A pilot study of [68Ga]Ga-DOTA-TATE PET-based radiation contouring for pituitary adenoma

Purpose: Radiation treatment planning for pituitary tumors traditionally involves magnetic resonance imaging (MRI) imaging.However, the gross tumor volume (GTV) may be difficult to delineate for patients after resection and recurrence.Advanced positron emission tomography (PET) imaging using [ 68 Ga]Ga-DOTA-TATE has been used for somatostatin-expressing tumors, and can be used for target volume delineation.We hypothesized that [ 68 Ga]Ga-DOTA-TATE PET scan-based GTV delineation would alter the target volume in comparison with MRI-based delineation. Methods and Materials:This IRB-approved protocol retrospectively contoured GTVs for seven patients who had undergone [ 68 Ga]Ga-DOTA-TATE PET for radiation treatment planning for pituitary tumors. Conclusions:These results support the conclusion that [ 68 Ga]Ga-DOTA-TATE PET alters treatment volumes in radiation planning for recurrent pituitary tumors.Whether PET imaging changes treatment outcomes is unknown.The use of this imaging modality for pituitary radiation planning should be studied prospectively.