Changes in diagnosis and operative treatment of insulinoma over two decades

PURPOSE

Most insulinomas are small solitary, benign neoplasms. Imaging and surgical techniques improved over the last 20 years. Thus, the aim of the present study was to analyze changes in diagnosis and surgery of insulinoma patients in a referral center over two decades.

METHODS

Operated patients with a histologically proven insulinoma were retrieved from a prospective database. Clinico-pathological characteristics and outcomes were retrospectively analyzed with regard to the time periods 2000-2010 (group 1) and 2011-2020 (group 2).

RESULTS

Sixty-one of 202 operated patients with pNEN had an insulinoma, 37 (61%) in group 1 and 24 (39%) in group 2. Of those 61 insulinomas, 49 (80%) were sporadic benign, 8 (13%) benign MEN1-associated insulinomas, and 4 (7%) sporadic malignant insulinomas. In 35 of 37 (95%) patients of group 1 and all patients of group 2, the insulinoma was preoperatively identified by imaging. The most sensitive imaging modality was endoscopic ultrasound (EUS) with correctly diagnosed and localized insulinomas in 89% of patients in group 1 and 100% in group 2. In group 1, significantly less patients were operated via minimally invasive approach compared to group 2 (19% (7/37) vs. 50% (12/24), p = 0.022). Enucleation was the most frequently performed operation (31 of 61, 51%), followed by distal resection (15 of 61, 25%) without significant differences between groups 1 and 2. The rate of relevant postoperative complications was not different between groups 1 and 2 (24% vs. 21%, p = 0.99). Two patients with benign insulinoma (1 out of each group) experienced disease recurrence and underwent a second resection. After a median follow-up of 134 (1-249) months, however, all 57 (100%) patients with benign insulinoma and 3 out of 4 patients with malignant insulinoma had no evidence of disease.

CONCLUSION

Insulinoma can be preoperatively localized in almost all patients, allowing for a minimally invasive, parenchyma-sparing resection in selected patients. The long-term cure rate is excellent.

[Diagnosis of and therapy for hepatocellular carcinoma]

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

Thoracoabdominal aneurysms and changes in adjacent vertebral bodies

AIM

The aim of this study was to assess if chronic intermittent pressure of a thoracoabdominal aortic aneurysm (TAAA) induces structural changes in vertebral bodies and if eroded vertebral bones can still be found after the extermination of syphilis.

METHODS

A retrospective analysis of computed tomography (CT) scans of patients with TAAA was performed. In the anatomical regions were the TAAA was in close contact with the vertebral bodies, the vertebral body alteration was distinguished into 4 categories. Category 0: no changes; 1: discrete changes, minimal asymmetry; 2: obvious asymmetry of the vertebral body with sustained cortical layer; 3: severe destruction of the vertebral body with loss of the cortical layer.

RESULTS

Eighty-six CT scans of patients (mean age 63; range 25-82 years) with TAAA pathology were examined (24 female, 62 male). The mean aneurysm diameter was 6.5 cm (4.3-14 cm). The results for scoring were: category 0: 33 patients; category 1: 46 patients; category 2: 5 patients and category 3: 2 patients. One of the category 3 patients suffered from acute spinal cord compression with complete paraplegia. In total, 62% of patients showed some degree of changes at vertebral bodies adjacent to the TAAA.

CONCLUSION

Intermittent pressure by either dissecting or non-dissecting TAAAs may induce structural changes in the vertebral bodies of the spine. Severe destruction of the bone is a rare, but existing complication.

[Cancer-to-cancer metastasis: amelanotic melanoma into renal cell carcinoma]

HISTORY AND PHYSICAL FINDINGS

A 54-year old man was admitted because of motor aphasia, behavioral changes and weight loss and suffered from a widely disseminated cancer with unknown primary origin (CUP) syndrome.

DIAGNOSIS

The autopsy revealed that he was affected by two malignant neoplasms simultaneously: an amelanotic malignant melanoma metastasizing into a localized renal cell carcinoma.

CONCLUSION

Cancer-to-cancer metastasis is an exceedingly rare, but well documented phenomenon. This is the third reported case of a malignant melanoma as donor tumor spreading into a renal cell carcinoma. Well-vascularized and slowly growing renal tumors are typical recipients for cancer-to-cancer metastases. The amelanotic character of the melanoma exerted a special diagnostic challenge. Clinical and autopsy findings as well as the immunophenotypical features of the metastatic amelanotic melanoma (HMB-45, Melan-A/MART-1, S100) and the renal cell carcinoma are described with a review of the relevant literature.

