Local Ablative Techniques Research Articles

Laser ablation for small hepatocellular carcinoma: State of the art and future perspectives.

During the last two decades, various local thermal ablative techniques for the treatment of unresectable hepatocellular carcinoma (HCC) have been developed. According to internationally endorsed guidelines, percutaneous thermal ablation is the mainstay of treatment in patients with small HCC who are not candidates for surgical resection or transplantation. Laser ablation (LA) represents one of currently available loco-ablative techniques. In this article, the general principles, technique, image guidance, and patient selection are reported. Primary effectiveness, long-term outcome, and complications are also discussed. A review of published data suggests that LA is equivalent to the more popular and widespread radiofrequency ablation in both local tumor control and long-term outcome in the percutaneous treatment of early HCC. In addition, the LA technique using multiple thin laser fibres allows improved ablative effectiveness in HCCs greater than 3 cm. Reference centres should be equipped with all the available techniques so as to be able to use the best and the most suitable procedure for each type of lesion for each patient.

Surgery for cervical intraepithelial neoplasia.

Cervical intraepithelial neoplasia (CIN) is the most common pre-malignant lesion. Atypical squamous changes occur in the transformation zone of the cervix with mild, moderate or severe changes described by their depth (CIN 1, 2 or 3). Cervical intraepithelial neoplasia is treated by local ablation or lower morbidity excision techniques. Choice of treatment depends on the grade and extent of the disease. To assess the effectiveness and safety of alternative surgical treatments for CIN. We searched the Cochrane Gynaecological Cancer Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE and EMBASE (up to November 2012). We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies. Randomised controlled trials (RCTs) of alternative surgical treatments in women with cervical intraepithelial neoplasia. Two review authors independently abstracted data and assessed risks of bias. Risk ratios that compared residual disease after the follow-up examination and adverse events in women who received one of either laser ablation, laser conisation, large loop excision of the transformation zone (LLETZ), knife conisation or cryotherapy were pooled in random-effects model meta-analyses. Twenty-nine trials were included. Seven surgical techniques were tested in various comparisons. No significant differences in treatment failures were demonstrated in terms of persistent disease after treatment. Large loop excision of the transformation zone appeared to provide the most reliable specimens for histology with the least morbidity. Morbidity was lower than with laser conisation, although the trials did not provide data for every outcome measure. There were not enough data to assess the effect on morbidity when compared with laser ablation. The evidence suggests that there is no obvious superior surgical technique for treating cervical intraepithelial neoplasia in terms of treatment failures or operative morbidity.

Novel endoscopic approaches in the diagnosis and management of biliary strictures

Indeterminate bilary strictures present the clinician with a wide differential diagnosis. Histological confirmation is usually required for treatment, but tissue acquisition remains challenging. Novel developments in endoscopic technology, such as single operator cholangioscopy and confocal endomicroscopy, have led to improvements in diagnostic accuracy in recent years. In patients with non-resectable malignant biliary obstruction, effective biliary decompression improves symptoms and enables patients to undergo palliative therapies. Improvements in endoscopic techniques, biliary stents and the development of local ablative techniques have led to further improvements in stent patency and survival in these patients. In this article, we review emerging diagnostic and therapeutic techniques for the endoscopic management of indeterminate biliary strictures.

Irreversible Electroporation for Unresectable Hepatocellular Carcinoma: Initial Experience and Review of Safety and Outcomes

The aims of this study were to evaluate the safety, feasibility and tumour response of _irreversible electroporation, a non-thermal ablation technique, for the treatment of unresectable hepatocellular carcinoma. The endpoints were safety and local treatment efficacy. Patients with unresectable tumours and tumours not amenable for radiofrequency _ablation because of their vicinity to organs vulnerable to thermal damage such as the bowel or because they were close to large blood vessels that would limit efficacy of ablation due to the heat sink effect were treated with irreversible electroporation using percutaneous _ultrasound and/or computed tomography guided electrode placement between November 2008 and _December 2009. Early, late, minor and major complications were recorded. Tumour response was determined on triphasic helical computed tomography follow-up at one month, then every three months post-procedure. Eleven patients received IRE therapy to 18 HCC lesions (Mean diameter 2.44 ± 0.99 cm; range 1.0-6.1 cm) with five patients having more than one treated HCC. Mean follow-up was 18 months (range 14-24 months). Six patients required repeat treatments for local residual or recurrent disease; two of these also had IRE for distant intrahepatic recurrence. No serious complications were observed despite seven lesions lying adjacent to important structures or organs. Four patients developed transient urinary retention and seven developed transient local post-procedure pain. After IRE therapy, 13 (72%) lesions were completely ablated with 93% success for lesions ≤ 3 cm (13/14). The local recurrence-free period was 18 ± 4 months and the distance recurrence free period was 14 ± 6 months. These preliminary results suggest that IRE is a safe and feasible technique for local ablation of HCC, particularly for lesions less than 3 cm. No major complications were encountered during this study even for tumours close to essential structures or organs.

