Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy (RT) for high and intermediate risk squamous cell cancer of the oropharynx: the MeRInO Study


Year:

Session type:

Claire Paterson1,Ian McCrea1,Sarah Allwood-Spiers1,Devlin Lynsey1,Lisa Hay1,Marimuthu Sankaralingam1,Philip McLoone2,Derek Grose1,Allan James1,Carolynn Lamb1,Mohammed Rizwanullah3,Christina Wilson1,Stefano Schipani1,Ioanna Nixon1,Maureen Thomson1,Mark McJury1,John Foster1,Aileen Duffton1
1NHS,2University of Glasgow,3N/A

Abstract

Background

Many patients with intermediate and high risk SCC of the oropharynx (OPSCC) relapse despite radical chemoradiotherapy (CRT). Toxicity of current treatment limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment, individualised and adaptive treatment strategies may be employed. 

The primary aim is to determine the threshold change in apparent diffusion coefficient (ADC) from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment

Method

This is a prospective observational imaging study with national REC approval (15/WS/0159); recruiting patients with intermediate and high risk, locally advanced OPSCC receiving radical RT/CRT.  Patients undergo DW- MRI immediately prior to #1and #11. ADC measurements are obtained for target lesions (primary and lymph nodes), and % change in ADC calculated. Disease status for each target lesion is noted at follow up. 

Results

Early Results:

54 patients have been recruited to date. 5 patients have relapsed disease (4 primary site, 1 LN). Mean ADC and % rise in ADC are shown below for relapsed lesions. No assessment can be made for patients who have not yet relapsed prior to completing 2 years of follow up.

 

 

Patient 4

(primary)

Patient 7

(primary)

Patient 10

(primary)

Patient 38

(primary)

Patient 22

(LN)

Baseline ADC (x10-6 mm2/s)

1306

1059

1355

1301

1375

Repeat ADC

(x10-6 mm2/s)

1438

1343

1566

1479

1621

% change

10.1

26.8

15.6

13.7

17.9

Conclusion

Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio. Previous studies examining DW-MRI as a predictive biomarker in SCCHN have included all sub-sites and biological sub-types. Further work will be done most robustly in a single sub-type with similar biological behaviour and uniform treatment approach. The MeRInO study will help establish these thresholds in OPSCC.