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Biomedical subjects

H Vermeersch

Publications and source records attributed to H Vermeersch.

At least 19 recordsLinked to original sources
PubMed2007

99mTc-HYNIC Annexin-V imaging of tumors and its relationship to response to radiotherapy and/or chemotherapy.

AIM: The aim of this study was to report on the relationship between preradiotherapy and prechemotherapy 99mTc-HYNIC Annexin-V tumor uptake values, reflecting ongoing apoptosis, and outcome to radiotherapy and/or chemotherapy. METHODS: Twenty-three cancer patients underwent staging examinations and a 99mTc-HYNIC Annexin-V scintigraphy and subsequent radiotherapy and/or chemotherapy. Tumor-to-background ratios derived from tomographic 99mTc-HYNIC Annexin-V images were related to treatment outcome as assessed by RECIST criteria. RESULTS: Six patients underwent radiotherapy or radiochemotherapy: 4 exhibited response to treatment, 1 had stable, and 1 progressive disease. Corresponding tumor-to-background ratio's were respectively >or=2.3 (in responders), 1.2 in the patient presenting with stable disease and 1 in the patient presenting with progressive disease. Seventeen patients were treated by chemotherapy alone: 8 were progressive, 1 patient presented with stable disease and 8 responded to treatment. In 1/8 progressive patients a tumor-to-background ratio of 1.4 was found, the others showed no uptake. In the patient presenting with stable disease a ratio of 0.1 was found. In the 8 responders, 7 patients had a tumor-to-background ratio >or=1.3 whereas in 1 patient a ratio of 0.3 was found. Tumor-to-background ratios in responders (complete plus partial) (median 2.5, range: 0.3-4.2) were significantly higher when compared to those obtained in non-responders (stable plus progressive disease) (median 1, range: 0.1-1.4) (P<0.001). CONCLUSION: The findings presented suggest that 99mTc-HYNIC Annexin-V pretreatment uptake may be useful to predict response to chemo- and radiotherapy.

Adult↗
PubMed2005

Recurrent colonization of successively implanted tracheoesophageal vocal prostheses by a member of the Fusarium solani species complex.

Tracheoesophageal vocal prostheses (TVP) in laryngectomized patients commonly deteriorate due to overgrowth by yeasts, particularly Candida species. We describe the first case of colonization of such devices by a member of the Fusarium solani species complex in a patient with a history of glottal carcinoma. Three isolates, from three prostheses, were found morphologically consistent with the traditional picture of F. solani. Ribosomal sequence analysis showed that the isolates belonged to a distinct, as yet apparently unnamed phylogenetic species within the F. solani species complex. This species, one of two distinct genetic types (genotype 2) traditionally considered part of the plant-pathogenic subtaxon Fusarium solani f. sp. radicicola, has not previously been identified as an agent of human or animal disease, although it is closely related to a known etiologic agent of mycetoma, an Acremonium-like species recently renamed Fusarium falciforme. Sequence and multisatellite M13 polymorphism analysis revealed no distinctions among the case isolates. Production of cyclosporine was detected for all three case isolates.

Aged↗
PubMed2001

An implementation strategy for IMRT of ethmoid sinus cancer with bilateral sparing of the optic pathways.

PURPOSE: To develop a protocol for the irradiation of ethmoid sinus cancer, with the aim of sparing binocular vision; of developing a strategy of intensity-modulated radiation therapy (IMRT) planning that produces dose distributions that (1) are consistent with the protocol prescriptions and (2) are deliverable by static segmental IMRT techniques within a 15-minute time slot; of fine tuning the implementation strategy to a class solution approach that is sufficiently automated and efficient, allowing routine clinical application; of reporting on the early clinical implementation involving 11 patients between February 1999 and July 2000. patients and methods: Eleven consecutive T1-4N0M0 ethmoid sinus cancer patients were enrolled in the study. For Patients 1-8, a first protocol was implemented, defining a planning target volume prescription dose of 60 to 66 Gy in 30-33 fractions and a maximum dose (Dmax) of 50 Gy to optic pathway structures and spinal cord and limit of 60 Gy to brainstem. For Patients 9-11, an adapted (now considered mature) protocol was implemented, defining a (planning target volume) prescription dose of 70 Gy in 35 fractions and a Dmax to optic pathway structures and brainstem of 60 Gy and to spinal cord of 50 Gy. RESULTS: The class solution-directed strategy developed during this study reduced the protocol translation process from a few days to about 2 hours of planner time. The mature class solution involved the use of 7 beam incidences (20-37 segments), which could be delivered within a 15-minute time slot. Acute side effects were limited and mild. None of the patients developed dry eye syndrome or other visual disturbances. The follow-up period is too short for detection of retinopathy or optic nerve and chiasm toxicity. CONCLUSION: Conventional radiotherapy of ethmoid sinus tumors is associated with serious morbidity, including blindness. We hypothesize that IMRT has the potential to save binocular vision. The dose to the optic pathway structures can be reduced selectively by IMRT. Further enrollment of patients and longer follow-up will show whether the level of reduction tested by the clinical protocol is sufficient to save binocular vision. An adaptive strategy of IMRT planning was too inefficient for routine clinical practice. A class solution-directed strategy improved efficiency by eliminating human trial and error during the IMRT planning process.