Robotic Radiosurgery for Liver Metastases

Purpose: The prevalence of liver metastases is very high for patients whose primary diagnosis are colorectal, pancreas, lung, and breast cancer. Local control of the disease may increase both quality of life and survival. The aim of this study to show feasibility, efficiency, and low morbidity combined with a high local control probability in use of robotic stereotactic body radiation therapy (rSBRT) treatment for liver metastases. Methods and Materials: A total of 55 patients with 84 liver metastases from different primary sites who underwent rSBRT in our center between July 2006 and December 2011 were reviewed for this study. Patients who refused surgery or judged inoperable were included in this study. Patients were required to have adequate liver function and more than three months minimum life expectancy. An average of three (3-5) fiducial markers were implanted percutaneously under CT-guidance with local anaesthesia. Maximum three liver metastases from any primary sites were treated and accepted for this study. Treatment planning CT, magnetic resonance imaging (MRI), and positron emission tomography-CT (PET-CT) were used for tumor delination. Treatment plan dose was prescribed at the PTV with an isodose line range 70-85% which was covering the 95% volume of PTV. We mandated that minumum 700 cc of normal liver had to receive at total dose less than 15 Gy in three to five fractions. The patients were examined every three months after rSBRT by biochemical examinations and imaging. PET-CT or MRI were performed at each follow-up. Results: Fifty-five patients (32 males, 23 females) who had liver metastases from various primary sites were treated with rSBRT using real-time tumor tracking system. Mean age of patients was 61 years (range 22 to 86 years). The primary sites included colorectal (n=23), pancreas (n=8), breast (n=7), lung (n=6), bladder (n=3), and others (n=8). The total prescribed dose was 45 Gy (range 24 Gy to 45 Gy) in median 3 (range three to six) fractions. The minimum normal liver volume (700 cc) was received mean 7.8 Gy (range 2 Gy to 14.6 Gy). Forty-nine (89%) patients were evaluated for tumor response, local control and survival analysis. The median follow-up was 12 months (range four to 39 months). CR was seen in 25 (51%) patients, PR in 12 (25%) patients, and SD in two (4%) patients at first follow-up. Ten (10%) patients had progressed inside the treated volume at first follow-up. The actuarial local control rate for patients is shown in Figure 2. The actuarial one-year and two-year local control rates were 61% (95% confidence interval (CI), 53%-69%) and 39% (95% CI, 28%-49%), respectively. The median overall survival was 16 months. The actuarial one-year and two-year overall survival rates were 79% (95% (CI), 73%-85%) and 56% (95% CI, 48%-63%), respectively. Conclusion: The results of our study have show that rSBRT for the treatment of liver metastases is feasible and safe with minimal side-effects. Further studies are required with larger patient series to compare rSBRT with other local ablative techniques and systemic therapies.

Irreversible electroporation

Local ablation techniques are a major focus of current developments in oncology. The primary aim is to retain organs and preserve organ functions without compromising the oncological outcome. Irreversible electroporation (IRE) is a novel ablation technique that involves the application of high-voltage pulses to induce cell apoptosis without causing thermal damage to the target tissue or adjacent structures. First published in 2005 IRE is currently undergoing preclinical and clinical trials in several areas of oncology and the initial results have been promising. The IRE technique could be a significant development in ablation treatment for renal cell carcinoma (RCC) but decisive proof of its effectiveness for local RCC has not yet been provided. This study presents the results of preclinical and initial clinical trials which are discussed and compared with those of other ablation techniques in order to demonstrate the current value of IRE.

