Dynamic differences between SUVmax and tumor to normal tissue ratio of ¹⁸F-BPA PET in radioresistant squamous cell head and neck cancer and soft tissue sarcoma

Objectives: Boron neutron capture therapy (BNCT) is effective for the treatment of radioresistant tumors. In clinical BNCT, the tumor-to-normal tissue ratio (TNR) calculated from 18F-BPA PET images at 1 h after administration has been used for selecting patients. We previously demonstrated that dynamic SUVmax curves of ¹⁸F-BPA in unresectable tumors from 30 to 120 min showed different patterns (Morita et al., Radiation Oncology 2018, SNMMI 2018 and 2019 abstracts). In this study, we evaluated dynamic SUVmax and TNR of ¹⁸F-BPA uptake in the squamous cell head and neck cancer (SCC) and soft tissue sarcoma (STS) from 30 to 120 min.

Methods: Our study included 20 cases of SCC and 19 cases of STS. The two parameters for ¹⁸F-BPA were obtained at 30, 60 and 120mins, The data were performed using one-way ANOVA and the paired t-test was employed.

Results: The patient characteristics and the ¹⁸F-BPA PET values are shown in Table 1. SUVmax of SCC and STS showed a gradual decrease, but the decrease was statistically significant only between 30 and 120 min. No significant TNR changes of ¹⁸F-FBPA were seen in SCC and STS.

Conclusions: SUVmax of ¹⁸F-BPA in SCC and STS showed significant differences between 30 and 120 min, while the TNR of SCC and STS showed no significant changes. Dynamic SUVmax and TNR of ¹⁸F-BPA uptake may show different changes in certain types of cancer. ¹⁸F-BPA TNR should be carefully interpreted to identify appropriate BNCT patients and improve the BNCT treatment.

• Download figure
• Open in new tab
• Download powerpoint