Biomedical subjects

T K Helmberger

Publications and source records attributed to T K Helmberger.

13 recordsLinked to original sources

PubMed2006

Percutaneous radiofrequency ablation of pulmonary tumors--is there a difference between treatment under general anaesthesia and under conscious sedation?

OBJECTIVE: This retrospective study aimed to compare feasibility, complication rate and local tumor control after radiofrequency ablation (RFA) of pulmonary tumors under conscious analgo-sedation (AS) versus general anaesthesia (GA). MATERIALS AND METHODS: Within 36 months 21 patients had RFA (36 tumors, 26 treatment sessions). One patient suffered from NSCLC, 20 had metastases (breast (8/20), colorectal (6/20), renal cell (2/20), pharyngeal carcinoma (1/20), malignant melanoma (3/20)). Patients were no surgical candidates due to underlying comorbidities. Eleven of 26 treatments were performed under GA, while in 15 of 26 treatments AS was used. Follow-up was scheduled 24 h, 6 weeks, 3 months, 6 months and then every 6 months after treatment. RESULTS: RFA was feasible in all treatments under GA, while under AS targeting of the lesion was not possible in 2/15. Six adverse events occurred in the GA group (three major, three minor), while seven complications happened in the AS group (three major, four minor) (p=0.57). During follow-up of 3-36 months local recurrence was detected in 3 of 21 tumors in the GA group and in 2 of 15 tumors in the AS group (p=0.79). DISCUSSION: Hospitalization, complication rates and types, and the rate of local tumor control did not differ substantially among both groups. Furthermore, there was no significant difference in technical success and feasibility. CONCLUSION: RFA of pulmonary tumors under GA or AS did not result in different tumor control and complication rates, respectively. Therefore, AS should be used except in anxious or agitated patients.

Adult↗

PubMed2004

[Radiofrequency ablation of lung tumors and -metastases].

BACKGROUND AND PURPOSE: Radiofrequency ablation is increasingly used to treat tumors "beyond the liver". The aim of this article is to perform a structured and critical review of the current literature concerning RFA of the lung and to compare these results with our own experience. MATERIAL AND METHODS: 16 patients with tumors or metastases of the lung were treated in our institution within 18 months. 8 of these 16 patients were treated in a multicenter trial. For this article we compared our results to the results of all publications concerning RFA of the lung since 1995. RESULTS: 8 of our 16 patients were not included in the international multicenter trial and were followed-up at least 15 months. Within this observation period, 2 of 8 patients had recurrence of the tumors while in 6 patients no recurrence was detected. Lee et al. published a study with 30 patients. In 10 of these 30 patients RFA was performed in a curative intention with a therapeutical success in 8 of 10 patients after one year. DISCUSSION: Radiofrequency ablation of lung tumors smaller than 3 cm appears to be an alternative to surgical removal. Moreover, RFA offers a higher quality of life for the patients due to a low morbidity and mortality. However, more studies with longer observation periods are necessary for a definite conclusions.

Catheter Ablation↗

PubMed2004

[RFA of bone and soft tissue tumors].

Radiofrequency ablation (RFA) of primary and secondary liver malignancies is a promising and rapidly evolving technique, which increasingly gains importance. A new field of RFA is the minimal invasive therapy of osseous and soft tissue tumors. In the management of osteoid-osteoma, RFA is a well established treatment option. Basic principles, indications, complications and results of RFA will be presented. A careful evaluation of indications for RFA in osseous or soft tissue neoplasms is mandatory. In patients who are neither candidates for surgical tumor resection nor respond to chemotherapy, there is a need for alternative treatment options. In these preselected patients a substantial improvement in quality of life with low associated morbidity can be provided by RFA. In malignancies of bone and soft-tissue tumors, RFA is a palliative treatment option. Therefore, the results can not be compared to those of surgical resection or chemotherapy which essentially are employed with curative intention. Our own experiences as well as data published in the literature indicate that RFA is a helpful tool in preserving patient's quality of life. The high technical and clinical success together with a low complication rate makes RFA of osseous and soft tissue neoplasms a valuable supportive tool for patients not referable for surgery or systemic therapy.

Bone Neoplasms↗

PubMed2003

[Technique and methods in uterine leiomyoma embolization].

