Short-course PET based simultaneous integrated boost for locally advanced cervical cancer

Area of Science:

• Radiation Oncology
• Medical Imaging
• Oncology

Background:

• Large, locally advanced cervical cancers (LACC) present significant treatment challenges.
• Current treatments require optimization for improved outcomes.

Purpose of the Study:

• To evaluate the feasibility of using 18F-FDG PET imaging for planning a simultaneous integrated boost (SIB) in external beam radiotherapy for LACC.
• To assess the potential for increased tumor shrinkage and local control with this SIB strategy.

Main Methods:

• Ten LACC patients with pre-treatment 18F-FDG PET/CT scans were analyzed.
• In silico dose escalation of the 18F-FDG avid tumor volume (MTV50) to 2.8 Gy/fraction for the first 10 fractions (SIB).
• Photon (VMAT) and proton (IMPT) therapy plans were generated and compared, with organ at risk (OAR) doses simulated.

Main Results:

• Dose escalation to MTV50 was achievable with both VMAT and IMPT, meeting dose constraints.
• A marginal increase in OAR doses was observed with the SIB approach, with mean differences below 2%.
• IMPT showed reduced low-to-intermediate OAR doses compared to VMAT but no added benefit for dose escalation.

Conclusions:

• Planning dose escalation for LACC based on FDG-avid volumes is feasible.
• This strategy may enhance tumor shrinkage prior to brachytherapy, offering clinical value for large tumors.