This study aimed to assess the feasibility and potential usefulness of a new intraoperative portable high-resolution imaging γ-camera for the localization of sentinel lymph node in patients with breast cancer.
Sixteen T1 to T2 breast cancer female patients were evaluated (mean age, 62 years) with preoperative lymphoscintigraphy, acquired 30 minutes after intradermal injection of 60 to 70 MBq (1.6-1.9 mCi) of 99mTc-nanocolloids in saline volumes of 0.1 to 0.2 mL. Surgery took place the day after (18-20 hours after tracer injection). For intraoperative sentinel lymph node localization, a traditional γ-probe was used by the surgeon. Moreover, a portable imaging γ-camera was used by the nuclear physician who was present in the operating room.
The portable imaging γ-camera showed very high spatial resolution (2.4 mm) in the 4.4 × 4.4 cm2 FOV, with a good sensitivity of 180 cps/MBq at a Plexiglas depth of 1 cm. In 11 patients, lymphoscintigraphy, γ-probe, and imaging γ-camera depicted the same number of radioactive lymph nodes (17 nodes; 5 of which were metastatic and detected in 6 different patients). In 6 patients, the portable imaging γ-camera detected 1 node more than lymphoscintigraphy (in total, 5 nodes more), one of which was metastatic (the only one metastatic in that patient).
Our preliminary results showed that a portable high-resolution hand-held imaging γ-camera is a feasible, not time-consuming, noninvasive procedure in intraoperative sentinel node localization, offering extra confidence to the surgeon. In our hands, it was a very useful auxiliary imaging tool especially in the identification of nodes located deep in the axilla, which are difficult to detect at the preoperative lymphoscintigraphy. Additional multicenter studies involving a greater number of patients are necessary to confirm these promising data.
From the *Department of Nuclear Medicine–PET/CT Center, and †Medical Physics Unit, Santa Maria della Misericordia Hospital, Rovigo; ‡Surgery Unit, San Luca Hospital, Trecenta; §Department of Pathology, and ¶General Hospital Direction, Santa Maria della Misericordia Hospital, Rovigo, Italy.
Received for publication August 8, 2012; revision accepted October 15, 2012.
Conflicts of interest and sources of funding: none declared.
Reprints: Sotirios Chondrogiannis MD, Department of Nuclear Medicine–PET/CT Center Santa Maria della Misericordia Hospital 45100 Rovigo, Italy. E-mail: firstname.lastname@example.org.