PET/CT Imaging

SNM Image of the Year 2008

SNM Image of the Year 2008

The PET/CT image submitted by Policlinico S. Orsola-Universita di Bologna in Italy was performed with gallium-68-DOTA-NOC. The PET probe binds to somatostatin receptors that are abundant in neuroendocrine tumors. The study asked if the patient had additional disease. Its presence was revealed in the image as a suspicious lesion in the left ear as well as the spread of cancer in a lymph node in the neck. It is depicted as the bright green hyperintensities to the left of the 3D CT image of the patient's skull. The patient was referred for restaging after having received surgery a few months earlier.

Restaging of neuroendocrine tumour with 68Ga-DOTA-NOC PET-CT

SNM Image of the Year 2008

Suspect relapse of NET at left ear. PET confirmed local relapse and nodal involvement.


SNM Image of the Year 2008

Date of the exam: April 10, 2007 Authors: Stefano Fanti, Paolo Castellucci, Valentina Ambrosini, Paola Tomassetti, GianCarlo Montini, Vincenzo Allegri, Domenico Rubello, Cristina Nanni, Roberto Franchi.
Institution: Azienda Ospedaliero-Universitaria di Bologna, Policlinico S.Orsola-Malpighi.



The study is an example of the use of somatostatin receptor PET to evaluate patients affected by neuroendocrine tumours (NET). NET are uncommon neoplasm which are known to overexpress somatostatin receptors on cell surface: for this feature nuclear medicine techniques (such as 111In-pentetreotide scintigraphy) have been successfully applied for diagnostic purposes. Recently somatostatin analog peptides have been developed for labelling with positron emitters, and in particular we started in 2006 to use 68Ga-DOTA-NOC for PET imaging of NET.

This case was referred for restaging of a neuroendocrine tumour located in the left middle ear. The patient was a young male treated by surgery a few months before; conventional imaging (including CT and MR) showed a suspect local relapse. PET-CT confirmed the local relapse, but also demonstrated a nodal involvement, thus a re-intervention was considered inappropriate. The finding was subsequently confirmed by CT, and the patient scheduled for systemic treatment.

The scan was acquired on a dedicated PET-CT tomograph (GE Discovery); patient was injected with 185 MBq of 68Ga-DOTA-NOC synthetized at our Radiopharmacy; uptake time was about 70 minutes.

I feel that this scan emphasize the clinical role of PET-CT in oncology with tracers different from 18F-FDG. While 18F-FDG remains the most diffused tracer, accounting for more than 90% of PET scanning worldwide, several other tracers have been introduced in recent years, and some of them already plays a role in clinical oncology. Unfortunately few of them have a commercial interest (due to difficulties of distribution and costs of registration), thus only Academic Institution are promoting their use at presnt, and mainly in Europe.

The recognition as authors of the Image of the Year is definitely very important for us. We entered in the field of PET less than a decade ago, but the contribution of everyone in the staff allowed to rapidly grow, both in the exams production (more than 9000 scans are expected to be done in 2008) and in the research area (more than 40 full papers published in last two years). This recognition is a great opportunity to further work, especially in the field of innovative tracers, which remains our main focus: an international conference on this topic will be held in Bologna in September