ICHNO-ECHNO 2022 - Abstract Book

S57

ICHNO-ECHNO 2022

mg every 2-week for 4 total administrations. Follow-up after last avelumab dose is performed monthly and adverse event data are collected at every visit. After 6 months, surgery and LOH re-assessment are performed. Results From November 2020 to August 2021 , 14 pts were screened. Of these, 5 pts had a LOH, 4 only on the chromosome 9p21 and the other one in both 9p21 and 3p14. Four pts completed the 4 avelumab administrations. Three out of 4 pts are females, and the median age is 67 years (range: 57-76). All pts treated had previous oral cancer. After a median follow up of 4.5 months, twenty-eight adverse events (AE) of any grade were reported, of these 10 were considered as immune related AEs (irAE). The most frequent was grade 1 (G1) oral pain (3/4 pts), disease related and managed with local painkillers. Only two G2 irAEs were reported, namely amylase/lipase increase and psoriasis. No grade 3-4 AEs and were described, and no patient had to stop immunotherapy because of toxicities. During the clinical follow-up also comprising narrow-band imaging, no pts experienced signs or symptoms of disease progression. Conclusion In pts with OPMD, immunotherapy with avelumab was safe and did not compromise surgery performed 6 months after treatment start. Trial Registration Number and Date of Registration ClinicalTrials.gov: NCT04504552, August 2020. Supported by AIRC grant nr 21740 to PB 1 San Giuseppe Moscati Hospital , Radiation Oncology Unit, Taranto, Italy; 2 San Giuseppe Moscati Hospital , Otorhinonolaryngoiatry Unit , Taranto, Italy; 3 San Giuseppe Moscati Hospital, Physic Unit , Taranto, Italy; 4 San Giuseppe Moscati Hospital, Radiation Oncology Unit, Taranto, Italy Purpose or Objective The use of IMRT in early glottic cancers is still a big concern and the use of simultaneous integrated boost (SIB) with moderately hypofractionation is an unconventional modality. This retrospective study was carried out to evaluate the influence of SIB with moderately hypofractionation on acute and late toxicity in T1-T2 N0 laryngeal glottic cancers. Materials and Methods Between 2015-2021, 45 patients (pts) with T1 and T2 N0 laryngeal squamous carcinoma proven cancers were treated with definitive radiotherapy (RT). Enodoscopic evaluation, MRI and PET imaging were mandatory for planning. Swallowing assessment and thyroid functions tests were also included. Definitive SIB RT within 30 fractions (frs) was applied with VMAT in 30 pts and Helical Tomotherapy in 15 pts. PTV1 consisted of the uninvolved larynx (CTV1) with a margin of 5 mm. GTV was the T glottic cancer as on endoscopy description and MRI and PET images fusion. An isotropic margin of 2-4 mm depending on the stage was provided to obtain PTV2. PTV1 received 60 Gy, 2 Gy/frs. SIB 66 Gy with 2.2 Gy/frs was delivered to PTV2. Dose coverages, HI and CI were in agreement with ICRU 83. As organ at risk (OARs) carotid arteries, thyroid, middle and inferior pharyngeal constrictors muscles and spinal cord were identified. The minimum, mean and maximum dose values for PTV, mean and maximum dose values for OAR, % of volume of PTV receiving at least 95% of the prescription dose were reported. Toxicity was scored according CTCAE ver. 4. Swallowing assessments with flexibile endoscopic one week before RT and one week, 3-6 months after RT were carried out with a 0-3 score ( no impairment – impairment in liquid, semisolid and solid colored food). Results For the majority of pts 100% of the prescription doses encompassed ≥ 95% of the PTVs. The average mean dose to carotid arteries was 40 Gy (25-50 Gy), while the average mean doses to thyroid was 30 Gy (20-41 Gy); the average maximum dose to spinal cord was 25 Gy (22-38). For pharyngeal conscrictors muscles the average mean dose was 43 Gy (40- 45 Gy). These constraints impacted on acute and late toxicity. No acute toxicity greater than grade 2 including mucositis and dermatitis was observed in all cases. Grade 2 acute dysphagia occurred in 15 pts (33 %) in the last week of treatment with a score 3 in solid swallowing tests recorded one week after the end of RT. The median follow-up time was 30 months (ranging from 4 to 45 months). No chronic dysphagia greater than 1 was observed. Score 0-1 in semisolid and solid swallowing tests was complained in 10 patients. No glottic stenosis was recorded. Impairment of thyroid tests was observed in 5 female pts. Conclusion Moderately hyprofractionated SIB definitve radiotherapy seems to offer a good dosimetry and a low rate and grade toxicity with fewer treatment sections. PO-0097 Hypofractionated SIB in VMAT and Tomotherapy for early glottic cancer: dosimetry and toxicity data. G. Lazzari 1 , M.A. De Cillis 2 , E. Verdolino 3 , G. Silvano 4

Poster: Minimal invasive and reconstructive surgery

PO-0098 Efficacy and safety of Thunderbeat energy-based device in harvesting pectoralis major flap

G. Halmos 1 , N. Kuipers 1 , J. Wedman 1 , B. van der Laan 2 , B. Plaat 1

1 University Medical Center Groningen, University of Groningen, Department of Otolaryngology, Head and Neck Surgery, Groningen, The Netherlands; 2 Haaglanden Medical Center, Department of Otolaryngology, Head and Neck Surgery, The Hague, The Netherlands