Speaker
Prof.
Adrian Merlo
(University of Basel)
Description
Low-grade gliomas (LGG) of astrocytic, oligodendrocytic or mixed phenotype represent an unmet medical need as orphan disease. Due to relatively long median survival time of 8-15 years, prospective clinical studies are rarely conducted. Recommended therapeutic regimens range from an observational strategy to extensive resection with awake craniotomy in order to diminish the risk of transformation into a higher grade glioma. We have conducted an observational study in 8 low grade gliomas using the radiopeptidic targeting vector [213Bi]/[90Y]-DOTA-substance over a period of 18 years (4-18 years, median ). Besides therapeutic efficacy, we assessed long-term effects, especially late neurotoxicity of beta- and alpha-therapy following local injection. Since biodistribution of the small peptidic vector (1.8 KD) extends over large parts of the ipsi- and possibly contralateral CNS, late toxicity is of principal concern although no NK-1 receptors are expressed in the normal supratentorial brain. The alpha particles releases their decay energy within an ultrashort range that represents the diameter of 1-2 tumor cells (virtual single cell radiotherapy) while beta-therapy targets many more cells (cross-fire effect). We are comparing long-term side effects following alpha-therapy (Bi-213, range 0.1mm) with those of beta-therapy (Y-90: range 5mm, 2.3 MeV). So far, no recurrence or late toxicity has been observed in newly alpha-treated LGG over a period of 18 (OGII), 11 (AII), 10 (AII), 7 (OGII), 4 (OGII) and 3 (AII) years. Injection of [213Bi]-DOTA-substance into an LGG infiltrating the motor cortex was well tolerated with only transient neurological deficits. In contrast, all Y-90 treated LGG cases either developed signs of late radiotoxicity or recurrence after an observation interval of 8-10 years. Two of these beta-cases were subsequently treated with one cycle of alpha-therapy. One of them showed a slight worsening of pre-existing aphasia, presumably due to previous application of high-dose beta irradiation. In conclusion, local alpha therapy appears to be superior to beta-therapy regarding long-term tumor control and late toxicity.
| Email Address | adrian.merlo@bluewin.ch |
|---|---|
| Presentation Type | Contributed Oral |
Primary author
Prof.
Adrian Merlo
(University of Basel)
Co-authors
Dr
Alfred Morgenstern
(European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Karlsruhe, Germany)
Dr
Dominik Cordier
(University of Basel)
Dr
Frank Bruchertseifer
(European Commission, Joint Research Centre, Directorate for Nuclear Safety and Security, Karlsruhe, Germany)
Prof.
Leszek Krolicki
(University of Warsaw Medical Center)
