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PubMed1996

New hardware for radio frequency powered glow discharge spectroscopies and its capabilities for analytical applications.

A new radio frequency (rf) hardware is developed for glow discharge spectroscopic methods. The resulting features and its capabilities for analytical applications are discussed. The electrical equipment developed allows to work as quickly, stably, reliably and easily as known from the direct current (dc) mode. Moreover, the rf power measurement has been improved. The hardware has been developed, optimised and tested for glow discharge optical emission spectroscopy (GDOES), but nevertheless it is possible to use it for all procedures applying glow discharge sources.

Journal Article↗
PubMed2002

FDG PET for staging of advanced non-small cell lung cancer prior to neoadjuvant radio-chemotherapy.

The aim of this study was to evaluate positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) for the staging of non-small cell lung cancer (NSCLC) before combined neoadjuvant, i.e. preoperative, radio-chemotherapy (RCT). From November 1998 until September 2001, 101 patients with NSCLC were investigated prospectively. The inclusion criterion was a histologically proven NSCLC of stage IIIA or B according to conventional staging including biopsy. The results of PET were compared with those obtained by mediastinoscopy, computed tomography (CT), bone scan and abdominal ultrasonography. Validation of discrepant findings was achieved by biopsy or repeated CT. PET proved to be highly accurate for the detection of lymph node metastases (sensitivity 96%, specificity 73%, positive predictive value 88%, negative predictive value 89%, accuracy 88%) as well as distant metastases (in 25/101 patients, all previously unknown). PET findings changed further treatment in 29/101 patients (29%). Twenty-five were excluded from RCT due to the presence of previously unknown distant metastases. One patient was free of metastases and therefore was operated on without pre-treatment. Two patients did not receive any further treatment because a malignant tumour could be excluded after PET. In the final patient PET demonstrated a tumour pattern not typical for NSCLC which could be attributed to a seminoma after repeated biopsy. FDG PET is the most accurate non-invasive diagnostic procedure for the staging of advanced NSCLC. Therefore use of FDG PET is highly recommended in order to select patients for neoadjuvant or other stage-dependent treatment modalities.

Adult↗
PubMed2002

(99m)Tc-MIBI radio-guided surgery for recurrent thyroid carcinoma: technical feasibility and procedure, and preliminary clinical results.

The preliminary results of technetium-99m methoxyisobutylisonitrile (MIBI) radio-guided surgery (RGS) in patients with differentiated thyroid carcinoma (DTC) and iodine-131-negative (non-functioning) recurrent disease are reported. Eight consecutive DTC patients were selected for RGS on the basis of pre-operative imaging findings: a (99m)Tc-MIBI scan consistent with local recurrence was taken as the principal inclusion criterion. The RGS procedure that we developed consisted in the injection of a low dose of (99m)Tc-MIBI (37 MBq) in the operating theatre a few minutes before the beginning of the intervention, with use of a hand-held gamma probe for the intra-operative detection of (99m)Tc-MIBI-avid tumoural foci. Radioactivity was measured in tumoural foci both in vivo and ex vivo, in the background and in the tumoural bed after lesion extirpation. After follow-up for 2-10 months, stable normalisation of serum thyroglobulin (Tg) levels was observed in six out of the seven patients in whom, during the intervention, the gamma probe-detected radioactivity in the neck fell to background values after tumour extirpation. In another patient the persistence of high radioactivity levels in the tumoural bed after lesion removal correctly suggested disease persistence (deep tracheal infiltration). These preliminary data suggest the feasibility of RGS in DTC patients with locoregional non-functioning but (99m)Tc-MIBI-avid recurrence by injection of a low, 37 MBq dose of (99m)Tc-MIBI just before the beginning of the intervention.

Adult↗
PubMed2002

A hand-held imaging probe for radio-guided surgery: physical performance and preliminary clinical experience.

