Is it Necessary to Perform Sentinel Lymph Node Biopsy in Thin Melanoma? A Retrospective Single Center Analysis.

Sentinel lymph node biopsy (SLNB) is a standard procedure for regional lymph node staging and still has the most important prognostic value for the outcome of patients with thin melanoma. In addition to ulceration, SLNB had to be considered even for a single mitotic figure in thin (<1 mm) melanoma according to AJCC7th guideline, therefore, a retrospective review was conducted involving 403 pT1 melanoma patients. Among them, 152 patients suffered from pT1b ulcerated or mitotic rate ≥ 1/ mm2 melanomas according to the AJCC7th staging system. SLNB was performed in 78 cases, of which nine (11.5%) showed SLN positivity. From them, interestingly, we found a relatively high positive sentinel rate (6/78-8%) in the case of thin primary melanomas ˂0.8 mm. Moreover, the presence of regression increased the probability of sentinel positivity by 5.796 fold. After reassessing pT stage based on the new AJCC8th, 37 pT1b cases were reordered into pT1a category. There was no significant relation between other characteristics examined (age, gender, Breslow, Clark level, and mitosis index) and sentinel node positivity. Based on our data, we suggest that mitotic rate alone is not a sufficiently powerful predictor of SLN status in thin melanomas. If strict histopathological definition criteria are applied, regression might be an additional adverse feature that aids in identifying T1 patients most likely to be SLN-positive. After reassessing of pT1b cases according to AJCC8th regression proved to be independent prognostic factor on sentinel lymph node positivity. Our results propose that sentinel lymph node biopsy might also be considered at patients with regressive thin (˂0.8 mm) melanomas.

Increased technetium-99m-HMPAO uptake in grade II astrocytoma.

Most brain tumors show decreased uptake of blood flow tracers in brain SPECT imaging and in some cases meningiomas show increased uptake, mainly associated with high regional blood flow values. A reason for regionally increased tracer uptake is partial epilepsy when a tracer is injected during the ictal phase. We present a case of a histologically proven Grade II astrocytoma in the mesial part of the left temporal lobe that caused complex partial seizures. After tracer injection during a phase without signs of clinical seizure, markedly increased uptake of 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) occurred, although the tumor was partially calcified.

Evaluation of technetium-99m-ECD in childhood epilepsy.

UNLABELLED: In childhood epilepsy, it is difficult, but of critical importance, to determine whether surgical intervention might be beneficial for an individual patient. Because both established procedures-MRI and electroencephalography (EEG)-have limitations, interictal and ictal regional cerebral blood flow (rCBF) SPECT has proven to be a valuable adjunctive method in the presurgical evaluation of children. METHODS: We evaluated the usefulness of the new rCBF tracer 99mTc-ECD in 14 children with focal epilepsy (mean age 9.7 yr). Eleven interictal and 8 ictal studies were performed. Results were correlated with ictal and interictal surface EEG, MRI and histological findings and the postsurgical outcome. RESULTS: On the basis of the presurgical evaluation, nine patients underwent surgery. MRI studies demonstrated pathological features with possible relation to epilepsy in 50%. Overall, interictal 99mTc-ECD SPECT showed areas of hypoperfusion in 80% of patients. Ictal rCBF SPECT was informative in all patients, including one who showed bifrontal hyperperfusion in accordance with EEG results. CONCLUSION: Technetium-99m-ECD has proven to be of value for interictal and ictal rCBF SPECT in childhood epilepsy. No side effects during or after tracer administration were noticed. Ictal and interictal rCBF SPECT showed good correlation with MRI and EEG results in patients in whom correlation with the postoperative situation was possible and presented additional significant information in those patients with normal MRI and uninterpretable EEG results. No false lateralizations occurred. In children with focal epilepsy, interictal rCBF SPECT may accelerate the application of long-term electrocorticography (ECoG) in patients with normal MRI results. Ictal rCBF SPECT may also help to avoid ECoG, if a focal hyperperfusion correlates with a focal MRI abnormality, and the surface EEG gives no contradictory information.

Ictal and interictal brain SPECT imaging in epilepsy using technetium-99m-ECD.

UNLABELLED: The aim of this study was to evaluate the use of 99mTc-ethyl cysteinate dimer (ECD), also known as 99mTc-bicisate, in the presurgical evaluation of patients suffering from medically intractable epilepsy. METHODS: Twenty-three brain SPECT studies (8 ictally and 15 interictally) were performed on 16 patients with a high-resolution annular SPECT system (CERASPECT). For the ictal studies, the tracer was injected in the very early phase of the seizure. The delay between seizure onset and 99mTc-ECD injection was 2-20 sec. RESULTS: Interictally, all patients showed circumscribed hypoperfusions. In four patients, the SPECT lesion represented only structural defects. Circumscribed increased tracer uptake was observed in all ictal studies. For all patients with temporal lobe epilepsy without significant mass lesion, in whom an interictal and ictal 99mTc-ECD-SPECT study could be obtained, the asymmetry index was 0.88 +/- 0.03 for the interictal and 1.23 +/- 0.08 for the ictal studies. CONCLUSION: The data suggest that 99mTc-ECD is an effective marker of cerebral perfusion imaging in epilepsy. In comparison to other tracers, it has a high in vitro stability and is therefore particularly useful for ictal studies in the very early phase after seizure onset.

