Technological advancements in treatment planning and delivery have propelled the use of intensity-modulated radiation therapy (IMRT) in head and neck squamous cell carcinoma (HNSCC). This review compares IMRT with conventional two-dimensional (2D) and/or three-dimensional (3D) radiotherapy (RT) in curative-intent management of HNSCC. Only randomized controlled trials (RCTs) offering curative-intent RT in patients with non-metastatic HNSCC were included. Outcome data was extracted independently by two reviewers, pooled using the Cochrane methodology, and expressed as risk ratio (RR) or hazard ratio (HR) as appropriate with 95% confidence intervals (CIs). Xerostomia was the primary outcome of interest whereas loco-regional control, overall survival and quality-of-life (QOL) were secondary endpoints. Seven RCTs involving 1155 patients directly comparing IMRT with 2D/3D-RT in HNSCC were included. The primary objective in five of seven index RCTs was reduction in xerostomia, with only one trial each using loco-regional control and overall survival as primary endpoints for sample size calculation. The use of IMRT was associated with a 36% relative risk reduction in ≥grade 2 acute xerostomia (RR = 0.64, 95%CI = 0.49–0.84; p = 0.001) compared to 2D/3D-RT. More importantly, IMRT significantly reduced the risk of ≥grade 2 late xerostomia (RR = 0.44, 95%CI = 0.34–0.57; p = 0.00001) compared to non-IMRT techniques at all time-points. Within the limitations of inadequate sample size and low statistical power, IMRT also resulted in 24% relative reduction in the risk of loco-regional relapse (HR = 0.76, 0.57–1.01; p = 0.06) and 30% relative reduction in risk of death (HR = 0.70, 95%CI = 0.57–0.88; p = 0.002) compared to 2D/3D-RT. However, this benefit of IMRT for loco-regional control and overall survival was limited to nasopharyngeal cancer patients alone, with no significant difference in efficacy between the two techniques in patients with cancers of the laryngo-pharynx in this analysis, highlighting the inconsistency in results of subgroup analyses stratified by primary site. Inadequate reporting of data precluded statistically pooling of results for QOL outcomes. There is consistent moderate-quality evidence that IMRT significantly reduces the risk of moderate to severe acute and late xerostomia compared to 2D/3D-RT in curative-intent radiotherapeutic management of HNSCC. However, the quality of evidence regarding the superiority of IMRT over conventional techniques for disease-related endpoints is rather low due to relative lack of power and inconsistency of results precluding robust conclusions.
Background: The dominant pattern of failure for squamous cell carcinoma of head and neck remains loco-regional, although distant metastases are now being increasingly documented. Radical radiotherapy with concurrent chemotherapy is contemporary standard of care in the non-surgical management of these loco-regionally advanced cancers, based on large randomized controlled trials utilizing high-dose cisplatin (80–100 mg/m2) cycled every three-weekly during definitive radiotherapy. Although efficacious, this is associated with high acute morbidity necessitating intensive supportive care with attendant resource implications. The aim of this retrospective study was to assess the efficacy and acute toxicity of an alternative schedule i.e. concurrent weekly cisplatin-based radical radiotherapy and it's potential to be an optimal regimen in advanced head and neck cancers. Methods: Outcome data of patients with Stage III & IV head and neck squamous cell carcinoma, excluding nasopharynx, planned for radical radiotherapy (66–70 Gy) with concurrent weekly cisplatin (30 mg/m2) treated in a single unit between 1996–2004 was extracted. Results: The dataset consisted of 264 patients with a median age of 54 years. The median radiotherapy dose was 70 Gy (range 7.2–72 Gy) and median number of chemotherapy cycles was 6 (range 1–7). Two-thirds (65%) of patients received ≥85% of planned cisplatin dose. With a mean follow-up of 19 months, the 5-year local control; loco-regional control; and disease free survival was 57%; 46%; and 43% respectively. Acute grade 3 or worse mucositis and dermatitis was seen in 77 (29%) and 92 (35%) patients respectively, essentially in patients receiving doses ≥66 Gy and 6 or more cycles of chemotherapy. Other toxicities (hematologic, nausea and vomiting) were mild and self-limiting. Overall, the acute toxicity of this concurrent weekly chemo-radiation regimen though mildly increased did not mandate intensive supportive care. Stage grouping, primary site, and intensity of treatment were significant predictors of loco-regional control and disease free survival. Conclusion: Radical radiotherapy with concurrent weekly cisplatin has moderate efficacy and acceptable acute toxicity with potential to be an optimal regimen in loco-regionally advanced squamous cell carcinoma of the head and neck, particularly in limited-resource settings. Stage grouping, primary site, and treatment intensity are important determinants of outcome.