Abstract 1446P
Background
The aim of this study was to evaluate survival rates, acute and late toxicity after hypofractionated palliative radiotherapy (RT) in low performance status and elderly patients (pts), unfit for standard RT treatment.
Methods
Between December 2010 and June 2020, 211 pts treated with hypofractionated palliative RT treatment were evaluated retrospectively. The prescribed dose was 36.75 - 42 Gy in 7-8 fractions (ff) given one fraction of 5.25 Gy weekly. A 3DCRT technique was used in 123 (pts) (58.3%) and a VMAT or IMRT technique in 88 (pts) (41.7%). Concomitant systemic chemotherapy (OT, CT or immunotherapy) was administered in only 41 pts (19.4%).
Results
At analyses 104 pts (49.3%) were male and 107 (50.7%) female; the mean age was 79 years old (range 42-100). The majority of pts were elderly with 2 or more comorbidities (88% pts were aged > 70 years old). The mean KPS was 70 (range 40-90). After a mean follow-up of 14 months the median OS was 11 months. Overall, 74.5% pts completed RT at the prescribed dose, and 25.5 % interrupted it due to PD, clinical worsening or lost motivation. A clinical or radiological examination response was observed in 56% of pts (CR 24%, PR 32%), SD in 6%, PD in 17% pts, and in 21% it was not possible to evaluate the response. In pts receiving the prescribed dose the response rate was 75%, of them 40% had a CR. Patients that completed RT treatment had a higher survival rate compared to pts who interrupted it (median 14 mths vs 3 mths; p-value 0.0001). Moreover, KPS > 70, PTV < 250 cc, systemic therapy during RT treatment and clinical or radiological response were prognostic factors regarding OS (p- value < 0.05). RT delivered technique did not influence survival rate or local response, however pts treated with 3DCRT had higher rates of ≥ G2 acute or late toxicity (p-value < 0.067). G3 ≥ acute toxicity was observed in only 1.8% of pts. A late toxicity ≥ G3 was observed in 8 pts (4.7%).
Conclusions
Weekly hypofractionated RT 36.75-42 Gy in 7-8 ff appears feasible in poor PS and elderly pts unfit of standard RT treatment with a good response rate of 75%. Total dose, KPS > 70, PTV < 259 cc, systemic therapy were prognostic factors regarding OS. IMRT-VMAT technique is recommended to be used to reduce G2 or higher toxicity.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.