INTERSTITIAL FLUID PRESSURE IN INTRACRANIAL TUMORS IN PATIENTS AND INRODENTS

Fluid transport parameters in intracranial tumours influence the deliv ery of therapeutic agents and the resolution of peritumoral oedema. Th e tumour and cortex interstitial fluid pressure (IFP) and the cerebros pinal fluid pressure (CSFP) were measured during the growth of brain a nd pial surface tumours [R3230AC mammary adenocarcinoma (R3230AC) and F98 glioma (F98)] in rats. Intratumoral and intracranial pressures wer e also measured in rodents and patients treated with dexamethasone, ma nnitol and furosemide (DMF), and hypocapnia. The results show that (1) for the R3230AC on the pial surface, IFP increased with tumour volume and CSFP increased exponentially for tumours occupying a brain volume of 5% or greater; (2) in F98 with volumes of approximately 10 mm(3), IFP decreased from the tumour to the cortex, whereas for tumour volume s > 16 mm(3) IFP equilibrates between F98 and the cortex; (3) DMF trea tment reduced the IFP of intraparenchymal tumours significantly and in duced a pressure gradient from the tumour to the cortex; and (4) in 11 patients with intracranial tumours, the mean IFP was 2.0 +/- 2.5 mmHg . In conclusion, the IFP gradient between intraparenchymal tumours and the cortex decreases with tumour growth, and treatment with DMF can i ncrease the pressure difference between the tumour and surrounding bra in. The results also suggest that antioedema therapy in patients with brain tumours is responsible in part for the low tumour IFP.