The influence of sentinel lymph node tumour burden on additional lymph node involvement and disease-free survival in cutaneous melanoma--a retrospective analysis of 392 cases

Twenty per cent of sentinel lymph node (SLN)-positive melanoma patients have positive non-SLN lymph nodes in completion lymph node dissection (CLND). We investigated SLN tumour load, non-sentinel positivity and disease-free survival (DFS) to assess whether certain patients could be spared CLND. Sentinel lymph node biopsy was performed on 392 patients between 1999 and 2005. Median observation period was 38.8 months. Sentinel lymph node tumour load did not predict non-SLN positivity: 30.8% of patients with SLN macrometastases (> or =2 mm) and 16.4% with micrometastases (< or =2 mm) had non-SLN positivity (P=0.09). Tumour recurrences after positive SLNs were more than twice as frequent for SLN macrometastases (51.3%) than for micrometastases (24.6%) (P=0.005). For patients with SLN micrometastases, the DFS analysis was worse (P=0.003) when comparing those with positive non-SLNs (60% recurrences) to those without (17.6% recurrences). This difference did not translate into significant differences in DFS: patients with SLN micrometastasis, either with (P=0.022) or without additional positive non-SLNs (P<0.0001), fared worse than patients with tumour-free SLNs. The 2-mm cutoff for SLN tumour load accurately predicts differences in DFS. Non-SLN positivity in CLND, however, cannot be predicted. Therefore, contrary to other studies, no recommendations concerning discontinuation of CLND based on SLN tumour load can be deduced.

Baseline staging in cutaneous malignant melanoma

BACKGROUND

Baseline staging in patients with primary cutaneous malignant melanoma (MM) is routine, but the diagnostic accuracy and the impact on clinical outcome are still unclear.

OBJECTIVES

To evaluate the sensitivity and specificity of baseline staging in the early detection of regional lymph node metastases or distant metastases in patients with MM.

METHODS

One hundred consecutive patients with MM of Breslow's tumour thickness over 1.0 mm were enrolled. All patients had an extensive baseline staging including physical examination, ultrasound (US) of the abdomen and regional lymph nodes, chest X-ray, whole-body positron emission tomography (PET) and sentinel lymph node biopsy. The sensitivity and specificity of detection of macroscopic or microscopic metastases in the regional lymph nodes or at distant sites were calculated for each method.

RESULTS

Sentinel lymph node biopsy was positive in 26 patients. US detected two of 26 histologically tumour-positive sentinel nodes (sensitivity 8%, specificity 88%) and PET two of 26 (sensitivity 8%; specificity 100%). There were three lymph node metastases with a diameter > 4 mm. All of them were found suspect at physical examination. Two of them were detectable with US, two with PET, and all were identified with either US or PET. Nine patients had suspect findings at distant sites, which were all false positive on further investigation (specificity of the combined staging procedures 91%). At 18 (6-37) months' follow-up, five of 26 (19%) patients with a positive sentinel node and four of 74 (5%) of patients with a negative sentinel node had recurrent or progressive disease.

CONCLUSIONS

The combination of physical examination and lymph node US detects the great majority of patients with macroscopic lymph node metastasis (approximately 3% of patients at baseline). Only 10% of patients who have a histologically tumour-positive sentinel node are macroscopically detectable. Altogether, approximately 25% of patients have a positive sentinel node biopsy, among 90% microscopic. The value of whole body staging at baseline remains limited, since distant metastases can hardly ever be detected. The survival benefit of baseline staging and surveillance in patients with cutaneous MM remains to be established by comparative prospective trials.

Sentinel lymph node evaluation in squamous cell carcinoma of the head and neck

OBJECTIVE

The aim of our study was to assess the feasibility of sentinel lymph node (SLN) radiolocalization in N0 neck in squamous cell head and neck carcinoma and its predictive value for occult metastasis.

STUDY DESIGN

Nineteen patients of an open prospective trial.

SETTING

After peritumoral injection of a 99m Tc labeled radiocolloid, the SLN was localized preoperatively by lymphoscintigraphy and intraoperatively through the intact skin by a hand-held gamma-probe. The histology of the SLN and the nodes of the elective neck dissection were compared.

