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

To explore fractionated half-body irradiation (HBI) for pain palliation and determine if it is more efficient and effective than single dose HBI.

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 doses 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.

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, SC-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 identical 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.

HBI is still the most effective and efficient way 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 responses in pain relief, duration of relief, PFS, OS, and quality of life.