Biomedical subjects

Jonas A Castelijns

Publications and source records attributed to Jonas A Castelijns.

28 records · Page 2Linked to original sources

PubMed2004

Supraglottic carcinoma treated with curative radiation therapy: identification of prognostic groups with MR imaging.

PURPOSE: To retrospectively assess the prognostic meaning of tumor characteristics depicted on pretreatment magnetic resonance (MR) images for local outcome in supraglottic squamous cell carcinoma treated with definitive radiation therapy. MATERIALS AND METHODS: Pretreatment MR images acquired in 84 patients with supraglottic carcinoma treated with curative radiation therapy were reviewed for tumor involvement of laryngeal sites including glottis, subglottis, pre-epiglottic space, laryngeal cartilages, and hypopharynx, and for extralaryngeal extension. The volume of each tumor was estimated, and mean tumor volume was calculated for the group of tumors in each T staging category. RESULTS: Results of univariate analysis showed MR imaging-determined primary tumor volume (P =.03), involvement of pre-epiglottic space (P =.008), abnormal signal intensity in thyroid cartilage (P =.04), and extralaryngeal extension beyond thyroid and/or cricoid cartilage (P =.02) to be significant predictors of local control rate. Results of multivariate analysis with the Cox regression model confirmed statistical significance for invasion of pre-epiglottic space (P =.004) and for abnormal signal intensities in thyroid cartilage adjacent to the anterior commissure (P =.04) and in cricoid cartilage (P =.01). Five-year local control rates were calculated from the regression coefficients of three independent MR imaging prognostic factors, and three prognostic groups were identified on the basis of these control rates. The 5-year local control rate in the high-risk group was 35%, significantly lower than the rates in the intermediate- and low-risk groups (60% and 89%, respectively; P =.002). CONCLUSION: MR imaging-determined pre-epiglottic space involvement and abnormal signal intensities in the thyroid cartilage adjacent to the anterior commissure and/or the cricoid cartilage are strong predictors of local outcome in supraglottic carcinoma treated with definitive radiation therapy.

Adult↗

PubMed2003

Positron emission tomography using [18F]fluorodeoxyglucose (FDG-PET) in the clinically negative neck: is it likely to be superior?

The capability of modern imaging techniques such as CT, MRI, US and US-guided fine-needle aspiration cytology (USgFNAC) to detect small tumour deposits is limited. Therefore, the detection of occult metastases in the clinically negative neck remains a diagnostic problem. One of the novel options to refine staging of head and neck cancer is [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET). To evaluate the diagnostic value of FDG-PET in the detection of occult malignant lymph nodes, we compared the results of FDG-PET with other diagnostic techniques and the histopathological outcome of 15 neck dissection specimens from 15 head and neck cancer patients with a clinically negative neck. Three sides contained metastases of squamous cell carcinoma. FDG-PET enabled detection of metastases in two sides, which were also detected by MRI or USgFNAC. FDG-PET and CT missed metastases in one patient, which were detected by both MRI and USgFNAC. In studies with a detailed examination of lymph nodes of a neck dissection, a low sensitivity of FDG-PET for the detection of occult lymph node metastases is found. It is unlikely that FDG-PET is superior in the detection of occult lymph node metastases in head and neck cancer patients with a palpably negative neck. The histopathological method used seems to be the most important factor for the differences in sensitivity in reported FDG-PET studies. New approaches such as the use of monoclonal antibodies labelled with a positron emitter may improve the results of PET in these patients.

Adult↗

PubMed2003

Detecting recurrent laryngeal carcinoma after radiotherapy: room for improvement.

Detecting recurrent laryngeal carcinoma after radiotherapy for a primary tumour can be difficult. Early detection however, is an important prognostic factor. Although a biopsy should be performed in case of clinical suspicion, repeated negative biopsies do not exclude the presence of viable tumour. The trauma caused by biopsies in irradiated tissue may initiate infection, further oedema and failure to heal. We investigated these problems and evaluated the current care and its usefulness. A survey of the current practice concerning diagnostic procedures for detecting recurrent laryngeal carcinoma after radiotherapy in the major institutions treating head and neck cancer in The Netherlands was performed by means of a questionnaire. Furthermore, we performed a comprehensive analysis of the extent and yield of diagnostic work-up in a cohort of patients clinically suspected of a recurrence, who had undergone direct laryngoscopy between 1986 and 1998 in our institution, with a follow-up of at least 6 months. In case of suspected recurrence, 94% of the departments use direct laryngoscopy under general anaesthesia with the taking of biopsies as a diagnostic technique. Imaging does not play an important role. In our department 207 laryngoscopies were evaluated in 131 patients. In 70 patients the first laryngoscopy was negative. Of these initial negative laryngoscopies, 22 (31%) turned out to be false negative within 6 months. Thirty-seven patients remained disease free. They underwent 65 unnecessary laryngoscopies to come to this conclusion. In the decision to perform direct laryngoscopy, the conventional work up leaves room for improvement. Too many unnecessary laryngoscopies are performed. New imaging techniques such as FDG-PET or new applications of CT or MRI may improve the yield of direct laryngoscopy.

