Effect of increase of radiation dose on local control relates to pre-treatment FDG uptake in FaDu tumours in nude mice

Preclinical Assessment of Efficacy of Radiation Dose Painting Based on Intratumoral FDG-PET Uptake

“…In contrast to our findings, a preclinical study in human head and neck squamous cell carcinoma xenografts of Schuetze and colleagues (41) have shown that 40% increase of radiation dose from 25 to 35 Gy had a greater effect on radiation response in tumors with high pretherapeutic FDG uptake than in tumors with low FDG uptake. This preclinical investigation, however, cannot be directly compared with this study because uniform irradiation was delivered to the tumors stratified by median SUV max to low or high FDG uptake tumors assuming that each tumor represents a subvolume of a tumor in a single patient, whereas in this study, the nonuniform dose distributions were applied on the basis of intratumoral FDG uptake.…”

Early Response Monitoring with 18F-FDG PET and Cetuximab-F(ab′)2-SPECT After Radiotherapy of Human Head and Neck Squamous Cell Carcinomas in a Mouse Model

“…The therapeutic effect could not be monitored with 18 F-FDG PET; tumor volume did not correlate with 18 F-FDG uptake at any time point. Earlier studies in another head and neck tumor model showed a conflicting relation between 18 F-FDG uptake and tumor control; Schutze et al (28) reported that higher 18 F-FDG uptake in FaDu xenografts related to a higher control after a single dose of 35 Gy, though this was not supported in a subsequent study by Bruechner et al (29) as the SUV max did not reflect the decrease in vital tumor area for tumors treated with 35 Gy. The chosen time points at which 18 F-FDG uptake was measured could be of influence because a previous study in a murine squamous cell carcinoma model showed only a significant decrease in uptake 3 d and not 7 d after a single dose of 20 Gy irradiation (30).…”

Efficacy of Systemic Radionuclide Therapy with p-131I-Iodo-l-Phenylalanine Combined with External Beam Photon Irradiation in Treating Malignant Gliomas

“…For this reason, whole-brain radiotherapy using 8 Gy of photon irradiation was chosen for a better analysis of the efficiency of the combined 131 I-IPA and radiotherapy treatment, compared with single treatments alone. However, an increase of radiation doses might have a greater effect on local tumor control (40), and the impact of an 131 I-IPA activity increase will be elucidated in ongoing studies by our group.…”