Adenocarcinoma↗
PubMed2001

Colonization of a voice prosthesis by Cryptococcus neoformans.

Tracheoesophageal voice prostheses in laryngectomized patients commonly deteriorate due to the presence of yeasts, particularly Candida species. We describe the first case of colonization of such a device by Cryptococcus neoformans in a patient with a history of glottic carcinoma. The isolate showed an identical genomic pattern with C. neoformans from pigeon excreta in the patient's environment.

Animals↗
PubMed2001

99Tc(m) labelled HL91 versus computed tomography and biopsy for the visualization of tumour recurrence of squamous head and neck carcinoma.

This phase I pilot study reports on (1) the safety and feasibility of 99Tc(m)-HL91, an amine oxime core radioligand that has shown oxygen dependent binding, and imaging; and (2) its usefulness for the visualization of local tumour recurrence of a biopsy proven squamous cell carcinoma of the head and neck (SCCHN) as compared to spiral computed tomogaphy (CT) and biopsy. Nine men (mean age 33 years, range 34-74 years) were prospectively included. For safety measurements, vital signs were recorded and serum chemical analysis carried out, with a complete blood cell count and urine analysis, and an ECG was performed prior to injection of 99Tc(m)-HL91 and repeated during the investigation. Single photon emission computed tomography (SPECT) scans of the head and neck, and of a standard, were performed at 2 h and 4 h post-injection of 740 MBq 99Tc(m)-HL91. Tumour-to-normal tissue background (T/N) ratios and percentage uptake were measured for all 99Tc(m)-HL91 scans. Spiral CT scans were obtained using a Somaton 4+ Siemens scanner within 1 week from the 99Tc(m)-HL91 scans. Based on CT and the 99Tc(m)-HL91 scan findings guided biopsies were performed. No adverse or subjective side effects were noticed. Vital signs, ECG findings, clinical laboratory, blood and urine assays remained stable in all patients. Spiral CT suggested local recurrence in 5/9 patients accompanied by nodal involvement in three, all of which proved positive on biopsy. 99Tc(m)-HL91 scintigraphy was false positive in one patient and true positive (TP) in 3/5 local recurrences and two out of three sites of lymph node involvement depicted by spiral CT. The mean T/N ratios at 2 h and 4 h in TPs were 1.28 (range 1.1-1.66) and 1.40 (range 1.0-1.6), respectively. The corresponding absolute percentages of 99Tc(m)-HL91 lesional uptake at 2 h and 4 h were mu = 0.05% (SD = 0.03%) and mu = 0.048% (SD = 0.035%). The findings suggest 99Tc(m)-HL91 is a safe radioligand and that metabolic binding in a large fraction but not all of local SCCHN recurrences may be expected. The inference that tumour 99Tc(m)-HL91 avidity could be a non-invasive measure of tumour hypoxia deserves however independent confirmation with needle oximetry.

Adult↗
PubMed2001

Mycobacterium interjectum as causative agent of cervical lymphadenitis.

A mycobacterial strain isolated from a lymph node of a 3-year-old female with cervical lymphadenitis was identified as Mycobacterium interjectum by means of sequencing of the 16S rRNA gene. Analysis of this case and previously published cases demonstrates the importance of M. interjectum as a causative agent of cervical lymphadenitis in young children.

Child, Preschool↗
PubMed2001

Recurrent focal epithelial hyperplasia due to HPV13 in an HIV-positive patient.

There are few reports on focal epithelial hyperplasia (FEH) in association with human immunodeficiency virus (HIV) infection; thus the relationship between them has not been completely clarified yet. We present a case of recurrent FEH in an HIV-positive man (the first described in Belgium), which, according to the PCR-DNA testing, was due to human papilloma virus type 13 (HPV13). To our knowledge, based on the accessible literature, this type of HPV has not been detected in any other documented study of FEH in HIV-positive patients before. Our patient experienced three recurrences of FEH in 1 year. It is therefore suggested that immunodeficiency due to HIV infection is responsible for the HPV-related FEH and the subsequent recurrences. In order to support the consideration of FEH as an oral manifestation of an HIV-related opportunistic infection, every new 'HPV-type' oral lesion in HIV-positive patients must be completely documented.

