ESTRO 2024 - Abstract Book

S2252

Clinical - Upper GI

ESTRO 2024

In this prospective study, the use of CPAP was associated with significant volumetric and dosimetric benefits in liver tumor patients receiving RT. The effectiveness and safety of CPAP have been demonstrated and should be evaluated further.

Keywords: Liver Cancer, CPAP, Radiation Therapy

2490

Digital Poster

Clinical outcomes of photon and proton beam therapy for cT4 esophageal cancer in a multicenter study

Yuichi Hiroshima 1,2 , Toshiki Ishida 1 , Hazuki Nitta 1 , Den Fujioka 1 , Hikaru Niitsu 1 , Motohiro Murakami 1 , Reiko Kanuma 2 , Masashi Mizumoto 1 , Toshiyuki Okumura 2 , Hideyuki Sakurai 1 1 University of Tsukuba, Radiation Oncology, Tsukuba, Japan. 2 Ibaraki Prefectural Central Hospital, Ibaraki Cancer Center, Radiation Oncology, Kasama, Japan

Purpose/Objective:

To evaluate the outcomes and toxicity of photon radiotherapy (RT) and proton beam therapy (PBT) for locally advanced esophageal cancer (LAEC) of clinical T stage (cT) 4.

Material/Methods:

From 2015 to 2022, 57 patients with cT4a and cT4b, evaluated by UICC 8th, LAEC patients who underwent radical radiotherapy were included. Fifty men were included, with a median age at the start of treatment of 67 and a range of 44-87. The number of cT4a/ cT4b cases was 12/ 45, respectively. The most common reason for cT4b was tracheal invasion. The pathology was squamous cell carcinoma in all but one patient. Concurrent chemoradiotherapy was performed in 54 patients. Thirty-four patients were treated with RT, 14 with PBT, and 9 with a combination.

Results:

All patients completed treatment as scheduled. Median follow-up was 14.2 months for all and 24.1 months for survivors only. Median/ 1-year/ 2-years/ 3-years of overall survival (OS), progression free survival (PFS), and local control rate were 18.5 months/ 63.7%/ 44.9%/ 35.0%, 13.4 months/ 50.5%/ 39.3%/ 32.1%, and 89.9 months/ 84.1%/ 84.1%/ 77.6%, respectively. When prognostic factors were evaluated, cT stage was significant for OS and PFS (p=0.041 and 0.040, respectively), and concurrent chemoradiotherapy was significant for PFS (p=0.041). By site, cervical esophageal cancer was significantly better for OS and PFS (p=0.046 and 0.019, respectively). No significant differences in dose escalation or RT/ PBT differences were found. Adverse events of Grade 3 or higher during follow-up included esophageal fistula in 12 patients. No other Grade 3 or higher non-hematologic toxicity was observed.