6th ICHNO Abstract Book

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6th ICHNO page 31
6th ICHNO Conference
International Conference on innovative approaches in Head and Neck Oncology
16 – 18 March 2017
Barcelona, Spain
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2VA Long Beach Healthcare System, Radiation Oncology,
Long Beach, USA
3VA Greater Los Angeles Healthcare System, Radiation
Oncology, Los Angeles, USA
Purpose or Objective
Post-laryngectomy stomal recurrence of head & neck
cancer may result from underdosage due to the well-
known skin-sparing effect of photon irradiation, even via
modern Volumetric Modulated Arc Therapy (VMAT)
technique. We aim to verify the VMAT dose coverage and
evaluate the dose-compensatory effect of bolus
placement by (1) using a physics phantom study and (2)
comparing the dose distributions of conventional anterior-
to-posterior (AP) and VMAT plans in real-case clinical
application.
Material and Methods
(1) Radiation dose distribution for post-laryngectomy
stoma was planned using a physics phantom made of
tissue-equivalent solid with a cylindrical hole opening
emulating the tracheal stoma. A tracheostomy tube
obturator was inserted and 5-mm thick bolus material was
used as tissue compensator. Small pieces of bolus cuts
were custom-made to reduce the air gaps between the
mechanical device and skin surface. Thermoluminescent
dosimetry (TLD) was used to verify the dose predicted by
a commercial treatment planning system (TPS) on the
stoma lumen and the peri-stoma skin. Three VMAT plans
were generated using 6MV photon beams: no bolus, bolus
with and without air gap compensation.
(2) A set of CT-simulation images for post-laryngectomy
case was used for meticulous contouring of the catheter
cuff, stoma lumen, peri-stoma skin and subclinical tumor
bed around the primary site. The resulting dosimetry plans
were analyzed with or without bolus placement. Wet
gauze was used to minimize the effect of any air gap. Four
plans were generated: AP superclavicular (SCV) plan with
or without bolus, and VMAT plan with or without bolus. A
dose of 60Gy in 30 fractions was prescribed at 3 cm depth
for AP SCV plan, and to 95% of the PTV volume for VMAT
plan.
Results
(1) The phantom study shows the dose difference between
TPS calculations and TLD measurements for VMAT to be
within 5%. The TLD result inside the stoma lumen differs
by <1% with vs. without bolus placement. The TLD under
the bolus on the peri-stoma skin receives full prescription
dose, while it is 20% less without bolus.
(2) The peri-stoma skin dose is sensitive to bolus
placement for the AP SCV plans (V95% of 20.7%, 33.0% and
94.8% for no bolus, bolus without and with air gap
compensation, respectively). The dose drops off rapidly in
depth for the stoma lumen. The dose distributions of the
two VMAT plans are moderately different for peri-stoma
skin (V95% of 95.0% with bolus and air gap compensation,
and 82.3% without bolus), but nearly identical for stoma
lumen (V95% of 91.5% and 92.0%, respectively).
Conclusion
The TPS dosimetric results are verified to be in agreement
with TLD measurements by the physics phantom study.
The clinical case analysis shows that the dose coverage
around the stoma in the VMAT plan is better than the
conventional AP SCV plan. For VMAT, it is still
recommended to place physical bolus and reduce the air
gaps in order to achieve optimal dose distribution.
PO-062 Retrospective analysis of 72 patients treated
with FEP regimen and CCRT for locally advanced NPC.
A. Ouhajjou1, Z. Fadoukhair1, H. Faouzi 1
1Oncology Center Alazhar, oncology, Rabat, Morocco
Purpose or Objective
The role of neoadjuvant chemotherapy (CT) followed by
concurrent chemo-radiotherapy is a matter of interest in
nasopharyngeal carcinoma. Several clinical phase III trials
have proved that induction chemotherapy based on three-
drugs, may significantly improve treatment outcomes in
patients with squamous cell carcinoma of the head and
neck. We conducted this study to evaluate the experience
of induction chemotherapy using modified increased doses
FEP regimen (mid FEP) (Epirubicin, Cisplatin, 5-FU, and
Leucovorin) followed by concurrent chemoradiation for
nasopharyngeal carcinoma (NPC).
Material and Methods
Between August 1994 and December 2009, 72 patients
with pathological proven nonmetastatic NPC were
enrolled. Ninty five percent of patients were locally
advanced (IIB – IVB). Patients were first treated with 3
cycles of induction chemotherapy with increased doses
FEP regimen (mid FEP) based on 5-FU 500 mg/m2 d1-4,
Leucovorin 200mg/m2 d1-4, Epirubicin 35mg/m2 d1-2,
Cisplatin 25mg/m2 d1-4 every 3 weeks, associated to
Granulocyte colony-stimulating factor (G-CSF). After
induction chemotherapy, weekly cisplatin was
administered concurrently with radiation. Radiation
consisted of 65-70 Gy to the planning target volumes of
the primary tumor and 45 -60 Gy to any positive nodal
disease using 1,8 Gy per fraction.
Results
Median follow-up of 96 months. After completion of
induction CT, 46 evaluable patients (35%) achieved
complete clinical response in regional nodes and
nasopharynx. After completion of the whole treatment,
small residual tumors were noted either at the primary
site and / or neck in 26 % of patients. The complete
response rate of the nodal area and primary location was
72 %. Residual tumors all showed complete regression
upon follow-up after 3 months. The estimated 5-year PFS
was 78%. The 5-year OS was 80 % and the estimated 8-year
PFS was 67%. The 8-year OS was 73 %. The main grade 3 to
4 (G3/G4) adverse events during neoadjuvant
chemotherapy were hematological but manageable.
Conclusion
Induction chemotherapy using modified increased doses
FEP regimen (mid FEP) (Epirubicin, Cisplatin, 5-FU, and
Leucovorin) followed by concurrent chemoradiation for
locoregionally advanced NPC is feasible and effective in
regard to locoregional control and distant metastasis with
high compliance. A long-term follow-up study is needed to
confirm these preliminary findings.
PO-063 Waiting time and fast track model for head and
neck cancer patients in Finland
H. Irjala1, E. Halme2, A. Makitie3, T. Atula3, P. Koivunen4
1Turku University Hospital, Department of
Otorhinolaryngology and Head and Neck Surgery, Turku,
Finland
2Tampere University Hospital, Otorhinolaryngology -
Head and Neck Surgery, Tampere, Finland
3Helsinki University Hospital, Otorhinolaryngology - Head
and Neck Surgery, Helsinki, Finland
4Oulu University Hospital, Department of
Otorhinolaryngology - Head and Neck Surgery, Oulu,
Finland
Purpose or Objective
Waiting time from referral to treatment has an effect on
cancer patients’ prognoses and in addition waiting can be