Читать книгу Leksell Radiosurgery - Группа авторов - Страница 23

The first goal after getting settled was to learn about frame-based or open stereotactic procedures. Erik-Olof Backlund was my primary mentor and a pioneer in craniopharyngioma surgery, but I quickly began to have regular meetings with Lars Leksell [5].

It was also during this time I became fascinated with the Gamma Knife as a technology to perform stereotactic radiosurgery. Originally called strålkniven in Swedish, or the radiation knife, the technology was called the gamma unit for some years before the more commonly used Gamma Knife emerged. The second prototype Gamma Knife was installed in the basement of the Karolinska Radiumhemmet, connected by a tunnel to the neurosurgery clinic, which had patient beds and the operating rooms. The procedure was analogous in every way to other surgical procedures, based on patient selection, admission, and the placement of a stereotactic frame on the head, imaging, dose planning, and dose delivery. The difference was no incision, taking advantage of the cross-firing of photon beams generated by the decay of 179 cobalt-60 pellets that were cross-fired onto the target by a secondary collimator with 4-, 8-, or 14-mm-beam diameters. Individual beams could be blocked to shape the eventual 3D field.

Leksell had developed perhaps the most unique surgical instrument in the world, an invention that ultimately changed the face of neurosurgery and eventually radiation oncology, which heretofore stipulated that all radiation must be delivered in multiple fractions in order to not induce collateral tissue damage [6]. I was able to assist in publications of Backlund (stereotactic treatment of aqueductal stenosis) [7] and Leksell (development of an imaging compatible probe holder to replace the arc during open CT stereotactic procedures) [8]. During this time, I listened to many conversations between Leksell and radiobiologist Borje Larsson and Hernan Bunge from Buenos Aires, who along with David Forster from Sheffield, UK, had persuaded Leksell to authorize construction of two additional Gamma Knife units. These new prototypes (Units 3 and 4) were built by Scanditronix, a Swedish company that had the license briefly. Remarkably, Leksell and Larsson had contemplated a bed assembly that would continuously move the target in the focus of the beams.

While in Sweden I was quite amazed to hear that Leksell had authorized the shipment of the original prototype Gamma Knife to Los Angeles, California, where his friend Robert Rand (who already included stereotactic radiosurgery as one of the surgical procedures listed on his letterhead) wanted to perform radiosurgical experiments on animals. The unit was shipped, loaded by boat from Stockholm to Long Beach, where it was mysteriously unloaded from the ship and transferred to a basement facility at UCLA. Although no known record exists of actual patient treatment, it is clear that at least 1 patient underwent radiosurgery as confirmed by photographs taken at the time.