AIDS-Related Opportunistic Infections↗
PubMed2001

Ectopic cervical thymus: case report and review of the literature.

The authors present a case of ectopic cervical thymus in a 4-month-old child. Ectopic cervical thymus is an uncommon etiology of a neck mass in a child. It is often misdiagnosed preoperatively as a possible malignancy. It is usually located along the embryologic course of thymus migration from the angle of the mandible to the superior mediastinum. Its treatment is surgical since malignant transformation and respiratory infection have been described. No case of immune deficit after total thymectomy has been described in the literature.

Choristoma↗
PubMed2000

Bilateral recurrent adult rhabdomyomas of the pharyngeal wall.

Adult rhabdomyomas of the head and neck are uncommon benign skeletal muscle tumors. Only a few cases occurring in the pharyngeal wall have been described in the world literature. We present a case of recurrent bilateral rhabdomyomas in the pharynx and discuss the clinicopathological features of this lesion, comparing it to those of other neoplasms from which it must be differentiated. To our knowledge, bilaterality of this type of lesion has not been described previously. Although adult rhabdomyomas have a distinct histology, they often are mistaken for a variety of other lesions, particularly granular cell tumor.

Adult↗
PubMed1999

Accuracy of single-sequence MRI for investigation of the fluid-filled spaces in the inner ear and cerebellopontine angle.

We prospectively studied 163 patients referred for MRI of the temporal bone. A presumed diagnosis was made using only one of three sequences: a single thick (12 mm) slice fast T2-sequence, 3D fourier transform constructive interference in steady state (3DFT-CISS) sequence and a gadolinium-enhanced T1-weighted sequence. The visibility of the cochlea, vestibule and superior, lateral and posterior semicircular canals of normal temporal bones was assessed on the T2-weighted images: they were almost always visible (98-100%), with exception of the superior semicircular canal, seen in only 35% of cases. The images were interpreted as abnormal in 34 patients (21%). Using only the fast T2-weighted, 3DFT-CISS and gadolinium-enhanced T1-weighted sequences a presumed false positive diagnosis was made in 5, 1 and 0 cases and a false negative diagnosis in 2, 2 and 4 cases respectively. The overall reliability of the thick-section fast T2-weighted images is limited. This study suggests that a combination of gadolinium-enhanced T1-weighted and 3DFT-CISS images can be considered the gold standard for temporal bone MRI and neither sequence performed separately is as accurate as both together.

Adolescent↗
PubMed1999

Membrane filtration test for rapid presumptive differentiation of four Candida species.

A rapid enzymatic two-step test for the presumptive differentiation of four Candida species commonly occurring in various clinical samples is described. The technique involves membrane filtration of a liquid sample, followed by preincubation of the membrane filter on Sabouraud glucose agar supplemented with ticarcillin-clavulanic acid to yield microcolonies. In a separate assay step, parts of the filter are placed on absorbent pads impregnated with fluorogenic 4-methylumbelliferyl (4-MU) enzyme substrates (4-MU-N-acetyl-beta-D-galactosaminide, 4-MU-phosphate, 4-MU-pyrophosphate, and 4-MU-beta-D-galactoside) in combination with 0.1% digitonin acting as a membrane permeabilizer. The membrane filter in contact with the assay medium is incubated to allow cleavage of the enzyme substrate, resulting in fluorescent microcolonies under long-wavelength UV light. This approach, tested on 301 clinical samples, is able to presumptively differentiate C. albicans, C. glabrata, C. krusei, and C. tropicalis and to distinguish them from other Candida spp. in about 9 to 11 h. Overall agreement with the conventional methods of 94.4% (one Candida species present in the sample) to 83.8% (multiple Candida spp. present) was obtained. The false-negative rates with reference to identification by traditional methods were 1.3% (single species) and 3.8% (multiple species).

Candida↗
PubMed1999

MRI prior to major tumor surgery in the head and neck.

MRI plays an important and specific role prior to tumor surgery in the head and neck region. It is especially interesting in providing a detailed description of the exact tumor extent close to the skull base and to investigate perineural and perivascular tumor spread. In selected cases this technique can give a presumed histopathological diagnosis for a mass that is clinically detected. This is especially true for some benign masses, such as hemangiomas, cysts and lipomas. The role of MRI with regard to a lymph node imaging survey in the neck is rather limited. MRI is moreover not routinely performed in neck regions where many motion artifacts can be expected, such as in the larynx.

