International journal of radiation oncology, biology, physics
-
Int. J. Radiat. Oncol. Biol. Phys. · Oct 2004
Gamma knife surgery for trigeminal neuralgia: outcome, imaging, and brainstem correlates.
To review our results with gamma knife surgery (GKS) in the treatment of trigeminal neuralgia (TN), and to determine whether pain relief, medication usage, and the development of facial numbness are affected by trigeminal nerve compression, MRI imaging quality, or brainstem radiation dose. ⋯ Gamma knife surgery is effective in the treatment of TN and has a favorable side effect profile. Treatment response and the development of facial numbness do not correlate with MRI imaging quality, presence of nerve compression, or radiation dose to the brainstem.
-
Int. J. Radiat. Oncol. Biol. Phys. · Oct 2004
Internal target volume determined with expansion margins beyond composite gross tumor volume in three-dimensional conformal radiotherapy for lung cancer.
Gross tumor volume (GTV) of lung cancer defined by fast helical CT scan represents an image of moving tumor captured at a point in active respiratory movement. However, the method for defining internal margins beyond GTV to account for its expected physiologic movement and all variations in size and shape during the administration of radiation has not been established. The goal of this study was to determine the internal margins with expansion margins beyond individual GTVs defined with (1) fast scan at shallow free breathing, (2) breath-hold scans at the end of tidal volume inspiration and expiration, and (3) 4-s slow scan to approximate the composite GTV of all scans. ⋯ The internal margins required to account for the internal tumor motion in three-dimensional conformal radiotherapy are substantial. For the use of symmetric and population-based margins to account for internal tumor motion, GTV defined with breath-hold scans at the end of tidal volume inspiration and expiration has a narrower range of internal margins in all directions than that of either a single fast scan or 4-s slow scan.
-
Int. J. Radiat. Oncol. Biol. Phys. · Oct 2004
Early FDG-PET imaging after radical radiotherapy for non-small-cell lung cancer: inflammatory changes in normal tissues correlate with tumor response and do not confound therapeutic response evaluation.
To investigate the relationship between positron emission tomography (PET) detected inflammatory changes in irradiated normal tissues and metabolic response at tumor sites in patients receiving radical radiotherapy for non-small-cell lung cancer. The prognostic significance of these changes was also studied. ⋯ Postradiotherapy inflammatory changes detected by FDG-PET are positively correlated with tumor response, suggesting that tumor radioresponsiveness and normal tissue radiosensitivity may be linked. Prognostic stratification provided by PET is not compromised by inflammatory changes if a meticulous visual response assessment technique is used.
-
Int. J. Radiat. Oncol. Biol. Phys. · Oct 2004
Potential survival advantage with early androgen deprivation for biochemical failure after external beam radiotherapy: the importance of accurately defining biochemical disease status.
We analyzed our experience treating localized prostate cancer to determine the impact of androgen deprivation (AD) on clinical outcome if administered at the time of isolated biochemical failure (BF) vs. after clinical failure (clinical failure), and the associated impact of various BF definitions. ⋯ The efficacy of AD after BF varies depending on the BF definition. When an optimal BF definition is applied, early AD decreases distant metastasis and improves survival. Prostate-specific antigen elevation to >/=2 or >/=3 ng/mL above nadir seems optimal in establishing clinically significant BF and the timing of AD intervention.
-
Int. J. Radiat. Oncol. Biol. Phys. · Oct 2004
IMRT dose escalation for positive para-aortic lymph nodes in patients with locally advanced cervical cancer while reducing dose to bone marrow and other organs at risk.
To evaluate the feasibility of dose-escalated para-aortic lymph node (PALN) intensity modulated radiation therapy (IMRT) in reducing the dose to bone marrow, bowel, spinal cord, and kidneys, compared with conventional radiation techniques of PALNs in patients with locally advanced cervical cancer and PALN metastases. ⋯ In this dosimetric analysis, we demonstrated that dose-escalated PALN-IMRT with conventional whole-pelvis radiotherapy is feasible with significant sparing of critical normal structures compared to PALN conventional radiation techniques.