High-Intensity Focused Ultrasound for Hepatocellular Carcinoma

This study aims to evaluate the outcome of patients with hepatocellular carcinoma (HCC) treated by high-intensity focused ultrasound (HIFU) in a single tertiary referral center. HIFU is the latest developed local ablation technique for unresectable HCC. The initial experience on its efficacy is promising, but the survival benefit of patients undergoing HIFU for HCC is poorly defined. From October 2006 to December 2008, 49 patients received HIFU for unresectable HCC. Each patient underwent a single session of HIFU with a curative intent. Treatment efficacy and survival outcome were evaluated. Clinicopathologic factors affecting the primary technique effectiveness and overall survival rates were investigated by univariate analysis. The median size of the treated tumors was 2.2 cm, ranging from 0.9 to 8 cm. The majority of patients had single tumors (n = 41, 83.6%). Thirty-one patients (63.2%) had artificial right pleural effusion during HIFU treatment to reduce damage to the lung and diaphragm. The hospital mortality rate was 2% (n = 1) and the complication rate was 8.1% (n = 4). The primary technique effectiveness rate was 79.5% (39 of 49 patients). It increased from 66.6% in the initial series to 89.2% in the last 28 patients. Tumor size (≥3.0 cm) was the significant risk factor affecting the complete ablation rate. The 1- and 3-year overall survival rates were 87.7% and 62.4%, respectively. Child-Pugh liver function grading was the significant prognostic factor influencing the overall survival rate. HIFU is an effective treatment modality for unresectable HCC with a high technique effectiveness rate and favorable survival outcome.

Local progression after radiofrequency ablation for pulmonary metastases

Local treatment for pulmonary metastases is considered to be a reasonable treatment option in patients with oligometastatic disease. Percutaneous radio frequency ablation (RFA) has been reported as an alternative to surgery. Results of RFA for local control of pulmonary metastases were evaluated. All consecutive patients treated with RFA for pulmonary metastases (2004-2009) were included. RFA was performed percutaneously under computed tomographic guidance. Follow-up was scheduled at 1, 3, and 6 months after treatment and every 6 months thereafter. Major outcome parameters were local and any-site progression, complications, and survival. Ninety pulmonary metastases were treated, in 46 patients at 65 sessions. Many patients had recurrent metastases after previous surgery (n = 36 of 46). Pneumothorax occurred in 34% (chest drain in 25%) and major complications in 6%. After median follow-up of 22 months (range, 2-65 months), 25 local progressions occurred after RFA; the 2-year local progression rate per lesion was 35%. Overall survival at 3 years was 69%. Notwithstanding its relatively low morbidity, follow-up after RFA for pulmonary metastases shows a considerable rate of local progression. The role of local ablation techniques for long-term disease control in oligometastatic disease is discussed.

Is Percutaneous Ethanol Injection Therapy Still Effective for Hepatocellular Carcinoma in the Era of Radiofrequency Ablation?

Percutaneous ethanol injection (PEI) therapy has been replaced by more-effective thermal ablation techniques that have lower local recurrence rates. However, PEI therapy remains useful in certain settings. Since PEI can be performed in any portion of the liver, PEI therapy can be valuable when tumors are located in close proximity to intestinal loops or other positions that are risky for thermal local ablative techniques. PEI therapy is also valuable in other situations where radiofrequency ablation (RFA) is difficult, including technically difficult masses that are not detected with ultrasound (US), are located in the hepatic dome, in the subcapsular area, and exophytically, or are surrounded by large vessels. PEI therapy contributes to combination therapy with transcatheter arterial chemoembolization or RFA in advanced-stage hepatocellular carcinoma (HCC), and also to the treatment of large HCC or extrahepatic metastasis from HCC. These roles of PEI therapy should be stressed for the treatment of HCCs in appropriate clinical situations. This comprehensive review of articles related to PEI therapy illustrates the recent role and indications of this therapy, which is currently valuable for HCC in the era of RFA.

Surgery for cervical intraepithelial neoplasia.

