Abstract
Direct instillation of colloidal phosphorus-32 into intracranial cystic tumors can be an effective means of controlling cyst growth and fluid production. Several techniques of administering the radioisotope are available, but rigorous pre- and postinstillation assessments are not routinely applied. This is further complicated by the challenges of imaging 32P, a pure beta-emitter. We have developed a treatment protocol for colloidal 32P therapy of cystic brain tumors, which uses both pre- and post-treatment assessments to improve delivery and verify postinstillation location of 32P. During a pretreatment computed tomography (CT) volume study, iodine contrast agent is injected into the cyst via an Ommaya system to permit better volume estimation on CT, patency of the Ommaya is checked, cyst leakage is detected, and cyst loculation is ruled out. Thus, this pretreatment assessment determines if 32P treatment is appropriate. During the administration of 32P, again a small amount of iodine contrast agent is injected into the cyst with the 32P. ACT done after instillation can locate the iodine contrast (and by inference, the 32P). Scintigraphic imaging can provide further confirmation of the presence of the 32P within the cyst. Iodine intensifies the 32P bremstraahlung, thereby enhancing scintigraphic imaging for verification of isotope location. The posttreatment assessments through CT and scintigraphy ascertain if the 32P instillation was effectively accomplished. Since instituting this treatment protocol at our medical centers, there have been no misadministrations of radioisotope or complications related to therapy. In nine patients treated during the past four years, there has been no cystic re-growth or recurrences of symptomatic cyst fluid production.
Original language | English (US) |
---|---|
Pages (from-to) | 211-216 |
Number of pages | 6 |
Journal | Journal of Brachytherapy International |
Volume | 15 |
Issue number | 3-4 |
State | Published - 1999 |
Keywords
- Cystic Brain Tumors
- Phosphorus-32
- Radiation Therapy
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cancer Research