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RT history (n=2). We retrospectively reviewed records of
80 patients about clinical stage, pathologic
characteristics, performing surgery or chemotherapy, aim
of radiotherapy, radiation dose and technique, and
clinical outcomes such as local recurrence, overall survival
according to radiation groups. We analyzed prognostic
factors of adjuvant RT such as stage, extent of surgery,
resection margin, radiation dose, and chemotherapy. We
also reviewed treatment related complication using
CTCAE criteria version 4.0. All analyses were performed
using SPSS, version 22.
Results
Median age at diagnosis was 51 years (21-82 years). Most
common sites were salivary glands (n=35, 43.8%), oral
cavity (n=14, 17.5%), and paranasal sinuses (n=12, 15.0%).
Half of patients (n=41, 51.3%) had a locally advanced
tumor at diagnosis (T3 : n=11, 13.8%), T4 : n=30, 37.5%).
Sixty-nine patients underwent surgery. Detailed patient's
characteristics according to RT aim were in table. Sixty-
nine (86.2%) patients underwent adjuvant radiotherapy
and 11 patients (13.8%) underwent definitive
radiotherapy. Radiation dose were 50.4 – 76 Gy per 24-42
fx (median 64.8 Gy). With median follow-up of 114.3
months (9.7 – 236.3 months), local tumor progression was
found in 21 patients (26.3%). 5 year overall surviva (OS)l
rate was 82.4-91.4% in adjuvant arm and 72.7% in
definitive arm. 5 year local recurrence free survival (LRFS)
rate was 74.1-97.1 % in adjuvant arm, and 48.5% in
definitive arm. Survival curves following treatment arms
and stage were in graph. All patients tolerated the
radiotherapy well.
Conclusion
Adjuvant radiotherapy to head and neck ACC seemed
better clinical outcomes compared with definitive
radiotherapy. However, in this report, all patients who
received definitive radiation therapy were advanced stage
(stage III :1, stage IV :10). Considering stage, 72.7% of
5YOS rate and 48.5% of 5YLRFS rate in definitive
radiotherapy arm were not inferior results.
Therefore definitive radiotherapy may be considered
alternative treatment modality in patients with
inoperable adenoid cystic carcinoma of head and neck.
EP-1068 Hypoxic imaging obtained at 2-h
postinjection in FMISO-PET
M. Kawamura
1
, M. Yoshimura
1
, T. Katagiri
1
, T.
Mitsuyoshi
1
, H. Inokuchi
2
, T. Ishimori
3
, Y. Nakamoto
3
, T.
Mizowaki
1
, M. Hiraoka
2
1
Kyoto University- Graduate School of Medicine,
Radiation Oncology and Image-Applied Therapy, Kyoto,
Japan
2
Japanese Red Cross Wakayama Medical Center,
Radiation Oncology, Wakayama, Japan
3
Kyoto University- Graduate School of Medicine,
Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan
Purpose or Objective
Positron emission tomography (PET) / computed
tomography (CT) using 18F-fluoromisonidazole (FMISO) has
been used as an imaging tool for tumor hypoxia. It has
been reported that several quantitative values in FMISO-
PET at 4-h postinjection were reproducible. However, it is
controversial whether they are reproducible when
scanning is performed in earlier time, e.g. 2-h
postinjection. If quantitative values at 2-h postinjection
are equivalent with those at 4-h postinjection, the total
examination time in FMISO-PET can be shortened. The
purpose of this study was to investigate the difference of
quantitative values in FMISO-PET at 2-h and 4-h
postinjection in patients with head and neck cancer.
Material and Methods
A total of 10 patients with untreated locally-advanced
head and neck cancer who underwent FMISO-PET/CT scan
from August 2015 to October 2016 in our institute were
analyzed. Image acquisition was performed twice, 2-h and
4-h after administration of FMISO using a combined
PET/CT scanner (Discovery IQ, GE Healthcare). After
taking a region of interest in a primary tumor, the
maximum standardized uptake value (SUVmax), SUVmean,
SUVpeak, tumor-to-blood ratio (TBR), tumor-to-muscle
ratio (TMR), metabolic tumor volume (MTV) and total
lesion hypoxia (TLH) were measured. We evaluated the
Spearman's rank correlation coefficients of these
quantitative values, and also calculated the percent
difference defined as difference between the two values
divided by average of two values.
Results
SUVmax (mean±SD) at 2-h and at 4-h were 2.4±0.8, and
2.6±1.0, respectively, in this population. The Spearman's
rank correlation coefficients of SUVmax, SUVmean,
SUVpeak, TBR, TMR, MTV, and TLH were 0.97, 0.97, 0.97,
0.93, 0.93, 0.95, and 0.95, respectively. The percent
differences (mean±SD) of these values were 8.3±5.6%,
6.8±6.3%, 4.1±5.1%, 16.8±12.5%, 17.1±9.1%, 42.7±52.7%,
and 41.7±58.1%, respectively. Quantitative values were
highly correlated between the two scans; however, there
were two cases in which %differences of MTV and TLH
exceeded 50%, i.e. 62.1% and 166.7% in MTV and 57.1% and
180.0% in
TLH.
Conclusion
Our preliminary data demonstrate that quantitative values
at 2-h and 4-h were highly reproducible. In a few patients,
volumetric parameters had moderate percent difference,