DR Scott and Dr Lewis answer your questions about Radiometals in Theranostics Applications

Read additionnal Q&A following Radiometals in Theranostics Applications Webinar: 
What do you think will be the best radioisotpe and best antibody?
It depends on the target and therapeutic approach. For intact antibodies, with long half lives, a beta emitter (eg Lu-177 (or for large tumours Y-90) may be possible for easily accessible tumours, or through the use of multi-step targeting approaches. This will reduce red marrow toxicity, and enhance the therapeutic window. For larger solid tumours, alpha emitters may also be a suitable approach. - Prof. Scott
Is there an application or need for brain tumor theranostics and how to bypass issues with the BBB? Furthermore, should one focus on stereotactic or systemic application of theranostics for brain cancer?
There certainly is a role, and a examples include the antibody-drug conjugate ABT-414 (against a tumour specific epitope of EGFR, found in ~ 60% of high grade brain cancers), and possibly Ga-68/Lu-177 peptides. BBB penetrance can be addressed by careful fine tuning of charge, solubility and protein design. Systemic delivery can be pursued, while stereotactic approaches may be challenged by infiltration of tumour cells deep into the cerebral cortex from the resection cavity. - Prof. Scott
Is autoradiolysis an issue with large molecules labeled with high LET emitters?
It can be during the labeling procedures if in high concentrations – there are ways to help mitigate e.g., gentistic acid. - Prof. Lewis
How does the theranostic pairing of 64/67Cu find a place in therapies currently dominated by 177Lu, both in the radiochemistry/dosimetry angle and the supply constraints of 64Cu vs 68Ga and 67Cu vs 177Lu?
I would actually say that all nuclides have a vulnerability in regards to robust supply – so its good to have options.  Dosimetry is a always an important consideration.  I think its gets back to the piaring choice being based on the right clinical question/goal.  - Prof. Lewis