[Role of MRI and CT in the evaluation of postirradiation status and complications in head and neck cancer]

Most head and neck cancer patients are treated with combined modalities such as surgery, radiotherapy (RT), chemotherapy (ChT). Concurrent chemo-radiation has improved treatment outcomes with increased toxic effects. Reactions after RT are divided into early and late changes. Early reactions are seen during the course of therapy or within 3 months; these are reversible in most cases. Late complications are observed 3 months to years after RT and they are generally irreversible. As typical late reaction radiation induced necrosis may occur in soft tissues, cartilage, bones and brain. Tumor recurrence and post-radiation necrosis typically appear at the same time, within 2-3 years after RT; the differentiation may be difficult. Computed tomography (CT) and magnetic resonance imaging (MRI) have become the gold standards not only for staging and assessing tumor response, but also to evaluate posttreatment status, to distinguish residual or recurrent tumor and RT complications. Using baseline CT or MRI between 2-3 months after treatment and performing standard follow-up imaging with strict clinical follow-up are required to establish early salvage treatment.

[Metachronous metastasis from rectal adenocarcinoma to the penis--case report]

Despite of its rich vascularization and extensive circulatory communication with neighboring organs, penile metastases are rare. Even more infrequent is a penile metastasis of rectum tumors. Since the first report of rectal carcinoma with metastasis to the penis (Ehbert 1870), approximately 50 cases have been reported, most of them from the USA, the remaining from Western Europe, the Middle East and Japan. The first Hungarian case is reported now of penile metastasis of a rectal carcinoma. The case of a 65-year-old man is presented: isolated penile metastasis discovered 4.5 years after the primary rectal cancer resection. IHC tissue diagnosis and detailed clinical investigations confirmed metastatic rectal adenocarcinoma. As our patient refused penectomy and KRAS mutation was proven, FOLFIRI chemotherapy was initiated without cetuximab. This was followed by chemoradiotherapy that resulted only in transient regression. Currently the patient receives the FOLFOX regimen. At present the patient is in good performance status,without pain. The size and the number of penile metastases have not shown significant changes. According to the literature the average survival of patients with penile metastases treated with radiochemotherapy is 8 months. New chemotherapeutic modalities may improve the survival.

The potential of ferumoxytol nanoparticle magnetic resonance imaging, perfusion, and angiography in central nervous system malignancy: a pilot study

OBJECTIVE

Ferumoxytol, an iron oxide nanoparticle that targets phagocytic cells, can be used in magnetic resonance imaging of malignant brain tumors and can be administered as a bolus, allowing dynamic imaging. Our objectives were to determine the optimum time of delayed contrast enhancement of ferumoxytol, and to compare ferumoxytol and gadolinium contrast agents for magnetic resonance angiography and perfusion.

METHODS

Twelve patients with malignant brain tumors underwent serial magnetic resonance imaging multiple times up to 72 hours after ferumoxytol injection at both 1.5 and 3-T. The enhancement time course was determined for ferumoxytol and compared with a baseline gadolinium scan. Perfusion, time-of-flight and dynamic magnetic resonance angiography and T1-weighted scans were compared for the two agents.

RESULTS

The lesions were detectable at all field strengths, even with an intraoperative 0.15-T magnet. Maximal ferumoxytol enhancement intensity was at 24 to 28 hours after administration, and the enhancing volume subsequently expanded with time into a non-gadolinium-enhancing, high T2-weighted signal region of tumor-infiltrated brain. Dynamic studies were assessed with both agents, indicating early vascular leak with gadolinium but not with ferumoxytol.

CONCLUSION

Our most important finding was that gadolinium leaks out of blood vessels early after injection, whereas ferumoxytol stays intravascular in the "early" phase, thereby increasing the accuracy of tumor perfusion assessment. As a magnetic resonance imaging contrast agent, ferumoxytol visualizes brain tumors at all field strengths evaluated, with delayed enhancement peaking at 24 to 28 hours after administration.