[Evaluation of a novel seldinger-needle for computed tomography guided interventions: initial experiences]

PURPOSE

To evaluate a new Seldinger puncture device for computed tomography-guided interventions under difficult conditions, to analyze applicability, and to investigate assets and drawbacks.

MATERIALS AND METHODS

From November 2007 to March 2008, we performed CT-guided interventions in 16 patients (7 women, 9 men; mean age 62 years old) using a new 20G-Seldinger needle (Sika-Med, Wiehl, Germany). This novel needle serves as a guide for many different interventional devices due to a guide wire welded on the proximal needle end. It allows continuous application of anesthesia via four tiny holes at the distal needle end until the region of interest is reached. Each intervention was subject to difficult interventional conditions. The indications for intervention were drainage (n = 7), Trucut biopsy of tumor (n = 8) and radiofrequency ablation (n = 1). Handling, success, advantages, drawbacks, complications and patient tolerance were noted after each procedure. A pain scale from 1 - 10 was used to grade the pain level during the intervention.

RESULTS

All interventions were performed successfully and no severe complications were observed. Patient tolerance was very good resulting in a mean pain score of 2 +/- 1. Regions with dangerous and difficult access were successfully reached with the new Seldinger needle in 15 of 16 cases by dilatation of the puncture tract and continuous administration of local anesthesia via the system. Furthermore, different devices such as Trucut systems and a drainage catheter were able to be inserted without complication via the needle. With a proximal removable luer-lock connection, liquid material was able to be aspirated in six cases.

CONCLUSION

Under difficult interventional conditions, the use of a Seldinger needle as a reliable technique for CT-guided interventions can provide a safe and successful procedure.

Multipolar hepatic radiofrequency ablation using up to six applicators: preliminary results

PURPOSE

To evaluate the clinical feasibility and safety of hepatic radiofrequency (RF) ablation using a multipolar RF system permitting the simultaneous use of up to six electrodes.

MATERIALS AND METHODS

Ten patients (3 female, 7 male, mean age 61) suffering from 29 hepatic metastases (range: 1 - 5) of different tumors were treated with a modified multipolar RF system (CelonLab Power, Celon Medical Instruments, Teltow, Germany) operating four to six needle-shaped internally cooled RF applicators. The procedure duration, applied energy and generator output were recorded during the intervention. The treatment result and procedure-related complications were analyzed. The achieved coagulation volume was calculated on the basis of contrast-enhanced CT scans 24 hours after RF ablation.

RESULTS

Complete tumor ablation was achieved in all cases as determined by the post-interventional lack of contrast enhancement in the target region using four applicators in five patients, five applicators in one patient and six applicators in four patients. A mean energy deposition of 353.9 +/- 176.2 kJ resulted in a mean coagulation volume of 115.9 +/- 79.5 cm (3). The mean procedure duration was 74.9 +/- 21.2 minutes. Four patients showed an intraabdominal hemorrhage which necessitated further interventional treatment (embolization; percutaneous histoacryl injection) in two patients.

CONCLUSION

Multipolar RF ablation of hepatic metastasis with up to six applicators was clinically feasible. In our patient population it was associated with an increased risk of intraabdominal bleeding probably due to the multiple punctures associated with the use of multiple applicators.

Computertomografisch gesteuerte Interventionen bei Kindern

In pediatric CT-guided interventions specific features have to be taken into account. Due to a lack of cooperation or limited ability to cooperate, procedures are often performed using analgosedation or general anesthesia. To provide radiation protection, justified indication for CT-guided intervention is necessary and sonography and MRI are to be preferred whenever possible. CT examinations also need to be dose-adapted with sequential scanning and a tube voltage and tube current reduction compared to pediatric diagnostic CT studies must be ensured. Gonad shields are recommended for male patients. Biopsy device selection depends on the assumed tumor entity since histology and also immunohistochemical, molecular pathological and cytogenetical analysis are necessary to differentiate pediatric tumors (small, round, blue cell tumors). In addition to diagnostic procedures, therapeutic interventions (drainage, injection therapies, neurolysis, and radiofrequency ablation) can also be used in children and can provide an alternative to surgery in selected cases. With justified indications and precise performance, CT-guided interventions can be successful in pediatric patients with limited risks.

Flüssigkeitsmodulierte RF-Ablation: In-vitro-Experimente

PURPOSE

To evaluate the potential of different fluids to enhance the effect of radiofrequency ablation.

