Paint by numbers.
Top Line: While it seems simple that increasing radiation dose should improve local control outcomes, we’ve recently learned just how complex that equation can be, particular in the chest.
The Study: The INT 0123 trial compared 64.8 Gy and 50.4 Gy, both at 1.8 Gy per fraction and both with concurrent cis/5FU, and found no improvement in survival or locoregional control with dose escalation for locally-advanced esophageal cancer. The ARTDECO trial now takes a modern look at the question of dose escalation. 260 patients with either squamous cell carcinoma (62%) or adenocarcinoma (38%) of the esophagus or EG junction were randomized to standard dose or escalated dose using a simultaneous integrated boost (SIB) technique. All were staged with PET/CT. The base treatment for both arms was a standard 50.4 Gy in 28 fractions to primary disease with a 3 cm craniocaudal expansion + any positive nodes and concurrent carboplatin and paclitaxel. Of note, M1 supraclav nodes were allowed on trial. In the dose escalation arm, a 2.2 Gy per fraction SIB was delivered to the primary tumor for a total dose of 61.6 Gy in 28 fractions. At 3 years, there was no difference in the primary outcome of local progression-free survival between standard and escalated dose (71% vs 73%). Although LPFS was superior for SCC (77%) vs adeno (60%), radiation dose had no effect on LPFS within histologies. There was no difference in local or regional progression, and also no difference in survival. Overall, most progression events were local-only followed by distant metastatic progression. There was no significant difference in the rate of grade 4 or grade 5 toxicity, however the latter was 8% with dose escalation versus 3% with standard dose.
TBL: For patients receiving definitive chemoradiation for esophageal cancer, dose escalation using a simultaneous integrated boost from 50.4 → 61.6 Gy does not improve local control or survival. | Hulshof, J Clin Oncol 2021