Impact of infrared laser light-induced ablation at different wavelengths on bovine intervertebral disc ex vivo: evaluation with magnetic resonance imaging and histology.

BACKGROUND AND OBJECTIVE: Percutaneous laser disc decompression is commonly used to lower high pressure in the nucleus pulposus in degenerative disc diseases. The aim of this study was to investigate the impact of diode laser disc decompression at different wavelengths (980-nm vs. 1,470-nm, i.e., different water absorption characteristics). MATERIALS AND METHODS: To model decompression, a flexible laser quartz fiber inserted into the nucleus pulposus of ex vivo bovine spines using computer-assisted surgical navigation was utilized to vaporize tissue. The same energy (500 J) was delivered using both 980-nm and 1,470-nm wavelength lasers. To determine the different impact of the wavelengths before and after the procedure we evaluated the discs with MRI (T(1), T(2), diffusion maps) and with histopathology. RESULTS: There were no visible changes on T(1) and T(2) maps after 1,470-nm wavelength laser irradiation; however, the 980-nm wavelength caused significant changes on T(1) (decrease) and T(2) (increase) in the vaporization zone at the site of the quartz fiber. Pathological findings showed carbonization and steam-bubble formation in addition to the T(1) and T(2) changes. No significant changes were detected in the value of apparent diffusion coefficient (ADC) measurements in intervertebral disc with the 980-nm wavelength, but significant ADC and T(1) signal increase was detected with the 1,470-nm wavelength when the whole nucleus pulposus was considered. CONCLUSION: The 1,470-nm laser light had an effect in the whole nucleus pulposus and not only at the site of the quartz fiber, whereas with the 980-nm laser irradiation, significant changes were demonstrated only at the application site.

Prolonged survival using anti-CD20 combined chemotherapy in primary prostatic intravascular large B-cell lymphoma.

Here we report a case of a 73-year-old man with primary intravascular large B-cell lymphoma localized to the prostate. Total prostatectomy was performed due to a benign adenoma suggested by ultrasonography. The diagnosis of IVLBL was obtained incidentally from the prostatectomy specimen. Eight months after the initial R-CHOP chemotherapy a relapse was detected in the left inguinal lymph node, where histologic examination revealed common diffuse large B-cell lymphoma with minimal intravascular component. The second complete remission was achieved by R-IEV therapy. Five months later a second relapse occurred and the patient died in the widespread disease and pneumonia. Primary prostate IVLBL is extremely uncommon; to date only four cases have been described. This is a well documented case, where we also confirmed that the initial primary IVLBL and the secondary lymph node involvement are clonally related. Successful treatment depends on early diagnosis of IVLBL, aggressive chemotherapy and the fact that IVLBL should be considered as a generalized disease in spite of negative staging results.