Preservation of tumour oxygen after hyperbaric oxygenation monitored by magnetic resonance imaging

Abstract

Summary Hyperbaric oxygen (HBO) has been proposed to reduce tumour hypoxia by increasing the dissolved molecular oxygen in tissue. Using a non-invasive magnetic resonance imaging (MRI) technique, we monitored the changes in MRI signal intensity after HBO exposure because dissolved paramagnetic molecular oxygen itself shortens the T1 relation time. SCCVII tumour cells transplanted in mice were used. The molecular oxygen-enhanced MR images were acquired using an inversion recovery-preparation fast low angle shot (IR-FLASH) sequence sensitizing the paramagnetic effects of molecular oxygen using a 4.7 tesla MR system. MR signal of muscles decreased rapidly and returned to the control level within 40 min after decompression, whereas that of tumours decreased gradually and remained at a high level 60 min after HBO exposure. In contrast, the signal from the tumours in the normobaric oxygen group showed no significant change. Our data suggested that MR signal changes of tumours and muscles represent an alternation of extravascular oxygenation. The preserving tumour oxygen concentration after HBO exposure may be important regarding adjuvant therapy for cancer patients.

Phase II trial of radiotherapy after hyperbaric oxygenation with chemotherapy for high-grade gliomas

“…Several experimental studies have indicated that the elevation in oxygen tension in the tumour is preserved for some time following HBO treatment, thereby allowing the administration of radiotherapy with an improved tumour/normal tissue oxygenation ratio (Kinoshita et al, 2000;Kunugita et al, 2001;Beppu et al, 2002). Using noninvasive MRI, Kinoshita et al (2000) demonstrated that the signal change related to the oxygen tension in SCCVII tumours decreased gradually but fell rapidly in muscle after HBO. Beppu et al (2002) conducted a direct stereotactic measurement of pO 2 in glioblastoma tissue of patients under various conditions.…”

“…However, recent studies suggest that the oxygen tension within tumours improves during HBO with the increase being maintained for minutes following cessation of HBO (Kinoshita et al, 2000, Kunugita et al, 2001Beppu et al, 2002). Many investigators have reported that malignant glioma cellular metabolism is anaerobic with the tumour exhibiting a lower oxygen consumption rate to normal white matter (Ito et al, 1982;Tyler et al, 1987;Mineura et al, 1994).…”

Hyperoxia retards growth and induces apoptosis and loss of glands and blood vessels in DMBA-induced rat mammary tumors

“…Hyperbaric oxygen treatment (HBO) offers one possibility to increase the oxygen content in various tissues [7][8][9][10]. The use of HBO in cancer therapy has been aimed at improving the radiation response in solid tumors [10] as well as to improve healing of normal tissue after radiation injury [11].…”

Гипербарическая Оксигенация И Рак – Обзор (Перевод С Англ. Митрохина А.А.)

“…Как и в нормальных тканях, рО 2 в раковой ткани под действием ГБО значительно увеличивается (Brizel, et al, 1995). Так было показано, что повышение давле-ния кислорода в опухоли клинически сохраняется при-близительно в течение 30 минут после воздействия ГБО (Kinoshita, et al, 2000;Beppu, et al, 2002). Лечение ГБО в настоящее время принято и рутинно применяется при множестве заболеваний, связанных с ишемией и/или ги-поксией (Gill, Bell, 2004).…”

“…Kohshi et al (Kohshi, et al, 1999) нашли, что во избежание опасных побочных эффектов облучение следует прово-дить немедленно после сеанса ГБО -но не одновремен-но с ним. Было показано, что нормоксические состояния персистируют некоторое время после воздействия ГБО благодаря продленной сатурации и кинетике вымывания (Kinoshita, et al, 2000;Beppu, et al, 2002). Так, изменение протоколов, вероятно, может снизить или предупредить серьёзные побочные эффекты и, таким образом, сделать оправданным применение ГБО для повышения чувстви-тельности к облучению (Mayer, et al, 2005).…”