Adult↗

PubMed2003

Localization of slow wave activity in patients with tumor-associated epilepsy.

OBJECTIVE: Brain tumors are frequently accompanied by abnormal low frequency magnetic activity (ALFMA). The prevalence and clinical meaning of ALFMA are not well known, although a relation with epileptic brain tissue has been suggested. We studied the prevalence, characteristics and clinical correlates of ALFMA in 20 patients with brain tumors. METHODS: In 20 patients with clinical seizures due to a supratentorial tumor, MEG was performed, followed by MR imaging. MEG signals were band pass-filtered (1-4 Hz); the sources of this activity were localized and projected onto the MRI of the patient. RESULTS: Peritumoral ALFMA could be detected in 13 of 20 patients. A pattern of ALFMA distribution around the tumor could be recognized. In eight cases ALFMA also appeared to be localized within the tumor. In three cases ALFMA was also detected in peritumoral white matter. CONCLUSIONS: Automatic detection of abnormal delta-activity in patients with a brain tumor and seizures can be performed in a clinical setting. When detected, ALFMA is mostly present in circumscribed regions around the tumor. Presence of ALFMA within the tumor might be an important warning signal for the neurosurgeon that the tumor area comprises functional brain tissue.

Adult↗

PubMed2003

Quantitative molecular detection of minimal residual head and neck cancer in lymph node aspirates.

PURPOSE: Staging of the clinically N(0) neck in patients with head and neck squamous cell carcinoma (HNSCC) using ultrasound-guided, fine needle aspiration cytology (USgFNAC) has a false-negative rate of approximately 20% that might be caused by inaccurate cytology. Molecular analysis of aspirate residues might reduce the false-negative rate, and we therefore set up a quantitative reverse transcription-PCR (Q-RT-PCR) assay based on TaqMan technology using the squamous cell-specific antigen E48 (Ly-6D) as molecular marker. EXPERIMENTAL DESIGN: The detection limit of the assay was determined in reconstruction experiments. The sensitivity of the assay was tested on cytological tumor-positive aspirate residues and the specificity on lymph node aspirate residues of noncancer controls. Subsequently, 235 lymph node aspirate residues of 64 HNSCC patients staged with USgFNAC were examined for the presence of E48 mRNA. E48 Q-RT-PCR results of the aspirated lymph nodes were compared with cytology and clinical outcome. RESULTS: The detection limit of E48 Q-RT-PCR was a single tumor cell in a background of 10(6) peripheral blood mononuclear cells. From the 41 aspirates that were not evaluable at cytology, 24 (59%) could be diagnosed with E48 Q-RT-PCR. In the 191 aspirates that were tumor negative or not evaluable at cytology, 8 samples from 6 patients were E48 positive. These results were confirmed by histology or clinical outcome in 3 of 6 patients. E48 Q-RT-PCR showed an increase in sensitivity from 56 to 67% and an increase in frequency of reached diagnosis from 97 to 100% compared with cytology. The specificity decreased from 100 to 92%. CONCLUSIONS: Real-time E48 Q-RT-PCR is an accurate technique for squamous cell detection in lymph node aspirates of HNSCC patients. The assay shows an increase in sensitivity and frequency of reached diagnosis compared with cytology. The test could be implemented routinely in USgFNAC to diagnose cases for which cytological examination is not conclusive.

Base Sequence↗

PubMed2002

Diffuse signal abnormalities in the spinal cord in multiple sclerosis: direct postmortem in situ magnetic resonance imaging correlated with in vitro high-resolution magnetic resonance imaging and histopathology.

In this study, we compared direct postmortem in situ (whole-corpse) sagittal spinal cord magnetic resonance imaging (1.5T) of 7 multiple sclerosis cases with targeted high-resolution in vitro axial magnetic resonance imaging (4.7T) and histopathology. On sagittal in situ magnetic resonance imaging, 1 case had a normal spinal cord, 2 had only focal lesions, 3 had a combination of focal and diffuse abnormalities, and 1 had only diffuse abnormalities. All spinal cords showed abnormalities on high-resolution magnetic resonance imaging and histopathology, confirming the existence of diffuse cord changes as genuine multiple sclerosis-related abnormalities while highlighting the limited resolution of in vivo magnetic resonance imaging.

