Radiation Recall Myositis T78.8

Rare myositic reaction that occurs after therapy with a chemotherapeutic agent in a radiation field. Radiation-recall refers to inflammatory reactions that are primarily triggered by cytotoxic agents and develop in previously irradiated areas.

The time interval between radiation and a subsequent radiation recall myositis (RR myositis) reaction ranges from concurrent radiation to 21 years after radiation, with most reactions occurring between 1 and 6 months (Friedlander PA et al. 2004). A review of the literature does not show that RR myositis is associated with a particularly high BED from radiation exposure.

The area of acute inflammation must correspond to and be limited to an area of previous radiation exposure in the imaging.

In the literature, corticosteroids have been successfully used to treat myositis. Independent of other treatment plans, NSAIDs have often been reported for pain management.

Radiation recall reactions usually occur cutaneously . The most frequently affected chemotherapeutic agents are anthracyclines and taxanes. Gemcitabine, a nucleotide analog, has also been detected in several cases.

Barrios-Anderson A et al. (2021): The case of a 56-year-old woman with locally advanced stage III pancreatic adenocarcinoma previously treated with localized radiotherapy and chemotherapy is reported. During a restaging CT scan, she was found to have multiple paraspinal fluid collections and was admitted due to the risk of multiple infectious abscesses. The patient showed no clinical signs of infection. Antibiotic therapy did not lead to improvement. Finally, she was diagnosed with RR myositis while receiving the fourth cycle of palliative gemcitabine and paclitaxel. After treatment with steroids, the condition improved.

1. Azria D et al. (2005) Radiation recall: a well-recognized but neglected phenomenon. Cancer Treat Rev. 31:555-570.
2. Barrios-Anderson A et al. (2021) Paraspinal radiation recall myositis after gemcitabine for pancreatic adenocarcinoma. BMJ Case Rep14:e240896.
3. Delavan JA et al. (2015) Gemcitabine-induced radiation recall myositis. Skeletal Radiol 44:451-455.
4. Eckardt MA, Bean A, Selch MT, Federman N. A child with gemcitabine-induced severe radiation recall myositis resulting in a compartment syndrome. J Pediatr Hematol Oncol. 2013;35(2):156-61.
5. Friedlander PA et al. (2004) Gemcitabine-related radiation recall preferentially involves internal tissue and organs. Cancer 100:1793-1799.