IMRT or Brachytherapy boost in oropharyngeal malignancies: A Randomized, open label study
OC-0023
Abstract
IMRT or Brachytherapy boost in oropharyngeal malignancies: A Randomized, open label study
Authors: Vibhay Pareek1, Rajendra Bhalavat2, Manish Chandra2, Lalitha Nellore2, Karishma George2, Dipalee Borade2
1National Cancer Institute, AIIMS, Radiation Oncology, New Delhi, India; 2Jupiter Lifelines Hospital, Radiation Oncology, Thane, India
Show Affiliations
Hide Affiliations
Purpose or Objective
Radical radiation therapy in oropharyngeal malignancies have a significant toxicity especially in relation to dose to
dysphagia aspiration related structures (DARS), mucositis and aspiration
which leads to prolonged overall treatment times, thereby, having an
impact on survival outcomes. Interstitial Brachytherapy (ISBT) has significant role in reducing these toxicities, however, literature comparing
Intensity modulated radiation therapy (IMRT) with Brachytherapy boost is
lacking. Our study looks in to the clinical outcomes and toxicity profile
while comparing the two treatment modalities.
Material and Methods
A total of 70 patients diagnosed histopathologically
as squamous carcinoma of oropharynx were randomized to receive radical
radiation therapy with IMRT (nZ35) or IMRT with ISBT boost (nZ35).
The total dose with IMRT was 70Gy and in ISBT, initial dose was 50Gy
with IMRT followed by 24.5Gy dose (3.5Gy in 12 fractions). Patients were
followed up as per institute protocol and assessed for a median follow-up
of 36 months. Assessment of survival outcomes in terms of progression
free survival (PFS) and overall survival (OS) were assessed. Toxicity
profile was assessed as per CTCAE 4.0 criteria and quality of life was
assessed as per EORTC-C30 and HN35 questionnaires. Dosimetric parameters for the target volumes were compared along with assessment of
various important organs at risk (OAR).
Results
After a median follow up of 36 months, PFS was 86% vs 81%
favoring ISBT arm (pZ0.032), however, there was no difference in
overall survival. On assessment of toxicities, dysphagia and xerostomia
were significantly reduced with ISBT boost with Grade II and III
toxicities 12% and 18% vs 18% and 24% respectively. On QoL
assessment, physical (p<0.001) and social functioning (pZ0.012)
favored ISBT boost. On symptom assessment, fatigue, dyspnea, appetite
loss, speech problems, swallowing and pain was significantly reduced
with ISBT boost. Dosimetric parameters showed significant dose
reduction to DARS (p<0.001) and parotid glands (p<0.001) with ISBT
boost.
Conclusion
ISBT boost has shown to be effective in improving PFS,
toxicity profile and quality of life outcomes in oropharyngeal malignancies
in spite of technological advancements in form of IMRT. ISBT should be
employed in treatment armamentarium to dose escalate and thereby
improve survival especially in oropharyngeal malignancies.