Improvements in the specificity of radiopharmaceutical compounds have been paralleled by an upsurge of interest in developing small detectors to assist surgeons in localizing tumour tissue during surgery. This study reports the main technical features and physical characteristics of a new hand-held gamma camera dedicated to accurate and real-time intra-operative imaging. First clinical experience is also reported. The POCI (Per-operative Compact Imager) camera consists of a head module composed of a high-resolution interchangeable lead collimator and a CsI(Na) crystal plate optically coupled to an intensified position-sensitive diode. The current prototype has a 40-mm diameter field of view, an outer diameter of 9.5 cm, a length of 9 cm and a weight of 1.2 kg. Overall detector imaging characteristics were evaluated by technetium-99m phantom measurements. Three patients with breast cancer previously scheduled to undergo sentinel lymph node detection were selected for the preliminary clinical experience. Preoperative images of the lymphatic basin obtained using the POCI camera were compared with conventional transcutaneous explorations using a non-imaging gamma probe. The full-width at half-maximum (FWHM) spatial resolution was investigated in both air and scattering medium; when the phantom was placed in contact with the collimator, the POCI camera exhibited a 3.2 mm FWHM. The corresponding sensitivity was 290 cps/MBq. The preliminary clinical results showed that POCI was able to predict the number and location of all SLNs. In one case, two deep radioactive nodes missed by the gamma probe were detected on the intra-operative images. This very initial experience demonstrates that the physical performance of the POCI camera is adequate for radio-guided surgery. These results are sufficiently encouraging to prompt further evaluation studies designed to determine the specific and optimal clinical role of intra-operative imaging devices.

Breast Neoplasms↗
PubMed2006

18F-FDG PET for assessment of therapy response and preoperative re-evaluation after neoadjuvant radio-chemotherapy in stage III non-small cell lung cancer.

PURPOSE: The aim of this study was to evaluate FDG-PET for assessment of therapy response and for prediction of patient outcome after neo-adjuvant radio-chemotherapy (NARCT) of advanced non-small cell lung cancer (NSCLC). METHODS: Seventy patients with histologically proven stage III NSCLC underwent FDG-PET investigations before and after NARCT. Changes in FDG uptake and PET findings after completion of NARCT were compared with (1) the histology of tumour samples obtained at surgery or repeat mediastinoscopy, and (2) treatment results in terms of achieved operability and long-term survival. RESULTS: The mean average FDG uptake of the primary tumours in the patient group decreased significantly during NARCT (p = 0.004). Sensitivity, specificity and overall accuracy of FDG-PET were 94.5%, 80% and 91%, respectively, for the detection of residual viable primary tumour, and 77%, 68% and 73%, respectively, for the presence of lymph node metastases. A negative PET scan or a reduction in the standardised uptake value (SUV) of more than 80% was the best predictive factor for a favourable outcome of further treatment. Progressive disease according to PET (new tumour manifestations or increasing SUV) was significantly correlated with an unfavourable outcome (p = 0.005). In this subgroup, survival of patients who underwent surgery was not significantly different from survival among those who did not undergo surgery, whereas for the whole patient group, complete tumour resection had a significant influence on outcome. CONCLUSION: FDG-PET is suitable to assess response to NARCT in patients with stage III NSCLC accurately. It was highly predictive for treatment outcome and patient survival. PET may be helpful in improving restaging after NARCT by allowing reliable assessment of residual tumour viability.

Adult↗
PubMed2002

Open radio-frequency thermal ablation of renal VX2 tumors in a rabbit model using a cooled-tip electrode: feasibility, safety, and effectiveness.

