By Marchello Barbarisi, MD
PET-CT has come to occupy a preeminent role in imaging of oncologic patients. It has clearly been demonstrated to be superior to CT or PET alone in staging and restaging of most cancers. [i] Additionally, the ability of PET-CT to assess tumor response as early as following a single cycle of chemotherapy is unmatched. [ii] This allows for earlier and more accurate determination of treatment efficacy allowing for more prompt treatment modifications, and therefore the avoidance of potentially unnecessary toxicities. Furthermore, PET-CT has shown significant promise as a prognostic marker for outcome predictions. For example, in a large-scale study of Hodgkin’s lymphoma, incomplete PET response after 2 cycles of chemotherapy was associated with 13% two-year progression free survival, whereas 95% of patients with complete PET response were progression free at two years. [iii] Similar results have been reported with a variety of solid tumors.[iv],[v]
However, PET-CT has, up until now, been limited by inherent technical factors of the PET portion of the exam. This is largely related to the analog nature of all PET-CT systems, which has significantly limited image resolution. Attempts to compensate for this have required long scan times and higher radioisotope doses, neither of which is desirable.
This has changed with the introduction of Main Line Health’s new solid-state digital PET-CT system, the first U.S. installation of the newest model of the recently introduced Siemens Biograph Vision PET-CT scanner. The solid-state digital technology combined with numerous other technical advances is a quantum leap forward in PET technology and a ‘game changer’ for patients. It’s nearly 4x higher sensitivity and its 3.5 mm spatial resolution are unmatched. This allows for scan acquisitions in less than half the time, at lower radiotracer doses, and with markedly improved image quality. In the short time this new scanner has been in operation, there have already been numerous instances of clinically significant finding detected which would almost certainly not have been possible on non-digital systems. Additionally, a 500lb table capacity and significantly larger bore diameter and shorter bore length allow for easy accommodation of larger and/or claustrophobic patients.
Centrally located, The Main Line Health PET-CT center at Newtown Square: offers easy access with free parking and same day appointment availability. The first digital PET-CT system in our region optimizes patient care with the highest possible lesion detectability at lower radiation doses and short scan times previously unheard of on PET-CT systems.
PET – CT Scheduling (484) 337-2200
PET – CT Center (484) 337-6133
[i] Czernin J, Allen-Auerbach M, Schelbert HR. Improvements in cancer staging with PET/CT: literature-based evidence as of September 2006. J Nucl Med. 2007;48(Suppl 1):78S–88
[ii] Benz MR, Czernin J, Allen-Auerbach MS, Tap WD, Dry SM, Elashoff D, et al. FDG-PET/CT imaging predicts histopathologic treatment responses after the initial cycle of neoadjuvant chemotherapy in high-grade soft-tissue sarcomas. Clin Cancer Res. 2009;15(8):2856–2863.
[iii] Gallamini A, Hutchings M, Rigacci L, Specht L, Merli F, Hansen M, et al. Early interim 2-[18F]fluoro-2-deoxy-d-glucose positron emission tomography is prognostically superior to international prognostic score in advanced-stage Hodgkin’s Lymphoma: a report from a joint Italian-Danish study. J Clin Oncol. 2007;25(24):3746–3752
[iv] Weber WA. Positron emission tomography as an imaging biomarker. J Clin Oncol. 2006;24(20):3282–3292.
[v] Schwarz J, Siegel B, Dehdashti F, Grigsby P. Association of posttherapy positron emission tomography with tumor response and survival in cervical carcinoma. J Am Med Assoc. 2007;298:2289–2295.