Cervical intraepithelial neoplasia (CIN) is the most common pre-malignant lesion. Atypical squamous changes occur in the transformation zone of the cervix with mild, moderate or severe changes described by their depth (CIN 1, 2 or 3). Cervical intraepithelial neoplasia is treated by local ablation or lower morbidity excision techniques. Choice of treatment depends on the grade and extent of the disease. To assess the effectiveness and safety of alternative surgical treatments for CIN. We searched the Cochrane Gynaecological Cancer Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE and EMBASE (up to April 2009). We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies. Randomised controlled trials (RCTs) of alternative surgical treatments in women with cervical intraepithelial neoplasia. Two review authors independently abstracted data and assessed risks of bias. Risk ratios that compared residual disease after the follow-up examination and adverse events in women who received one of either laser ablation, laser conisation, large loop excision of the transformation zone (LLETZ), knife conisation or cryotherapy were pooled in random-effects model meta-analyses. Twenty-nine trials were included. Seven surgical techniques were tested in various comparisons. No significant differences in treatment failures were demonstrated in terms of persistent disease after treatment. Large loop excision of the transformation zone appeared to provide the most reliable specimens for histology with the least morbidity. Morbidity was lower than with laser conisation, although the trials did not provide data for every outcome measure. There were not enough data to assess the effect on morbidity when compared with laser ablation. The evidence suggests that there is no obvious superior surgical technique for treating cervical intraepithelial neoplasia in terms of treatment failures or operative morbidity.

Spontaneous Regression of Multiple Pulmonary Metastases After Radiofrequency Ablation of a Single Metastasis

We report two cases of spontaneous regression of multiple pulmonary metastases occurring after radiofrequency ablation (RFA) of a single lung metastasis. To the best of our knowledge, these are the first such cases reported. These two patients presented with lung metastases progressive despite treatment with interleukin-2, interferon, or sorafenib but were safely ablated with percutaneous RFA under computed tomography guidance. Percutaneous RFA allowed control of the targeted tumors for >1 year. Distant lung metastases presented an objective response despite the fact that they received no targeted local treatment. Local ablative techniques, such as RFA, induce the release of tumor-degradation product, which is probably responsible for an immunologic reaction that is able to produce a response in distant tumors.

Preclinical Analysis of Irreversible Electroporation on Rat Liver Tissues Using a Microfabricated Electroporator

A microfabricated electroporator (MFE) for the irreversible electroporation (IRE) of tissues has been developed by miniaturizing a clinical electroporator with a two-needle array while keeping the same electric field strength distribution. Since IRE was brought to special attention as one of the local tissue ablation techniques to treat tumors, many preclinical studies have been conducted to investigate the efficacy of IRE on animal tissues. However, some technical difficulties have been frequently encountered due to the macroscale dimension of clinical electroporators, particularly in experiments on small animal models such as the mouse or rat. Here, the MFE was proposed to solve the associated problems, resulting in time- and cost-effective experimental procedures. With the developed MFE, the effect of IRE on rat liver tissues was analyzed with time by immunohistological stainings and electrical measurement, and the experimental results were compared with those operated with the corresponding real-scale clinical electroporator.

72 INTRATUMORAL ADMINISTRATION OF HOLMIUM LOADED MICROSPHERES AS A NOVEL MINIMALLY INVASIVE THERAPY FOR KIDNEY CANCER; AN ANIMAL STUDY

You have accessJournal of UrologyKidney Cancer: Basic Research I1 Apr 201072 INTRATUMORAL ADMINISTRATION OF HOLMIUM LOADED MICROSPHERES AS A NOVEL MINIMALLY INVASIVE THERAPY FOR KIDNEY CANCER; AN ANIMAL STUDY Judith Jans, Wouter Bult, Stephanie Kroeze, Freek Beekman, Ruud Bosch, and Frank Nijsen Judith JansJudith Jans More articles by this author , Wouter BultWouter Bult More articles by this author , Stephanie KroezeStephanie Kroeze More articles by this author , Freek BeekmanFreek Beekman More articles by this author , Ruud BoschRuud Bosch More articles by this author , and Frank NijsenFrank Nijsen More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.120AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The widespread use of cross-sectional imaging techniques resulted in a dramatic increase of incidentally detected small kidney tumours. Less invasive treatments need to be developed to eradicate these masses. Besides partial nephrectomy, minimally invasive techniques presently used include cryoablation and radiofrequency ablation. These thermoablative techniques employ either freezing or heat to eradicate tumours. Here, we present a novel local ablation technique using small (12 μm) holmium-166 acetylacetonate microspheres (166HoAcAc MS). 166Ho, in addition to high-energy beta particles, emits gamma rays that allow for nuclear imaging. Moreover, non-radioactive holmium-165 can be visualized by CT and MRI, due to its high electron density and paramagnetism, respectively. These imaging opportunities offer many advantages such as imaging of the distribution of holmium MS post treatment for direct therapy evaluation and follow-up. The objective of this study was to assess the efficacy of 166HoAcAc MS in a mouse kidney cancer model. METHODS HoAcAc MS were prepared as described by Bult et al. (Pharm Res 2009;26) and neutron irradiated to render them radioactive. 10 μl of the 166HoAcAc MS suspension was administered intratumorally in kidney tumour bearing mice. Post administration CT, SPECT and MRI was performed. At several timepoints after administration of MS mice were sacrificed and tissue was analyzed for presence of tumour-kill, proliferation and apoptosis. RESULTS HoAcAc MS were successfully administered to tumour bearing mice. Post administration CT imaging revealed depots of HoAcAc MS in the kidney. The SPECT images showed selective deposition in the kidney and no leakage of MS to the lungs (Fig 1). As expected, tumours in the control group showed a strong growth over time. In contrast, a striking near-complete tumour-control was observed in the 166HoAcAc treated group. No toxicity was observed. Figure 1. Small animal imaging: CT (top), SPECT (middle) and SPECT-CT fusion (bottom). The yellow arrow indicates the depot of MS. CONCLUSIONS We demonstrate the potential of intratumorally administered 166HoAcAc MS as a local treatment of RCC. In addition to a strong cancer control, it provides powerful multimodality imaging opportunities. We anticipate that this is a powerful novel minimally invasive approach to combat small renal masses. Utrecht, Netherlands© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e30-e31 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Judith Jans More articles by this author Wouter Bult More articles by this author Stephanie Kroeze More articles by this author Freek Beekman More articles by this author Ruud Bosch More articles by this author Frank Nijsen More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Research advancement in local ablation therapy for liver cancer

