This work illustrates a procedure to assess the overall accuracy associated with Gamma Knife treatment planning using plugging. The main role of source plugging or blocking is to create dose falloff in the junction between a target and a critical structure. We report the use of MAGAT gel dosimeter for verification of an experimental treatment plan based on plugging. The polymer gel contained in...

Brainstem glioma usually carries a poor prognosis and prolonged survival is very infrequent. In a detailed Pubmed, Medline search for prolonged survival, authors could got a longest survival only up to seventeen years, reported by Umehara et al, who was subjected to gamma knife therapy and got symptomatic, MRI brain reveled large tumor growth during pregnancy necessitating emergency surgery and...

A 43-year-old woman, previously misdiagnosed as having primary hyperthyroidism and treated with antithyroid drugs, presented to us with overt hyperthyroidism, high levels of thyroid hormones and elevated thyroid-stimulating hormone (TSH). Μagnetic resonance imaging (MRI) revealed a pituitary microadenoma extending suprasellarly. The patient responded favorably to initial treatment with somatost...

Brain metastasis from colorectal cancer is infrequent and carries a poor prognosis. Herein, we present a patient alive 10 years after the identification of a first brain metastasis from sigmoid colon cancer. A 39-year-old woman underwent sigmoidectomy for sigmoid colon cancer during an emergency operation for pelvic peritonitis. The pathological finding was moderately differentiated adenocarcin...

BACKGROUND AND PURPOSE MR image-guided gamma knife radiosurgery is often used to treat intra-axial metastatic neoplasms. Following treatment, it is often difficult to determine whether a progressively enhancing lesion is due to metastatic tumor recurrence or radiation necrosis. The purpose of our study was to determine whether relative cerebral blood volume (rCBV), relative peak height (rPH), a...

PURPOSE To evaluate an automated treatment planning system for gamma knife radiosurgery. This planning system was developed in our clinic and is now in routine clinical use. The system simultaneously optimizes the shot sizes, locations, and weights. It also guides the user in selecting the total number of radiation shots. METHODS AND MATERIALS We assessed the clinical significance of the auto...

A microchamber, PTW Pinpoint 31006, was used to measure transverse beam profiles for an Elekta Gamma Knife, Model B, and compared with profiles measured with film dosimetry. The microchamber sensitive volume has a diameter of 2 mm, which is smaller than the gamma knife beams, and a length of 5 mm. The chamber was mounted in a custom cassette in a spherical plastic phantom, supplied by Elekta, a...

Stereotactic radiosurgery of small arteriovenous malformations (AVMs) and certain benign and malignant brain tumors using a gamma knife with 201 sources of cobalt-60 has been used to treat 300 patients at our institution since August 1987. This gamma knife-like earlier units developed in Stockholm, Buenos Aires, and Sheffield, England-was designed for closed-skull destruction of selected AVMs a...