RESULTS

Localization of the SLN by lymphoscintigraphy was possible in 18 of 19, and with the hand-held gamma-probe in all 19 patients. Six SLN revealed occult metastatic disease. No skip metastasis were found in the 13 neck specimen with negative SLN.

CONCLUSION

SLN evaluation in N0 neck in squamous cell carcinoma of the head and neck is accurately feasible and seems to adequately predict the presence of occult metastasis.

Body composition abnormalities in children with Prader-Willi syndrome and long-term effects of growth hormone therapy

Obesity and hypothalamic GH deficiency contribute in different ways to the disturbances of body composition in Prader-Willi syndrome (PWS); while both increase the fat compartment, the reduction of lean tissue mass has been attributed mainly to GH deficiency. Therefore, body composition measured by dual-energy X-ray absorptiometry was prospectively studied in 12 overweight children with PWS and weight for height (WfH) SDS >0 before and during 3.5 years of treatment with hGH (0.037 mg/kg/day) on average. In the long term, there is a net reduction of body fat from 3.1 to 1.2 SD, with a minimum at the end of the second year of treatment. WfH SDS correctly reflects body fat mass and its changes. The initial deficit of lean mass (-1.6 SD) is counteracted by GH only during the first year of therapy (increase to -1.25 SD). But in the long term, GH therapy does not further compensate for this deficit, when lean mass is corrected for its growth-related increase. In conclusion, exogenous GH changes the phenotype of children with PWS: fat mass becomes normal, but, at least in the setting studied, GH is not sufficient to normalize lean tissue mass.

Cardiovascular risk factors improve during 3 years of growth hormone therapy in Prader-Willi syndrome

Cardiovascular risk factors in Prader-Willi syndrome (PWS, OMIM 176270) may be independently caused by overweight or hypothalamic growth hormone (GH) deficiency. The present observational study in 23 children with PWS, aged 0.3-14.6 years, focuses on the specific pattern, age-dependency and interrelation of cardiovascular risk factors, namely percentage fat mass and regional fat distribution, triglycerides (TG), lipoprotein cholesterols (LDL-C, HDL-C), lipoprotein (a) (Lp(a)), apolipoproteins A-I (Apo A-I) and B (Apo B), as well as on the longer-term effects of GH therapy (ca. 0.037 mg/kg per day for 3 years on average). We report that in children above 4 years, percentage body fat was increased in all and waist-to-hip-ratio (WHR) in 35%. Abnormal levels of LDL-C, Apo B, HDL-C and TG were found in 6, 7, 6 and 3 children, respectively. Lp(a) was above 300 mg/l in 5 patients and remained unchanged during GH therapy. However, percentage fat mass dropped to the upper normal range and WHR became normal in all patients receiving GH therapy, as did the ratio of LDL-C to HDL-C, subsequent to decreasing LDL-C and increasing HDL-C. Nevertheless, we could not find any significant correlation between parameters of total fat mass or fat distribution and serum lipid parameters, except for abdominal fat distribution (trunk-/leg-fat ratio) to TG before therapy.

CONCLUSION

Several cardiovascular risk factors are already present in prepubertal children with Prader-Willi-syndrome and they are improved by growth hormone treatment, acting both on body composition and lipid metabolism.

Prevention of osteoporosis in heart transplant recipients: a comparison of calcitriol with calcitonin and pamidronate

Bone loss and osteoporotic fractures are common in cardiac transplant recipients. To compare two prophylactic medical regimens after heart transplantation, 26 consecutive heart transplant recipients were randomized to receive either continuous oral calcitriol (0.5 microg/day) combined with nasal salmon calcitonin (200 U/day) for the first 3 months (group A) or intermittent intravenous pamidronate (0.5 mg/kg body weight) every third month (group B). Bone mineral density (BMD) and biochemical indices of bone turnover were measured at baseline and 3, 6, 12, and 18 months after transplantation. The mean pretransplant BMD, measured by dual energy X-ray absorptiometry (DXA) was significantly lower in the patients compared with age-matched healthy controls. During the first year of treatment, rates of bone loss at the lumbar spine and femoral neck were slightly but significantly slower in the patients treated with pamidronate, but there was no longer a significant difference between the two groups after 18 months of heart transplantation. Irrespective of the mode of osteoporosis prevention, osteocalcin levels increased whereas urinary deoxypyridinoline decreased after transplantation, and significant bone loss was observed in both treatment groups. We found no relationship between initial BMD, markers of bone turnover, cumulative glucocorticoid dose, or cyclosporine levels and the rate of bone loss after cardiac transplantation. In summary, we found that the rapid and severe bone loss following heart transplantation could be attenuated by two preventive measures, pamidronate or calcitriol with calcitonin.