MATERIALS AND METHODS

A bipolar radiofrequency system with an internally cooled needle electrode was used to heat three samples of 16 different fluids. Each sample had a volume of 20 ml. The generator output was set to 20 watt as recommended by the vendor. Energy was applied until the temperature of the sample reached 80 degrees C or the duration of heating exceeded 30 minutes. If a fluid was not able to be heated because the resistance was too high, 15 ml of the fluid were mixed with 5 ml of a 1-mol saline solution. During energy deposition, the temperature was measured every 15 seconds. The applied energy, impedance, resistance, voltage and flowing current were recorded continuously.

RESULTS

The ionic contrast agent Telebrix Gastro was heated to 80 degrees C within 620 +/- 95 seconds which was the shortest time needed. It was not possible to heat the contrast agents Solutrast 300, Isovist 240, Gadovist and Lipiodol as well as a 40 % glucose solution and 95 % ethanol. The longest time was needed to heat the 40 % glucose solution + the 1-mol saline solution (1755 +/- 26 seconds). The correlation coefficients (Pearson) showed only a marginal connection between resistance and maximum temperature (r=0.52) and duration for heating up to 80 degrees C, respectively (r=- 0.54). The same is true for the connection between impedance and maximum temperature (r=0.52) as well as duration for heating up to 80 degrees C (r=- 0.57).

CONCLUSION

The selection of an appropriate fluid allows an increase in the effect of radiofrequency ablation or the generation of a protective effect. Especially HAES, Magnevist and Telebrix Gastro are suitable for enhancing heating. Glucose solution or non-ionic contrast agents could be used to generate a protective effect during radiofrequency ablation. The heating of fluids by means of a bipolar radiofrequency ablation system is not only influenced by the electric properties but also by other parameters such as the specific heat capacity.

16-Zeilen-Spiral-CT des knöchernen Beckens nach Schraubenosteosynthese der iliosakralen Gelenke - Untersuchungen zur Dosisanpassung in einem Ex-vivo-Modell

PURPOSE

The study was performed to assess the necessity of dose adjustment (kV or mAs (eff.)) in 16-slice CT (MDCT) in postoperative controls of iliosacrally inserted osteosynthetic screws (OS) on preserved human cadaver specimens. The minimal tube settings for diagnostic imaging of the pelvic bone were analyzed and the effective doses and important organ doses were calculated.

MATERIALS AND METHODS

16 preserved human cadaver specimens with transiliac osteosynthetic screws were scanned on a 16-slice CT (collimation 16 x 0.75 mm, pitch 0.7) with 10 different tube settings (35, 50, 75, 100, 150 mAs (eff.) and 120 and 140 kV). 32 datasets (blinded for name and scan parameters) with and without OS were independently evaluated by four observers. The 10 series were sorted by subjective image quality (image noise, contours, artifacts), and the series with the lowest but still diagnostic quality was selected. The statistical analysis included multi-rater-kappa-test and Wilcoxon test for paired samples.

RESULTS

The multi-reader agreements for sorting the series were fair (kappa = 0.38). The agreements in comparing the lowest diagnostic image qualities were slight to fair (kappa = 0.08-0.23). The paired sample test comparing the lowest diagnostic image quality with and without OS showed no statistical significance (p = 0.29). 87.5 % of the readouts (n = 64 [16 examinations, 4 readers]) with OS and 78.1 % of those without OS could be adequately diagnosed using the three series with the lowest effective doses (0.9-1.4 mSv for men, 1.4-2.0 mSv for women; 120 kV-35 mAs (eff.), 120-50, 140-35).

CONCLUSION

MSCT scans of the pelvic bone can be performed with very low effective doses. It is not necessary to adjust tube settings when imaging bones with osteosynthetic screws. If the concept for the control of the pelvic osteosynthetic screw position includes more than 2 conventional films (for example anterioposterior view with additional inlet and outlet views), a low dose CT is preferable to conventional radiography.

[First results with catheter and magnetically guided and detached polymerized ferromagnetic particle filaments and heat-induced particle release using the Stereotaxis Niobe system]

PURPOSE

To develop a new technique for intravascular guidance and the release of magnetized ferromagnetic nanoparticles using a polymerized filament by means of an external magnetic field.

