Prospective evaluation of Intensity Modulated Radiation Therapy with Simultaneous Integrated Boost (IMRT-SIB) in head and neck squamous cell carcinoma in patients not suitable for chemo-radiotherapy.

Background: With conformal radiotherapy techniques, acute and late toxicities can be reduced because of better dose conformity and reduced doses to normal tissue. With Intensity Modulated Radiation Therapy (IMRT) further dose escalation is possible and one of the methods is IMRT with simultaneous integrated boost (IMRT-SIB).

Aim: To evaluate feasibility, toxicity patterns and loco-regional control rates of IMRT-SIB technique in head and neck cancer patients who are not suitable candidates for concurrent chemoradiation.

Study Design: Prospective study of 30 patients treated with IMRT-SIB technique and evaluation of clinical results.

Method And Materials: 30 patients received definitive treatment using IMRT-SIB without concurrent chemotherapy. Patients were monitored during and after treatment for toxicity using the Radiation Therapy Oncology group (RTOG) criteria. Analysis of acute and late toxicity and early efficacy is presented.

Results: The median treatment duration was 42days (range 41-43days). Overall, maximum acute Grade 3 toxicity of mucositis, skin, pharynx/esophageal toxicity and laryngeal were 56.66%, 30%, 26.67%, and 6.67% respectively at treatment completion. None of the patients had Grade 4 acute toxicity. No haematological toxicity was seen. Overall, grade 2 late toxicities were 7% (subcutaneous toxicity) and 13.3% (Xerostomia). Loco regional control rate at a median follow up of 13months was 86%.

Conclusion: IMRT-SIB is a safe and acceptable treatment option for patients of head and neck squamous cell carcinoma unsuitable for definitive chemo-radiotherapy.