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Biomedical subjects

P L Jager

Publications and source records attributed to P L Jager.

At least 19 recordsLinked to original sources
PubMed2006

Scintigraphic evaluation for tear drainage, after dacryocystorhino- stomy, in relation to patient satisfaction.

AIM: To measure the degree of physiological patency of the tear drainage system using dacryoscintigraphy before and after external dacryocystorhinostomy (EDCR) in relation to patient complaints. METHODS: Prospective evaluation of 29 eyes of 24 patients with primary acquired nasolacrimal duct obstruction (PANDO) who underwent EDCR. The epiphora complaints were measured subjectively. Dacryoscintigraphy was performed in all eyes preoperatively, and was repeated 6 months after DCR together with the complaints score. For evaluation of dacryoscintigraphy, we determined T1 (percentage of administered dose still present after 1 min) and linear clearance rate (LCR), defined as: 100%(T1-T15)/T1) from the tracer disappearance curve. Dacryoscintigraphy findings were compared with the results of 20 eyes of normal volunteers without any symptoms. Scintigraphic findings were compared before and after the operation, with the change in patient complaints score as well as with normal values. RESULTS: Significant improvement occurred after the operation in the complaints score, T1 and LCR. However, despite absence of complaints (score=0) postoperative scintigraphic values were still abnormal as compared to normal individuals. CONCLUSION: Despite almost complete remission of epiphora complaints, DCR does not result in normalization of the tear drainage system.

Adult↗
PubMed2006

Impact of [18F]fluorodeoxyglucose positron emission tomography on surgical management of melanoma patients.

BACKGROUND: Several studies have shown adequate sensitivity and specificity of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) for the detection of metastases from melanoma, but few have addressed its impact on treatment. The aim of this retrospective study was to assess the impact of FDG-PET on treatment of melanoma in three Dutch university medical centres. METHODS: The medical records of 257 patients were reviewed. The indications for FDG-PET and findings were recorded. Unexpected findings of suspected (pre)malignant tumours other than melanoma were assessed. Treatment plans before and after FDG-PET were recorded and analysed to evaluate changes in disease management. RESULTS: Most scans (71.2 per cent) were requested for staging, mainly to detect distant metastases in patients with stage III disease. Overall, 56 patients (21.8 per cent) were upstaged as a result of PET. In 44 patients (17.1 per cent) treatment was changed, usually from surgery to systemic treatment in patients with stage III disease. Unexpected tumours were detected (mainly colorectal) in 11 patients (4.3 per cent). CONCLUSION: FDG-PET is most valuable in patients with stage III melanoma for detection of distant metastases and identification of candidates for surgery and/or systemic treatment. Unexpected FDG-PET findings should not be disregarded, as (pre)malignant, clinically relevant, tumours may be identified.

Adolescent↗
PubMed2005

Molecular imaging: what can be used today.

Biochemical cellular targets and more general metabolic processes in cancer cells can be visualised. Extensive data are available on molecular imaging in preclinical models. However, innovative tracers move slowly to the clinic. This review provides information on the currently available methods of metabolic imaging, especially using PET in humans. The uptake mechanisms of tracer methods and a brief discussion of the more 'molecular' targeted methods are presented. The main focus is on the different classes of tracers and their application in various types of cancer within each class of tracers, based on the current literature and our own experience. Studies with [18F]FDG (energy metabolism), radiolabelled amino acids (protein metabolism), [18F]FLT (DNA metabolism), [11C]choline (cell membrane metabolism) as general metabolic tracer methods and [18F]DOPA (biogenic amine metabolism) as a more specific tracer method are discussed. As an example, molecular imaging methods that target the HER2 receptor and somatostatin receptor are described.

Animals↗
PubMed2005

Positron emission tomography in patients with breast cancer using (18)F-3'-deoxy-3'-fluoro-l-thymidine ((18)F-FLT)-a pilot study.

BACKGROUND: This pilot study investigated the feasibility of (18)F-3'-deoxy-3'-fluoro-l-thymidine ((18)F-FLT) as a positron emission tomography (PET) tracer for the visualisation of breast cancer. METHODS: Patients with breast cancer underwent (18)F-FLT-PET prior to surgery. The uptake of (18)F-FLT was determined in the primary tumour and in the axilla. RESULTS: Eight tumours were visualized by (18)F-FLT-PET with a mean uptake value (SUV(mean)) of 1.7 and mean tumour-non-tumour ratio (TNT) of 5.0. In seven patients, axillary lymph-node metastases were found at pathological examinations, however, (18)F-FLT-PET showed uptake in only two large (and clinically evident) lymph-node metastases. CONCLUSIONS: (18)F-FLT shows uptake in most primary breast tumours and in large axillary lymph-node metastases.

