Intraperitoneal distribution imaging in ovarian cancer patients

Optimal delivery of intraperitoneal (i.p.) chemotherapy is dependent on adequate drug distribution. An accurate understanding of the limitations of i.p. distribution is critical if we are to improve cytotoxic delivery through this route.

Using repeated scintigraphic peritoneography we investigated peritoneal fluid distribution in patients receiving i.p. therapy. Both early (1-6 h) and late (24-48 h) images were performed. The peritoneal cavity was divided into six regions; pouch of Douglas, left and right paracolic gutters, left and right subphrenic spaces and the right subhepatic space. The distribution in each region was classified as absent (0), faint (1) or intense (2). A total distribution score was calculated from the summation of distribution values for each of the six regions. Distribution was then graded according to the total distribution score as follows: Grade 0 = 0-3; Grade 1 = 4-6; Grade 2 = 7-9; and Grade 3 = 10-12.

Twenty-six participants were included in the study: all 26 patients had early imaging performed and 21 of these also had late imaging. Thirteen (50%) and 15 (71%) patients had grade 1 or 2 i.p. distribution on early and late imaging respectively. The most common abdominal regions to show maldistribution were the subphrenic spaces.

This study highlights the deficiencies of distribution following i.p. drug delivery, with the majority of patients demonstrating multiple regions of faint or absent uptake on scintigraphic peritoneography imaging. Future large clinical studies investigating i.p. chemotherapy should include analyses of i.p. distribution to improve our understanding of optimal drug delivery through this route.