Evaluating the effectiveness and safety outcomes of administering radiotherapy at the same time with DCEP salvage chemotherapy in patients with multiple myeloma.

This study investigated the effectiveness and safety outcomes of administering radiotherapy (RT) at the same time as DCEP salvage chemotherapy in patients with unresponsive multiple myeloma (MM). This study concluded that RT administered at the same time with DCEP salvage chemotherapy was effective and well-tolerated by most of the patients, with low rates of blood-related and RT-related toxicity.

Multiple myeloma (MM) is a type of cancer that comes from blood cells called plasma cells. A high number of patients with MM experience relapse (the tumor grows after treatment) or are refractory (not responsive to the treatment) to standard treatment. Currently, the treatment strategies for relapsed/refractory (r/r) MM are based on the different combinations of conventional drugs and novel drugs, chemotherapy, and radiotherapy. CRT involves administering both chemotherapy (CT) and performing radiation therapy (RT). In concurrent CRT (cCRT), both CT and RT are administered during the same treatment period.

Dexamethasone (Decadron), cyclophosphamide (Cytoxan), etoposide (Vepesid), and cisplatin (Platinol), or DCEP, is one of the most commonly used salvage chemotherapy combinations. However, the effectiveness and safety outcomes of administering RT at the same time as DHEP salvage chemotherapy in patients with r/r MM are unknown.

This study involved 55 patients with r/r MM. Patients received RT to 64 different sites within three weeks of receiving DCEP. An average dose of 20 Gy was delivered in an average of 5 fractions. Patients received an average of 1 cycle of DCEP. Patients were followed up for an average of 59.8 months. 

RT was completed in 98% of the patients. 15% of the patients experienced RT-related side effects during treatment which decreased to 6% one month after completing RT. 21% of the patients experienced severe blood-related side effects before RT, which increased to 35% one month after RT, before decreasing to 12% 3 to 6 months after RT. The most common side effect was low platelet counts.

Pain resolved in 94% of patients with symptomatic MM. Stable disease or better was observed in 87% of the targeted lesions on imaging. The average overall survival was 9.9 months.

This study concluded that RT given at the same time with DCEP salvage chemotherapy was effective and well-tolerated by most of the patients, with low rates of blood-related and RT-related toxicity.

This study looked back in time at medical records. The sample size was very small. This study only included patients treated at a single medical institution in the USA.