Fractionated half-body irradiation for pain palliation in widely metastatic cancers: Comparison with single dose

Abstract

Purpose : To explore fractionated half-body irradiation (HBI) for pain palliation and determine if it is more efficient and effective than single dose HBI. Methods and Materials : During the last 13 years, 75 out of 115 HBIs (64%) at the University of Maryland Medical Center were given for palliation of various widely metastatic cancers (28%) prostate, 25% breast, 12% lung). The HBI fields were 28% upper, 25% mid, and 47% lower; three patients had both upper and lower HBI. An initial performance status (PS) 3&4 with a life expectancy <3 months was found in 50% of patients. The HBI techniques used on consecutive patients were: single dose (SD) in 54% with escalating does of 4–10 Gy; split-course (SC) in 12% with two 4 Gy single doses separated by 2 weeks; and daily fractionated (DF) in 34% with five fractions of 3 Gy each. There were 68 of 75 HBI (91%) given for pain control purposes. Results : The percent total (complete) pain relief was SD-73(32), SC-50(13), and DF-96(49). Time to maximum and (complete) relief was; SD 5 days each and DF HBI 7(11) days. Pain-free survival (PFS) was short but so was overall survival (OS). PFS was SD-5, SD-4.5, and DF-19 weeks. The percent of the remaining patient's life spent pain free without retreatment (NPR) was SD-38, SC-34, and DF-68. Differences in pain relief, PFS, OS, and NPR were significant and carried over primary tumor types; prostate, breast, and surprisingly GI were very responsive (90, 84, and 83%, respectively). On multivariate analysis only the PS and degree of relief were independent variables. Despite lack of premedication in DF-HBI, toxic reactions were idententical to SD-HBI with premedication. No Grade 4 toxicities occurred. Grade 3 toxicities were 4%. Retreatment was 3% in SD and 13% in fractionated HBI; these differences were not significant. Conclusion : HBI is still the most effective and efficient was to palliate pain from widely disseminated cancer. Fractionating HBI eliminates need for the premedication and close patient monitoring required for SD-HBI. It also allows for an increase in total dose which can produce better response in pain relief, duration of relief, PFS, OS, and quality of life.