J. Siegfried – författare

Local interstitial radiation therapy of intrinsic and inaccessible brain tumors is confronted with two major problems: 1. The tolerance of normal brain tissue, which is usually involved in local tumor irradiation, i.e. perifocal white matter edema and demyelinating effects, is crucial. 2. Data on radiation effects of implanted radioactive sources on neoplastic tissue, i.e. data on the radiosensitivity and on the biology of tumors, are still widely unavailable. In clinical practice the dose with which to achieve a given volume of tumor necrosis is roughly estimated. This report deals with the experimental findings of Iodine-125 and Iridium-I92 permanent implants in healthy and neoplastic brain tissue. Our own experimental findings are correlated with experimental data on Yttnul11-l)O irradiation from the literature. The study is directed to collect data on the tolerance non-tumoral brain tissue and to attempt to establish a dose-response relationship. Morphologic Changes in the Dog Brain Following Interstitial Iodine-125 Irradiation Iodine-I25 seeds (manufactured by 3 M Company, St. Paul, M. N.) with an activity of 3.55 mCi were permanently implanted under stereotactic conditions into the subcortical white matter of the gyrus coronalis of the left hemisphere in 6 beagle dogs. One animal with a non-radioactive seed implanted under similar operative conditions served as a control. The animals were allowed to survive 25, 46, 71, 94, 248, 368 days, respectively, after the implantation. The control animal survived 46 days. A detailed description of the experimental procedure is given elsewhere 16. 17.

The phenomenon of phantom limb was described in medical literature at least as early as 1545 by Ambroise Pare, according to the notes in the translation of Lemos' dissertation, "On the Continuing Pain of an Amputated Limb", by Price and Twombly [9]. This strange experience was brought to public attention by a popular essay anonymously published 1866 by Mitchell concerning the story of George Dedlow, a quadriamputee who described his invisible limbs [7]. In 1871 Mitchell wrote under his own name, and was the. first to use the term "phantom limb" [8]. In this work, he also corrected some erroneous beliefs that had arisen from his 1866 essay [13]. Most amputees report feeling a phantom limb almost immediately after amputation of an arm or a leg [11]. It is a positive sensation, usually described as tingling or numbness, which is not painful. The most distal parts of the limb, particulary the digits, thumb, and index, are the strongest and most persisting phantom sites, and may be the only parts to appear even after removal of a whole limb. The elbow or knee is sometimes involved, the forearm or lower leg rarely, and the upper arm and thigh almost never [5]. The phantom thus appears to consist predominantly of those parts which have the most extensive representa­ tion in the thalamus and in the cerebral cortex.

The phenomenon of phantom limb was described in medical literature at least as early as 1545 by Ambroise Pare, according to the notes in the translation of Lemos'' dissertation, "On the Continuing Pain of an Amputated Limb", by Price and Twombly [9]. This strange experience was brought to public attention by a popular essay anonymously published 1866 by Mitchell concerning the story of George Dedlow, a quadriamputee who described his invisible limbs [7]. In 1871 Mitchell wrote under his own name, and was the. first to use the term "phantom limb" [8]. In this work, he also corrected some erroneous beliefs that had arisen from his 1866 essay [13]. Most amputees report feeling a phantom limb almost immediately after amputation of an arm or a leg [11]. It is a positive sensation, usually described as tingling or numbness, which is not painful. The most distal parts of the limb, particulary the digits, thumb, and index, are the strongest and most persisting phantom sites, and may be the only parts to appear even after removal of a whole limb. The elbow or knee is sometimes involved, the forearm or lower leg rarely, and the upper arm and thigh almost never [5]. The phantom thus appears to consist predominantly of those parts which have the most extensive representa­ tion in the thalamus and in the cerebral cortex.