A pilot study of a digital workflow for navigated tumor bed marking to reduce clinical target volume during adjuvant radiotherapy for oral squamous cell carcinoma.

PURPOSE: The treatment of advanced-stage oral squamous cell carcinoma (OSCC) often requires adjuvant radiotherapy to improve the survival rate. Accurately defining the clinical target volume (CTV) is critical for radiation treatment to maximize the radiation dose and minimize negative side effects. However, precise planning remains difficult because of postoperative anatomical changes, which may lead to oversized volumes with increased collateral damage to adjacent tissues. The aim of this study is to suggest a digital planning algorithm to improve the precision of CTV definition.

METHODS: In this pilot study, intraoperative digital tracings of tumor resection margins were located in the preoperative computed tomography (CT) datasets of ten patients with advanced OSCC using the Brainlab Curve navigation system. OSCCs of the tongue were excluded from this analysis because of their unique anatomical features. The preoperative scans with digital tracings were aligned with the postoperative scans to identify the desired CTV. The digitally navigated CTVs were compared with the CTVs resulting from conventional planning.

RESULTS: Our findings demonstrated that the digital workflow can be easily integrated into the surgical procedure and provides a straightforward and reproducible method to achieve a statistically significant average reduction of 25.71% in the CTV.

CONCLUSION: This innovative approach to digital tracing of the resection margins in postoperative CT scans significantly increases the precision of CTV planning. Clinical studies will be needed to test the oncological safety compared to conventional planning algorithms and the potential for improved outcomes with respect to side effects and quality of life.