Radiation did not work, options now?

Hi, here's a brief summary of my case:

- On dialysis for the last 28 years
- Early Liver Cirrhosis from Hepatitis C infection (treated successfully a few years back), liver function normal
- Diagnosed in January 2025 with well-differentiated adenocarcinoma of the GE Junction Stage 1-2, not present anywhere else, no symptoms, discovered by accident while doing an endoscopy
- HER2 FISH Positive
- Resection attempted but unsuccessful due to severe bleeding
- 28 sessions of Radiation ended April 30
- PET CT after 2 months of last radiation treatment showed "moderate response" only. Tumour is about 44% in size and 38% activity (Vmax) comapred to before treatment.
- Biopsy taken during endoscopy shows that cels are malignant

So, now that the radiation did not work fully, what are the other options? Resection is ruled out, chemo is also not an option as per the oncologist. With a positive HER2 FISH, I believe they will try targeted therapy with Trastuzumab or an equivalent.

Does anyone have experience with this drug? Can I hope for complete remission? Or will it only be palliative? Any thoughts or suggestions would be helpful. Thanks!