ESTRO 2024 - Abstract Book

S2011

Clinical - Mixed sites, palliation

ESTRO 2024

further increase in the prescription dose could have been possible whilst maintaining acceptable target coverage [4].

Results:

117 courses of treatment were evaluated. The frequency of the most common primary histology was as follows: Breast (n = 15) > lung, colorectum, pancreas (all, n = 11) > prostate (n = 7). The median time since previous radiotherapy was 1.4 years (range 0.2 – 30 years). The median number of targets per treatment was 1 (range 1 - 4). Median PTV volume was 27.8 cc (range 1.6 – 555.1 cc). The median prescription dose was 40Gy (range 30 – 60Gy), with a median of 5 fractions (range 3 – 8). Of these treatments, 26 met both criteria for possible dose escalation. Demographic and clinical information for these cases in listed in Table 1. The most common sites for possible dose escalation were abdominal nodes (n = 8) > thoracic nodes (n = 7), followed by liver and mediastinum (both n = 5). The median time elapsed since previous radiotherapy was 1.4 years. 14 patients previously received conventional RT, with another 12 patients previously receiving SABR. Type 2 was the most frequent re-irradiation classification (n = 13), followed by Type 1 (n = 11).

Conclusion:

Re-irradiation to moving targets has been successfully delivered in a wide range of indications. In this review we have identified a suitable patient cohort highlighting the feasibility of isotoxic dose escalation.