UNASSIGNED: 201 Background: Various schedules of palliative radiotherapy (pRT) are prescribed for @entity0 ( @entity0 ) @entity1 . Length of treatment can vary from a single day to three weeks. Single fraction pRT provides similar @entity158 relief vs. multi-fraction pRT for bone metastases, but retreatment rates are higher. In the era of targeted and hormonal therapy, @entity1 with @entity0 can survive many years after their initial diagnosis. We investigated whether @entity1 with @entity0 who were prescribed single fraction pRT had poorer prognoses and experienced shorter survival than @entity1 who were prescribed multi-fraction pRT. METHODS: @entity1 at a single institution with @entity0 underwent pRT, with fractionation schedules including 8 Gy in 1 fraction (fx), 20 Gy in 5 fx, 30 Gy in 10 fx, 37.5 Gy in 15 fx between 2001-2015. 392 treatments were prescribed (109/241/29/13 in each regimen as above). Date of @entity204 was obtained from medical records, Social Security Death Index, or published obituaries. @entity1 who were alive or whose date of @entity204 could not be determined were censored at the date of their last encounter. Survival was calculated from the start of treatment to the date of @entity204 or censorship. RESULTS: @entity1 treated with 37.5 Gy in 15 fx ( @entity15 20 months, p = 0.002) or 30 Gy in 10 fx ( @entity15 22 months, p = 0.03) experienced longer survival than @entity1 treated with 8 Gy in 1 fx ( @entity15 8 months). There was no significant survival difference between @entity1 treated with 20 Gy in 5 fx ( @entity15 18 months, p = 0.49) and @entity1 treated with 8 Gy in 1 fx. There was no significant survival difference between @entity1 treated by the three multi-fractionation schedules. CONCLUSIONS: @entity0 @entity1 who were prescribed 37.5 Gy and 30 Gy lived longer than @entity1 who were prescribed 8 Gy of pRT. No statistically significant difference was found between @entity1 who were prescribed 20 Gy compared to 8 Gy, possibly due to the lower number of @entity1 who received these regimens. Single fraction pRT was more likely to be prescribed to @entity1 who would ultimately have shorter survival. More research is needed, ideally across multiple institutions, to explore the correlation between physician estimation of @entity1 survival and selection of pRT regimen for @entity1 with @entity0 .

Fractionation of palliative radiotherapy in XXXX : Selection and survival.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients', 'patient'] @entity0 :: ('MESH:D001943', 'Disease') :: ['metastatic breast cancer', 'MBC'] @entity158 :: ('MESH:D010146', 'Disease') :: ['pain'] @entity204 :: ('MESH:D003643', 'Disease') :: ['death'] @entity15 :: ('MESH:D009103', 'Disease') :: ['MS']
@entity0 :: (MESH:D001943,Disease) :: ['metastatic breast cancer']