Adult↗
PubMed2005

Comparison of FP-CIT SPECT with F-DOPA PET in patients with de novo and advanced Parkinson's disease.

PURPOSE: Diagnosis of Parkinson's disease (PD) can be difficult. F-DOPA PET is able to quantify striatal dopa decarboxylase activity and storage capacity of F-dopamine, but is expensive and not generally available. FP-CIT binds to the dopamine transporter, and FP-CIT SPECT is cheaper and more widely available, but has a lower resolution. The aim of this study was to compare these two methods in the same patients with different stages of PD to assess their power in demonstrating deficits of the striatal dopaminergic system. METHODS: Thirteen patients with de novo PD and 17 patients with advanced PD underwent FP-CIT SPECT and static F-DOPA PET. After data transfer to standard stereotactic space, a template with regions of interest was used to sample values of the caudate, putamen and an occipital reference region. The outcome value was striato-occipital ratios. Patients were clinically examined in the "off state" (UPDRS-III and H&Y stage). RESULTS: Good correlations were found between striatal F-DOPA uptake and striatal FP-CIT uptake (r = 0.78) and between putaminal F-DOPA uptake and putaminal FP-CIT uptake (r = 0.84, both p < 0.0001). Both striatal uptake of FP-CIT and that of F-DOPA correlated moderately with H&Y stage (rho = -0.52 for both techniques), UPDRS-III (rho = -0.38 for F-DOPA; rho = -0.45 for FP-CIT) and disease duration (rho = -0.59 for F-DOPA; rho = -0.49 for FP-CIT, all p < 0.05). CONCLUSION: FP-CIT values correlate well with F-DOPA values. Both methods correlate moderately with motor scores and are equally able to distinguish patients with advanced PD from patients with de novo PD.

Adult↗
PubMed2005

[Sentinel lymph node biopsy for melanoma: prognostic value and disadvantages in 300 patients].

OBJECTIVE: The aim of this study was to evaluate the advantages and disadvantages of sentinel lymph node biopsy (SLNB) in patients with cutaneous melanoma. DESIGN: Descriptive follow-up study. METHOD: In the period 1995-2004, 300 patients with cutaneous melanoma (Breslow thickness: > or = 1.0 mm) underwent SLNB and, in case of a tumour-positive result, regional lymph node dissection. Results of the SLNB procedure, postoperative complications, follow-up, recurrences, disease-free survival and disease-specific survival were evaluated. RESULTS: The SLNB detection rate was 99%. 85 patients had a tumour-positive SLNB (28%) and underwent completion regional lymph node dissection; 215 patients underwent SLNB alone. The rate of postoperative complications after SLNB was 7%. With a median follow up of 51 months, the false-negative rate was 11%. The recurrence rate was 23% (SLNB negative: 19%; SLNB positive 34%; p = 0.005). In-transit metastases were found in 4% of the SLNB-negative group and in 20% of the SLNB-positive group (p < 0.001). The 5-year disease-free survival and disease-specific survival rates were 79% and 86%, respectively, in SLNB-negative patients and 57% and 71%, respectively, in SLNB-positive patients. Multivariate analysis showed that the independent prognostic factors for disease-free survival were presence of ulceration (p < 0.001) and SLNB positivity (p < 0.01). Prognostic factors for overall survival were presence of ulceration (p < 0.001) and male sex (p < 0.05), but not the SLNB results. Multivariate analysis also showed that SLNB positivity (p < 0.001) and presence of ulceration (p < 0.01) were independent prognostic factors for developing in-transit metastases. CONCLUSION: SLNB in patients with cutaneous melanoma is still only of prognostic value since survival benefit is not proven. Disadvantages of SLNB were the false-negative rate, the possibility of an increased risk of in-transit metastases in SLNB-positive patients, and postoperative complications. These must be kept in mind when offering patients SLNB.

Adolescent↗
PubMed2005

Clinical value of dacryoscintigraphy using a simplified analysis.