Autonomic nervous system dysfunction involving the gastrointestinal and the urinary tracts in primary Sjögren's syndrome.

OBJECTIVE: Antibodies reacting with the m3 subtype muscarinic acetylcholine receptor appear to be an important pathogenic factor in primary Sjögren's syndrome (pSS). As this receptor subtype is functionally important in the gastrointestinal and urinary tracts, and very little is known about the autonomic nervous system function in these organs in pSS patients, the occurrence and clinical significance of an autonomic nervous system dysfunction involving the gastrointestinal and urinary tracts were investigated. METHODS: Data on clinical symptoms attributable to an autonomic dysfunction were collected from 51 pSS patients. Gastric emptying scintigraphy and urodynamic studies were performed on 30 and 16 patients, respectively, and the results were correlated with patient characteristics and with the presence of autonomic nervous system symptoms. RESULTS: Gastric emptying was abnormally slow in 21 of the 30 examined patients (70%). Urodynamic findings, compatible with a decreased detrusor muscle tone or contractility were found in 9 of the 16 patients tested (56%). Various symptoms of an autonomic nervous system dysfunction were reported by 2-16% of the patients. CONCLUSION: Signs of an autonomic nervous system dysfunction involving the gastrointestinal and the urinary systems can be observed in the majority of pSS patients. This high occurrence is rarely associated with clinically significant symptoms. The authors presume a role of autoantibodies reacting with the m3 muscarinic acetylcholine receptor in the elicitation of the autonomic dysfunction.

Value of 99m-Tc MIBI and 99m-Tc(V) DMSA scintigraphy in evaluation of breast mass lesions.

Among several investigative methods currently undergoing evaluation for the differentiation of biological features of breast mass lesions, mammoscintigraphy with different radiopharmaceuticals appears promising. This study evaluated the efficacy of 99m-Tc MIBI and 99m-Tc(V) DMSA mammoscintigraphy in the detection of malignant focal breast lesions. Mammography, ultrasonography, 99m-Tc MIBI and 99m-Tc(V) DMSA mammoscintigraphy were performed in 51 women with palpable breast mass lesions. Following surgical removal of the abnormalities, histological examination revealed 40 malignant and 11 benign breast mass lesions. In mammoscintigraphy, early (5 minute p.i. of MIBI, 2 hours p.i. of DMSA) and late (2 hours p.i. of MIBI and 5 hours p.i. of DMSA) planar images of the breast and the axillary regions were evaluated visually and quantitatively. The efficacy of the methods was assessed via ROC curves and variance analysis. The visual scores and the quantitative T/NT values with MIBI demonstrated a significant difference between malignant and benign breast mass lesions. A significant difference was also found as concerns the grade of malignancy from the MIBI accumulation. The late MIBI images seemed optimal. The DMSA values indicated no relationship with the breast lesion malignancy. In the detection of metastatic lymph node involvement the sensitivity and specificity with mammography and ultrasonography were 57% and 85%, with MIBI 53% and 81%, and with DMSA 53% and 95%, respectively. It is concluded that MIBI (2 hours p.i.) mammoscintigraphy is a useful and simple method for differentiation of malignant breast abnormalities from benign lesions and for determination of the grade of malignancy. DMSA mammoscintigraphy appears superior to MIBI only in the detection of axillary lymph node metastases.

The effects of somatostatin and octreotide on the human sphincter of Oddi.

OBJECTIVE: Somatostatin acts at different sites in the human gastrointestinal tract and generally inhibits the release and effects of many gastrointestinal hormones and neuropeptides. Together with its long-acting analogue octreotide, somatostatin is widely used in the treatment of hormone-producing tumours, variceal bleeding, etc., but multi-centre trials have failed to prove a beneficial effect in the treatment of acute pancreatitis or in the prevention of post-ERCP pancreatitis (pancreatitis following endoscopic retrograde cholangiopancreatography). The aim of the present work was to study the effects of somatostatin and octreotide on the human sphincter of Oddi by means of quantitative hepatobiliary scintigraphy (QHBS). METHOD: Fifteen cholecystectomized patients were enrolled in the study, six in the somatostatin group and nine in the octreotide group. QHBS was performed initially with a standard protocol (baseline data), then repeated after 0.1 mg octreotide or a 250 microg bolus + 250 microg/h somatostatin administration. In the 60th min of QHBS, 0.5 mg glyceryl trinitrate (GTN) was administered sublingually. RESULTS: QHBS demonstrated that both somatostatin and octreotide caused a marked impairment in the bile flow: the half-time of excretion (T1/2) over the common bile duct was significantly prolonged compared with baseline data (somatostatin group: common bile duct T1/2 180 min versus 59.7+/-31 min; octreotide group: common bile duct T1/2 140.9+/-60.5 min versus 30.7+/-11.7 min). Glyceryl trinitrate administration accelerated the transpapillary bile flow, with significant decreases in the elevated T1/2 in both groups. CONCLUSION: Increased transpapillary flow induced by glyceryl trinitrate may be beneficial in the treatment of acute or post-ERCP pancreatitis.

