ESTRO 2023 - Abstract Book

S949

Digital Posters

ESTRO 2023

Purpose or Objective The functional outcome after treatment for hypopharyngeal cancer is strongly related to patients’ quality of life and prognosis. The purpose of this study is to identify predictive factors for laryngo-esophageal function preservation in patients with hypopharyngeal cancer treated with definitive radiotherapy. Materials and Methods Patients with hypopharyngeal squamous cell carcinoma treated with curative-intent intensity-modulated radiation therapy (IMRT) between 2007 and 2019 at our institution were retrospectively reviewed. Laryngo-esophageal dysfunction-free survival (LDFS) and overall survival (OS) rates were estimated using Kaplan-Meier method. LDFS was measured from the initiation of radiation therapy until the date of local recurrence, laryngo-esophageal dysfunction (defined by tracheostomy or feeding tube dependence) or death from any cause, whichever occurred first. Possible predictive factors of LDFS were explored in the univariable and multivariable analyses using the Cox proportional hazards model. Results A total of 80 patients were included in the study. Seventy-two patients were male and 8 were female, and their median age was 69 years old (range: 40-84). Concurrent and/or induction chemotherapy was delivered in 65 and 37 patients, respectively. With a median follow-up period of 58 months, the 5-year rates for LDFS and OS were 48% and 60%, respectively. The events for LDFS were observed in 49 (61%) patients, including 23 local recurrences, 10 dysfunctions and 16 deaths. The univariable analysis showed that cT4-category (hazard ratio [HR]= 3.16; 95% CI [confidence interval]: 1.65-6.05; p<0.001) and lower pretreatment prognostic nutritional index (PNI; calculated as 10 × serum albumin [g/dL] + 0.005 × peripheral lymphocyte count [/mm3]) taking the cut-off value as <48 (HR= 2.18; 95% CI: 1.22-3.89; p=0.009) were significantly associated with lower LDFS. Smoking/alcohol history, age, comorbidities, body mass index and cN-category were not significantly associated with LDFS. On multivariable analysis, cT4-category (HR= 2.79; 95% CI: 1.44-5.41; p=0.002) and lower PNI (HR= 1.95; 95% CI: 1.08-3.51; p=0.027) remained as independent predictors for lower LDFS.

Conclusion Advanced primary tumor stages and lower pretreatment PNI were identified as predictors for poor laryngo-esophageal functional outcome after definitive radiotherapy for hypopharyngeal cancer.

PO-1187 Patterns of failure and clinical outcomes following adjuvant radiotherapy in oral tongue cancer.

K. Ratanchandani 1 , N. Bathija 1 , S. Rath 1

1 The Gujarat Cancer and Research Institute, Radiation Oncology, Ahmedabad, India

Purpose or Objective Surgery is often the treatment of choice for oral cavity squamous cell carcinoma (OCSCC). Post operative radiotherapy (RT) is indicated for advanced stage OCSCC or with adverse prognostic factors. Intensity modulated radiotherapy (IMRT) is a conformal technique with improved target coverage and normal tissue sparing, but it may cause marginal failures Materials and Methods Total 2400 patients of head and neck cancer were identified from the hospital data from July 2016 to June 2021, out of which 127 patients of oral tongue cancer were included in this retrospective study. Patients who received neoadjuvant chemotherapy or failed to complete radiation or lost to follow up were excluded. Surgery included wide local excision (WLE) or hemiglossectomy (HG) with ipsilateral and/or contralateral neck dissection. Pathological findings like tumor of pT3 or more, positive nodes, close margins, positive lymphovascular Invasion (LVI), positive perineural invasion (PNI), depth of invasion (DOI) of >4mm were considered as risk factors for locoregional recurrence. Patients with any of the above factors were irradiated with IMRT using 6 MV photons to a dose of 60 Gy (range-54 to 66 Gy) using 1.8-2 Gy dose per fraction,