After induction chemotherapy for head and neck squamous cell carcinomas, CT-scanner is used to assess tumor response1 but lacks rationalised measurement methods2,3. In T3 laryngeal squamous cell carcinoma, vocal cord remobilisation is a major prognostic factor4 and an essential tumor response criterion5. We compare the performances of three CT-scanner assessment methods: RECIST 1.1, WHO criteria and volumetric method to predict remobilisation.

Retrospective cohort study 43 consecutive patients with vocal cord fixation treated for T3 laryngeal squamous cell carcinoma between 1999 and 2010 All patients received induction chemotherapy (Cisplatin + 5-FU or later Cisplatin + 5-FU + Docetaxel) Contrast enhanced cervical CT-scanners were acquired before and during induction chemotherapy (after 2 or 3 cycles) Tumor size was assessed according to: RECIST 1.1 method: one dimension measurement6 Fig. 1 WHO criteria: two dimensions measurement7 Fig. 1 Volumetric methods: semi-automatic method with handfree correction if needed. Tumor shrinkage after...

Areas under the curves were : 0.763 (95%CI [0.615; 0.911]) for RECIST 1.1 Fig. 2 0.779 (95%CI [0.63; 0.971]) for WHO criteria Fig. 3 0.763 (95%CI [0.623; 0.904]) for the volumetric evaluations Fig. 4 No significant difference: RECIST 1.1 versus WHO criteria p = 0.78 WHO criteria versus Volumetric method p = 0.66 RECIST 1.1 versus Volumetric method p = 1 Optimal cutoffs were - 29% (Se = 70.8%; Sp =68.4%) - 47% (Se = 91.7%; Sp = 63.2%) - 64% (Se = 75%; Sp...

RECIST 1.1, WHO criteria or volumetric measurements with CT-scanner equally predict vocal cord remobilisation after induction chemotherapy in patients with T3 laryngeal squamous cell carcinoma. Interestingly, the optimal cutoffs we found were very close to the thresholds of tumor partial response used in the standardised methods we evaluated : RECIST 1.1: -29% (partial response threshold : tumor shrinkage ≥ 30%6). WHO criteria: -47% (partial response threshold : tumor shrinkage ≥ 50%7). The volumetric method is as performant as the other methods but more time consuming....

ACR – ASNR – SPR Practice Parameter for the Performance of Computed Tomography (CT) of the extracranial Head and Neck. Revised 2016. Forastiere, A. et al., 2013. Long-Term Results of RTOG 91-11: A Comparison of Three Nonsurgical Treatment Strategies to Preserve the Larynx in Patients With Locally Advanced Larynx Cancer. Journal of Clinical Oncology, 31(7), pp.845–852 Richard, J.M. et al., 1998. Randomized trial of induction chemotherapy in larynx carcinoma. Oral Oncology, 34(3), pp.224–228. Gorphe, P. et al., 2015. Influence of the vocal cord mobility in...