Study design and early result of a phase I study of SABR for early-stage glottic cancer

The Evolving Role of Stereotactic Body Radiation Therapy for Head and Neck Cancer: Where Do We Stand?

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.

Outcomes of hypofractionation for early-stage glottic carcinoma

BACKGROUND

Our goal is to evaluate hypofractionation in early-stage glottic carcinoma of a single center in line with randomized trials.

MATERIALS AND METHODS

Between June 2016 and January 2021, 33 early glottic carcinoma patients treated with IMRT (intensity-modulated radiotherapy) in the Radiation Oncology Department were analyzed. Descriptive statistics and survival analysis were applied. Survival analysis and curves were done via the Kaplan-Meier method. Survival curves were analyzed due to the T stage. Log-rank test was used for the analysis of T stage survival curves.

RESULTS

Twenty (60.1%) patients were T1 whereas six (18.2%) and seven (21.2%) were Tis. 56.25 Gy, 63 Gy, and 65.25 Gy were delivered to the patients with Tis, T1, and T2, respectively. All groups were treated with 2.25 Gy per fraction. T2 stage had lesser DFS (disease-free survival) compared to Tis and T1 stage and it was statistically significant (P = 0.035).

CONCLUSION

Hypofractionation with 2.25 Gy per fraction may be standard for early glottic carcinoma with similar results compared to microsurgery and conventional fractionation radiotherapy.

Hypofractionated radiotherapy for early stage glottic cancer: efficacy of 3.5 Gy per fraction

Purpose

The purpose of this study was to evaluate the treatment outcomes and toxicity profile of patients with early glottic cancer who underwent hypofractionated radiation therapy (RT) with 3.5 Gy per fraction.

Materials and Methods

A retrospective review was performed of the medical records of 35 patients with early stage (T1-2N0M0) glottic cancer who underwent definitive RT. The dose fractionation scheme was 59.5 Gy in 17 fractions. Posterior commissure was excluded from the clinical target volume (CTV) for 26 patients (74.3%) without glottic lesions close to this region.

Results

With a median follow-up of 16.23 months (range, 6.82 to 67.15 months), no local, regional, or distant recurrence was reported. Acute hoarseness (65.7%), mucositis (68.6%), radiation dermatitis (60.0%) was frequent. One patient (2.9%) reported grade 3 acute toxicity (mucositis) and there was no grade 4–5 acute toxicity. There was no grade ≥3 late toxicities; however, grade 1 late intermittent hoarseness was frequent (45.7%). The receiver operative characteristic analysis revealed that mean hypopharyngeal dose was predictive for acute grade ≥2 mucositis (area under the curve=0.9314; 95% confidence interval, 0.8524–1). The optimal threshold of mean hypopharyngeal dose for occurrence of acute grade ≥2 mucositis was 26.31 Gy, with a specificity and sensitivity of 83.3% and 88.2%, respectively.

Conclusion

Hypofractionated RT with fraction size of 3.5 Gy for early glottic cancer is effective. The hypopharyngeal mean dose could predict the occurrence of grade ≥2 acute mucositis. The posterior commissure can be safely excluded from the CTV.

[Radiotherapy for patients with early-stage glottic squamous cell carcinoma of the larynx: Interest of hypofractionation?]

Hypofractionated radiotherapy of early-stage squamous cell carcinoma of the glottic larynx is a promising treatment option. This can be divided into radiotherapy with moderate hypofractionation (up to 2.5Gy per fraction), more intense hypofractionation (between 2.5 and 4.5Gy per fraction) and stereotactic radiotherapy (above 4.5Gy per fraction). Most studies evaluating moderate hypofractionation show a local control rate between 85 and 95%. Acute laryngeal toxicity is superior to conventional treatment, but only for grades 1 and 2, with no significant difference reported for severe toxicity. Stereotactic radiotherapy in this pathology is also an emerging entity, but some authors have reported significant toxicity. There are currently no standardized guidelines for treatment and management regimen. We conducted a systemic review of published prospective and retrospective trials to evaluate efficacy, toxicity, and discuss future directions.

Stereotactic body radiotherapy (SBRT) for primary non-metastatic head and neck cancer: When less is enough

The advantage of highly conformal dose distribution and steep dose gradient has resulted in rapidly increasing use of stereotactic body radiotherapy (SBRT) in multiple cancer sites. Also there has been a surge in the use of SBRT in head neck cancer over the last decade. It is predominantly exploited in retreatment setting for recurrent and second primary head neck cancer as well as in metastatic setting. The literature on SBRT in primary non-metastatic head neck cancer is sparse and evolving. In the current review, available literature was critically analyzed focusing on the potential applications of SBRT in primary untreated non-metastatic head neck cancer. SBRT boost following external beam radiotherapy is temping as a method of dose escalation. Special attention was paid to the application of SBRT as a sole modality of treatment. The shorter treatment schedule makes it an attractive option for treatment in primary head neck cancer especially in elderly, co-morbid and medically unfits patients. Future investigation is needed to establish SBRT as an additional armamentarium in the radiotherapeutic management of head and neck cancers.

Clinical analysis of EBRT vs TLM in the treatment of early (T1-T2N0) glottic laryngeal cancer

Objective: To analyze the clinical efficacy of external beam radiation therapy (EBRT) vs transoral laser microsurgery (TLM) in patients with early glottic laryngeal carcinoma (T1-T2N0) and the effect of treatment choice on vocal function.

Methods: A retrospective analysis of patients with T1-T2N0 glottic laryngeal carcinoma who underwent EBRT or TLM between January 2012 and December 2018 in PUMCH. The Kaplan-Meier method was used to analyze local control, progression-free survival and overall survival, and the VHI-30 scale was used to evaluate the effects of EBRT and TLM on vocal function.

Results: A total of 185 patients, all with pathologically confirmed squamous cell carcinoma, were enrolled. The median age was 62 years (38-88). N0 disease was confirmed by imaging: 142/185 (76.76%) patients had T1N0 disease, and 43/185 patients (23.24%) had T2/N0 disease. A total of 91/195 (49.19%) patients received an EBRT dose of 66-70 Gy/30-35f, at 2.0-2.3 Gy/f. 94/185 (50.81%) patients received TLM. The median follow-up time was 42 months (12-92), and the 3-year LC, PFS, and OS rates for the EBRT and TLM groups were 96.9% vs 94.1%(p=0.750), 95.3% vs 93.1%(p=0.993) and 93.3% vs 95.4%(p=0.467), respectively. The VHI-30 scales were used at the baseline showed no significant difference between the two groups 19.20±3.324 vs 21.65±9.80 (p=0.250), but the EBRT group had a low voice handicap after treatment, 10.24±6.093 vs 19.45±5.112 (p=0.001) (6 months) and 9.45±5.112 vs 14.97±7.741 (12 months). No CTCAE grade 3 or above side effects were observed in the EBRT group, but 3 cases of vocal cord stenosis were observed in the TLM group.

Conclusion: The application of EBRT for early glottic laryngeal carcinoma (T1-T2N0) had an obvious curative effect with high LC and OS rates, no serious side effects, and a low voice handicap rate.