Myocardial ischaemia in children with isolated ventricular non-compaction

AIMS

Isolated ventricular non-compaction is a rare congenital cardiomyopathy with a high morbidity and mortality due to malignant arrhythmias and pump failure. Areas affected by non-compaction are characterized by increased trabecularization and deep inter-trabecular spaces. We hypothesized perfusion defects in these areas and performed positron emission tomography to evaluate the myocardial perfusion in non-compacted areas.

METHODS AND RESULTS

Five children (age 10-14 years) with isolated ventricular non-compaction underwent positron emission tomography using N-13-ammonia as flow marker and intravenous dipyridamole for stress testing. Myocardial blood flow was quantified using the positron emission tomography time-activity curves in non-compacted areas and normal myocardium, which were diagnosed by echocardiography, magnetic resonance imaging, and angiography. Coronary angiography, performed in two children with extensive forms of left ventricular non-compaction, demonstrated normal coronary arteries. Myocardial blood flow measurements at rest and after dipyridamole application demonstrated 16-33% and 32-57% perfusion impairment, respectively, in non-compacted areas compared to normal myocardium. Areas of restricted myocardial perfusion corresponded well to the non-compacted areas, defined echographically and by magnetic resonance imaging.

CONCLUSION

Positron emission tomography demonstrates restricted myocardial perfusion and decreased flow reserve in areas of ventricular non-compaction in children. The myocardial perfusion defects in non-compacted areas may be the cause of myocardial damage and possibly form the basis of arrhythmias and pump failure.

Radiographically negative stress related bone injury. MR imaging versus two-phase bone scintigraphy

PURPOSE

To assess the diagnostic value of MR imaging relative to two-phase bone scintigraphy in radiographically negative stress-related injuries.

MATERIAL AND METHODS

Sixteen consecutive patients presenting with stress-related bone injuries and normal standard radiographs were examined with two-phase bone scans and MR imaging. MR imaging protocols varied according to the region to be examined. The MR and scintigraphic images were evaluated blindly and separately by respectively two radiologists and two nuclear medicine physicians. The standard of reference was represented by a combination of clinical and scintigraphic findings as well as clinical follow-up.

RESULTS

For MR imaging, sensitivity, specificity, and positive and negative predictive values for the presence of stress-related injuries for the two readers were 69/63%, 100/80%, 100/91%, and 50/40%, respectively. Interobserver agreement was good (kappa = 0.62). For scintigraphy, all abnormal and normal findings were correctly identified.

CONCLUSION

For patients with clinically suspected stress-related injuries and a low probability of other active bone diseases (such as infection or neoplasm), bone scintigraphy should be the initial imaging modality.

Treatment with human growth hormone in patients with Prader-Labhart-Willi syndrome reduces body fat and increases muscle mass and physical performance

Twelve children with documented Prader-Labhart-Willi syndrome were treated with human growth hormone (24 U/m2/week) during 1 year. The children were divided into three groups: group 1: overweight and prepubertal (n=6, age 3.8-7.0 years); group 2: underweight and prepubertal (n=3, age 0.6-4.1 years); group 3: pubertal (n=3, age 9.2-14.6 years). In group 1, height increased from -1.7 SD to -0.6 SD, while weight decreased from 1.1 SD to 0.4 SD, with a dramatic drop in weight for height from 3.8 SD to 1.2 SD. Hand length increased from -1.5 SD to -0.4 SD and foot length from -2.5 SD to -1.4 SD. Body fat, measured by dual X-ray energy absorptiometry, dropped by a third, whereas muscle mass increased by a fourth. Physical capability (Wingate test) improved considerably. The children were reported to be much more active and capable. In group 2, similar changes were seen, but weight for height increased, probably because muscle mass increase exceeded fat mass decrease. Changes in group 3 were similar as in group 1, even though far less distinct.

CONCLUSION

Growth hormone treatment in Prader-Labhart-Willi syndrome led to dramatic changes: distinct increase in growth velocity, height and muscle mass, as well as an improvement in physical performance. Fat mass and weight for height decreased in the initially overweight children, and weight for height increased in underweight children.

