A 41-year-old woman presented with pT4dN1aM0, right-sided, inflammatory breast cancer. She had a co-morbid diagnosis of systemic lupus erythematosus (SLE) at the age of 20 and was found to have significant kidney involvement (lupus-associated nephritis) at the age of 28. She went on to receive six cycles of neoadjuvant chemotherapy consisting of fluorouracil, epirubicin, cyclophosphamide, and docetaxcel (FEC-D) after which she had radiographically stable disease. She then had definitive treatment with bilateral mastectomy. Pathology showed a 4-cm residual invasive ductal carcinoma in the right breast and three residual metastatic lymph nodes in the right axilla. After extensive discussions with the patient, which included counseling on the potential increased risk of radiation-induced side effects, she received 50.4 Gy in 28 fractions of adjuvant radiotherapy (RT) to the chest wall and regional lymphatics including the internal mammary chains (IMCs). To minimize the risk of pulmonary toxicity, RT field arrangement consisted of a field-in-field modulated supraclavicular anterior/posterior parallel pair matched to shallow, photon tangent pair with 0.5 cm bolus to the lateral aspect of the chest wall and two matched direct anterior electron fields of 9 MeV with 1 cm bolus and 12 MeV with 0.5 cm bolus medially to cover the remaining residual chest wall and IMCs. This was immediately followed by a boost of 7.5 Gy in three fractions delivered via a photon tangent pair with 1 cm bolus to an area 6 cm superior and inferior to the surgical scar. Total treatment time was 50 days. The patient tolerated the therapy well but she developed grade three acute dermatitis. There were no pulmonary, shoulder joint movement, or brachial plexus side effects. This case is unusual in that SLE is generally considered a contraindication for elective RT. However, given her high risk for breast cancer recurrence, RT was offered with additional caution to minimize lung dose. Having completed the treatment, the side effects experienced were no greater than what would be expected in someone who did not have a diagnosis of SLE.
Keywords: breast cancer; lupus; radiotherapy.