Dose Escalation

Hypoxia occurs in about 80% of head and neck tumors. Based on experimental and clinical data, hypoxia is a useful parameter for pretherapeutic stratification. These radioresistant regions can be detected with FMISO PET/CT. Moreover, hypoxic subvolumes of tumors can be evolving as target volumes for radiotherapy ("dose painting") in hypoxia imaging-based dose escalation.

Patients with a biochemical recurrence after radical prostatectomy for moderate- or high- risk prostate cancer are randomly assigned to hypofractionated, accelerated high dose radiation therapy group (65 Gy, 26 fractions) and a control group of standard treatment group (66 Gy, 33 fractions). The criteria for stratification at randomization include 1) risk groups, 2) androgen deprivation therapy, and 3) PSA before salvage radiation therapy, which affect biochemical recurrence. It is expected that hypofractionated, accelerated high dose radiation therapy will have a superiority in terms of biochemical control to conventional radiation therapy, and the present study would like to confirm this. In addition, we aimed to evaluate and compare the toxicity and quality of life index of two radiation therapy regimens.