Aims and objectives
Prostate cancer is the most common non-cutaneous malignancy in men in the Western world.
It represents an extremely variable disease with a very different biological behavior from an indolent disease to a very aggressive one and with extensive dissemination.
Within the wide variety of imaging studies for its evaluation,
PET/CT with 68Ga-PSMA has proved to be an accurate imaging technique.
Although this radiotracer has high sensitivity,
the specificity is relatively low,
both at initial diagnosis and recurrence.
Despite its name,
68Ga-PSMA is not a prostate-specific...
Methods and materials
We retrospectively analyzed 68Ga-PET/CT PSMA studies performed at our center Uruguay from August 2015 to August 2018 and described the unexpected imaging findings suggesting.
We selected only cases that were confirmed by pathology.
We included 733 patients with a range of ages between 46 and 90 years with a median of 69 years.
The minimum PSA was 0.02 ng/mL (maximum: 1000,
average of 77).
All studies were analyzed by a nuclear medicine and radiologist specialist.
Of the 733 patients analyzed,
39 presented unexpected findings (p < 0.001).
We considered an unexpected findingthose where the morphology and/or topography of the lesion or distribution of the radiotracer was unexpected for metastasis from prostate cancer.
Of the unexpected findings 25 were pulmonary (64%) and 14 in other locations (36%,
P < 0.0001).
Of the pulmonary ones: 5 corresponded to primary lung cancer,
one presented mild uptake in a pulmonary BK infiltrate and in some consolidations and pulmonary cavities of an inflammatory cause.
68Gallium PET CT PSMA has showed to be an excellent imaging method for the evaluation of biochemical relapse in prostate cancer but despite its name is not a specific radiotracer.
growing evidence suggests increased PSMA uptake in a variety of other malignant tumor entities and in some benign lesions.
Knowledge and recognition of these possibilities are important to avoid scan misinterpretation and in many opportunities the anatomical CT pattern allows differential diagnoses and leads to therapeutic changes.
Margarita Garcia Fontes Radiologist Specialist at Uruguayan Center of Molecular Imaging,Head of Magnetic Resonance and Pet-MRI Department.
van der Meulen J,
Methodological considerations in assessing the utility of imaging in
early prostate cancer.
Curr Opin Urol 2015; 25: 536–42.
and predictors of positive (68)Ga-prostate-specific
membrane antigen positron emission tomography in advanced prostate
Cancer: a systematic review and meta-analysis.
3.von Eyben FE,
von Eyben R,
prostate-specific membrane antigen ligand...