Current role of radiation therapy for multiple myeloma.
BACKGROUND
Radiation therapy (RT) is a treatment modality traditionally used in patients with multiple myeloma (MM), but little is known regarding the role and effectiveness of RT in the era of novel agents, i.e., immunomodulatory drugs and proteasome inhibitors.


METHODS
We retrospectively reviewed data from 449 consecutive MM patients seen at our institute in 2010-2012 to assess indications for RT as well as its effectiveness. Pain response was scored similarly to RTOG 0631 and used the Numerical Rating Pain Scale.


RESULTS
Among 442 evaluable patients, 149 (34%) patients and 262 sites received RT. The most common indication for RT was palliation of bone pain (n = 109, 42%), followed by prevention/treatment of pathological fractures (n = 73, 28%), spinal cord compression (n = 26, 10%), and involvement of vital organs/extramedullary disease (n = 25, 10%). Of the 55 patients evaluable for pain relief, complete and partial responses were obtained in 76.4 and 7.2%, respectively. Prior RT did not significantly decrease the median number of peripheral blood stem cells collected for autologous transplant, even when prior RT was given to both the spine and pelvis. Inadequacy of stem cell collection for autologous stem cell transplant (ASCT) was not significantly different and it occurred in 9 and 15% of patients receiving no RT and spine/pelvic RT, respectively. None of the three cases of therapy-induced acute myelogenous leukemia/MDS occurred in the RT group.


CONCLUSIONS
Despite the introduction of novel effective agents in the treatment of MM, RT remains a major therapeutic component for the management in 34% of patients, and it effectively provides pain relief while not interfering with successful peripheral blood stem cell collection for ASCT.
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Giampaolo
G
Talamo
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Christopher
C
Dimaio
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Kamal K S
KK
Abbi
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Manoj K
MK
Pandey
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Jozef
J
Malysz
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Michael H
MH
Creer
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Junjia
J
Zhu
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
Muhammad A
MA
Mir
Penn State Milton S. Hershey Medical Center , Hershey, PA , USA.
John M
JM
Varlotto
multiple myeloma; palliative therapy; pathologic fractures; radiation therapy; stem cell collection