identified who had no metastases when they were first seen and who had been treated by local resection and adjuvant radiation therapy. Complete data were collected for each patient for the following variables: age; sex; location of the tumor and its size, grade, depth, and compartmental status; chemotherapy; and dose of radiation. The surgical margins were characterized as positive or negative for histological evidence of disease on the basis of an independent review of the pathological and operative reports by a surgeon and a radiation oncologist who were experienced in the management of sarcoma. Cox multivariate analysis was used to determine which of these variables contributed to local recurrence and evidence of systemic disease. Adequacy of the margin of resection was the only variable that was associated with local relapse (p = 0.0004). The size of the tumor (p = 0.0008) was the major determinant of the risk of systemic disease.

Adolescent↗
PubMed1988

Important prognostic factors influencing outcome of combined radiation and hyperthermia.

Clinical experience with combined local-regional hyperthermia and radiation therapy has been rapidly accumulating over the past few decades. Its superior efficacy to the use of radiation alone has been demonstrated in several retrospective and prospective reports in the literature. It is evident now that there are several important factors that will influence the final outcome of the treated patients. The parameters that will be discussed in this paper include: I. Pretreatments factors: 1. tumor dimension 2. tumor histology 3. tumor site. II. Treatment factors: 1. radiation therapy dose 2. hyperthermia parameters: (a) thermal variables (b) number of heat treatments (c) sequence of hyperthermia and radiation treatments (d) hyperthermic device. Finally, evaluation of response and complications will also be discussed. The importance of abiding by an accepted reporting system will be emphasized, and clarification of times at which response assessments were made will also be discussed. With the availability of longer term follow-up, use of an actuarial method of reporting becomes more important. The future of hyperthermia and radiation remains very promising but a lot of questions still need to be answered by well-conducted and reported clinical trials.

Combined Modality Therapy↗
PubMed1988

Bladder cooling in patients treated with regional hyperthermia of the pelvis using an annular phased array.

Regional hyperthermia for the treatment of deep seated tumors is often limited by excessive heating of normal tissues, usually with associated patient pain and/or discomfort. The use of bladder cooling via perfusion of distilled water through a modified tri-lumen irrigation catheter as an aid to circumventing this problem in one anatomical region is described. This relatively simple technique provided rapid pain relief and permitted completion of the hyperthermia treatment in a satisfactory manner. Modifications of this technique may permit selective heating and/or cooling of the bladder during regional hyperthermia treatments in the pelvis.

Adult↗
PubMed1986

Primary lymphoma of the breast.

Primary lymphoma of the breast is a rare entity. This paper adds a further 16 cases to the world literature. Axillary nodal status appears to be an important prognostic factor for survival. Stage IE patients should be treated with an excisional biopsy followed by radiation to the breast and to the regional nodes. Combined treatment with systemic chemotherapy with local irradiation should be considered for patients with Stage IIE disease (breast and axillary nodes).

Adult↗