International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 1998
Perineural invasion and Gleason 7-10 tumors predict increased failure in prostate cancer patients with pretreatment PSA <10 ng/ml treated with conformal external beam radiation therapy.
It has been well established that prostate cancer patients with pretreatment PSA <10 ng/ml enjoy excellent bNED control when treated with definitive external beam radiation therapy. This report identifies predictors of failure for patients with pretreatment PSA <10 ng/ml. These predictors are then used to define favorable and unfavorable prognostic subgroups of patients for which bNED control is compared. ⋯ (1) This report identifies Gleason 7-10 and the presence of PNI as well as palpation stage T2C/T3 as factors that predict worse bNED outcome for patients with pretreatment PSA <10 ng/ml who are treated with radiation therapy alone. (2) Patients with these pretreatment prognostic factors may benefit from adjuvant therapies or altered treatment programs. (3) In order to make fair comparisons between radiation therapy and prostatectomy series, the distribution of perineual invasion and Gleason 7-10 must be taken into account.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 1998
Subdiaphragmatic stage I & II Hodgkin's disease: long-term follow-up and prognostic factors.
To report long-term follow-up results and to analyze prognostic factors for overall and disease-free survival in patients with subdiaphragmatic Stage I & II Hodgkin's disease. ⋯ Long-term follow-up of this group of patients revealed similar overall and disease-free long-term survival, as would be expected from supradiaphragmatic Hodgkin's disease. For patients with central Stage II disease, it is anticipated that supradiaphragmatic radiation therapy would improve the disease-free survival.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 1998
Daily CT localization for correcting portal errors in the treatment of prostate cancer.
Improved prostate localization techniques should allow the reduction of margins around the target to facilitate dose escalation in high-risk patients while minimizing the risk of normal tissue morbidity. A daily CT simulation technique is presented to assess setup variations in portal placement and organ motion for the treatment of localized prostate cancer. ⋯ In our experience, prostate motion after 50 Gy was significantly less than previously reported. This may reflect early physiologic changes due to radiation, which restrict prostate motion. This observation is being tested in a separate study. Intrapatient and overall population variance was minimal. With daily isocenter correction of setup and organ motion errors by CT imaging, PTV margins can be significantly reduced or eliminated. We believe this will facilitate further dose escalation in high-risk patients with minimal risk of increased morbidity. This technique may also be beneficial in low-risk patients by sparing more normal surrounding tissue.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 1998
Edema associated with I-125 or Pd-103 prostate brachytherapy and its impact on post-implant dosimetry: an analysis based on serial CT acquisition.
To characterize the magnitude and duration of post-implant edema following the implantation of I-125 or Pd-103 seeds into the prostate and to investigate its effect on the CT-based calculation of the total dose delivered by the implant. ⋯ Post-implant edema increased the prostate volume by factors which ranged from 1.33 to 1.96 (mean: 1.52). The edema resolved exponentially with an edema half-life which varied from 4 to 25 days (mean: 9.3 days). Edema had a significant effect on the post-implant dosimetry in 7 of 10 cases. Factors that affect the impact of edema on the dosimetry are the magnitude of the edema and the planned margin between the prescribed isodose line and the periphery of the prostate.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 1998
Conformal radiotherapy of Stage III non-small cell lung cancer: a class solution involving non-coplanar intensity-modulated beams.
We developed a semiautomatic class solution to irradiate centrally located Stage III non-small cell lung cancer (NSCLC), involving a beam intensity modulation technique and optimization using a biophysical cost function. ⋯ The BIM2 plan is a candidate class solution for dose escalation studies in centrally located Stage III NSCLC.