Evaluation of cerebral vasoreactivity by SPECT and transcranial Doppler sonography using the acetazolamide test.

rCBF SPECT with 99mTc-HMPAO was performed prospectively in 29 patients (3 controls and 26 stroke patients) as well as TCD studies in 20 patients (3 controls and 17 stroke patients) before and after 1 g i.v. acetazolamide. The sensitivity of rCBF SPECT increased from 62% to 77% after acetazolamide provocation in stroke patients. In patients with a reversible neurological deficit, the sensitivity under resting conditions was 50% which increased to 71%, while in cases with a permanent deficit it increased from 75% to 83%. In the evaluation of the cerebrovascular reserve capacity the results of rCBF SPECT and TCD coincided in 91% of the hemispheres. The correlation was statistically significant.

The relevance of interictal rCBF brain SPECT in temporal lobe epilepsy: diagnostical value and effects of spatial resolution.

Interictal rCBF-SPECT is frequently being used as an adjunctive method for localization of an epileptogenic area during presurgical evaluation of patients suffering from medically refractory temporal lobe epilepsy. This study retrospectively evaluates interictal rCBF-SPECT using Tc-99m-HMPAO in comparison to the results of MRI. The final results of surface EEG and ECoG and the postsurgical clinical results as to seizure frequency were used a a 'gold-standard' for the evaluation of both imaging procedures. As spatial resolution is discussed to be the major reason for higher sensitivity of F-18-DG-PET compared to rCBF-SPECT, special attention has been paid to the spatial resolution of the different SPECT systems being used in this study. In 55 patients the complete data set could be obtained retrospectively, 36 of them being evaluated using SPECT systems with relatively low spatial resolution (Picker Dyna 2000, Elscint Helix) and 19 pt. being evaluated using moderate- to high-resolution SPECT systems (ADAC Genesys, DSI Ceraspect). Overall sensitivity of the interictal rCBF-SPECT was 75%, with 69% for low-resolution systems and 84% for high-resolution systems. Approximately at the same time when our institution installed the ADAC Genesys, the MRI equipment was changed form the 1.5 T Philips Gyroscan S15 to the 1.5 T Philips Gyroscan ACS II, the latter allowing superior imaging opportunities. Overall sensitivity of MRI was 60%, with 56%, for the Gyroscan S15 and 68% for the Gyroscan ACS II. The overall positive predictive value (PPV) was 87% for the interictal rCBF-SPECT and 87% for the MRI. Due to the lack of true negative studies in this population specificity was not calculated. False lateralization using rCBF-SPECT occurred in 5 pts. (9%), however, in 3 pts. the area of hypoperfusion correlated with a detectable MRI pathology, yet EEG/ECoG revealed the epileptogenic focus to be elsewhere. In conclusion, the interictal rCBF-SPECT revealed reasonable sensitivity and PPV in pt. suffering from focal temporal lobe epilepsy and modern SPECT systems showed significantly improved results. Since there is a variety of possible reasons for regional cortical hypoperfusion, the interictal SPECT could add significant information prior to the application of ECoG. This specially appeared to be useful in patients with abnormal MRI scan. Furthermore, in patients presenting with a clear pathology on MRI and a corresponding EEG focus, ECoG could be avoided if the interictal rCBF-SPECT additionally showed localized and singular involvement of the affected temporal lobe. ECoG was mainly applied in those patients with relatively wide-spread hypoperfusion additionally involving frontal or parietal cortical areas.

Investigation of gamma camera detector uniformity using a dynamic line phantom.

BACKGROUND: Investigation of the applicability of the dynamic line phantom for determination o the uniformity of circular and rectangular field-of-view gamma cameras. METHODS: Count rate - activity and uniformity - count rate functions were determined by the dynamic line phantom on three circular field-of-view gamma cameras with 37 PMTs, on one circular field of view camera with 19 PMTs, and on one rectangular field-of view gamma camera with 59 PMTs, with and without a collimator. For an evaluation of the efficacy of the dynamic line phantom, the results were compared with the uniformity values obtained with a 99mTc point source and a 57-Co sheet source. RESULTS: In the optimum count rate range (20,000-30,000 cps for a circular field-of-view, 15,000-65,000 cps for a rectangular field-of-view) determined individually for each gamma camera, the uniformity values obtained with the dynamic line phantom did not differ statistically from the refined with the 99mTc point source or the 57-Co sheet source. CONCLUSIONS: The dynamic line phantom is suitable for the determination of detector uniformity, but the measurements should be performed within a well-defined activity (count rate) interval.