Defining patient-based minimal clinically important effect sizes: a study in palliative radiotherapy for painful unresectable pelvic recurrences from rectal cancer

PURPOSE: To measure patient-based minimal clinically important effect sizes (minimal incremental benefit that an individual would require to accept one treatment option over another) for pain relief between two contrasting palliative radiotherapy regimens for painful pelvic recurrences from rectal cancer. METHODS AND MATERIALS: Forty-three patients with a history of cancer pain without prior pelvic radiotherapy participated in decision …