The purpose of this study was to evaluate the feasibility, safety, and effectiveness of radio-frequency (RF) ablation using an internally cooled-tip electrode on renal VX2 tumors implanted in rabbits. Thirty-three rabbits with implanted renal VX2 tumors were divided into two groups: an RF ablation (RFA) group ( n=27) and a control group ( n=6). In the RFA group, RFA was performed on 27 implanted VX2 tumors using a cooled RF electrode and they were divided into three subgroups according to the follow-up period: acute (1-3 days, n=12); subacute (1-4 weeks, n=9); and chronic (2-7 months, n=6). Contrast-enhanced spiral CT was performed before the RFA and at the day, day 3, weeks 1, 2, 4, and months 2 and 7, after the RFA. The therapeutic efficacy was evaluated by the survival rate, CT, and pathologic findings. The RFA of renal tumors was technically successful in each instance. Complete tumor ablation was achieved in 22 of the 27 rabbits (81.5%) in the RFA group: 5 rabbits survived longer than 8 weeks without any evidence of viable tumor (18.5%) and 17 rabbits were found free of viable tumors when killed (63.0%). Five rabbits showed local tumor relapse and/or hematogenous lung metastasis after ablation (a recurrence rate of 18.5%). There were 11 (40.7%) complications related to the procedure. This experimental study demonstrates the feasibility of RFA therapy to treat renal VX2 tumors in rabbits, although RFA for central tumors carries some major potential complications, including renal arterial injury.

Animals↗
PubMed2003

Percutaneous treatment of liver tumors with an adapted probe for cooled-tip, impedance-controlled radio-frequency ablation under open-magnet MR guidance: initial results.

Percutaneous radio-frequency (RF) ablation of liver tumors is usually performed under guidance of real-time US, but some tumor nodules in some patients cannot be adequately visualized with this technique. We report our preliminary results with an MR-compatible, internally perfused 17-G RF probe adapted to a standard RF generator for impedance-controlled RF ablation under MR guidance. Following initial testing of the probe for MR compatibility, artifacts and macroscopic effects on an ex vivo pig liver, four patients with eight neoplastic liver nodules (five metastatic and three primary), which could not be properly targeted by US, were treated with the cooled-tip technique under MRI guidance in an open 0.23-T magnet. Metallic artifacts produced by the probe were useful for accurate placement and did not interfere with MRI monitoring at the end of the procedure. Based on imaging findings, the immediate result of RF was considered adequate in all instances. Local recurrence occurred in one instance after 6 months, requiring repeat treatment. No adverse effects were noted. Initial experience suggests that the probe we used allows to perform impedance-controlled cooled-tip RF ablation of liver tumors under open-magnet MR guidance.

Adult↗
PubMed2003

Radio-frequency thermal ablation with hypertonic saline solution injection of the lung: ex vivo and in vivo feasibility studies.

The aim of this study was to assess the effects of simultaneous instillation of NaCl solutions during radio-frequency ablation (RFA) on the dimension of the ablated lesion in ex vivo bovine lung tissue and in vivo rabbit lung tissue. The RFA was induced in ex vivo bovine lung tissue which was inflated with room air and in vivo rabbit lung tissue by a 500-kHz RF generator and a 17-G cooled-tip electrode. In in vivo experiments, RFA was performed using CT guidance. The RF energy was applied for 5 min with or without instillation of 0.9 or 36% NaCl solutions. The changes in tissue impedance, current, power output, and temperature of the electrode tip were automatically measured. The maximum diameter of all thermal lesions was measured perpendicular to the electrode axis by two observers. In an ex vivo study, the mean lesion diameters using 36 and 0.9% NaCl solutions were larger than those of the control group: 51+/-8, 34+/-6, and 5+/-2 mm ( p<0. 05). In in vivo rabbit lung tissue, the mean lesion diameter with NaCl solution (15.3+/-3.1 mm) was larger than that of the lesion without NaCl solution (8.5+/-1.4 mm; p<0.05). With instillation of NaCl solutions, a marked decrease of tissue impedance (>100 Omega) and corresponding increase of current flow occurred in both ex vivo and in vivo studies. This experimental study demonstrates that RF ablation with simultaneous NaCl solution infusion of the lung is more effective in achieving coagulation necrosis than conventional RFA procedure.

