Radiation recall reaction with docetaxel administration after accelerated partial breast irradiation with electronic brachytherapy.
OBJECTIVE
Accelerated partial breast irradiation (APBI) offers several advantages over whole breast irradiation. Electronic brachytherapy may further reduce barriers to breast conserving therapy by making APBI more available. However, its toxicity profile is not well characterized.


METHODS
A 60-year-old woman was treated with APBI using Axxent (Xoft, Sunnyvale, CA) electronic brachytherapy. One month after APBI, a cycle of docetaxel and cyclophosphamide was given. Within 3 weeks, the patient developed an ulcerative radiation recall reaction in the skin overlying the lumpectomy cavity. To investigate this toxicity, the skin dose from electronic brachytherapy was compared with the dose that would have been delivered by an iridium-192 ((192)Ir) source. Additionally, a dose equivalent was estimated by adjusting for the increased relative biologic effectiveness (RBE) of low energy photons generated by the electronic source.


RESULTS
Using electronic brachytherapy, the skin dose was 537cGy per fraction compared with 470cGy for an (192)Ir source. Given an RBE for a 40kV source of 1.28 compared with (192)Ir, the equivalent dose at the skin for an electronic source was 687cGy-equivalents, a 46% increase.


CONCLUSIONS
We present a case of an ulcerative radiation recall reaction in a patient receiving APBI with electronic brachytherapy followed by chemotherapy. Our analysis shows that the use of electronic brachytherapy resulted in the deposition of significantly higher equivalent dose at the skin compared with (192)Ir. These findings suggest that standard guidelines (e.g., surface-to-skin distance) that apply to (192)Ir-based balloon brachytherapy may not be applicable to electronic brachytherapy.
Chen
Sea S
SS
Department of Radiation Oncology, Rush University Medical Center, Chicago, IL, USA.
Strauss
Jonathan B
JB
Shah
Anand P
AP
Rao
Ruta D
RD
Bernard
Damien A
DA
Griem
Katherine L
KL
D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001918:Brachytherapy / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D000077143:Docetaxel; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D011855:Radiodermatitis / Q000209:etiology*; D043823:Taxoids / Q000009:adverse effects* / Q000627:therapeutic use
D000970:Antineoplastic Agents; D043823:Taxoids; D000077143:Docetaxel