International journal of radiation oncology, biology, physics
-
Int. J. Radiat. Oncol. Biol. Phys. · Apr 1998
Sublethal damage repair times for a late-responding tissue relevant to brachytherapy (and external-beam radiotherapy): implications for new brachytherapy protocols.
Data were analyzed from recent experiments with the end point of late rectal obstruction in rats, involving acute and various protracted radiation exposures. Because the end point is of direct relevance both for brachytherapy as well as external beam radiotherapy, the goal was to estimate the linear-quadratic (LQ) parameters alpha/beta and T1/2, which are of importance for designing improved protraction/fractionation schemes. ⋯ The long estimated repair time for a late-responding normal-tissue end point with direct relevance to brachytherapy suggests a variety of possible brachytherapy protocols that may be more efficacious than continuous low dose rate irradiation. Just as a difference in alpha/beta ratios between early- and late-responding tissues are a central tenet in radiotherapy, so corresponding differences in T1/2 values have the potential to be exploited, particularly for brachytherapy.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 1998
Clinical TrialMucosa-adhesive water-soluble polymer film for treatment of acute radiation-induced oral mucositis.
To examine the usefulness and safety of a mucosa-adhesive water-soluble polymer film (AD film) containing anesthetics and antibiotics for the treatment of acute radiation-induced oral mucositis. ⋯ The AD film, containing topical anesthetics and antibiotics, proved useful to alleviate pain due to acute radiation-induced oral mucositis, maintain good peroral feeding, and prevent secondary oral infections, without inducing adverse reactions.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 1998
Preoperative chemoradiation for extraperitoneal T3 rectal cancer: acute toxicity, tumor response, and sphincter preservation.
To evaluate whether or not an intermediate dose of preoperative external radiation therapy intensified by systemic chemotherapy could improve the tumor response, sphincter preservation, and tumor control. ⋯ Preoperative combined modality therapy seems to afford some potential advantages in nonrandomized trials: patients are able to tolerate higher chemotherapy doses and they experience a lower acute toxicity. Tumor downstaging and resectability rates are high; sphincter preservation is feasible. Larger T3 tumors remained less influenced by this treatment; thus, taking into account the low toxicity rate recorded, a more aggressive schedule should be applied in these resectable tumors.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 1998
Timing of computed tomography-based postimplant assessment following permanent transperineal prostate brachytherapy.
To establish the rate of resolution of prostatic edema following transperineal interstitial permanent prostate brachytherapy, and to determine the results and impact of timing of the postimplant assessment on the dose-volume relationship. ⋯ Most of the prostatic edema induced by brachytherapy appears to resolve by postoperative day 30. Scans performed on postimplant day 30 appear to adequately describe the time-averaged dose coverage of the prostate. This suggests that waiting approximately 1 month to perform postimplant analysis gives the most accurate prostatic volume and, consequently, dosimetric description of the implant.
-
Int. J. Radiat. Oncol. Biol. Phys. · Mar 1998
Factors determining outcome for breast-conserving irradiation with margin-directed dose escalation to the tumor bed.
A prospectively applied treatment policy for breast-conserving therapy used margin assessment as the exclusive guide to the intensity of therapy directed at the tumor-bearing quadrant. ⋯ Graded tumor-bed dose escalation in response to FMS results in an exceptionally low risk of "early" local recurrence within the first 5 years of follow-up. However, this strategy is unable to completely overcome the longer term adverse influence of young age and positive FMS.