First results of a phase III multi-centre randomized controlled trial of intensity modulated vs. conventional radiotherapy in head and neck cancer: PARSPORT (CRUK/03/005)
Title: First results of a phase III multi-centre randomized controlled trial of intensity modulated vs. conventional radiotherapy in head and neck cancer: PARSPORT (CRUK/03/005)
Reviewer: Christine E. Hill-Kayser, MD
Presenter: Christopher Nutting on behalf of the PARSPORT Trial Management Group, Cancer Research UK
Radiation therapy is a mainstay of treatment for head and neck cancers. Unfortunately, this can lead to significant side effects including xerostomia, which can lead to dental problems, swallowing difficulty, nutritional issues and osteonecrosis. Intensity-modulated radiotherapy (IMRT) can allow one or both parotid glands to be spared, maintaining saliva production, which cannot be achieved with conventional radiation therapy. The PASSPORT trial was designed to assess the benefits of IMRT in squamous cell cancer of the head and neck.
94 patients requiring radiation therapy for a head and neck cancer were randomized to receive either IMRT or conventional radiation (CXRT); 47 were assigned to each group. There were some differences in side effects, with more CXRT patients experiencing dry mouth and difficulty swallowing (91% vs. 71%, p= 0.02 and 98% vs. 87%, p=0.05, respectively). More IMRT patients experienced fatigue (76% vs. 41%, p<0.01).
Assessment of xerostomia was done using the LENTSOM scale, which graded this effect on a 1-4 scale. At 12 months post-treatment, the incidence of LENTSOM grade 2 or greater xerostomia was significantly higher in patients who were treated with CXRT versus IMRT (74% versus 39%, p = 0.004). Differences were observed at 3, 6 and 18 months as well. Overall survival and progression free survival were similar in both groups.
The authors conclude that IMRT significantly reduces the risk of subjective xerostomia by about 50% for patients with pharyngeal cancers. They note that studies with longer follow-up are warranted, but that the data presented here support adoption of IMRT as the standard of care for head and neck cancer patients.
Also see Interpreting a Cancer Research Study