Imaging Tumor Perfusion and Oxidative Metabolism in Patients With Head-and-Neck Cancer Using 1- [11C]-Acetate PET During Radiotherapy : Preliminary Results

• Background A growing body of in vitro evidence links alterations of the intermediary metabolism in cancer to treatment outcome. This study aimed to characterize tumor oxidative metabolism and perfusion in vivo using dynamic positron emission tomography (PET) with 1- [11C]-acetate (ACE) during radiotherapy. Methods and Materials Nine patients with head-and-neck cancer were studied. Oxidative metabolic rate (kmono) and perfusion (rF) of the primary tumors were assessed by dynamic ACE-PET at baseline and after 15, 30, and 55 Gy was delivered. Tumor glucose uptake (Tglu) was evaluated with [18F]-fluorodeoxyglucose PET at baseline. Patients were grouped into complete (CR, n = 6) and partial responders (PR, n = 3) to radiotherapy. Results The 3 PR patients died within a median follow-up period of 33 months. Baseline kmono was almost twice as high in CR as in PR (p = 0.02) and Tglu was lower in CR than in PR (p = 0.04). kmono increased during radiotherapy in PR (p = 0.004) but remained unchanged in CR. There were no differences in rF between CR and PR at any dosage. kmono and rF were coupled in CR (p = 0.001), but not in PR. Conclusions This study shows that radiosensitive tumors might rely predominantly on oxidative metabolism for their bioenergetic needs. The impairment of oxidative metabolism in radioresistant tumors is potentially reversible, suggesting that therapies targeting the intermediary metabolism might improve treatment outcome.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

1- [11C]-acetate PET

Perfusion

Oxidative metabolism

Head-and-neck cancer

Radiotherapy

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