====== 1990 ======

[[1989]]-[[1991]]

The [[Guglielmi Detachable Coil]] is a block of platinum [[coil]] commonly used in intracranial non-invasive surgery for the occlusion of [[intracranial aneurysm]]s. It was invented by Italian interventional neuroradiologist Dr. Guido Guglielmi in [[1990]] and was gradually introduced in the later 1990s as an alternative to surgical clipping, which requires invasive surgery. In September [[1995]], the Guglielmi Detachable Coil (GDC) system received formal approval from the Food and Drug Administration (FDA) for the treatment of surgically high-risk intracranial aneurysms
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In 1990, Macdonald et al.defined the criteria for evaluating response to treatment and disease progression. They suggested that variations in the tumor-enhancing area, neurological function, and steroid dosage should be considered in the assessment of tumor response
((Macdonald DR, Cascino TL, Schold SC Jr, Cairncross JG. Response criteria for
phase II studies of [[supratentorial]] [[malignant glioma]]. J Clin Oncol. 1990
Jul;8(7):1277-80. PubMed PMID: 2358840.
)).
Although these criteria have since been the cornerstone in response evaluation in many [[phase II]] clinical trials, some doubts have been expressed regarding the evaluation of disease progression in patients treated with TMZ concomitant with radiotherapy.
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In [[1990]], [[Parviz Kambin]] described a triangular safe zone bordered by the exiting root anteriorly, the traversing root medially, and the superior endplate of the lower lumbar vertebra inferiorly
((Kambin P: Arthroscopic Microdiscectomy: Minimal Intervention Spinal Surgery Baltimore, MD, Urban & Schwarzenberg, 1990)).
The anatomical description of this safe zone allowed the field of endoscopic spine surgery to outgrow the technique of percutaneous [[nucleotomy]], which was limited by the use of small needlelike instruments. [[Kambin's triangle]] was a working corridor that allowed larger instruments and working channels to be introduced in even closer proximity to foraminal pathology without injuring the exiting nerve.