PURPOSE: To study the discriminatory ability of dacryoscintigraphy in differentiating between patients with epiphora and volunteers using a simple method. METHODS: Twenty eyes in ten volunteers and 66 eyes in 55 patients with severe epiphora were studied. Dacryoscintigraphy (15 frames of 1 min) was performed after administration of 4 MBq (99m)Tc-pertechnetate (10 mul) in both eyes. By mapping a single region of interest (ROI) over the conjunctival sac we determined T1 (%dose in first minute) and linear clearance rate (LCR, defined as [see text] from the tracer disappearance curve. Reproducibility was determined in volunteers. Conjunctival resorption was determined from completely obstructed systems. Sensitivity and specificity were calculated and receiver operating characteristics (ROC) analysis was conducted. RESULTS: In volunteers mean T1 was 52.8+/-11.9% (95% CI 47.1-58.4%), and LCR was 74.2+/-11.1% (95% CI 69.0-79.4%). Reproducibility was good (mean difference 4.1+/-13.3% for T1 and 0.7+/-17% for LCR). Epiphora patients had clearly higher T1 (82.1+/-15.2%, P<0.0001) and lower LCR (38.9+/-22.5%, P<0.0001) values. Tracer resorption was 24%. Based on ROC analysis 70% for T1 and 50% for LCR were considered optimal cut-off levels to separate patients from volunteers. Sensitivity/specificity were 77/95% for T1 and 71/100% for LCR. T1 and LCR values did not correlate with symptom scores or Anel test results. CONCLUSION: Dacryoscintigraphy, using LCR and T1 as parameters, is a reliable and objective method to detect tear-flow abnormalities.

Adult↗
PubMed2005

Life expectancy in differentiated thyroid cancer: a novel approach to survival analysis.

In differentiated thyroid carcinoma 10-year survival rates amount to 80-95%. Because age at diagnosis varies widely, these survival rates strongly depend on age at presentation. The aim of the present study was to analyse the attributable risk factors, including therapy per se, on survival in thyroid cancer after proper adjustment for the baseline mortality rate in the general population and to elucidate the adverse treatment effects on survival. Initial treatment in 504 patients consisted of thyroidectomy and 131I ablation. High-dose 131I was administered for residual disease. Patients in complete remission underwent an annual physical examination and thyroglobulin measurements during TSH suppression. Survival time was studied after transformation to standardised survival time to adjust for the baseline mortality rate in the general population. Median follow-up since diagnosis was 9 years. The 10-year overall survival was 83% and disease-specific survival 91%. After initial treatment, persistent disease occurred in 75 patients (15%). In univariate analysis, T4, N1, M1 status and Hürthle cell type were prognostic for persistent and recurrent disease. Age was not prognostic for recurrent disease in multivariate analysis. The standardised survival time was not altered in disease-free patients. However, patients with persistent disease had a median standardised survival time of only 0.60 (95% confidence interval 0.47;0.72), ranging from 0 to above 1, independent of initial tumour status or age. The cumulative proportion of persistent disease was at least 20% of the whole group. Disease-free patients after thyroid carcinoma have a normal residual life span. In contrast, in cases of persistent disease the life expectancy ranges widely with its median being reduced to 60%. Overall, treatment including radioiodine is safe but unsuccessful in 20% of the patients. Age is not a disease-specific risk factor and should not be used as an independent factor in treatment algorithms.

Adult↗
PubMed2004

The value of FDG-PET in the detection, grading and response to therapy of soft tissue and bone sarcomas; a systematic review and meta-analysis.

BACKGROUND: Sarcomas represent a significant diagnostic and therapeutic challenge that requires techniques to provide better assessment of the disease than provided by traditional means. FDG-PET depicts the increased metabolism in abnormal tissues, enabling visualisation and quantification in vivo. The objective of this review was to assess the diagnostic value of FDG-PET in the detection, grading and therapy response of soft tissue and bone sarcomas. METHODS: A systematic review and meta-analysis of clinical studies on FDG-PET and sarcomas was conducted. Databases of PubMed, Embase and Cochrane were searched for studies. Besides that, the references of identified studies were reviewed. Three reviewers independently assessed the methodological quality. Statistical pooling was possible for studies concerning detection and grading of studies with mixed sarcomas (soft tissue and bone) and studies with soft tissue sarcomas only. RESULTS: Twenty-nine studies met the inclusion criteria. There was disagreement between the reviewers in 21.5% of the questions from the criteria list. The methodological quality of most of the included studies was poor. Pooled sensitivity, specificity and accuracy of PET for the detection of sarcomas were 0.91, 0.85 and 0.88, respectively. The difference between the mean Standard Uptake Value (SUV) in malignant and benign tumours for the studies concerning mixed and soft tissue sarcomas was statistically significant, as well as the difference in FDG uptake between low and high grade mixed sarcomas. CONCLUSIONS: The meta-analysis in this study was limited by the fact that only a few studies had mutual comparable outcome parameters. Moreover, the methodological quality of the studies was generally poor. Nevertheless, our results indicate that FDG-PET can discriminate between sarcomas and benign tumours and low and high grade sarcomas based on the mean SUV. The diagnostic implications of these results have to be investigated, especially the discrimination between benign tumours and low grade sarcomas. Based on this meta-analysis, there is no indication to use FDG-PET in the standard treatment of sarcomas. In the future PET imaging in bone and soft tissue sarcomas should be directed to the clinical implication for the detection and grading of sarcomas and the treatment evaluation of locally advanced sarcomas.

