Biomaterial Database

An accurate and simple method for megavoltage radiation therapy of retinoblastoma. 1983

J Schipper

A simple but highly accurate irradiation method for the "conservative" treatment of retinoblastoma has been developed at the Utrecht Retinoblastoma Centre. Treatment is carried out with a 6 MV or 8 MV linear accelerator using a lateral D-shaped field of 26 X 32 mm2. This D-shaped field is specially contoured to include the entire retinal surface or vitreous and 10 mm of the anterior optic nerve and to protect the sensitive anterior structures of the eye, particularly the lens, as much as possible. Accurate positioning of the sharply collimated treatment field is easily done by magnetic fixation of the eye to the beam defining collimator by use of a low vacuum contact lens. As the fixed eye is located in the isocentre of the accelerator, the radiation beam can be directed at any angle by simple rotation of the gantry or table, without alteration of the position of the eye within the treatment field. Simultaneous irradiation of bilateral retinoblastoma is just as easily possible and can be done with the same accuracy by fixation of both eyes with contact lenses and alternately applying two opposing lateral fields. Prior to treatment, the axial dimensions of each eye are determined by ultrasonic biometry to ascertain the exact volume to be irradiated.

UI	MeSH Term	Description	Entries
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D011882	Radiotherapy, High-Energy	Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.	Megavolt Radiotherapy,High-Energy Radiotherapy,Radiotherapy, Megavolt,High Energy Radiotherapy,Radiotherapy, High Energy
D003261	Contact Lenses	Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)	Lenses, Contact,Contact Lens,Lens, Contact
D005123	Eye	The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.	Eyes
D005134	Eye Neoplasms	Tumors or cancer of the EYE.	Cancer of Eye,Eye Cancer,Cancer of the Eye,Neoplasms, Eye,Cancer, Eye,Cancers, Eye,Eye Cancers,Eye Neoplasm,Neoplasm, Eye
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000758	Anesthesia	A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures.
D012175	Retinoblastoma	A malignant tumor arising from the nuclear layer of the retina that is the most common primary tumor of the eye in children. The tumor tends to occur in early childhood or infancy and may be present at birth. The majority are sporadic, but the condition may be transmitted as an autosomal dominant trait. Histologic features include dense cellularity, small round polygonal cells, and areas of calcification and necrosis. An abnormal pupil reflex (leukokoria); NYSTAGMUS, PATHOLOGIC; STRABISMUS; and visual loss represent common clinical characteristics of this condition. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2104)	Glioblastoma, Retinal,Glioma, Retinal,Neuroblastoma, Retinal,Eye Cancer, Retinoblastoma,Familial Retinoblastoma,Hereditary Retinoblastoma,Sporadic Retinoblastoma,Cancer, Retinoblastoma Eye,Cancers, Retinoblastoma Eye,Eye Cancers, Retinoblastoma,Familial Retinoblastomas,Glioblastomas, Retinal,Gliomas, Retinal,Hereditary Retinoblastomas,Neuroblastomas, Retinal,Retinal Glioblastoma,Retinal Glioblastomas,Retinal Glioma,Retinal Gliomas,Retinal Neuroblastoma,Retinal Neuroblastomas,Retinoblastoma Eye Cancer,Retinoblastoma Eye Cancers,Retinoblastoma, Familial,Retinoblastoma, Hereditary,Retinoblastoma, Sporadic,Retinoblastomas,Retinoblastomas, Familial,Retinoblastomas, Hereditary,Retinoblastomas, Sporadic,Sporadic Retinoblastomas
D014463	Ultrasonography	The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.	Echography,Echotomography,Echotomography, Computer,Sonography, Medical,Tomography, Ultrasonic,Ultrasonic Diagnosis,Ultrasonic Imaging,Ultrasonographic Imaging,Computer Echotomography,Diagnosis, Ultrasonic,Diagnostic Ultrasound,Ultrasonic Tomography,Ultrasound Imaging,Diagnoses, Ultrasonic,Diagnostic Ultrasounds,Imaging, Ultrasonic,Imaging, Ultrasonographic,Imaging, Ultrasound,Imagings, Ultrasonographic,Imagings, Ultrasound,Medical Sonography,Ultrasonic Diagnoses,Ultrasonographic Imagings,Ultrasound, Diagnostic,Ultrasounds, Diagnostic