Main Session

Sep 29

PQA 07 - Head and Neck Cancer, Lung Cancer/Thoracic Malignancies, and Nursing and Supportive Care

3560 - Twice Daily, Four Days a Week: Single-Institution Outcomes of Accelerated RT 60 Gy/30 for T1 Glottic Cancer with/without Weekly Docetaxel

03:45pm - 05:00pm ET

Poster Hall - Exhibit Hall A

Screen: 1

POSTER

Presenter(s)

Hideki Minatogawa, MD, PhD - Japanese Red Cross Kitami Hospita , Kitami, Hokkaido

H. Minatogawa¹, A. Yamazaki², Y. Fujita³, T. Wada⁴, Y. Ishida⁴, and K. Ochi⁵; ¹Department of Radiology,Japanese Red Cross Kitami Hospita, Kitami, Japan, ²Department of Radiology,Japanese Red Cross Kitami Hospita, kitami, Japan, ³Department of Radiation Oncology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan, ⁴Department of Otolaryngology - Head and Neck Surgery,Japanese Red Cross Kitami Hospita, kitami, Japan, ⁵Department of Radiological Technology, Division of Medical Technology, Japanese Red Cross Kitami Hospita, kitami, Japan

Purpose/Objective(s):

We hypothesized that an accelerated twice-daily (BID) radiotherapy regimen (60 Gy in 30 fractions, 4 days/week) achieves high local control (LC) with minimal late laryngeal toxicity in early glottic cancer by shortening the overall treatment time (OTT) to counteract tumor repopulation. Additionally, we explored the outcomes and safety of this regimen with or without concurrent low-dose docetaxel.

Materials/Methods:

We retrospectively analyzed patients with T1a–T1bN0M0 glottic cancer treated at our institution between 2010 and 2024. All patients received BID radiotherapy (60 Gy/30 fractions, 4 days/week; inter-fraction interval =6 hours). Weekly docetaxel (20 mg/body) was administered at the physician's discretion. The primary endpoint was LC, with events defined as persistent or recurrent disease. Secondary endpoints included OS, laryngeal preservation, major late laryngeal events, and acute pharyngeal mucositis assessed by toxicity grade and analgesic requirements. OS was estimated using the Kaplan–Meier method, while LC and laryngeal preservation were estimated using cumulative incidence functions to account for competing risks.

Results:

Thirty-one patients were included (T1a/T1b = 20/11). Median age was 73 years (IQR, 68–80). Concurrent docetaxel was administered to 20 patients (64.5%) with a median of 4 cycles (IQR, 4–5). Median OTT was 28 days (IQR, 27–28). With a median follow-up of 4.7 years (95% CI, 4.2–7.1), no local failures were observed among 28 evaluable patients who achieved complete response; 2- and 5-year LC rates were both 100%. The 5-year OS was 86.0%. No major late laryngeal events occurred. Acute mucositis was Grade 1 in 5 and Grade 2 in 26 patients. Strong opioids were required by 6 patients (19.4%), and all patients completed the planned radiotherapy.

Conclusion:

Accelerated BID radiotherapy (60 Gy/30 fractions, 4 days/week) provides excellent local control and a favorable toxicity profile for T1 glottic cancer. These results support this regimen as a feasible curative approach. Given the 100% LC rate observed, the additional benefit of concurrent docetaxel remains exploratory and warrants further investigation to clarify its specific role.

Table 1: Patient Characteristics, Treatment, and Toxicities (N=31)

Category	Subcategory	Data
1.Age	Median(IQR)	73 (68–80)
2.T-Stage	T1a:T1b	20:11
3.Docetaxel	Concurrent Use	20 (64.5%)
4.Treatment Duration	Median OTT,days(IQR)	28 (27–28)
5.Local Control	2-year and 5-year LC	100%
6.Overall Survival	5-year OS	86.0%
7.Acute Mucositis	Grade 1/Grade 2	5/ 26
8.Analgesics:None/NSIADs	Patients(n)	7/16
9.Anagesics:Opioids	Weak/Strong	2/6
10.Late Toxicity	Major late events	0