MATERIALS AND METHODS

Ferromagnetic nanoscaled beads were embedded in temperature-sensitive gels to form filaments after polymerization. Deflection of the filaments was assessed in a Stereotaxis Niobe magnetic navigation system (MNS) in comparison with dedicated guide wires. The curvature was measured as a surrogate parameter for deflection. In combination with commercially available catheters, the filaments were navigated in a perfused aneurysmatic vessel model and a perfused branched vessel model under the influence of two permanent magnets of the Niobe MNS. The magnetic field vector was varied in all three dimensions. After positioning, the magnetic colloid-containing filaments were exposed to an electromagnetic field of 45 kA/m, 200 kHz for a period of 5 minutes for non-invasive heating.

RESULTS

The filaments showed superior deflectability compared to the dedicated guide wires (p = 0.0091). The curvature was 0.54 +/- 0.12 mm(-1) for the filaments and 0.33 +/- 0.21 mm(-1) for the guide wires. In combination with angiography catheters, magnetic guidance and accumulation of specially designed filaments were possible in the perfused vessel model. Inductive heating allowed non-invasive disintegration and releasing of the nanoparticles in all filaments.

CONCLUSION

This feasibility study shows that magnetic guidance and targeting of a specially designed magnetic colloid-containing filament and subsequent disintegration are feasible. This technique offers the potential for controlled local drug release.

Dosisreduzierte 16-Schicht-Multidetektor-Spiralcomputertomographie bei Säuglingen und Kleinkindern mit bronchoskopischem Verdacht auf vaskulär bedingte Trachealstenosen - erste klinische Ergebnisse

PURPOSE

To evaluate the diagnostic accuracy of contrast-enhanced dose-reduced 16-slice multidetector-row CT (MDCT) in newborns and infants with fiberoptic bronchoscopically suspected vascular-induced tracheal stenosis.

MATERIALS AND METHODS

12 children (4 days to 3 years, 1.2 - 13.5 kg body weight) were examined using i. v. contrast-enhanced 16-slice MDCT (SOMATOM Sensation 16, Forchheim, Germany) without breath-hold and under sedation (11/12). All MDCTs were performed with a dose reduction. The beam collimation was 16 x 0.75 mm, except in the case of one child. MPRs along the tracheal axis in the x-, y- and z-directions and volume-rendering-reconstructions (VRTs) were calculated based on a secondary raw data set in addition to conventional axial slices. 2 radiologists used a three-point grade scale to evaluate the image quality, motion, and contrast media artifacts as well as the usefulness of the 2D- and 3D-reconstructions for determining the diagnosis. Statistical analysis was performed on the basis of a Kappa test.

RESULTS

In all cases the cause of the fiberoptic bronchoscopically suspected tracheal stenosis was revealed: compression due to the brachiocephalic trunk (n = 7), double aortic arch (n = 2), lusorian artery (n = 1), vascular compression of the left main bronchus (n = 2). In 3 patients further thoracic anomalies, such as tracheobronchial (n = 2), and vascular (n = 2) and vertebral (n = 1) anomalies were found. The attenuation in the anomalous vessels was 307 +/- 140 HU. The image noise was 9.8 +/- 1.9 HU. The mean dose reduction was 82.7 +/- 3.2 % compared to a standard adult thoracic CT. All examinations were rated as diagnostically good (median 1, range 1, k = 1). 3D images did not show any stair artifacts (median 2, range 1 - 2, k = 1). The image noise was minor to moderate and hardly any motion artifacts were seen (median 1, range 1 - 2, k = 0.8). Contrast media artifacts were rated zero to minor (median 1.5, range 1 - 2, k = 0.676). MPRs (median 1, range 1, k = 1) and VRTs (median 1, range 1, k = 1) were found to be useful for diagnosis. Subsequent vascular surgery was performed on 8 patients.

CONCLUSION

Contrast-enhanced dose-reduced 16-slice MDCT is effective for demonstrating the cause of fiberoptic bronchoscopically suspected vascular-induced tracheal stenosis even in very small and severely ill children despite the small contrast media amount and free breathing.

Multipolar radiofrequency ablation: first clinical results

Common systems of radiofrequency ablation (RFA) are monopolar devices which require grounding pads on the thighs in order to close the electrical circuit. Bipolar RFA does not require grounding pads, because both electrodes are located on one probe and alternating current circuit is confined within the target tissue. In this paper we report on the first clinical application of a new ablation device which enables both, bipolar (1 probe) and multipolar (up to 3 internally cooled probes simultaneously) radiofrequency ablation. We report on bi- and multipolar applications in liver tumors (9 patients), osteoid osteoma (2 patients) and renal cell cancer (1 patient).