Читать книгу Intracranial Gliomas Part II - Adjuvant Therapy - Группа авторов - Страница 49

In 1895, Wilhelm Conrad Roentgen first discovered X-rays [1]. It was not long before this technology was applied for cancer therapy. Regaud and Ferraux performed experiments in the 1920s in which multiple smaller doses of radiation given over a prolonged period of time targeted rapidly dividing cells while sparing slower dividing ones. FRT was soon applied for oncologic indications as a technique to maximally spare normal surrounding tissue while targeting tumors. Historically, photons generated by radioactive decay of isotopes, such as cobalt-60 (⁶⁰Co), provided the primary source of therapeutic X-rays. In the modern era, X-ray based FRT is generally delivered utilizing a linear accelerator (LINAC). Electrons are accelerated within a LINAC and interact with the nucleus of a metallic target creating high-energy X-rays. These, in turn, interact with tissue to produce DNA damage and cell death.

Radiotherapy planning for intracranial gliomas begins with a CT-based simulation wherein a thermoplastic mask is constructed for immobilization purposes. The CT data set is typically transferred to a planning station and fused with the most recent relevant MRI sequences for treatment planning. After the physician defines the target and normal tissues at risk, a dosimetrist utilizes the treatment planning software for beam arrangements and dose modeling. The final treatment plan is approved by the physician. Quality control of the plan and assurance of the mechanical accuracy of treatment machine are performed by a medical physicist and actual dose delivery is administered by the radiation therapist.