Top Line: Can FDG-PET be used to dose-escalate the primary tumor when treating locally advanced head and neck cancer?
The Study: FDG-PET is commonly used in staging and treatment planning of locally advanced head and neck cancer. In this phase 3 trial, 221 patients receiving definitive chemoradiation were randomized to a standard treatment plan or a FDG-PET guided treatment plan. The standard plan consisted of 70 Gy in 35 fractions to gross disease and 54.25 Gy in elective volumes. In the experimental arm, a PET-GTV was defined using 50% of the SUVmax of the primary tumor plus a 3mm margin. Dose was prescribed heterogeneously within this volume from a minimum of 70 Gy peripherally to 84 Gy centrally. Surrounding GTV that had <50% of the maximum SUV was expanded an additional centimeter, and this volume received a slightly lower 67-69 Gy in 35 fractions. Of note, gross nodal disease in the experimental arm received the standard 70 Gy in 35 fractions. At 2 years, local control was 81% in the experimental arm and 74% in the standard arm, but this difference was not statistically significant. In fact, most of the locoregional recurrences in both arms were within the PET-GTV. Post-hoc subgroup analysis found that PET-guided treatment was associated with better locoregional control among patients with oropharyngeal primaries and low volume, N0-1 nodal disease. Toxicity was fairly similar between arms, however PET-guided dose escalation actually increased the rate of grade 3+ pharyngolarygeal stenosis.
TBL: In the ARTFORCE trial, simultaneously boosting the most hypermetabolic portion of head and neck primaries did not dramatically improve locoregional control. | de Leeuw, Radiother Oncol 2024
The Study: FDG-PET is commonly used in staging and treatment planning of locally advanced head and neck cancer. In this phase 3 trial, 221 patients receiving definitive chemoradiation were randomized to a standard treatment plan or a FDG-PET guided treatment plan. The standard plan consisted of 70 Gy in 35 fractions to gross disease and 54.25 Gy in elective volumes. In the experimental arm, a PET-GTV was defined using 50% of the SUVmax of the primary tumor plus a 3mm margin. Dose was prescribed heterogeneously within this volume from a minimum of 70 Gy peripherally to 84 Gy centrally. Surrounding GTV that had <50% of the maximum SUV was expanded an additional centimeter, and this volume received a slightly lower 67-69 Gy in 35 fractions. Of note, gross nodal disease in the experimental arm received the standard 70 Gy in 35 fractions. At 2 years, local control was 81% in the experimental arm and 74% in the standard arm, but this difference was not statistically significant. In fact, most of the locoregional recurrences in both arms were within the PET-GTV. Post-hoc subgroup analysis found that PET-guided treatment was associated with better locoregional control among patients with oropharyngeal primaries and low volume, N0-1 nodal disease. Toxicity was fairly similar between arms, however PET-guided dose escalation actually increased the rate of grade 3+ pharyngolarygeal stenosis.
TBL: In the ARTFORCE trial, simultaneously boosting the most hypermetabolic portion of head and neck primaries did not dramatically improve locoregional control. | de Leeuw, Radiother Oncol 2024