FLEX October 2023

256

International Journal of Radiation Oncology Biology Physics

Aaltonen et al.

in those who received radiation therapy. Patients treated with radiation therapy re ported less hoarseness-related inconvenience in daily living 2 years after treatment. Three patients in each group had local cancer recurrence within 2 years from random ization. Conclusions: Radiation therapy may be the treatment of choice for patients whose re quirements for voice quality are demanding. Overall voice quality was similar in both treatment groups, however, indicating a need for careful consideration of patient related factors in the choice of a treatment option. 2014 Elsevier Inc.

handicap. These results suggest that radiation ther apy may be a treatment of choice for patients whose requirements for voice quality are demanding. However, careful consider ation of patient-related fac tors is essential when choosing the treatment option.

Patients

Introduction

Eligible patients had previously untreated, histologically confirmed squamous cell carcinoma limited to 1 mobile vocal cord, staged as T1aN0M0 (5), and were capable of collaboration in voice evaluation tests. To achieve homo geneity in voice quality assessments, and because glottal cancer is infrequent in women (6), female patients were not included. The study protocol was approved by an ethics committee of the Helsinki and Uusimaa Hospital District. The patients provided written consent before entry into the study. The study was not registered (trial registration was not the norm in 1998). Study participants were randomized to the treatments at a 1:1 ratio by means of a computer program with random digits weighted according to the proportions of past randomiza tions to yield a roughly balanced number of randomizations between the groups in a concealed fashion. Randomization was carried out by a hospital staff member who was inde pendent of the study. Tumor site in the vocal cord was used as a stratification factor at randomization. The result of randomization was communicated to the centers by phone. Patients allocated to radiation therapy had their treatments started within 6 weeks after randomization. The larynx was irradiated with 6-MeV photons from 2 opposing 4.5 4.5 to 5 5 cm wedge fields to a total cumulative dose of 66 Gy in 2-Gy daily fractions over 6.5 weeks with a linear accelerator. When necessary an anterior bolus was added to achieve the desired dose at the anterior commissure. The uniformity criteria within the planned target volume were defined according to the International Commission on Ra diation Units and Measurements Report 50 (7). The clinical target volume encompassed the larynx with no attempt to irradiate the regional lymphatics. Patients assigned to TLS had the tumor excised under general anesthesia within 6 weeks from randomization by Randomization Treatments

Patients with early glottal carcinoma are usually treated with either radiation therapy or transoral laser surgery (TLS). The choice between these treatments is controver sial, and treatment may vary by geographic region (1). The current evidence is insufficient to guide management decisions (2), and a recent systematic review and meta analysis failed to identify a single randomized study comparing TLS with radiation therapy (1). The meta analysis suggested that a higher larynx preservation rate can be achieved with TLS, but owing to the generally poor quality of the evidence, this result was considered inconclusive. The relative merits of TLS and radiation therapy for local cancer control, the functional outcomes including voice quality, and laryngeal preservation remain unknown. Inasmuch as most (85%-95%) laryngeal carcinomas limited to 1 vocal cord are cured either by TLS or by radiation therapy (3, 4), a key objective of treatment beyond recovery is maintaining good voice quality. We compared in the present randomized study the effects of TLS and external beam radiation therapy on quality of voice in a patient population with early glottal carcinoma limited to 1 vocal cord.

Methods and Materials

Design

The purpose of this randomized, multicenter, parallel-group study was to compare TLS with external beam radiation therapy as the primary treatment for early glottal carcinoma limited to 1 vocal cord. The primary endpoint was voice quality 2 years after treatment.

Setting

Given that the outcome of laser surgery, in particular, may depend on the operator’s skills, the study took place in large referral hospitals. The 3 largest university hospitals in Finland participated.