Effect of 6 months of growth hormone treatment in young children with Prader-Willi syndrome

Nine prepubertal children with Prader-Willi syndrome were treated with growth hormone (GH; 24 IU/m2/week) for 6 months. Mean height increased by 0.8 SD and mean weight for height decreased by 0.7 SD over this 6-month treatment period. Body fat, measured by dual-energy X-ray absorptiometry, decreased by 22.5% over the period of GH treatment, whereas fat-free mass increased by 14%. These preliminary results indicate that GH is effective in increasing height and normalizing body composition in patients with Prader-Willi syndrome.

Radioiodine-labelled alpha-methyl-tyrosine in malignant melanoma: cell culture studies and results in patients

Tyrosine is a precursor of melanin synthesis and might thus present a valuable marker for melanoma. The aim of this study was to evaluate the uptake of alpha-methyl-tyrosine (AMT) in melanoma cell cultures and to assess its usefulness as a radiopharmaceutical for staging melanoma patients with whole-body scintigraphy. Melanoma (M19-cell lines) and fibroblast (negative control) cell cultures were incubated with 125I-AMT and the radioactive uptake in the cell lines was measured in a gamma-counter over 24 h. For in vivo studies, planar whole-body scintigraphy and single photon emission computed tomography (SPECT) of the tumour region was performed following injection of 250-350 MBq 123I-AMT in six patients with known melanoma metastases. Findings were compared with results of whole-body positron emission tomography using 18F-fluorodeoxyglucose (FDG-PET) as a standard of reference. Fibroblasts showed an unchanged uptake of (mean +/- SD) 0.56 +/- 0.09% 15 min and 0.066 +/- 0.09% 24 h, respectively, after incubation of 125I-AMT, whereas there was an increased uptake in melanoma cell cultures over time from 0.9 +/- 0.05% to 7.5 +/- 1.6%. In staging melanoma patients, the sensitivity of whole-body AMT-scintigraphy compared with FDG-PET was 37% (10 of 27 metastases). AMT is transported and metabolized to a high extent in melanoma cells and 123I-AMT is accumulated in melanoma metastases. Owing to its low sensitivity, however, the clinical use of whole-body AMT scintigraphy cannot be recommended.

[123I-alpha-methyltyrosine scintigraphy in malignant melanoma]

AIM

The aim of the study was to evaluate the ranking of the scintigraphy with L-3-123I-alpha-methyltyrosine (123I-AMT) in metastasized melanoma.

METHODS

26 metastases and one primary tumor of a malignant melanoma in six patients were examined with 123I-AMT whole-body scintigraphy and SPECT. Positron Emission Tomography with 2-18F-fluoro-2-desoxy-D-glucose (18F-FDG) was used as the golden standard.

RESULTS

With 123I-AMT-SPECT 8/10 metastases in the thorax > 1.6 cm were detected (ratio T/NT 1.2-1.8), metastases < 1.6 cm were not detectable with SPECT. In 123I-AMT whole-body scintigraphy not one lesion showed a positive tumor uptake.

CONCLUSION

In single cases 123I-AMT scintigraphy can be helpful in staging of malignant melanoma.

Octreotide scintigraphy and catecholamine response to an octreotide challenge in malignant phaeochromocytoma

OBJECTIVE

Octreotide scintigraphy has been reported to visualize chromaffine tumours. This study in patients with malignant phaeochromocytoma was designed to assess octreotide in comparison with standard m-iodobenzylguanidine (MIBG) scintigraphy and to study functional activity of somatostatin receptors. Finally, two cases of octreotide treatment are reported.

DESIGN

Open, prospective clinical trial.

PATIENTS

In 12 patients with histologically proven malignant phaeochromocytoma, 111In-octreotide scintigraphy, 123I-MIBG scintigraphy and computed tomography were performed. In ten patients plasma catecholamine response to a single dose of octreotide (200 micrograms i.v.) was monitored up to 5 hours after injection. Two patients were treated with octreotide over several months.

MEASUREMENTS

Plasma catecholamines were measured by high performance liquid chromatography (HPLC). Scintigraphy was performed using a large field gamma camera and SPECT technique where appropriate.

