Impact of radiation therapy on pain relief of cancer patients affected by on malignant psoas syndrome: 26 years of experience

Aim: The malignant psoas syndrome (MPS) is a rare and complex cancer-related clinical entity, with a significant impact on cancer patients' quality of life. The literature describing malignant infiltration of the psoas muscle as well as its management is limited. The primary endpoint of the study was the assessment of pain relief in symptomatic terminal-stage MPS patients. Materials and Methods: Patients underwent hypofractionated (two- or three-dimensional conformal) radiotherapy as palliative treatment. A dose of 42.5 Gy in 17 daily fractions (2.5 Gy/fraction) was prescribed. Pain response was measured before 3 and 6 months after radiation delivery. Results: Between May 1992 and April 2019, eight patients were treated. The median age was 75 years (range: 59-87 years). All patients had distant metastatic disease at the time of treatment. We found a significant pain relief (median duration of response of 105 days) and an improvement in health-related quality of life. Conclusions: Radiotherapy had a favorable outcome and can be considered an effective analgesic treatment in case of painful MPS.