Results of a Phase II Clinical Trial of 2-Fractionated Half-body Irradiation in Treatment of Patients with Multiple Painful Bony Metastases

KH Wong, C Gaffney, SM Chow, TM Chan

Hong Kong J Radiol 2005;8:162-71

Objective: A prospective phase II study was conducted to evaluate the effectiveness in pain palliation and toxicity of a 2-fractionated half-body irradiation.

Patients and Methods: From 25 December 2000 to 16 January 2002, 30 patients receiving half-body irradiation for pain palliation were studied. Three patients received upper halfbody irradiation (6 Gy in 2 fractions over 4 days) and 27 patients received lower half-body irradiation (6 to 8 Gy in two fractions over 4 to 5 days). The pain response was assessed with a 5-point verbal analog pain score.

Results: Out of the 27 evaluable patients, the overall and complete pain response rates were 81% and 30%, respectively, with 75% of patients experiencing onset of pain relief within 4 days. The actuarial pain progression-free rates at the fourth, 12th, 20th and 36th weeks after treatment were 80%, 62%, 49% and 25%, respectively. Analgesia requirement was reduced in 63% of patients. The mean percent net pain relief was 47%. Forty four percent of patients developed grade 3 to 4 Radiation Therapy Oncology Group acute toxicity, with 15% of patients having grade 3 nausea and vomiting and 37% of patients having grade 3 to 4 haematologic toxicity.

Conclusion: This 2-fractionated half-body irradiation scheme had comparable effectiveness in pain palliation of multiple osseous metastases with most published single-dose and dailyfractionated half-body irradiation schemes. The scheme was found to be logistically feasible for a busy treatment unit and convenient to patients with multiple painful bony metastases.