Welcome to the forum Shakti13 although I'm sorry to read that your dad has been diagnosed with stage 4a inoperable lung adenocarcinoma.
Your dad's medical team are in the best position to let you know about any new treatment options that may be available to your dad at this time but do feel free to give our cancer nurses a call about this as well. Their number is 0808 800 4040 and lines are open Monday - Friday between 9a.m - 5p.m.
Our members know how tough it can be to support a loved one on their cancer journey and now that I've replied I'm sure those who have been in similar situations will be along soon to offer their support and advice.
Kind regards,
Steph, Cancer Chat Moderator