After developing for more than 20 years, image-guided local ablation therapy has become one of the major treatments of hepatocellular carcinoma (HCC). In particular, percutaneous radio-frequency ablation has been widely accepted as the first-line treatment of early-stage HCC. A number of randomized controlled trials have shown some differences between these local ablation techniques. This article reviewed the development of local ablation therapy in the past few years.

Surgical Management of Colorectal Liver Metastases

Colorectal cancer is the third most commonly diagnosed cancer with approximately half of the patients developing liver metastases during the course of their disease. Modern multimodal therapies have improved the overall survival. Liver resection remains the most important modality in the treatment of colorectal liver metastases. The evolution of the criteria for resectability has resulted in more patients being offered a hepatectomy. This is further augmented with the utilization of adjuncts to liver resection, including portal vein embolization and local ablative techniques. Two-stage hepatectomy is also being used to increase resectability. Overall survival is improved by the deployment of new chemotherapeutic agents and the use of combination chemotherapy. Neoadjuvant chemotherapy is a promising development in the treatment of colorectal liver metastases. Patients with colorectal liver metastases can achieve long-term survival. A multidisciplinary approach is essential in the management of these patients.

Radiologisch interventionelle Therapie von Lebertumoren

Image guided minimally invasive local and locoregional tumor ablation techniques like radiofrequency ablation, interstitial brachytherapy, transarterial chemoembolization (TACE) and selective internal radiotherapy (SIRT) with (90)Yttrium ( (90)Y) microspheres have been established as valuable amendments in oncologic therapy concepts. These techniques allow the destruction of extensive liver tumors with an acceptable toxicity profile. Necessity for a safe performance of these procedures is a close collaboration between interventional radiologist and anesthetist.

Robotic radiosurgery of liver metastases of solid tumors

e15049 Background: The number of patients (pts) suffering from isolated liver metastases is growing. Although surgical excision is the treatment of choice many pts do not qualify for surgery. So local ablative techniques like radiofrequency ablation, laser induced thermal ablation therapy, brachytherapy and different external beam radiation therapies have been employed. We here report the therapeutic efficacy of a robotic radiosurgery device for local control of liver metastases of solid tumors. Methods: Patients with liver metastases not qualifying for surgery were treated with single session radiosurgery (24 Gy) using robotic image-guided real-time tumor tracking. In a prospective analysis, follow-up was done by MRI scanning at two months after the treatment, and subsequently at 3-month intervals to evaluate local control. For inclusion into the radiosurgery treatment protocol, tumor volumes had to be smaller than 80cc. Results: 27 pts (median age 62 years) with a total of 43 target lesions were evaluated. 17 pts were treated with single, 10 pts with multiple targets. Metastases (n=27) originated from: colon (12), rectum (2), pancreas (2), lung (1), bladder (2), malignant melanoma (1), stomach (1), cholangiocellular carcinoma (2), breast (1), ovary (1), appendix (1) and endometrium (1). Median tumor volume was 21cc (range 2.2–79.3). Median KPS was 100% (range 80–100). The median follow up was 12 months. 23 pts (85%) reached local control of the disease, 4 pts (15%) had local recurrence. Grade 2–4 adverse events due to cyberknife treatment were not observed. Conclusions: Robotic radiosurgery with image-guided real-time tumor tracking of liver metastases is a new and promising treatment approach for pts not eligible for surgical resection and might enhance the possibilities of multidisciplinary oncological treatment concepts. No significant financial relationships to disclose.

