Radiation therapy for squamous cell carcinoma of the subglottic larynx

Abstract

Objective This study aims to summarize our institution's experience in treating patients with primary subglottic squamous cell carcinoma (SCC) with radiotherapy (RT) and to define the optimal treatment plan for these patients. Methods We retrospectively reviewed the medical records of 18 patients with subglottic SCC curatively treated with RT between 1977 and 2009. T 1 and T 2 cancers were considered early disease; T 3 and T 4 lesions were considered advanced disease. Patients were stratified according to whether they received RT alone or RT and surgery. Patients treated surgically tended to have more advanced disease and required a total laryngectomy. Patients were excluded if they had distant metastasis at diagnosis or if their tumor was glottic in origin and extended inferiorly into the subglottis. Results Twelve patients (67 %) had advanced disease, and six patients (33 %) had early disease. Local control was achieved in 100 % of the patients with early disease, regardless of treatment group. Of the patients with advanced disease, local control was achieved in five of the seven patients (71 %) treated with RT alone and in four of the five (80 %) treated with surgery and RT. Ultimate local control was achieved in six of the seven patients (86 %) with advanced disease treated with RT alone. Overall local control was 83 % at 5 years, with a 5-year cause-specific survival of 66 % and a 5-year overall survival of 44 %. Local-regional control mirrored that of local control, with an overall local-regional control rate of 83 %. No patient suffered a severe acute or late complication or acute toxicity during the treatment process. Conclusion Patients with SCC of the subglottic larynx have a high likelihood of local-regional control after undergoing RT along or combined with surgery. Those with T 1-T 2 and low volume T 3-T 4 cancers have high probability of local control with voice preservation after definitive RT.

Prognosis of subglottic carcinoma: Is it really worse?

“…Radiotherapy or chemoradiotherapy can yield comparable results with surgery in the treatment of subglottic carcinoma. Early‐stage cases can be treated with radiation fields directed at the larynx with a 1‐ to 2‐cm margin . Radiation fields for advanced‐stage cases usually include the larynx, bilateral cervical, supraclavicular, and upper mediastinal lymph nodes.…”

“…Radiation fields for advanced‐stage cases usually include the larynx, bilateral cervical, supraclavicular, and upper mediastinal lymph nodes. Total dose ranges between 50 and 75 Gy …”

“…There is a general agreement that the inferior border of the subglottis is the inferior border of cricoid cartilage but there is no agreement about the superior border, which is considered to be an imaginary line passing 5 mm below the free margins of the vocal folds by some authors 2 and from 0 to 1 cm below the vocal folds by others. 3 It may also be defined as 1 cm below the apex of the laryngeal ventricle 4 (Figure 1). Ferlito and Rinaldo 3 published a review of subglottic carcinoma in 2000 and they reported the many different definitions of the upper border of the subglottis according to various authors.…”

“…Early-stage cases can be treated with radiation fields directed at the larynx with a 1-to 2-cm margin. 4 Radiation fields for advanced-stage cases usually include the larynx, bilateral cervical, supraclavicular, and upper mediastinal lymph nodes. Total dose ranges between 50 and 75 Gy.…”

“…Total dose ranges between 50 and 75 Gy. 4,17,21 Lymphatic vessels of the subglottic region drain into the prelaryngeal (Delphian), pretracheal, and paratracheal lymph nodes, 8,9 and proper management of these lymph nodes along with the primary tumor is of utmost importance. It is generally believed that the prelaryngeal lymph node (Delphian node) is specific to subglottic carcinoma.…”