OBJECTIVE: Uterine leiomyomas are the most common benign tumors of the female urogenital tract. Beside the classic surgical treatment options the minimal-invasive embolization therapy of the leiomyomas increasingly gains importance world-wide. Technique, complications, and results of uterine leiomyoma embolization will be presented. METHODS: After careful evaluation of indications for embolization the procedure is mostly performed under conscious sedation. A single-sided femoral access route together with cross-over technique generally allows for a flow-directed embolization via both uterine arteries. After embolizing the vessels supplying the tumor, the uterine arteries should be still patent. RESULTS: The success rate of embolization of uterine leiomyomas ranges between 85 and 100%, whereas a reduction in size of the tumors in 42 to 83% and a relief of symptoms in up to 96% can be achieved. The total complication rate is about 10% with mainly "minor complications". Worldwide only three deaths following embolization of uterine leiomyomas were reported. CONCLUSION: The high technical and clinical success rate together with a low complication rate make the embolization of uterine leiomyomas a minimally-invasive alternative to the classic treatment. As long term results are not available indication to embolization of uterine leiomyomas must be carefully established in consensus with gynecologists.

Adult↗

PubMed2003

[State and development of uterine myoma embolization in Germany].

BACKGROUND: To evaluate the current situation and implementation of embolization of uterine leiomyomas into the treatment concept in women with symptomatic uterine leiomyomas in Germany. MATERIAL AND METHODS: A questionnaire addressing the clinical background of uterine myomas, recommended treatment concepts, preclinical evaluation, technical approach and complications was sent to 164 departments of gynecology and radiology in Germany. RESULTS: 33 radiological departments and 19 gynecological departments submitted a completed questionnaire. Only 7 departments of radiology reported to have own experience with embolization of uterine leiomyomas, while only 2 departments of gynecology considered embolization as an alternative treatment option in patients with symptomatic leiomyomas. 18/33 radiological departments offer this treatment option but get no patient referrals. Agreement was found concerning the indications for treatment, preclinical evaluation by ultrasound and MRI, preferable location of treatable fibroids, technical approach and pain management. CONCLUSION: The embolization of uterine leiomyomas in patients with symptomatic myomas is regardless of the well documented high efficacy and low complication rate not yet an established treatment option in Germany. Interventional radiologists and gynecologists have to evaluate the indications for the embolization of uterine leiomyomas together before the procedure is advised to the patient, because it seems mandatory to add this procedure to the standard armamentarium of treatment options in uterine myomas.

Adult↗

PubMed2003

[Percutaneous vertebroplasty (pv): indications, contraindications, and technique].

PURPOSE: Percutaneous vertebroplasty (pv) is a worldwide increasingly performed interventional therapeutic procedure. This article addresses indications, patient preparation, technical requirements and approach as well as possible complications of percutaneous vertebroplasty. TECHNIQUE: Percutaneous vertebroplasty is a technique consisting in an injection of bone cement into a vertebral body under imaging guidance. This procedure is performed to relief pain and support the mechanical stability in partially collapsed vertebral bodies. RESULTS: In the management of spinal compression fractures secondary to osteoporosis, myeloma, osteolytic metastases and aggressive hemangiomas, percutaneous vertebroplasty yields analgesic effect, and provides additional fortification in weakened segments of the vertebral column. Contraindications include major bleeding disorders, radicular pain and pain caused by compression of the myelon. DISCUSSION: Percutaneous vertebroplasty results in prompt pain relief and rapid rehabilitation. In experienced hands, using correct technique, pv is a safe and effective procedure for treating pain, caused either by osteoporotic or malignant vertebral compression fractures.

Aged↗

PubMed2003

[Vertebroplasty in osteoporotic vertebral compression].