Animals↗
PubMed2003

Radio-frequency tissue ablation of the liver: in vivo and ex vivo experiments with four different systems.

The aim of this study was to test the efficacy of four different radio-frequency ablation (RFA) systems in normal hepatic parenchyma in large animals. The RFA was applied to pig livers in vivo and to calf livers ex vivo using the Radionics cluster needle, RITA starburst XL needle, Radiotherapeutics Le Veen 4.0 needle, and the Berchtold 14-G saline-perfused 15-mm active-tip needle based on constructor specifications. The volume of tissue coagulation from RF was calculated from measurements of the vertical diameter (Dv) and transverse diameter (Dt). Lesion shape was characterized using the ratio between Dt/Dv. Radiotherapeutics and RITA produced in vivo lesion volume of 42+/-10, 39+/-4 cm3 with a reproducible spherical shape (Dt/Dv of 1.01+/-0.16 and 0.97+/-0.1, respectively). Radionics produced in vivo RF lesions volume of 29+/-11 cm3) with an ovoid shape (Dt/Dv 0.88+/-0.09). The RF lesions with the Berchtold device could not be assessed in vivo as 5 of 8 animals died during treatment. Ex vivo RF lesions had similar volumes with each system; however, the Radiotherapeutics device produced more reproducible shaped lesions than the other systems. In our experimental study, we found no difference between expandable needle systems in vivo. Cooled needles produced slightly smaller and ovoid shape in vivo lesions.

Animals↗
PubMed2003

Primary lung cancer: treatment with radio-frequency thermal ablation.

Primary lung cancer is the most frequently diagnosed malignancy in the world and the leading cause of death from cancer [1]. When the initial diagnosis is made, most cases are inoperable or the patients' condition does not permit surgical interventions [2]. For patients with inoperable lung cancer, percutaneous radio-frequency thermal ablation (RFA) under CT guidance represents an alternative and minimally invasive treatment. It can also be applied in combination with radiation therapy and chemotherapy. We report three cases treated by percutaneous CT-guided RF ablation, from which two had post-operative recurrent tumor and one was inoperable.

Adenocarcinoma↗
PubMed2004

Radio-frequency ablation of colorectal liver metastases in 167 patients.

The objective of this paper is to report our results from a prospective study of 167 patients with colorectal liver metastases treated with radio-frequency ablation (RFA). Three hundred fifty-four treatments were performed in 167 patients, 99 males, mean age 57 years (34-87). The mean number of metastases was 4.1 (1-27). The mean maximum diameter was 3.9 cm (1-12). Fifty-one (31%) had stable/treated extra-hepatic disease. Treatments were performed under general anaesthesia using US and CT guidance and single or cluster water-cooled electrodes (Valleylab, Boulder, CO). All patients had been rejected for or had refused surgical resection. Eighty percent received chemotherapy. Survival data were stratified by tumour burden at the time of first RFA. The mean number of RFA treatments was 2.1 (1-7). During a mean follow-up of 17 months (0-89), 72 developed new liver metastases and 71 developed progressive extra-hepatic disease. There were 14/354 (4%) major local complications and 22/354 (6%) minor local complications. For patients with < or =5 metastases, maximum diameter < or =5 cm and no extra-hepatic disease, the 5-year survival from the time of diagnosis was 30% and from the time of first thermal ablation was 26%. Given that the 5-year survival for operable patients is a median of 32%, our 5-year survival of 30% is promising.

Adult↗
PubMed2000

Treatment of VX2 liver tumor in rabbits with "wet" electrode mediated radio-frequency ablation.

