18F-FDG PET/CT imaging for an early assessment of response to sunitinib in metastatic renal carcinoma: preliminary study.
OBJECTIVE
Sunitinib is a new standard for the treatment of metastatic renal-cell carcinoma (RCC). We evaluated the accuracy of 18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in assessing early response to this antiangiogenic drug, which cannot be obtained with conventional CT.


METHODS
Patients had an FDG-PET/CT at baseline and another one for follow-up at the end of the first cycle (at day 42). For each examination, all lesions were registered and the maximum standardized uptake value (SUV(max)) was measured. The metabolic response on PET at day 42 was assessed, using European Organization for Research and Treatment of Cancer criteria. Morphologic response on CT at day 84 (after two cycles), using Response Evaluation Criteria in Solid Tumors criteria, was used as the reference standard. The long-term outcome was assessed by the progression-free survival.


RESULTS
Twelve (12) patients who completed at least two cycles of sunitinib were assessed. The SUV(max) for the lesions with the highest uptake ranged between 2.9 and 11.8 for the 12 patients (mean = 6.3). Early PET/CT findings, after one cycle of sunitinib, were consistent with later CT results in 9 patients of 11 assessable patients: 1 patient progressed on PET and CT, 7 patients had stable disease, and 1 had a partial response. The other 2 patients had a metabolic partial response on PET and stable disease on CT. However, 1 patient achieved a partial response later in follow-up, suggesting that metabolic early changes are an indication of sunitinib activity.


CONCLUSIONS
FDG-PET/CT seems to be an interesting tool for the early evaluation of response to sunitinib in metastatic RCC. Larger studies are needed to confirm these preliminary results and establish a prognostic value for PET/CT.
Vercellino
Laetitia
L
Nuclear Medicine Department, St. Louis Hospital, Paris, France.
Bousquet
Guilhem
G
Baillet
Georges
G
Barré
Emmanuelle
E
Mathieu
Olivier
O
Just
Pierre-Alexandre
PA
Desgrandchamps
François
F
Misset
Jean-Louis
JL
Hindié
Elif
E
Moretti
Jean-Luc
JL
D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011758:Pyrroles / Q000627:therapeutic use*; D019275:Radiopharmaceuticals; D000077210:Sunitinib; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D007211:Indoles; D011758:Pyrroles; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000077210:Sunitinib