Magnetic resonance imaging-controlled laser-induced interstitial thermotherapy.

RATIONALE AND OBJECTIVES: Laser-induced interstitial thermotherapy (LITT) may become an attractive modality for minimally invasive tumor therapy. Magnetic resonance imaging (MRI) could be used to assist this procedure. METHODS: A T1-weighted turbo fast low-angle shot (FLASH) sequence for on-line monitoring of the laser-influenced region (liver, muscle) was investigated. Sequence parameters were optimized for maximal image contrast. Magnetic resonance imaging-controlled LITT was performed in vitro, in vivo (rabbits), and in 8 human investigations (6 patients). Special laser applicators were used to establish a uniform laser light distribution. RESULTS: With the MRI sequence used, the LITT region is visualized as a bright area outlined by a dark border. This dark border corresponds to an isotherm of 45 +/- 2 degrees C depending on the sequence parameters used. CONCLUSION: With the T1-weighted turbo-FLASH sequence, MRI can be used for on-line monitoring of interstitial laser-induced thermotherapy in moving organs.

[Radioimmunoscintigraphy of colorectal tumors with 99m-Tc marked CEA antibodies. Indications and clinical value]. / Radioimmunszintigraphie kolorektaler Tumoren mit 99m-Tc-markierten CEA-Antikörpern. Indikationen und klinische Wertigkeit.

In Germany, radioimmunoscintigraphy (RIS) (scintigraphic, specific imaging of benign and malignant diseases by radioactively labelled monoclonal antibodies) has been employed since 1985 in clinical trials involving patients with colorectal cancer. After proving successful for identifying primary tumors, RIS is now increasingly being used for the early diagnosis of recurrent and metastatic lesions. In this prospective study involving 75 patients with colorectal tumors confirmed by endoscopy and biopsy, it was shown that RIS using the SPECT technique with 99m-Tc-labelled monoclonal CEA antibodies has a sensitivity of 78% in the detection of local recurrent disease in cases in which diagnostic work-up has been inconclusive.

[Angiographic and computed tomographic findings in intra-arterial cytostasis of colorectal liver metastases]. / Angiographische und computertomographische Befunde bei intraarterieller Zytostase kolorektaler Lebermetastasen.

Between October 1983 and January 1986, sixteen patients with inoperable liver metastases from colorectal carcinomas were treated by single or cyclical intraarterial chemotherapy introduced either through an angiographic catheter or by means of a subcutaneously implanted access point (Port-A-Cath). Before each treatment cycle, the position of the catheter and the state of the vessels was examined by subtraction angiography in order to avoid complications and to confirm that the cytostatic agents were actually perfusing metastases, as shown by angio-CT. The complementary nature of the information obtained by these methods and their superiority over scintigraphy with 99mTc macroaggregated albumin particles is documented and the most frequent complications of regional tumour therapy are described.