RESULTS

At least one metastatic lesion was visualized by octreotide scintigraphy in eight patients while the remaining four patients had negative findings. In total, 43 out of 54 known metastases (79.6%) were detected by MIBG, 24 (44.4%) by octreotide. Nevertheless, octreotide scintigraphy detected six metastases that were negative by MIBG. There was no correlation between the results of octreotide scintigraphy and catecholamine suppression after i.v. octreotide. In two patients on octreotide treatment, symptomatic improvement, but not mass reduction, could be documented.

CONCLUSIONS

Octreotide scintigraphy behaves in part complementary to MIBG, thus, increasing diagnostic sensitivity. Presence of somatostatin receptors, as demonstrated by octreotide scintigraphy, does not necessarily predict functional activity or therapeutic response.

Malignant blue naevus with distant subcutaneous metastasis

Malignant blue naevus is a distinct but rarely documented variant of malignant melanoma, and we describe the triple recurrence of a suprapatellar cellular blue naevus over 12 years in a middle-aged woman. Staging investigations revealed a distant subcutaneous metastasis of the right thigh. Immunohistochemistry of the primary lesion and all recurrences showed S-100, HMB-45, NKI/C-3 and Ki-67 positive cells. However, non-malignant cellular blue naevi from five consecutive other patients were all Ki-67 negative. The change from negative to positive Ki-67 responsivity may therefore be a valuable marker of malignant and metastatic potential in early cellular blue naevi.

[Bone density and laboratory parameters of bone metabolism in patients with terminal heart disease]

PURPOSE

The purpose of this study was to assess bone mineral density (BMD) and parameters for bone metabolism in patients with end-stage heart disease awaiting heart transplantation to determine whether these patients are at increased risk of bone disease.

PATIENTS AND METHODS

39 adult men (mean age 52.3, range 21-65 years) with ischemic (41%), idiopathic (43.5%), valvular (2.5%) and diverse (13%) end-stage heart disease were studied prior to heart transplantation. BMD was measured using dual-energy x-ray absorptiometry at the lumbar spine (L2-L4) and at the upper femur (Ward's triangle and femoral neck). Renal and bone biochemical profiles, parathyroid hormone (PTH), 25-OH-vitamin D3, testosterone, alkaline bone phosphatase, osteocalcin, and deoxypyridinoline and calcium excretion were measured.

RESULTS

No fractures were found. Mean z-scores were -1.06 +/- 2.02 (mean +/- SD) at the lumbar spine, -1.12 +/- 2.03 at the femoral neck and -0.25 +/- 1.06 at Ward's triangle. Significantly decreased values were seen at the lumbar spine and at the femoral neck compared to age matched healthy controls. Mean values of serum creatinine and parathyroid hormone were elevated (114.4 +/- 29.5 mumol/l and 84.3 +/- 67.8 ng/l, respectively). 7 (18%), 10 (26%) and 22 (56%) of the 39 patients had values beneath the normal range of 25-OH-vitamin D3, testosterone and osteocalcin respectively. Mean urinary deoxypyridinoline/creatinine ratios were elevated (9.46 +/- 8.52 nmol/mmol, normal range 2.5-5). No correlation existed between osteocalcin and urinary deoxypyridinoline/creatinine ratio. Using a multiple linear regression model, serum PTH and cardiac ejection fraction (EF) weakly predicted BMD at the femoral neck (r2 = 0.26).

CONCLUSIONS

(1.) Lumbar spine and femoral neck BMD are low in patients awaiting heart transplantation. (2.) A low EF and a high PTH weakly correlate with a decrease in BMD at the femoral neck. (3.) In patients with end-stage heart failure the coupling of bone formation to bone resorption is frequently disturbed. (4.) Testosterone and 25-OH-vitamin D3 levels are low in a number of patients and in such cases replacement therapy may be appropriate.

[The value of 3-phase skeletal scintigraphy for early diagnosis of Sudeck disease]

PURPOSE

In a prospective study the value of the three-phase bone scintigraphy in the early diagnosis of Sudeck's atrophy was analysed.

MATERIAL AND METHODS

137 patients with the clinical suspicion on Sudeck's atrophy in stage I were examined. By means of the clinical course and additional examinations (block response), pain experts confirmed the diagnosis separately.

