Radiation-recall dermatitis with docetaxel: Establishment of a requisite radiation threshold

DOCETAXEL IS a member of the taxane group of chemotherapeutic agents that cause disruption of cell division by enhancing microtubule assembly and inhibiting tubulin depolymerisation. It has been reported to show promising results in the treatment of metastatic breast cancer [l]. We report a particularly striking case of radiation-recall dermatitis, the first to be associated with docetaxel, and the first in which a threshold for the radiation dose could be clearly established. A 51 year-old woman was initially diagnosed to have carcinoma of the right breast in 1992. She underwent modified radical mastectomy and axillary dissection followed by adjuvant tamoxifen therapy. She remained well until December 1995 when she was found to have liver metastases for which she received weekly intravenous 5-fluorouracil whilst continuing with tamoxifen. In January 1996 she was referred to our institute for further management. Bone scintigraphy showed metastases in the skull, at multiple levels of the spine, in multiple ribs, the bony pelvis and both scapulae and femori. As her main symptom was severe bone pain, mainly involving the lower spinal and pelvic areas, she was given palliative radiotherapy to the spine and pelvis. Over a lo-day period from January 23 (day l), she received 30 Gy in 10 fractions to the TlO-L4 spine and pelvis. Photons (6 MeV) from a linear accelerator was given to the patient in a prone position (Figure la). The spine was treated by a single posterior field. The skin dose at the back and front were 8.7 Gy and 18.7 Gy, respectively. The pelvis was treated by a pair of anterior-posterior opposing fields and the skin dose at the back and front were 16.8 Gy and 21.5 Gy, respectively. The difference in dose was due to the presence of a thin perspex support apposing the skin at the front. During this time, she suffered mild nausea and vomiting, and developed severe diarrhoea from day 13 to day 24, which