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Clinical Significance of Postradiotherapy [18F]-Fluorodeoxyglucose Positron Emission Tomography Imaging in Management of Head-and-Neck Cancer—a Long-Term Outcome Report
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M. Yao, R. B. Smith, H. T. Hoffman, G. F. Funk, M. Lu, Y. Menda, M. M. Graham, and J. M. Buatti
These authors report the accuracy and prognostic significance of post-radiotherapy [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) in 188 patients with head-and-neck squamous cell carcinoma. The median interval from radiation completion to PET imaging was 15.14 weeks. All living patients had ≥ 1 year of follow-up after the PET study. The results showed that a negative post-radiotherapy PET is highly predictive of long-term local and regional control. There is a high false-positive rate for the primary site, however, especially when the larynx is irradiated. The high negative predictive value makes PET a valuable tool in the assessment of treatment response and the selection of patients for neck dissection after radiation.
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Predicting the Risk of Pelvic Node Involvement Among Men With Prostate Cancer in the Contemporary EraPage 104
P. L. Nguyen, M.-H. Chen, K. E. Hoffman, M. S. Katz, and A. V. D'Amico
In this study of the SEER registry of men diagnosed with prostate cancer in 2004, the authors found that the risk of occult positive lymph nodes appeared to be lower than what would have been predicted by the widely used Roach formula (2/3 x PSA) + 10(Gleason score - 6), possibly due to the shift towards earlier-stage disease (mainly T1c or T2a) among modern patients. The updated estimates presented here may be useful for patient selection and/or stratification for future clinical trials assessing treatment of the pelvic lymph nodes.
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Vascular Injury After Whole Thoracic X-Ray Irradiation in the RatPage 192
S. N. Ghosh, Q. Wu, M. Mäder, B. L. Fish, J. E. Moulder, E. R. Jacobs, M. Medhora, and R. C. Molthen
This work explores techniques to identify post-irradiation injuries incurred during accidental or terrorism-related radiological exposure. The authors have developed a rat model of single, sub-lethal whole-thoracic irradiation. Lung structure and function were examined using microfocal X-ray imaging methods to identify physiological markers of radiation exposure. In this rat model, a 5 Gy dose caused few significant effects. In contrast, the response to 10 Gy included a transient pneumonitis after 2 months, accompanied by a decrease in vascular density and right ventricular hypertrophy. Several of the indices of vascular remodeling during pneumonitis were reversed partially or wholly by 1 year.
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Volumetric Intensity-Modulated Arc Therapy vs. Conventional IMRT in Head-and-Neck Cancer: A Comparative Planning and Dosimetric StudyPage 252
W. F. A. R. Verbakel, J. P. Cuijpers, D. Hoffmans, M. Bieker, B. J. Slotman, and S. Senan
Volumetric intensity-modulated arc therapy using RapidArc (RA) is a novel approach for rapidly delivering highly conformal dose distributions. The authors compared the performance of RA versus conventional intensity-modulated radiotherapy (IMRT) for treating 12 cases of advanced naso- and oropharyngeal tumors. RA delivery using two arcs provided better PTV dose homogeneity than did IMRT, with at least comparable sparing of organs at risk. If more than 99% of the PTV should receive at least 95% of the prescribed dose, the authors recommend using double-arc RA, an approach which also showed better agreement between the measured and calculated dose for patient-specific QA.
