ESTRO 36 Abstract Book

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S568 ESTRO 36 2017
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cancer.
EP-1035 Dose-volume analysis of the hypoglossal
nerve and its correlation with Dysarthria-Dysphagia
Syndrome
F. Chen1, R. Rer 2
1 Chenzhou No.1 People's hospital, radiation oncology,
chenzhou, China
2 Yee-Ren Hospital, Radiation Oncology, taibei, Chinese
Taipei
Purpose or Objective
Cranial nerve palsy is a radiotherapy-related late toxicity
in nasopharyngeal cancer patients after radiotherapy, and
the glossopharyngeal, vagus and hypoglossasl nerve are
the most commonly damaged, causing speech and
swallowing handicap. Damage to the larynx or pharyngeal
constrictor muscles have been mentioned as the cause of
swallowing disorder in head & neck cancer patients after
radiotherapy. We hypothesize that direct radiation
damage to the nerve is the etiology of hypoglossal palsy
and the subsequent dysarthria-dysphagia syndrome. This
study aims to test our hypothesis using dosimetric data.
Material and Methods
Twelve Nasopharyngeal Cancer Patients were enrolled in
this study, with three patients for each stage. They all
received IMRT technique. We gave 70 Gy to the
nasopharynx and positive neck lymph node, 60 Gy to the
high-risk neck and 50 Gy to the low-risk neck. We
contoured the larynx and the constrictor muscles including
superior, middle, inferior, cricopharyngeus, and the
proximal esophagus. Hypoglossal nerve was also
delineated and divided into cisternal, intracanalicular,
carotid, horizontal, and lingual part. The Maximal Dose,
Minimal Dose, Mean Dose, V50, V55, V60, V65 and
V70 were derived using Varian Eclipse planning system,
respectively.
Results
Of the constrictor muscle, the superior always had the
highest dose in all stages. V65 of the superior constrictor
muscle was 60%±15%, 100%±20%, 100%±21.6% and
78.4%±14.3% for stage I, II, III & IV, respectively. V60 of
the larynx was 2.75%±0.65%, 11.7%±0.3%，1 2.3%±0.6%，
15.2%±1.8% for stage I, II, III & IV, respectively. For
hypoglossal nerve, the intracanalicular and the carotid
segment had the highest dose. V65 of the intracanalicular
segment were 43%±12.5%, 42%±6.2%, 48%±22% and
80%±14%, for stage I, II, III, and IV, respectively. It
was 53%±12.5%,81%±2%,82%±7% and 86%±14%, for the
carotid segment.
Conclusion
Hypoglossal nerve palsy and the subsequent Dysarthria-
Dysphagia Syndrome in nasopharyngeal cancer
patients may be related to the high dose of the carotid
segment of the hypoglossal nerve. Constrictor muscle and
larynx are less likely to be the underlying
etiology according to dose-volume data.
EP-1036 18F-FDG-PET in Guiding Dose-painting with
IMRT in Oropharyngeal Tumours (FiGaRO) – Swallow
Results
C. Doughty1, J. Dunton 1, A. Michaelidou 2, M. Lei 2, T.
Guerrero Urbano2
1 Guy's and St.Thomas' Hospital NHS Foundation Trust,
Speech and Language Therapy, LONDON, United Kingdom
2 Guy's and St.Thomas' Hospital NHS Foundation Trust,
Radiotherapy, LONDON, United Kingdom
Purpose or Objective
The FiGaRO trial is a Phase 1 multicentre study that aims
to determine the feasibility and safety of 18 F-FDG-PET/CT
dose-painted IMRT in locally advanced oropharyngeal SCC.
Dose escalation strategies are explored, with target
volume definition and toxicity being the main challenges.
It is well recognised that swallowing dysfunction is a
significant determinant of long term quality of life. We
present early swallow outcomes in the first 15 patients.
Material and Methods
Patients with ≥T2, HPV-negative or high-risk HPV-positive
disease, suitable for radical treatment with neo-adjuvant
chemotherapy and chemo-IMRT, are eligible. Swallow
measures are taken at 3 time points: at baseline, at 3 and
12 months post treatment. The Performance Status Scale
- Normalcy of Diet subset (PSS – NoD) is based on the
patient’s reported current diet. The Penetration-
Aspiration scale (PAS) is scored from presentation on
videofluoroscopy (VF).
Results
Fifteen patients (14-male, 1-female; mean age-61, range
49-71) were treated April’14-March’16, across two centres
(median follow-up 10 months, range 4-26 months.
All patients had a baseline assessment:
On the PSS - NoD 73% (n=11) scored 100 (full diet, no
restrictions), 27% (n=4) scored 50 (soft chewable foods).
On the PAS 60% (n=9) scored 1 (material does not enter
the airway), 27% (n=4) scored 2 (material enters the
airway, remains above the vocal folds and is ejected from
the airway), 13% (n=2) scored 8 (material enters the
airway, passes below the vocal folds and no effort is made
to eject).
Fourteen patients were assessed at 3 months post-
treatment (one declined):
On the PSS - NoD 14% (n=2) scored 100 (full diet, no
restrictions), 50% (n=7) scored 50 (soft chewable foods),
21% (n=3) scored 40 (soft foods requiring no chewing), 7%
(n=1) scored 30 (pureed foods) and 7% (n=1) scored 20
(warm and cold liquids).
On the PAS 7% (n=1) scored 1 (Material does not enter the
airway), 14% (n=2) scored 2 (Material enters the airway,
remains above the vocal folds and is ejected from the
airway), 7% (n=1) scored 6 (Material enters the airway,
passes below the vocal folds and is ejected into the larynx
or out of the airway, 7% (n=1) scored 7 (Material enters
the airway, passes below the vocal folds and is not ejected
from the trachea despite effort) 64% (n=9) scored 8
(Material enters the airway, passes below the vocal folds
and no effort is made to eject).
No patient was nil oral at 3 month follow – up and no
patient reported a history of chest infections.
Conclusion
VF assessment of swallow following PET/CT-guided
selective dose escalation demonstrates deterioration of
swallow status at 3 months. However, clinical significance
is yet to be determined. 12 month post-treatment swallow
measures are currently being taken.
EP-1037 Chronic radiation-associated dysphagia (RAD)
after curative reirradiation in head and neck cancer
L. Gutierrez Bayard1, M. Salas Buzón1, E. Porras Alonso2,
S. Garduño Sánchez1, M. Macias1, L. Ingunza Barón1, E.
Gonzalez Calvo1, I. Villanego Beltran1, V. Diaz Diaz1
1Hospital Universitario Puerta del Mar, Radiation
Oncology, Cadiz, Spain
2Hospital Universitario Puerto Real, Otorrinilaringology,
Puerto Real, Spain
Purpose or Objective
Chronic radiation-associated dysphagia (RAD) is a complex
toxicity. The Total Dysphagia Risk Score (TDRS) was
developed to predict which patients are most at risk to
develop grade ≥ 2 dysphagia at 6 months following
radiotherapy (RT). The mylo/geniohyoid complex (MHM)
V69 ( the volume receiving ≥69 Gy), , and superior
constrictor muscle (SPC V70), especially in older patients
(>62-years), were associated with chronic-RAD.Acute
during the course of RT are strong prognostic factors for
late dysphagia. There is no effective treatment to reverse
chronic-RAD in longterm survivors; and intensive and
costly therapies are required for incremental gains in
functionality.