BACKGROUND AND PURPOSE: Osteoporotic vertebral compression fractures are a frequently encountered clinical problem. We aimed to perform a critical, structured review of the current literature and to compare the results with our own experiences. MATERIAL AND METHODS: A structured review of 7 studies about vertebroplasty in osteoporotic compression fractures was performed; each study assessed at least 16 patients and was published in English since 1997. The results were compared to our own experience in 22 patients treated in 2002. RESULTS: Over the past decade, vertebroplasty has increasingly been performed for the treatment of painful osteoporotic vertebral body compression fractures. In good correlation with our own results, all authors reported a significant improvement of pain immediately after treatment and a reduction of pain of up to 90% within 24 h after vertebroplasty. Furthermore, a significant reduction in the use of analgetics and a substantial improvement of functional status has been described in recent studies. In our own evaluation, we were also able to demonstrate a significant improvement of pain after vertebroplasty in 17 of 22 (77%) of our patients. 18 of 22 (82%) patients were able to diminish or even discontinue their analgesic medication. DISCUSSION: Reported results for vertebroplasty have demonstrated a rapid improvement in pain and physical functioning in patients with osteoporotic vertebral compression fractures. Percutaneous vertebroplasty has proven to provide a valuable treatment option for osteoporotic vertebral compression fractures.

Bone Cements↗

PubMed2002

[New abdominal CT angiography protocol on a 16 detector-row CT scanner - first results].

PURPOSE: Purpose of this study was the implementation of a new abdominal CT angiography protocol on a 16 detector-row CT scanner and the comparison to selective catheter angiography. METHODS: 76 patients with various vascular disorders underwent abdominal CT angiography on a recently developed 16 detector-row CT scanner using submillimeter slice collimation (16 x 0.75 mm). Results were compared with mesenteric and/or hepatic angiography in 17 patients performed during tumor embolization. Opacification was provided using individually tailored contrast application with a test bolus setting. To evaluate the contrast injection protocol density measurements within the vessel lumen were performed. RESULTS: Diagnostic image quality was achieved in all patients with angiographic comparison (n = 17). Within the hepatic and mesenteric vasculature up to 4th generation vessels could be identified. Compared to selective angiography CT angiography provided equivalent morphologic information up to the detectable vessel generation. With the applied contrast application regimen there were no significant differences in vessel enhancement along the abdominal aorta and iliac arteries. CONCLUSION: 16 detector-row CT enables whole abdominal angiographic studies with submillimeter resolution in a single breath-hold. The improved spatial resolution enables for high quality 3D visualization. Compared to invasive angiography, 16 detector-row CT reveals equivalent morphologic information.

Abdomen↗

PubMed2001

Contrast agents for MR imaging of the liver.

A variety of different categories of contrast agents, and within each category a number of individual agents, are currently available for clinical use in magnetic resonance (MR) imaging of the liver. In this review, the use of nonspecific extracellular gadolinium chelates, reticuloendothelial system-specific iron oxide particulate agents, hepatocyte-selective agents, and combined perfusion and hepatocyte-selective agents are described. Most clinical experience is with nonspecific extracellular gadolinium chelates. The relatively low cost, safety, good patient tolerance, and ability to help detect and characterize a wide range of liver diseases have rendered gadolinium chelates as commonly used agents. Reticuloendothelial system-specific agents improve lesion detection by decreasing the signal intensity of background liver on T2-weighted MR images, which increases the conspicuity of focal hepatic lesions with negligible reticuloendothelial cells (eg, metastases). Hepatocyte-selective agents increase the signal intensity of background liver on T1-weighted images, which increases the conspicuity of focal lesions that do not contain hepatocytes (eg, metastases). The clinical application of the different categories of contrast agents, techniques for their administration, sequences to be used, and appearances of common entities on contrast agent-enhanced studies are described.

Contrast Media↗

PubMed1999

T2-weighted breathold imaging of the liver: a quantitative and qualitative comparison of fast spin echo and half Fourier single shot fast spin echo imaging.

