Apache2 ProxyPass without query string

Question

I want to provide static looking URLs to internal graph generators without passing on potentially malicious query parameters from the client.

I got a VirtualHost configuration that looks kinda like this

<VirtualHost *:443>
# ServerName, ServerAlias, SSLEngine, SSLCertificate...

    SSLProxyEngine on
    ProxyPass      /graph/great-graph1.png https://some.internal.host/the-graph.png?width=..&height=..&<more params>
    ProxyPass      /graph/great-graph2.png https://other.internal.host/the-graph.png?width=..&height=..&<more params>
</VirtualHost>

And it almost works as I want it to. The graphs are loaded from the correct hosts, but two things to not work:

1. The configured query parameters are ignored
2. The query parameters given by the client are passed on to the internal host

I tried adding noquery to the end of the line of the ProxyPass of which the existence is mentioned here but without any effect.

I also tried various RewriteRules (with enabled RewriteEngine) but I couldn't figure out the correct approach here as well.