RESULTS

With the findings of hyperperfusion of all 5 phalanges, homogeneous hyperaemia of the affected hand or the foot and periarticular increased uptake of the whole extremity a reliable diagnosis of Sudeck's atrophy was possible. The sensitivity was 95.9%, the specificity 100%. With bone scintigraphy Sudeck's atrophy could be clearly differentiated from an inactivity atrophy.

CONCLUSION

Three-phase bone scintigraphy is an excellent tool for the objective diagnosis of Sudeck's atrophy in stage I.

Whole-body PET: physiological and artifactual fluorodeoxyglucose accumulations

The purpose of this study was to semiquantitatively identify artifactual and physiological soft-tissue accumulations in whole-body FDG-PET scans with the aim of defining their frequency and anatomic distribution.

METHODS

Fifty whole-body FDG-PET scans performed for the staging of malignant melanoma were obtained from transaxial scans and reconstructed without absorption correction by filtered backprojection in the form of coronal and sagittal sections. The patients were asked to stay n.p.o. for at least 4 hr and interrogated about their physical activity prior to injection and until scanning. Classification of FDG organ accumulations was done using grades 0-6. Means and standard deviations on this scale were then calculated for multiple organs and muscle groups and tabulated.

RESULTS

On this grading scale, viscera showed uptake grades between 1.7 +/- 0.5 and 2.05 +/- 1.0. Except for the intestines, the activity in these organs was homogeneously distributed. Relatively high average uptake values of 2.0-4.2 (s.d. > or = 2.3) were found in various muscle groups, especially the orbital musculature. Myocardial uptake was visible in 90% of the scans. Reconstruction artifacts were seen around the renal collecting system and the bladder.

CONCLUSION

Most of the "normal" accumulations of FDG in nonattenuation corrected whole-body PET are readily recognized and distinct from the usually focal FDG accumulation associated with metastatic disease, but the diagnostician must be familiar with them. Muscular FDG uptake is related to physical activity prior and immediately following injection and can be minimized by proper patient instructions and positioning.

Lack of expression of dopamine D2 receptors in malignant melanoma: evidence for interaction of iodobenzofurans with melanin

OBJECTIVES

(1) To compare scintigraphy using the new dopamine D2 receptor binding radioligand iodobenzofuran (IBF) versus whole-body positron emission tomography (PET) in demonstrating metastasizing melanoma, and (2) to determine, for the first time using a panel of histochemical techniques, whether the ability of D2 receptor binding radioligands to detect melanoma metastases is due to tumor-expressed D2 receptors.

METHODS

Seven patients with metastatic melanoma were examined using 123I-IBF scintigraphy. Findings were compared to the results of PET and metastasis histochemistry: D2 receptor mRNA assay (metastases: n = 5; melanoma cell lines: n = 4) using the reverse transcriptase polymerase chain reaction (RT-PCR) versus D2 receptor-transfected Chinese hamster ovary cell controls: in vitro 125I-IBF binding (n = 19), and immunohistochemical staining for dopamine D2 receptor protein (n = 19).

RESULTS

IBF scintigraphy detected 2/10 melanoma metastases detected by PET (sensitivity 20%). No dopamine D2 receptor mRNA was found in melanoma cells using RT-PCR. The binding of 125I-IBF correlated with the amount of melanin present in the metastases; two amelanotic melanomas both failed to bind 125I-IBF. Immunohistochemical staining was negative in all metastases.

CONCLUSION

Melanoma cells do not appear to express dopamine D2 receptors. Although IBF had high dopamine D2 receptor affinity, its ability to detect melanoma metastases is more likely explained by low affinity binding to melanin than by the presence of dopamine receptors.

[Dopamine-D2 receptor scintigraphy with 123I-iodobenzofuran in malignant melanoma]

In recent publications dopamine-D2 receptor scintigraphy with benzamides was postulated for specific imaging of melanoma. In a prospective study the value of 123I-iodobenzofuran (IBF), a highly specific and affine dopamine-D2 receptor ligand was evaluated for the detection of melanoma metastases. With IBF-D2 receptor scintigraphy only 2 of 17 melanoma metastases could be detected. The interpretation of the abdomen was impaired by the hepatobiliary and renal excretion of the radionuclide. The ratio striatum/frontal cortex of 2.75 +/- 0.49 3 h p.i. demonstrated a high D2-receptor binding of the ligand. IBF-D2-receptor scintigraphy is not suitable as a method of staging melanoma.

