Clinical Outcomes and Patterns of Failure After Intensity-Modulated Radiotherapy with Simultaneous Integrated Boost...

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Conformal radiotherapy reduces toxicity by improving dose conformity to normal tissues.
• Intensity Modulated Radiation Therapy (IMRT) allows for further dose escalation in cancer treatment.
• Nasopharyngeal cancer treatment requires precise radiation delivery to maximize efficacy and minimize side effects.

Purpose of the Study:

• To evaluate clinical outcomes and failure patterns in nasopharyngeal cancer patients treated with IMRT-SIB/VMAT.
• To assess the safety and efficacy of IMRT-SIB/VMAT in combination with chemotherapy.
• To analyze survival rates and patterns of recurrence after IMRT-SIB/VMAT for nasopharyngeal carcinoma.

Main Methods:

• Retrospective analysis of 60 nasopharyngeal squamous cell carcinoma patients treated between March 2017 and December 2021.
• Patients received definitive treatment with IMRT-SIB and chemotherapy targeting primary and bilateral cervical nodes.
• Monitoring included assessment of local and regional failure, distant metastasis, locoregional progression-free survival, and overall survival.

Main Results:

• The 2-year survival rates were high: 81.5% local control, 82.9% regional control, 86.9% distant metastasis-free, 77.7% locoregional progression-free, and 92.9% overall survival.
• 11 patients experienced local failure and 10 experienced regional failure, with a median time to failure of 12.2 months.
• A trend towards lower regional control in N+ disease (74.2%) compared to N0 (100%) was observed (p=0.07).

Conclusions:

• IMRT-SIB/VMAT is a safe and acceptable treatment for nasopharyngeal carcinoma.
• Observed local failures within the target volume suggest that locally advanced T-stage disease may necessitate higher biological doses.
• Further research into dose optimization for advanced stages is warranted to improve local control rates.