Results of a randomised phase III trial of dysphagia-optimised intensity modulated radiotherapy (Do-IMRT) versus standard IMRT (S-IMRT) in head and neck cancer.


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Chris Nutting, Keith Rooney, Bernadette Foran, Laura Pettit, Matthew Beasley, Laura Finneran, Justin Roe, Justine Tyler, Tom Roques, Audrey Cook, Imran Petkar, Shree Bhide, Devraj Srinivasan, Cheng Boon, Emma de Winton, Robert Frogley, Mark Sydenham, Marie Emson, Clare Griffin, Emma Hall, On behalf of DARS TMG

Abstract

Background

Most oro- and hypopharyngeal cancers (OPC, HPC) are treated with (chemo)radiotherapy with curative intent at the consequence of adverse effects on quality of life. DARS (CRUK/14/014; ISRCTN25458988) tested if using Do-IMRT to reduce radiation dose to the dysphagia/aspiration related structures (DARS) improved swallowing function compared to S-IMRT.

Method

Patients (T1-4, N0-3, M0 OPC/HPC) were randomised (1:1) to S-IMRT (65 gray (Gy)/30 fractions (f) to primary and nodal tumour; 54Gy/30f to remaining pharyngeal subsite and nodal areas at risk of microscopic disease) or Do-IMRT. For Do-IMRT the volume of the superior and middle pharyngeal constrictor muscle (PCM) (OPC) or inferior PCM (HPC) lying outside the high-dose target volume had a mandatory mean dose constraint. Patients were blind to treatment allocation. Primary endpoint was MD Anderson Dysphagia Inventory (MDADI) composite score 12 months after radiotherapy. Secondary endpoints included University of Washington (UW)-Qol, Performance Status Scale Head & Neck (PSS-HN) domain scores (range: 0-100), swallow volume, swallow capacity and local control.

Results

112 patients were randomised from 22 UK centres from 06/2016-04/2018. Mean age was 57 years; 80% were male; 97% had OPC; 90% had AJCC stage 3&4 disease; 90% had concomitant chemotherapy. Radiation dose and outcome measures at 12 months are summarised below. Three local recurrences (1 S-IMRT, 2 Do-IMRT) were reported.


S-IMRT (n=56)Do-IMRT (n=56)p-value
Mean radiotherapy dose (Gy) (median, (IQR))
Inferior PCM49.8
(47.1-52.4)
28.4
(21.3-37.4)
<0.0001
Superior and middle PCM57.2
(56.3-58.3)
49.7
(49.4-49.9)
<0.0001
Swallowing outcomes
MDADI score
Mean (SD)
70.5
(17.3)
77.7
(16.1)
0.037
Swallow volume (ml/swallow)
Median
20.016.70.071
Swallow capacity (ml/sec)
Median
12.512.50.336
PSS-HN normalcy of diet>50
PSS-HN eating in public score>50
58.1%
74.4%
70.6%
84.3%
0.297
0.351
UW-QoL “able to swallow as well as ever”15.2% (7/46)40.4% (21/52)0.010


Conclusion

Do-IMRT reduced radiotherapy dose to the DARS and improved patient-reported swallowing function compared with S-IMRT.


Impact statement

Do-IMRT can improve quality of life for OPC patients requiring radiotherapy.