International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1999
Familial prostate cancer: outcome following radiation therapy with or without adjuvant androgen ablation.
To compare the outcome of familial versus sporadic prostate carcinoma after definitive external radiation. ⋯ This study provides no evidence for any substantial difference between familial and sporadic prostate cancer either in clinicopathological features, in response to treatment, or in ultimate outcome.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1999
A dynamic model for the estimation of optimum timing of computed tomography scan for dose evaluation of 125I or 103Pd seed implant of prostate.
The dosimetric evaluation of permanent 125I or 103Pd prostate implant is based on the assumption that both prostate and seeds are static throughout the entire treatment time which lasts months. However, the prostate is often edematous after the surgical implantation of seeds. Therefore, both the volume of the prostate and the seed locations change dynamically as the edema resolves. This effect has impact on the validity of postimplant analysis based upon a CT scan. If a CT scan is taken too early after implantation while there is edema in the prostate, the dose delivered by the implant may be underestimated. If the imaging is delayed too long, the dose may be overestimated. The magnitude of this effect depends on both of the half-life of the isotope used and the half-life and magnitude of the edema. This study describes a dynamic biomathematical model which takes edema into account in calculating the dose delivered by the implant and is used to investigate the optimum time to obtain the postimplant CT scan. ⋯ A dynamic biomathematical model to correct for the effects of edema in calculating the total dose delivered by an 125I or 103Pd seed implant has been developed. The model has been used to investigate the optimum time window during which the postimplant CT scans for analysis should be obtained.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1999
Mammographic, pathologic, and treatment-related factors associated with local recurrence in patients with early-stage breast cancer treated with breast conserving therapy.
We retrospectively reviewed our institution's experience treating early-stage breast cancer patients with breast conserving therapy (BCT) to determine clinical, pathologic, mammographic, and treatment-related factors associated with outcome. ⋯ In patients with early-stage breast cancer treated with BCT, age < or = 35 years and calcifications on preoperative mammography appear to be associated with an increased risk of local recurrence.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1999
Normal tissue complication probabilities correlated with late effects in the rectum after prostate conformal radiotherapy.
Radiation therapy of deep-sited tumours will always result in normal tissue doses to some extent. The aim of this study was to calculate different risk estimates of late effects in the rectum for a group of cancer prostate patients treated with conformal radiation therapy (CRT) and correlate these estimates with the occurrences of late effects. Since the rectum is a hollow organ, several ways of generating dose-volume distributions over the organ are possible, and we wanted to investigate two of them. ⋯ 1) High-dose levels corresponding to small volume fractions of the cumulative dose-volume histograms were best correlated with the occurrences of late effects in the rectum as measured with questionnaires. This is compatible with a more serial organisation of the rectal tissue architecture than previously reported. 2) Reducing the Lyman-Kutcher model's volume parameter, thus allowing small high-dose regions to determine the NTCP, improved the correlation, but not beyond that of high-dose levels corresponding to small volume fractions of the cumulative dose-volume histograms.