Radio-frequency ablation (RFA) has been considered as an alternative therapy for liver tumors. A "wet" electrode with interstitial infusion of hypertonic saline was tested for the RFA of liver tumor in rabbits. Seventy-eight liver tumors ( 1.5 to 3.0 cm) were induced in 41 rabbits by VX2 carcinoma implantation. Fifty-one tumors in 27 rabbits were treated with RFA. Under laparotomy, the RF energy was delivered while 5 % saline was infused through the electrode into the tumor at 1 ml/min. Six rabbits with 12 tumors were treated with only intratumoral 5 % saline infusion without RFA. Another 8 rabbits with 15 tumors received sham operation as untreated controls. The efficacy of the therapy was evaluated with survival rate, MRI, microangiography, and histopathology. In the RFA group, 6 rabbits survived longer than 6 months (absolute eradication rate 22.2 %); 12 rabbits were found free of viable tumor at the moment when they were sacrificed (relative eradication rate 44.4 %); 9 rabbits showed local tumor relapse and/or lung metastasis 2-10 weeks after ablation (recurrent rate 33.3 %). In control groups of saline infusion and sham operation, all 14 rabbits died within 3 months (mortality rate 100 %). Three-month survival rates between RFA group and control groups were significantly different (p < 0.05). Findings of MRI, microangiography, and histology supported these outcomes. Radical treatment of liver malignancy in rabbits is possible with the present modified RFA technique. Its clinical usefulness has to be further proven.

Animals↗
PubMed2005

[Unusual digital articular destructions after radio-synovectomy and cortisone injection therapy for Bouchard arthrosis].

UNLABELLED: Starting in 1998, a female patient suffering from activated Bouchard arthrosis was treated with intra-articular steroid injections into digits of both hands. In September 2001, an additional therapy with erbium-169 injections into the same joints was begun. The injections were continued until March 2003. No benefit was observed. Instead, severe destruction of the involved joints with articular necroses and marked periarticular calcifications had occurred. The course of events are documented by plain film examinations. CONCLUSIONS: The indication for alternating steroid injections and radio-synovectomies in patients with activated Bouchard arthrosis has to be reconsidered. In vivo and in vitro experiments are necessary to evaluate the potential harms of this combination of therapies. A close clinical and radiological control of treatment outcome with reevaluation of the indication is necessary.

Arthritis↗
PubMed1999

Mesomelic dysplasia with periosteal thickening, radio-humeral dislocation, osteoporosis and multiple fractures.

UNLABELLED: We report a boy with a new form of mesomelic dysplasia characterised by short stature, multifocal periosteal thickening, radio-humeral dislocation, osteoporosis and multiple fractures with minimal trauma. Electrophoresis of fibroblast collagens detected defects in type III and type V collagen. CONCLUSION: Bone dysplasias presenting with osteopenia, abnormal trabecular pattern, bone fragility, and periosteal thickening suggest a collagenopathy. A possible collagen defect requires biochemical investigations.

Abnormalities, Multiple↗
PubMed2006

[Oral squamous cell carcinoma Retrospective analysis of therapy results and prognosis by neoadjuvant, preoperative radio-chemotherapy].

We investigated the charts of 129 patients treated for oral squamous cell carcinoma (SCC) in the Department of Oral and Maxillofacial Surgery, University of Cologne, between 1995 and 2004. Only patients treated preoperatively with combined radio-chemotherapy (carboplatin/39.6 Gy) were included. The purpose of the present study was to show the therapeutic outcome and the survival rates for this regimen. The mean age of the patients was 56.6 years. Male patients outnumbered female patients by 3:1. The floor of the mouth was the most common location (48.1%), and three out of four tumours (76.7%) had a G2 grading, while 82.9% were keratinized. Grade T4 was most the common (53.4%), and all patients were operated after preoperative treatment. In 82.2% of the cases, there were no tumour cells detectable microscopically (R0). In 34.1% there were viable tumour cells in the cervical lymph nodes, whereas in 66.7% these cells were found in the primary tumour despite preoperative treatment. A total of 38.8% of patients showed a recurrence of SCC. Mean survival was 4.8 years and 5 year survival 46.6%. The overall survival time of the disease was significantly influenced by pT (P=0.004), pN (P>0.001), R0 resections (P=0.0002), viable tumour cells in lymph node metastasis (P=0.0001), viable tumour cells in the primary (P=0.0004) and recurrence of the disease (P>0.001). In comparison to the current literature, no improvements in prognosis and survival of oral squamous cell carcinoma could be observed.

