Breast cancer ulcerated tumor (cancer is isolated in one area only) could i opt for radiation to shrink tumor prior to surgery, or must i have chemo?

Not recommended: Neoadjuvant chemotherapy (meaning prior to surgery) is sometimes indicated depending on the malignancy type. Most "ulcerated tumors" are consistent with inflammatory breast cancer. The recommendations are chemotherapy first followed by surgery (typically a mastectomy in this case) followed by radiation. A mastectomy is indicated for an inflammatory breast cancer.

Best AFTER surgery: A tumor such as yours is classified as a locally advanced tumor; if surgery is done first, a mastectomy is the only option. However, if chemorx is given first (neoadjuvant rx), there is a chance that the tumor will shrink enough to allow a lumpectomy alone; radiation rx would then be necessary after surgery. Preoperative radiation rx is insufficient to rx alone and could complicate the surgery.

Skin ulceration: Is a signed of not only local aggression, but distant metastasis. Usually a biopsy establishes receptor status, type iof systemic therapy. Doing XRT first does not improve control, does not improve survival, and is not recommended. Time to follow advice. Uncontrolled chest wall disease is not a pretty outcome.