Image-guided adaptive radiotherapy improves acute toxicity during intensity-modulated radiation therapy for head and neck cancer

Radiation-induced skin injury in the head and neck region: pathogenesis, clinics, prevention, treatment considerations and proposal for management algorithm

Worldwide increase of head and neck cancers ranks these malignancies among top causes of cancer in human population. Radiation induced skin injury (RISI) is one of the major side effects of radiotherapy (RT). Skin of the neck is exposed to radiation due to necessity of therapeutic or prophylactic (elective) irradiation of neck lymph nodes and target organs, including the larynx and hypopharynx. The location of the neck exposes these regions of the skin to various additional exposomes such as ultraviolet radiation (UVR), pollution and cigarette smoke. There are many controversies or inconsistencies regarding RISI, from molecular aspects and therapy to terminology. There is lack of high-quality and large-sample studies in both forms of RISI: acute (aRISI) and chronic (cRISI). Finally, no gold standards in the management of aRISI and cRISI have been established yet. In this article, the authors discuss the pathogenesis, clinical picture, prevention and clinical interventions and present a proposed treatment algorithm.

Weekly Adaptive Radiotherapy vs Standard Intensity-Modulated Radiotherapy for Improving Salivary Function in Patients With Head and Neck Cancer: A Phase 3 Randomized Clinical Trial

Importance

Xerostomia is a major toxic effect associated with intensity-modulated radiotherapy (IMRT) for oropharyngeal cancers.

Objective

To assess whether adaptive radiotherapy (ART) improves salivary function compared with IMRT in patients with head and neck cancer.

Design, Setting, and Participants

This phase 3 randomized clinical trial was conducted in 11 French centers. Patients aged 18 to 75 years with stage III-IVB squamous cell oropharyngeal cancer treated with chemoradiotherapy were enrolled between July 5, 2013, and October 1, 2018. Data were analyzed from November 2021 to May 2022.

Interventions

The patients were randomly assigned (1:1) to receive standard IMRT (without replanning) or ART (systematic weekly replanning).

Main Outcomes and Measures

The primary end point was the frequency of xerostomia, measured by stimulating salivary flow with paraffin. Secondary end points included salivary gland excretory function measured using technetium-99m pertechnetate scintigraphy, patient-reported outcomes (Eisbruch xerostomia-specific questionnaire and the MD Anderson Symptom Inventory for Head and Neck Cancer questionnaire), early and late toxic effects, disease control, and overall and cancer-specific survival.

Results

A total of 132 patients were randomized, and after 1 exclusion in the ART arm, 131 were analyzed: 66 in the ART arm (mean [SD] age at inclusion, 60 [8] years; 57 [86.4%] male) and 65 in the standard IMRT arm (mean [SD] age at inclusion, 60 [8] years; 57 [87.7%] male). The median follow-up was 26.4 months (IQR, 1.2-31.3 months). The mean (SD) salivary flow (paraffin) at 12 months was 630 (450) mg/min in the ART arm and 584 (464) mg/min in the standard arm (P = .64). The mean (SD) excretory function of the parotid gland at 12 months, measured by scintigraphy, improved in the ART arm (48% [17%]) compared with the standard arm (41% [17%]) (P = .02). The 2-year-overall survival was 76.9% (95% CI, 64.7%-85.4%) in both arms.

Conclusions and Relevance

This randomized clinical trial did not demonstrate a benefit of ART in decreasing xerostomia compared with standard IMRT. No significant differences were found in secondary end points except for parotid gland excretory function, as assessed by scintigraphy, or in survival rates.

Trial Registration

ClinicalTrials.gov Identifier: NCT01874587.