Staging of metastatic melanoma by whole-body positron emission tomography using 2-fluorine-18-fluoro-2-deoxy-D-glucose

Metastatic melanoma was staged in 15 patients using whole-body positron emission tomography (PET) and the radiopharmaceutical 2-fluorine-18-fluoro-2-deoxy-D-glucose (FDG). PET correctly demonstrated 30 metastases in lung, brain, pancreas, nasal cavity, skin and subcutaneous tissue, and lymph nodes. It detected 97% of all metastases exceeding its spatial resolution (> 5 mm). Two cutaneous metastases (approximately 3 mm) did not show increased FDG uptake; the overall detection sensitivity was 91%. Two false-positive lesions in one patient were due to severe wound infection. PET correctly excluded malignancy in four cases where suspicious lesions were found with conventional cross-sectional imaging modalities but later ruled out by fine-needle biopsy. PET therefore proved to be an excellent method for staging of metastatic melanoma. Due to its high sensitivity for malignant lesions and the possibility of covering the whole body in one examination, it can replace staging techniques employing multiple imaging modalities: chest X-ray, ultrasonography and computed tomography. Furthermore, it provides information on the malignant potential of the detected lesion.

Anti-melanoma monoclonal antibody 225.28S immunoscintigraphy in metastatic melanoma

BACKGROUND

Accurate staging and early detection of metastases are crucial to melanoma management. It would thus be of great value to have a widely available, cost-effective method that allows to examine the whole body and is more specific than current imaging modalities.

OBJECTIVE

The purpose of the study was to assess the value of immunoscintigraphy with 99mTc-radiolabeled F(ab')2 fragments of the 225.28S monoclonal antibody in the staging of melanoma.

METHODS

29 patients with known or suspected metastases were enrolled in the study and examined by monoclonal antibody fragment scintigraphy. The results were compared to physical examination, other imaging modalities and, where available, histology.

RESULTS

Antibody scintigraphy detected 9/34 metastases. There were 2 false-positive lesions. Diagnostic accuracy was 41%, sensitivity 26% and specificity 83%.

CONCLUSION

99mTc-radiolabeled F(ab')2 monoclonal antibody-fragment scintigraphy cannot be recommended for staging of melanoma patients. The search for more sensitive radiopharmaceuticals for scintigraphy should thus be encouraged.

Dopamin-D2-Rezeptorszintigraphie mit 123I-Jodbenzofuran beim malignen Melanom

In jüngsten Publikationen wurde die Dopamin-D2-Rezeptorszintigraphie mit Benz-amiden zur spezifischen Darstellung von Melanomen vorgeschlagen. In einer prospektiven Studie wurde die Wertigkeit von 123I-Jodbenzofuran (IBF), einem hochspezifischen und hochaffinen Dopamin-D2-Rezeptorliganden zum Nachweis von Melanommetastasen untersucht. Mit der IBF-D2-Rezeptorszintigraphie ließen sich nur 2 von 17 Melanommetastasen nachweisen. Die Beurteilung des Abdomens war durch die hepatobiliäre Ausscheidung des Radionuklids stark eingeschränkt. Der Quotient Striatum/Frontalhirn von 2,75 ± 0,49 3 h p.i. belegte die hohe D2-Rezeptorbindung des Liganden. Die IBF-D2-Rezeptorszintigraphie ist als Staginguntersuchung beim Melanom nicht geeignet.

Decreased benzodiazepine receptor binding in panic disorder measured by IOMAZENIL-SPECT. A preliminary report

Single photon emission tomography (SPECT) imaging of the central benzodiazepine receptor (BZr) became possible with the newly developed ligand 123I-IOMAZENIL. The BZr binding was investigated in ten patients with panic disorder (PP) compared to ten epileptic patients (EP). Panic patients had lower IOMAZENIL uptake rates in the frontal, occipital and temporal cortex than EP indicating the involvement of the BZr complex in panic disorder.

[Detection of primarily unrecognized fractures in severely injured patients by skeletal scintigraphy]

Even in despite of diligent investigation clinical and radiological diagnostics can leave fractures unrecognized in seriously injured patients. Bone-scans of 53 patients revealed 68 additional fractures. In 45% of all cases the initial diagnosis was altered, 19% resulted in therapeutical consequences. Routine diagnostics should be supplemented by a bone-scan if clinical and radiological findings are not in line. A bone-scan can exclude any osseous lesion and can survey the full extent of injuries especially in the disoriented or unconscious patient.