Aged↗

PubMed2002

Wait-and-see policy for the N0 neck in early-stage oral and oropharyngeal squamous cell carcinoma using ultrasonography-guided cytology: is there a role for identification of the sentinel node?

BACKGROUND: Management of the N0 neck in patients with head and neck squamous cell carcinoma (SCC) remains controversial. We describe the outcome of patients who underwent transoral tumor excision and a wait-and-see policy for the neck staged N0 by ultrasonography-guided cytology (USgFNAC). Because selection of lymph nodes for USgFNAC is currently based on size criteria, we investigated the additional value of sentinel node (SN) identification. METHODS: The outcome of 161 patients with T1-T2 oral/oropharyngeal SCC was determined. In a subgroup of 39 patients the SN was identified and aspirated in addition. RESULTS: SN identification and aspiration was possible in 38 of 39 patients but without decreasing the false-negative rate of USgFNAC. During follow-up (12-99 months) 34 of 161 (21%) patients developed lymph node metastases. After therapeutic neck dissection and postoperative radiotherapy, 27 of 34 (79%) could be salvaged (88% regional control). CONCLUSIONS: Wait-and-see seems justified in case of negative USgFNAC. Strict follow-up with USgFNAC is required. SN identification and aspiration is feasible but did not improve lymph node selection.

Biopsy, Needle↗

PubMed2002

Differentiation of multiple sclerosis from other inflammatory disorders and cerebrovascular disease: value of spinal MR imaging.

PURPOSE: To determine the value of magnetic resonance (MR) imaging in the spinal cord to differentiate multiple sclerosis (MS) from other inflammatory disorders and cerebrovascular diseases (together, other neurologic disease [OND]). MATERIALS AND METHODS: The study population included 66 patients with OND and 25 patients with MS, who were matched for age, sex, and symptom duration or severity. Brain MR imaging included gadolinium-enhanced T1-weighted and dual-echo T2-weighted spin-echo sequences to assess the number, size, and appearance of lesions, contrast enhancement, and compatibility with diagnostic criteria for MS. Spinal cord MR imaging included cardiac-triggered gadolinium-enhanced sagittal T1-weighted spin-echo and dual-echo T2-weighted sequences to assess the general appearance (normal, focal lesion, diffuse abnormality) and number or size of focal lesions. Images obtained in MS and OND patients were compared. Specificity, sensitivity, accuracy, and positive and negative predictive values with MR images were calculated. RESULTS: Brain images were abnormal in all MS patients and in 65% of OND patients. Abnormal cord images were found in 92% of MS and 6% of OND patients. The combination of brain and spinal cord images increased accuracy of diagnosis compared with use of brain images alone. CONCLUSION: In contrast to MS, cord lesions are very uncommon in OND. This finding can help differentiate these disorders.

Adult↗

PubMed2002

Assessment of patency of the internal jugular vein following neck dissection and microvascular flap reconstruction by power Doppler ultrasound.

The objective of this study was to assess patency of the internal jugular vein following modified radical or selective neck dissection and microvascular flap reconstruction by power Doppler ultrasound and its impact on free flap survival. In 23 patients who underwent selective or modified radical neck dissection and microvascular flap reconstruction the patency of the internal jugular vein was examined by power Doppler ultrasound on the first post-operative day and after follow-up of at least four months. On the first post-operative day in one patient partial thrombosis was found, while in the other 22 patients the internal jugular vein was normal patent. During follow-up in 17 (74 per cent) patients a normal patent internal jugular vein was found, while partial and complete thrombosis were found in three (13 per cent) patients each. On the first post-operative day 22 of the 23 (96 per cent) free flap veins were visualized. There was no free flap loss during follow-up. Power Doppler ultrasound is a valuable diagnostic technique for determination of internal jugular vein patency and may be useful as screening method or in case of clinical suspicion of thrombosis to determine internal jugular vein patency. Late internal jugular vein thrombosis may probably not effect free flap survival due to neovascularization.

Adult↗

PubMed2001

Imaging of lymphadenopathy in the neck.

Imaging is playing a major role in the assessment of cervical lymphadenopathy. In infectious disease, the assessment of abscess formation and the relation of the abscess to surrounding vital structures is crucial for its management. In head and neck malignancies, imaging can be helpful for staging. Imaging of the neck for the assessment of nodal metastases can be used to detect occult metastases or to assess operability of palpable metastases. The detection of small occult metastases has limitations, as micrometastases cannot be depicted; however, imaging can fulfill a role in diminishing the risk of occult metastases, and thus influence management. For this purpose a very sensitive technique is necessary. The currently used radiological criteria are not sensitive enough to accomplish enough reduction of the risk of occult metastases; therefore, more sensitive CT and MRI criteria, but especially ultrasound-guided aspiration, should be employed to assess the clinically negative neck.

Biopsy, Needle↗