Selective Internal Radiotherapy with Yttrium-90 Microspheres for Hepatic Metastatic Neuroendocrine Tumors: A Prospective Single Center Study

Background: To assess prospectively the safety and efficacy of Yttrium-90 microspheres in patients with unresectable liver metastases from neuroendocrine tumors. Materials and Methods: Microspheres were administered via a temporarily placed hepatic catheter. Patients were monitored prospectively. All patients were followed with laboratory and imaging studies at regular intervals to determine response rates. Toxicity and quality of life scores were measured. Results: Nine patients (7 female) with a mean age of 58.8 years were enrolled in this prospective trial. The mean tumor load was 58.8%. The estimated percentage shunting to the lungs on MAA scans was 5.04 ± 2.4%. Visceral artery embolization of extrahepatic arteries before treatment was performed in 6 patients. The median dose of microspheres was 2.1 ± 0.4 GBq. A total of 12 therapy sessions was performed. The mean follow-up was 21.7 months. Technical success was 100%. No major complications occurred. Survival rates were 100, 57 and 57% for 1, 2 and 3 years, respectively. Three months after SIRT therapy partial response (PR) was seen in 6 patients (66%). Calculated reduction of liver metastasis volume was 49%. In 3 patients (33%) stable disease was seen with a calculated tumor reduction of 13%. The estimated time to progression was 11.1 months. Conclusion: Radioembolization with ⁹⁰Y microspheres is safe and produces high response rates even with extensive tumor replacement for up to 1 year. Acute and late toxicity was very low. Further investigations compared with other local ablative techniques is warranted.

Photodynamic therapy for non-resectable perihilar cholangiocarcinoma

Photodynamic therapy (PDT) has emerged as a useful tool for palliative treatment of the otherwise difficult to treat perihilar cholangiocarcinoma (CC). PDT is a minimally invasive and effective technique for local tumour ablation with rare and predictable side effects. A modest number of studies and randomised trials using porfimer (Photofrin) could demonstrate an improvement in quality of life and survival time. A novel approach to a priori non-resectable perihilar CC was proven in a pilot study using neoadjuvant porfimer-PDT for down-sizing of the tumour followed by R0 resection. These days, active phase II and phase III trials investigate if the tumouricidal activity can be increased using temoporfin (Foscan) as an alternative photosensitiser with higher penetration capability and whether porfimer-based PDT plus stenting is superior to biliary stenting alone in terms of overall survival, respectively. The local tumour ablation and correction of obstructive cholestasis with PDT will allow for novel multimodal strategies to treat cholangiocarcinoma.

Neuroendokrine Tumoren des Gastrointestinaltraktes

Two thirds of all neuroendocrine tumors (NET) are located in the gastroentero-pancreatic system. Depending on its localisation, each tumor presents a different histological pattern as well as different clinical symptoms and prognosis. Symptoms are usually due to the mass effects of the local tumor or tumor-related fibrosis. The classical "carcinoid-syndrome" with flush and diarrhea is seen in fewer than 10 %. Tests like chromogranin A (serum) or 5-hydroxyindolacetic acid (24h urine-collection) are indicators for the initial diagnosis of NET. Somatostatin-receptor scintigraphy is the most valuable imaging modality. In addition CT/MRI can be used for further topographical definition. Endoscopic techniques like the use of capsule endoscopy are being evaluated for the diagnosis of small intestinal NETs. The only curative treatment of NET is still complete surgical resection. However, it can only be done in 20 %, depending on localization and local extension of the primary tumor. If the liver is involved local ablation techniques should be considered. The gold standard for medical treatment is the use of somatostatin analogs, although interferons show a comparable therapeutic potential. Traditional cytotoxic agents should only be used for poorly differentiated tumors refractory to other forms of treatment. New compounds that target different pathways at the intra- and intercellular level are under investigation. Supportive therapy should be considered for the control of symptoms.