Adolescent↗
PubMed2004

Axillary recurrence after sentinel lymph node biopsy.

UNLABELLED: Sentinel lymph node biopsy (SLNB) without further axillary dissection in patients with sentinel node-negative breast carcinoma appears to be a safe procedure to ensure locoregional control. During a median follow-up of 35 months the false-negative rate was 1% in our study population of 185 patients. BACKGROUND: The objective of this prospective study is to provide data on follow-up of patients with primary operable breast carcinoma staged with SLNB without axillary lymph node dissection (ALND) if the sentinel lymph nodes (SLNs) were tumour-negative. METHODS: One hundred and eighty-five patients were enrolled. Preoperative dynamic and static lymphoscintigraphy were performed; both a vital blue dye and a gamma detection probe were used intraoperatively. Patients with tumour-positive SLNs received completion ALND or if no SLNs could be identified. All patients were monitored according to regional follow-up protocols. RESULTS: The SLNs were identified in 179 out of the 185 patients. In 73 patients the SLNs were tumour-positive and in 106 patients tumour-negative. The median follow-up was 35 months (range 17-59). In one SLN-negative patient an axillary recurrence occurred 26 months after the SLNB (false-negative rate: 1%). CONCLUSIONS: SLNB without ALND appears to be a safe procedure to ensure locoregional control in SLN-negative breast carcinoma, if carried out by an experienced team.

Adult↗
PubMed2004

Pitfalls in the sentinel lymph node procedure in vulvar cancer.

OBJECTIVES: There is an increasing interest among gynecologic oncologists to implement the sentinel lymph node (SLN) procedure in vulvar cancer patients in clinical practice. However, the safety of this promising method of staging still has to be proven in a randomized trial. MATERIALS AND METHODS: Two vulvar cancer patients are reported to illustrate pitfalls in the sentinel lymph node procedure. RESULTS: The phenomena of bypassing the sentinel lymph node and confusion about the number of removed sentinel lymph nodes are presented and discussed. CONCLUSION: Gynecological oncologists who perform the sentinel lymph node procedure in vulvar cancer patients should perform this technique by following a strict protocol and within the protection of a clinical trial.

Aged↗
PubMed2004

Sentinel node detection in patients with breast cancer: low-energy all-purpose collimator or medium-energy collimator?

Sentinel node detection in patients with breast cancer is routinely performed in our department. Images frequently show star-shaped activity at the site of injection caused by septum penetration. These star-shaped artifacts could possibly impair visualization of nearby sentinel nodes. The aim of this study was to determine whether sentinel node detection in patients with breast cancer can be improved using a medium-energy all-purpose (ME) collimator instead of a low-energy all-purpose (LEAP) collimator. For this purpose, 15 patients were studied and a phantom study was performed. The LEAP collimator was used for a dynamic study immediately after injection, and both the LEAP and the ME collimators were used for static studies. A total of 20 sentinel nodes were found with both collimators. All sentinel nodes were found in the axilla. To separate sentinel nodes from the injection site, the ME collimator gave the best results in 4 of 15 patients, but only within the first hour after injection. To separate 2 nearby sentinel nodes from each other, the LEAP collimator gave the best results in 3 of 15 patients. Our conclusion is that the LEAP collimator gave better results than the ME collimator as a result of the better resolution and the higher sensitivity. Use of the ME collimator did not improve sentinel node detection.

Adult↗
PubMed2004

Gated blood-pool SPECT automated versus manual left ventricular function calculations.