[Quantitative nuclear medicine kidney diagnosis with kidney tubule traversing radioisotopes]

In modern nuclear medicine, renal function scintigraphy has been improved and its range of applications extended by the development of new radiopharmaceuticals (iodine-123-hippuran, technetium-99m-MAG3) combining the properties of short half-life, favourable radiation energy and high renal clearance. Three significant advantages recommend the use of scintigraphic methods: 1. Being non-invasive and non-nephrotoxic, the examinations do not affect the patient. The radiation exposure the patient is subjected to is about the same as with a comparable X-ray investigation or, with respect to the reproductive glands, even lower. Allergic reactions do not occur. 2. In contrast to the situation with other imaging methods, the functional defect itself (and not only secondary changes in the morphology) can mostly be detected. Not only diffuse alterations, but also defined functional lesions of a small part of a kidney, can be diagnosed. 3. Various renal parameters can be calculated more accurately than with any other routine clinical method. The radioisotopic methods discussed yield reliable results with excellent reproducibility concerning glomerular filtration rate, effective renal plasma flow, side-to-side functional ratio, renal perfusion, and urine drainage. Most of these parameters can be obtained by means of a single investigation. These radioisotopic methods make it possible to detect or exclude a wide range of functional lesions of the kidneys and the urinary tract, which are often due to non-specific symptoms. In addition, they allow answers to highly specific clinical and scientific questions in nephrology and urology.

[Importance of whole body skeletal scintigraphy within the scope of staging of neoplasms in the ENT area]

Concerning malignant tumours of the oral cavity, pharynx and larynx, bone metastases are in general rarely seen. For the specification to which patients the whole body bone scintigraphy as detection method should be applied, the findings of 370 patients were analysed retrospectively. In respect of primary staging, bone metastases could be found by scintigraphy in only 1.4% of the patients. On the other hand, there was a detection rate of 12% during the further course of the disease, especially in case of clinical symptoms pointing at spreading metastases or in tumour recurrences. Nevertheless, positive scan findings which were not due to metastases could be found in both groups with equal frequency (12 and 13%, respectively). Therefore the routine performance of whole body bone scintigraphy as a screening method does not seem to be useful in the primary staging of cancer of the mouth, pharynx and larynx. Contrary to this, in the follow-up of these tumours bone scanning proves to be a valuable and sensitive method for detecting skeletal metastases.

[The clinical relevance of anti-CEA immunoscintigraphy with the 99mTc-labelled monoclonal antibody BW 431/26. A critical assessment after 119 studies]

The results of 119 radioimmunoscintigraphies (RIS) in 113 patients with the 99mTc-labeled monoclonal anti-CEA-antibody BW 431/26 (Behring) have been analysed. The aim of our study was the estimation of the method's sensitivity and specificity under different aspects to find out for which indications and questions the 99mTc-RIS is useful. Colorectal primary tumours in 19 patients were scintigraphically detected with a sensitivity of 83% and a specificity of 100%; 3 out of 7 other tumour sites were localised correctly. 55 patients were examined during the follow-up of colorectal cancer. There were 17 out of 22 true positive findings of local recurrences (sensitivity 77%, specificity 88%). Liver metastases were imaged as hot lesions with only 41% sensitivity and 86% specificity. The detection of extrahepatic tumour sites is difficult because of the persistently high blood-pool activity of the monoclonal antibody and, in the pelvic area, the unspecific bowel activity. Skeletal metastases were recognised in 7 out of 9 cases. In 14 patients with other non-colorectal carcinomas, RIS was successful in single cases. It is not helpful, however, when searching for tumours of unknown origin or for the screening of patients with elevated CEA levels without tumour history. The high technical, methodological and time effort required by RIS is justified in the follow-up of cancer patients when conventional diagnostic procedures are inconclusive or the status of morphological findings remains unclear. The use of RIS as an unspecific screening tool in tumour diagnosis must be rejected because of the not completely explored risks of the examination. Repeated applications of monoclonal antibodies require controls of the patients' HAMA titers before performing RIS.