May Gamal Ashour

Stereotactic body radiation therapy (SBRT) is a precise and conformal radiation therapy (RT) that aims to deliver a high dose of radiation to the tumor whilst sparing surrounding normal tissue, making it an attractive option for head and neck cancer (HNC) patients who are not suitable for the traditional long course of RT with comprehensive RT target volume. Definitive SBRT for HNC has been investigated in different settings, including early stage glottis cancer, and as an alternative to brachytherapy boost after external beam RT. It is also used as a primary treatment option for elderly or medically unfit patients. More recently, an SBRT combination with immunotherapy in the neoadjuvant setting for HNC showed promising results. Salvage or adjuvant SBRT for HNC can be used in appropriately selected cases. Future studies are warranted to determine the optimum dose and fractionation schedules in any of these indications.

BACKGROUND: Radiotherapy (RT) is an appropriate treatment option for early-stage glottic cancer (ESGC) that achieves high local control and preserves voice quality. However, the optimal radiation treatment schedule remains unknown. We present our institution's 14-year experience in treating ESGC with definitive radiotherapy between 2005 and 2019 inclusively.

MATERIALS AND METHODS: We reviewed the medical records of 104 patients; 63 (60.5%) were treated with conventional fractionation (CF), and 41 (39.5%) were treated with hypofractionated radiotherapy (HF). The clinical T-stage was T1a in 50 patients (48%), T1b in 27 (26%), and T2 in 27 (26%). Age, gender, anterior commissure involvement, stage, radiotherapy technique, radiation fraction size, and overall treatment time (OTT) were analyzed as prognostic factors. The survival outcomes, local regional control (LRC), and laryngeal preservation rate were evaluated.

RESULTS: The 5-year overall survival (OS) and LCR were 83.3% and 78%, respectively. On univariate analysis, treatment with CF (p = 0.02), prolonged OTT > 49 days in CF and > 40 days in HF (p = 0.04), and RT total dose < 66 Gy (p = 0.03) were associated with poor LRC. Multivariate analysis showed a non-significant association with LRC (all p > 0.05). The 5-year OS rate in the CF and HF-treated patients was 84.9% and 72.1%, respectively (p = 0.99), and in patients who had T1a, T1b, and T2 disease, were 78.2%, 96.0%, and 82.1%, respectively (p = 0.43). All patients and tumor variables showed no statistically significant association with OS. Only low-grade acute toxicity was observed.

CONCLUSION: Non-inferiority results supported the HF schedule to ESGC, including high local disease control and decreased overall treatment time. Our study supports its efficacy in the primary care of ESGC with manageable side effects.

BACKGROUND: Dysphagia is a distressing symptom during and after radiotherapy treatment in head and neck cancer (HNC) patients. The objective of this prospective study was to investigate whether swallowing sparing intensity modulated radiotherapy (SW-IMRT) reduces the occurrence of swallowing dysfunction compared to the standard IMRT (ST-IMRT).

METHODS: We randomized, planned, and treated patients with HNC who needed whole neck irradiation using the simultaneous integrated boost (SIB) IMRT technique. Doses of 70, 60, and 54 Gy (over 33 daily fractions) were prescribed to the primary tumor, high-risk and low-risk regions, respectively. The postoperative cases received 60 and 54 Gy (over 30 daily fractions) to the high-risk planning target volume (PTV) and low-risk PTV. We contoured organs at risk related to swallowing dysfunction (SWOARs) in all cases. In the ST-IMRT group, parotids only were spared. In the SW-IMRT group, parotids and SWOARs outside the high-risk PTV were spared. Assessment of dysphagia included clinical and instrumental evaluation.

RESULTS: One hundred forty-six patients ended their radiotherapy treatment. Dose distribution showed comparable PTV coverage and no difference in parotid glands sparing between the two groups. SWOARs dose reduction with SW-IMRT differs according to tumor location and its overlap with SWOARs. Using different assessment methods, SW-IMRT was associated with a lower occurrence of dysphagia up to one year after treatment. There was no difference between the two groups regarding acute dysphagia ( = 0.262), overall survival ( = 0.811), and disease-free survival ( = 0.876).

CONCLUSION: SW-IMRT is significantly better than ST-IMRT regarding a physician-rated and objective assessment of swallowing dysfunction at short- and long-term post-treatment follow-up.