The imaging characteristics of two EPI-hybrid breath-hold sequences, T2-weighted fast spin-echo [FSE, effective echo time (TEeff) 138 ms] and half Fourier single shot turbo spin-echo (HASTE, TEeff 60 ms), were compared in hepatic imaging. A total of 111 patients with suspected hepatic disease were studied at 1.5 Tesla using a body phase-array coil. The signal-to-noise (S/N) and contrast-to-noise (C/N) ratios for organs and lesions were calculated and quantitatively compared. Organ delineation, visualization of anatomical structures and pathological lesions, artifacts, and total image quality were qualitatively assessed and statistically compared. The final diagnoses were metastases from colorectal, breast, and pancreatic cancer in 23/111, hepatocellular carcinoma in 15/111, cysts in 19/111, hemangiomas in 9/111, several other lesions in 7/111, and no lesions in 38/111 of the cases. A total of 139 lesion in 73% of the patients were seen while 85% of the lesions were at least 1.5 cm in size. Regarding S/Ns HASTE was significantly (P < 0.03) superior to FSE with only minor (P > 0.05) differences in C/Ns between the two sequences for anatomical and pathological structures. HASTE demonstrated in almost all (97.3%) of the cases no artifacts, while on fast SE imaging moderate to minor artifacts were present in 23.5-51.7% of the cases. The overall image quality and diagnostic confidence was rated significantly higher (good 43.2%, excellent 53.2%) for HASTE than for fast SE imaging (good 44.8%, excellent 17.6%). Providing comparable C/Ns for anatomical and pathological structures, breatheld HASTE imaging proved to be superior to fast SE in T2-weighted imaging of the upper abdomen regarding general image quality, and, with adequate technical prerequisites, may be a suitable substitute of fast T2-imaging techniques.

Evaluation Studies as Topic↗

PubMed1999

Pediatric liver neoplasms: a radiologic-pathologic correlation.

Only 1-2 % of all pediatric tumors occur in the liver. Two thirds of these tumors are malignant and almost all of the tumors cause clinical symptoms due to their mass effects. Besides the poor prognosis in most of the malignant tumors, for further treatment the origin and nature of the neoplasm has to be known. Due to the mostly unimpeded growth into the peritoneal cavity, the origin of the tumors is primarily often unclear and can non-invasively only be determined by advanced imaging techniques. The display of the macro- and microhistological key features of primary pediatric liver neoplasms, including hepatoblastoma (HB), infantile hemangioendothelioma (IHE), mesenchymal hamartoma (MH), undifferentiated (embryonal) sarcoma (UES), and hepatocellular carcinoma (HCC), together with their imaging representation by ultrasound, computed tomography, and magnetic resonance imaging, may deepen the understanding of the underlying pathology and its imaging appearance. Furthermore, in many cases sufficient information may be provided not only to differentiate benign from malignant tumors, but also to guide for adequate treatment.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Embolization of uterine fibroids.

Since the first description of uterine artery embolization for the treatment of symptomatic fibroids of the uterus in 1994, this minimally invasive procedure has been increasingly performed in many Western countries. The method is characterized by a high technical success rate of about 85%, a highly significant relief of symptoms, and a very low rate of complications that make this method an appealing alternative to classic treatment options of surgical or laparoscopic myomectomy or hysterectomy. These characteristics have made the procedure well accepted by affected women. Nevertheless, indications and potential contraindications have to be evaluated carefully, especially in patients of childbearing age whenever a considerable number of deliveries is reported after uterine fibroid embolization. This article discusses the clinical background, indications and contraindications, angiographic techniques, potential complications and side effects, and the mid-term results known at present.

Embolization, Therapeutic↗

PubMedDate not supplied

Pancreatic neoplasms: MR imaging and pathologic correlation.

Magnetic resonance (MR) imaging can aid in the detection and characterization of many pancreatic neoplasms. The MR imaging appearances of common pancreatic neoplasms such as ductal adenocarcinoma are well-known. However, MR imaging features of more unusual pancreatic neoplasms are not well understood. Such tumors include mucin-hyper-secreting carcinoma, serous microcystic neoplasm, mucinous macrocystic neoplasm, solid and papillary epithelial neoplasm, multiple cysts associated with von Hippel-Lindau disease, acinar cell carcinoma, pancreaticoblastoma, and endocrine neoplasms (eg, nonfunctioning islet cell tumors, insulinoma, and gastrinoma). In general, pancreatic neoplasms demonstrate high signal intensity on T2-weighted images; the signal intensity on T1-weighted images is more variable but is often intermediate or low. Gadolinium enhancement is often helpful in further characterizing pancreatic neoplasms. The gross and histologic features of pancreatic neoplasms are also not well-known. Correlation with the underlying pathologic features enhances understanding of the MR imaging characteristics of both common and unusual pancreatic neoplasms.

Adenocarcinoma, Mucinous↗