Planar gated blood-pool imaging (GBPI) is a standard method for non-invasive assessment of left ventricular (LV) function. Gated blood-pool single photon emission computed tomographic (GBPS) data acquisition can be accomplished in the same time as GBPI, with the benefit of enabling visualization of all cardiac chambers simultaneously. The purpose of this investigation was to evaluate the degree to which automated and manual LVEF calculations agree with one another and with conventional GBPI LVEF measurements. GBPI studies were performed in 22 consecutive, unselected patients, followed by GBPS data acquisition. GBPS left ventricular ejection fraction (LVEF) calculations were performed by available software (NuSMUGA, Northwestern University, Chicago, IL) automatically and manually, using all LV gated short axis slices. Automatic LVEF assessed by GBPS correlated well with conventional planar GBPI (r = 0.88, P < 0.001). Mean planar GBPI LVEF was 50% +/- 12%, and mean GBPS automatic LVEF was significantly lower at 45% + 14% (P = 0.001), with a mean difference of 6% +/- 5%. Manual GBPS LVEF also correlated well with conventional planar GBPI (r = 0.90, P < 0.0001). Mean LVEF measurement by manual GBPS versus GBPI was significantly higher at 59% +/- 13%, with a mean difference of 10% +/- 6% (P < 0.001). Manual GBPS LVEF values were also significantly higher than automatically determined GBPS LVEF values (P < 0.001). It is concluded that LVEF values assessed by NuSMUGA GBPS software were reproducible, and automatic and manual values correlated well with conventional GBPI values. However, both automatic and manual GBPS calculations were significantly different from one another and from GBPI values, so that GBPI and NuSMUGA calculations cannot be considered to be equivalent.

Adult↗
PubMed2004

Impact of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in patients with biochemical evidence of recurrent or residual medullary thyroid cancer.

BACKGROUND: Conventional imaging such as with (99m)Tc(V)dimercaptosunnic acid (DMSA), (111)In-octreotide scintigraphy, computed tomography (CT), and magnetic resonance imaging (MRI) rarely localizes occult medullary thyroid cancer (MTC). The role of (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is not well defined. The aim of this study was to examine the usefulness of postoperative FDG-PET in localizing MTC metastases. METHODS: FDG-PET was performed in 26 patients with elevated serum tumor markers after total thyroidectomy with central compartment dissection and additional neck dissection on indication. Patient- and lesion-based results were compared with the findings of conventional nuclear imaging and validated by morphological imaging (CT, MRI, ultrasonography), including bone scintigraphy and pathology when possible. Clinical impact was evaluated. RESULTS: FDG-PET detected foci in 50% of patients with lesion-based sensitivity of 96%. (111)In-octreotide detected foci in 19% with sensitivity of 41%, and (99m)Tc(V)DMSA scintigraphy and morphological imaging detected foci in 21% and 40%, respectively, with sensitivity of 57% and 87%. No lesions were found in 11 patients (42%). Positive FDG-PET findings led to surgical intervention in nine patients (35%). They all underwent surgery for removal of residual tumor or metastases. One patient achieved disease-free status. In all patients who underwent surgery, serum calcitonin levels were reduced by an average of 58 +/- 31%. CONCLUSIONS: For detection of occult MTC lesions, FDG-PET is superior to conventional nuclear imaging and is the best detection method yet available. FDG-PET in postoperative follow-up has clinical value and may be used for guiding reoperation and additional morphological imaging preoperatively.

Adolescent↗
PubMed2004

Diagnostic and therapeutic approach of systemic amyloidosis.

Amyloidosis is a group of diseases, all characterised by deposition of protein fibrils with a beta-sheet structure. This structure generates affinity of amyloid for Congo red dye and is resistant to proteolysis. Three types of systemic amyloidosis are important for the clinician: AA (related to underlying chronic inflammation), AL (related to underlying monoclonal light chain production) and ATTR amyloidosis (related to old age or underlying hereditary mutations of transthyretin). Signs and symptoms vary considerably among the three types and the choice of treatment differs completely. A stepwise approach in diagnosis and therapy is presented. When amyloidosis is suspected the first step is histological proof of amyloid and the second is proof of systemic involvement. The next two steps are determination of the type of amyloid followed by detection of the precursor protein. The fifth step is a thoughtful clinical evaluation, necessary for assessment of prognosis and therapy. Subsequently, the choice of therapy is based on the 'precursor-product' concept. In the final step, the effects of therapy on the underlying disease as well as on the amyloidosis are assessed during follow-up. In this evaluation serum amyloid P component (SAP) scintigraphy helps to show organ involvement and therapy response.

Amyloid↗