This chapter presents a series of questions and answers with case studies on radiotherapy for early-stage Invasive Breast Cancer. It commences with a discourse on appropriate method for postlumpectomy breast radiotherapy, and ends with the question of Does the plan for radiotherapy change post lumpectomy for breast cancer patients who have a positive sentinel node biopsy without completion axillary node dissection (AND). The chapter focuses on the question: can postlumpectomy breast radiotherapy be omitted for some breast cancer patients. The case studies discussed in the chapter includes a 63-year-old postmenopausal female reported with an abnormal screening mammogram of a new 8 mm spiculated mass, and a healthy 71-year-old woman found to have a breast cancer.