Radiation recall dermatitis with pemetrexed

Pemetrexed has recently been approved for use in combination with cisplatin as first-line chemotherapy for malignant pleural mesothelioma (MPM). Radiation therapy is frequently administered to the thoracic orifices and no data are available about the interactions between radiotherapy and pemetrexed. We report the first case of radiation recall dermatitis occurring after pemetrexed chemotherapy in a patient with MPM previously treated with radiation therapy to the thoracoscopy and drainage orifices. The patient received chemotherapy with pemetrexed and cisplatin 19 days after completion of chest wall radiation therapy delivering 21 gray in 3 days. Conventional premedication by folic acid and intramuscular administration of Vitamin B12 and prednisolone was correctly performed. Twelve days later, confluent erythematous and pruritus rash of the irradiated skin was observed. The toxicity grade of this lesion was evaluated at 2 according to the Acute Radiation Morbidity Scoring Criteria proposed by the Radiation Therapy Oncology Group. Pemetrexed challenge was performed without worsening of skin lesions. Three weeks later, skin cicatrisation was observed after a desquamative phase. Persistent hyperpigmentation was seen in the irradiated skin. Pemetrexed could also act as a radiosensitizing agent that should be used with care for several weeks after radiotherapy.