Head and Neck Neoplasms↗
PubMed1999

Invasive surgery for paranasal sinus cancer: is there still any indication for lateral rhinotomy and non endoscopic approaches?

A combined intracranial and transfacial approach for often very malignant lesions of the sino-nasal complex yields the best chance of curation. The operative risk diminishes in a centre with a large turnover after an initial learning curve and it is the only possibility to try to cure the patient from his or her disease. The removal of a rather small malignant lesion in the anterior part of the middle meatus can be safely done through the nostril with correct oncologic margins. In case of inoperability because of local destructions or because of the histological type (malignant melanoma e.g.) freeing up the nasal airway endoscopically can help patients symptomatically and repeatedly.

Endoscopy↗
PubMed1999

Postoperative radiotherapy of paranasal sinus tumours: a challenge for intensity modulated radiotherapy.

BACKGROUND AND PURPOSE: Intensity modulated radiotherapy (IMRT) is used in our department for treatment of paranasal sinuses. We describe the methodology that was developed together with the clinical implementation, illustrated by a case report. MATERIAL AND METHODS: Patient history, treatment and short follow-up are described. An IMRT, obtained by superposition of static beam segments was implemented. Electronic portal images, compared to digitally reconstructed radiographs (DRR) were used to evaluate and adjust patient positioning. RESULTS, DISCUSSION AND CONCLUSION: IMRT is an appropriate and feasible treatment technique for head and neck cancer in anatomical regions that are difficult to treat. A high tumour dose can be combined with a good sparing of the surrounding organs at risk (OAR's).

Adenocarcinoma↗
PubMed1998

Liquid chromatographic separation of doxycycline and 4-epidoxycycline in a tissue depletion study of doxycycline in turkeys.

Liver and muscle tissue residues of doxycycline in turkeys were determined following administration of 25 mg doxycycline x HCl/kg BW in the drinking water under field conditions. Quantitation was performed using a validated HPLC method with fluorescence detection. The method was able to separate doxycycline and its 4-epimer, 4-epidoxycycline. This epimer was found in both liver and muscle tissue. The detection limits of the method were estimated at 1.2 ng/g and 1.0 ng/g of doxycycline in liver and muscle tissue, respectively, using a signal-to-noise ratio of 3:1. The recovery of doxycycline was determined from spiked tissues and was 63+/-3.8% and 66+/-3.1% for liver and muscle, respectively (n = 6). Within-day and between-day imprecision, expressed as the R.S.D. was below 7.4%. Linear calibration curves (r>0.997) were obtained in spiked liver between 0 and 1500 ng/g and in spiked muscle between 0 and 500 ng/g. A good stability of doxycycline was observed in liver samples after storage for 22 days at -20 degrees C. The correlation between the residues in the liver and the muscle was expressed as the correlation coefficient r and was 0.9884. The depletion kinetics of doxycycline fitted a one-compartment model. The elimination half-life (T1/2) of doxycycline was 77.7 h and 78.0 h in muscle and liver, respectively. Furthermore, the residue depletion kinetics were used to establish a withdrawal period in conformity with official guidelines. The withdrawal times necessary to reach concentrations below maximum residue limits (MRLs), as imposed by the EU, were 12 days and 17 days for liver and muscle tissue, respectively.

Animals↗
PubMed1998

Schwannoma of the tip of the nose: MRI.

We report a schwannoma with a rare location at the tip of the nose in a 20-year-old woman with an otherwise unremarkable medical history. The imaging findings underline the usefulness of MRI in narrowing down the differential diagnosis of masses in this region. Once the diagnosis was focussed on a neural origin of the mass, the exact nature of the tumour could not be predicted from the MRI, although the presence of a capsule on imaging studies as well as at operation suggested it was probably a schwannoma. A schwannoma must be considered when one encounters a sharply delineated mass at the tip of the nose, showing high signal on T2-weighted images and strongly contrast enhancement.

Adult↗
PubMed1998

Laryngeal embryonal rhabdomyosarcoma in a child: MRI appearance.

We report a rare case of a young girl with an embryonal rhabdomyosarcoma of the right aryepiglottic fold. Local disease recurrence, occurring 7 years after subtotal resection and adjuvant chemotherapy, was studied with plain radiography, CT and MRI. To the best of our knowledge, this is the first report illustrating the MRI characteristics of a laryngeal embryonal rhabdomyosarcoma in a child.

Child↗