Local control of T₁ vocal cord cancer with radiation therapy: The importance of tumor character VS. Treatment parameters

Abstract

Ninety-one patients with T1 vocal cord carcinoma received primary irradiation treatment. The 5- and 10-year determinate disease-free survival was 80%; the 5- and 10-year determinate survival including surgical salvage was 92%. Tumors involving more than one-half of a vocal cord or involving the anterior commissure or exhibiting an exophytic growth pattern had numerically, but not statistically, higher local failure rates than tumors without these characteristics. Precise radiation treatment technique appears more important for local control (LC) than tumor character. The crucial treatment factors for high LC with few radiation complications are reproducible daily patient positioning, use of contour-compensating devices (wedges), field size of 5 X 5 cm, and a radiation prescription with a time-dose fractionation value of 101 to 106.

Prognostic Value of Malignancy Grading and DNA Measurements in Small Glottic Carcinomas

“…However, other features, such as the local extent with anterior commissure involve ment may be of greater prognostic signifi cance. According to Hintz et al [ 1983] accu rate radiation treatment is more important for local control than the tumor character of small glottic carcinomas.…”

American college of radiology appropriateness criteria® treatment of stage I T1 glottic cancer

“…Some series suggest inferior local control when larger field sizes are used (although many included patients with T2 disease, perhaps demanding a larger field and expected to manifest inferior control) . Others report better local control with a field size >5 cm × 5 cm, or no impact of field size on local control, or excellent outcomes with smaller field sizes . In a randomized controlled trial for patients with T1 disease, subjects were treated with either a 5 cm × 5 cm or 6 cm × 6 cm field.…”

Primary Radiotherapy of Tl and T2 Glottic Carcinoma: Analysis of treatment results and prognostic factors in 223 patients

“…Optimal treatment demands tumour control and preservation of laryngeal function. Radiotherapy offers the possibility of preservation of voice quality and local control rates between 80% to 95% and 65% to 85% for T1 and T2 tumours respectively (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Factors related to tumour (6, 7, 10, 1 I, 13, 15, 19-21, 23), patient (15,21,23) and treatment (12, 14, 16-18, 22, 24-27), explaining the heterogeneity in treatment outcome, have been searched for, especially among T2 tumours.…”