Serial changes in tumor oxygenation during the early phase of radiation therapy in cervical cancer-are we quantitating hypoxia change? Re: Lying et al., IJROBP 2000; 46:935-946

Complete response to radiation therapy of orbital metastasis from hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is increasing in the United States, and 50%-75% of patients with HCC will develop metastatic disease. Orbital metastases from HCC are extremely rare. We report the case of a 52-year-old male with known metastatic HCC, who presented with severe proptosis and diplopia. An orbital mass was identified on magnetic resonance imaging (MRI) and confirmed to have hypermetabolic activity on positron emission tomography/computed tomography. He received a palliative course of external beam radiation therapy to the right orbit. Intensity modulated radiation therapy (IMRT) was used to allow sparing of critical normal tissues in close proximity to the tumor. One month after completion of IMRT to 58 Gray in 30 fractions delivered over 6 wk, the patient had a complete clinical, radiologic (MRI) and symptomatic response. The patient continues to have local control in the orbit 1.7 years after therapy completion. All critical normal structures were kept below the tolerance dose using IMRT, and no toxicities were observed.

Arterial spin labeling blood flow magnetic resonance imaging for the characterization of metastatic renal cell carcinoma(1)

RATIONALE AND OBJECTIVE

This study sought to assess the feasibility of arterial spin labeling (ASL) blood flow (BF) magnetic resonance imaging (MRI) for the study of metastatic renal cell carcinoma (RCC) in the body, where the respiratory, cardiac, and peristaltic motions present challenges when applying ASL.

MATERIALS AND METHODS

ASL was performed using a background-suppressed single-section flow-alternating inversion recovery (FAIR) preparation and a single-shot fast spin-echo imaging sequence on a 3.0-T whole body imager. Tumor BF was evaluated for 26 patients with RCC metastatic to the liver, bone, lung, or lymph nodes before VEGF receptor inhibitor therapy. Two cases with tumor size change after treatment were also scanned 1 month after therapy. For validation, kidney cortex BF in five normal volunteers was measured with the same technique and compared with literature values.

RESULTS

ASL was successfully performed in all normal volunteers and in 20 of 26 patients. The six failures resulted from a systematic error, which can be avoided in future studies. For normal volunteers, measured kidney cortex BF was 275 +/- 14 mL/min/100 g, a value consistent with the literature. ASL determined tumor BF averaged across tumor volume and subjects was 194 mL/min/100 g (intersubject SD = 100), resulting in high perfusion signal and conspicuity of lesions. Bright signal was also seen in large vessels and occasionally in bowel. In the two cases studied 1 month after therapy, ASL perfusion changes were consistent with tumor size changes.

CONCLUSION

With background suppression, ASL MRI is a feasible method for quantifying BF in patients with renal cell carcinoma. This technique may be useful for evaluating tumor response to antiangiogenic agents.