Adult↗
PubMed2004

Radio-frequency ablation of hepatic metastases from colorectal cancer.

BACKGROUND: The aim of our study is to present the preliminary results of an ongoing radio-frequency (RF) ablation study in patients with hepatic metastases from colorectal cancer. PATIENTS AND METHODS: From November 2003, two patients affected with metachronous liver metastases from colorectal cancer were treated with RF ablation. The mean age of the patients was 66 years (58 and 74 years). Tumours were unifocal right-lobe lesions in one patient and bifocal in the second patient. Under general anaesthesia, a Radionics 200-W RF generator was used to ablate lesions with H2O-cooled electrodes via laparotomy. Patients' follow-up ranged from two to five months including evaluation of salient clinical, radiological and laboratory parameters. RESULTS: The patients experienced moderate-to-severe pain in the right abdomen lasting for 2-3 days and mild fever for 3-6 days after treatment. During the follow-up period no local recurrence was observed. CONCLUSIONS: RF ablation emerges to be a promising method for the treatment of hepatic metastases from colorectal cancer.

Adenocarcinoma↗
PubMed2004

Radiological follow-up study of rheumatoid wrists after radio-lunate limited arthrodesis with ulnar head resection.

Radio-lunate limited arthrodesis (RLA) is an established surgical intervention for damaged rheumatoid arthritis (RA) wrists. The goal of RLA is to conserve the range of motion (ROM) and level of activities of daily life (ADL) by delaying more extensive fusion. In this study, we retrospectively reviewed the outcome of RLA with ulnar head resection (UHR) in terms of pain score, ROM, and radiographic parameters, including carpal height ratio, ulnar translation ratio, and palmar subluxation. The clinical factors, such as dose of corticosteroids per day and laboratory examination data before surgery, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF), did not influence the results of the surgery. The changes in these clinical factors were also statistically analyzed in relation to the Schulthess classification of preoperative radiographs of wrists reported by Simmen and Huber: Type I (ankylosis type), Type II (osteoarthritis type), and Type III (disintegration type). This study hypothesized that RLA with UHR would provide no significant improvement in Type III wrists. The results showed that RLA with UHR resulted in stable wrists with excellent pain relief and with limited, but temporary, functional ROM, suggesting that this procedure seems to be applicable for all types of wrists within this group of patients.

Journal Article↗
PubMed2005

Simultaneous measurements of local tissue temperature and blood perfusion rate in the canine prostate during radio frequency thermal therapy.

Local tissue temperature and blood perfusion rate were measured simultaneously to study thermoregulation in the canine prostate during transurethral radio-frequency (RF) thermal therapy. Thermistor bead microprobes measured interstitial temperatures and a thermal clearance method measured the prostatic blood perfusion rate under both normal and hyperthermic conditions. Increase in local tissue temperature induced by the RF heating increased blood perfusion throughout the entirety of most prostates. The onset of the initial increase in blood perfusion was sometimes triggered by a temporal temperature gradient at low tissue temperatures. When tissue temperature was higher than 41 degrees C, however, the magnitude and the spatial gradient of temperature may play significant roles. It was found that the temperature elevation in response to the RF heating was closely coupled with local blood flow. The resulting decrease in or stabilization of tissue temperature suggested that blood flow might act as a negative feedback of tissue temperature in a closed control system. Results from this experiment provide insights into the regulation of local perfusion under hyperthermia. The information is important for accurate predictions of temperature during transurethral RF thermal therapy.

Animals↗