The phase II LUMEN study explores the dynamic changes in dosimetric parameters during Peptide Receptor Radionuclide Therapy (PRRT) with [177Lu]Lu-DOTA-TATE for patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). The study reveals significant variability in absorbed doses and activity concentrations, particularly when comparing tumor sites to organs-at-risk such as the kidneys and red marrow. In pancreatic NETs, absorbed doses in tumors were observed to decrease over the course of treatment cycles, with an approximate reduction of 13% per cycle. Conversely, the kidneys demonstrated an increasing trend in absorbed dose, rising by about 8% per cycle.
These findings emphasize the importance of personalized dosimetry protocols. The variability in dose distribution suggests that standard, one-size-fits-all approaches may not be sufficient to optimize patient outcomes. Instead, individualized treatment planning, tailored to patient-specific and tumor-specific characteristics, holds the potential to enhance both the efficacy and safety of PRRT.
