phosphorus-radioisotopes and Meningeal-Neoplasms

A novel (32)P brachytherapy source has been in use at our institution intraoperatively for temporary radiation therapy of the spinal dura and other localized tumors. We describe the dosimetry and clinical implementation of the source.. Dosimetric evaluation for the source was done with a complete set of MCNP5 Monte Carlo calculations preceding clinical implementation. In addition, the depth dose curve and dose rate were measured by use of an electron field diode to verify the Monte Carlo calculations. Calibration procedures using the diode in a custom-designed phantom to provide an absolute dose calibration and to check dose uniformity across the source area for each source before treatment were established.. Good agreement was established between the Monte Carlo calculations and diode measurements. Quality assurance measurements results are provided for about 100 sources used to date. Clinical source calibrations were usually within 10% of manufacturer specifications. Procedures for safe handling of the source are described.. Clinical considerations for using the source are discussed.

Topics: Brachytherapy; Calibration; Dura Mater; Health Physics; Humans; Meningeal Neoplasms; Monte Carlo Method; Phantoms, Imaging; Phosphorus Radioisotopes; Quality Control; Radiation Protection; Radiotherapy Dosage

The management of multiple symptomatic intracranial pathological processes in a single patient presents a rare and challenging problem for the neurosurgeon and the patient. Neurosurgeons must utilize a full spectrum of neurosurgical options to achieve the best patient outcome.. We present a unique case of a 63-year-old woman who presented with a large convexity meningioma causing headaches, an acoustic neuroma causing deafness and imbalance and a suprasellar arachnoid cyst compromising the visual fields. Therapeutic intervention was staged based on the primum non nocere concept. First, the patient underwent stereotactic intracavitary cyst irradiation using colloidal 32P. Secondly, microsurgical resection of the convexity meningioma was performed. Finally, Gamma Knife radiosurgery of the acoustic neuroma was performed. One year after multimodality management, the patient was neurologically improved. There was no evidence of meningioma or cyst recurrence and the growth of the acoustic neuroma was arrested.. This case demonstrates the value of multi-modality treatment of neurosurgical pathology, utilizing minimally invasive techniques when possible.

Topics: Arachnoid Cysts; Female; Humans; Magnetic Resonance Imaging; Meningeal Neoplasms; Meningioma; Middle Aged; Minimally Invasive Surgical Procedures; Neuroma, Acoustic; Phosphorus Radioisotopes; Radiosurgery; Radiotherapy, Adjuvant; Sella Turcica; Stereotaxic Techniques; Tomography, X-Ray Computed; Treatment Outcome

The authors report on 40 brain tumor patients treated with CT-guided stereotactic injection of 198Au and 32P. Among the 40 cases were astrocytoma in 23 cases, craniopharyngioma in 9, meningioma in 4, pituitary adenoma in 2, and pinealoma and metastatic carcinoma each in 1 case. The tumors were all located in deep or important areas of the brain which were difficult to deal with by conventional operation. 62 injections of colloidal isotopes were performed, and all were successful. No major adverse effects or complications occurred on follow-up of 6-12 months, 28 patients were improved in their clinical symptoms, and CT scanning showed that the tumor sizes were diminished. The effective rate is 70%.

Topics: Adenoma; Adult; Astrocytoma; Brain Neoplasms; Craniopharyngioma; Female; Gold Radioisotopes; Humans; Male; Meningeal Neoplasms; Meningioma; Phosphorus Radioisotopes; Pinealoma; Pituitary Neoplasms; Radiosurgery; Stereotaxic Techniques; Tomography, X-Ray Computed

In a series of 60 patients 62 intraoperative measurements with the 32-P (radiophosphorus) tumour marker were performed. Using miniature semiconductor probes a reliable discrimination between normal brain and neoplastic tissue was possible in nearly all brain tumours. The best results were found in meningiomas, where even small, visually hardly discernible tumour resides within the matrix zone could be reliably detected. Only in low-grade gliomas the application of the 32-P marker was impossible due to count rates similar to or below the basic rates of normal brain. This simple to use, non-invasive method proved its usefulness in all situations where a local radical tumour removal was important.

Topics: Adult; Aged; Biomarkers, Tumor; Brain Neoplasms; Female; Humans; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Neoplasms, Nerve Tissue; Phosphorus Radioisotopes

A method for the intraoperative detection of brain tumor propagation is described. Based on the well-known radiophosphorus test, a very sensitive semiconductor probe was tested in 16 brain tumor operations. With this miniaturized sensor, the beta-emission of 32P could be measured with a high topographical resolution. Especially in high-grade gliomas, in meningiomas and in metastases a good discrimination of normal and tumor-infiltrated tissue was possible. The perspectives of a technical improvement of this method and the application of more specific tumor markers are discussed.

Topics: Brain Neoplasms; Female; Glioma; Humans; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Phosphorus Radioisotopes; Radionuclide Imaging; Tomography, X-Ray Computed