B2: Residual oropharyngeal cancer following radical radiotherapy
1Edinburgh Cancer Centre, Edinburgh, UK
Chemoradiation is the preferred first line treatment for locally advanced OPC, but there remains uncertainty regarding the assessment and management of nodal disease
We conducted a retrospective audit of OPC 142 patients presenting 2006-2010. Data collected includes risk factors (smoking/alcohol) stage, management, and outcome. The management of those who failed to respond completely to radiation based treatment was assessed
39 out of 142 patients had neo-adjuvant chemotherapy (NAC). 98 were treated with concomitant chemo-radiotherapy (CRT) while 44 received radiotherapy alone (RT).
78% patients (111) had a complete response evaluated clinically (cCR), 16% (23) had residual disease and 6% (8) had progressive or distant disease. 36 cCR, were confirmed by post treatment scan, 44 not imaged. 27 cases that were felt to have cCR, had residual disease on 4 month post treatment imaging.
In 41 cases of radiologically suspected residual disease 22 patients went onto have salvage surgery. Only 18% (4) cases had pathologically proven residual disease. Only 1 of those who underwent salvage surgery had a PET scan and it was equivocal. In those who had pathologically proven residual disease, it was detected clinically in only 50%. The median time to salvage surgery was 115 days
We have demonstrated the difficulty in confidently determining response to treatment. We were unable to determine any statistically significant factors in predicting pathological residual disease due to sample size. Only small numbers underwent salvage treatment and there was discordance between clinical, radiological and ultimately pathological response. In this cohort PET scanning was less frequent than present day and PETNECK study may enlighten the value in reporting residual disease. Re-audit in present day with standardized post treatment imaging and PET correlation in the case of radiological uncertainty may help to better identify those with pathological disease who are likely to benefit from salvage surgery