International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Sep 2003
Patterns of failure after the multimodality treatment of uterine papillary serous carcinoma.
Uterine papillary serous carcinoma (UPSC) is an aggressive variant of endometrial carcinoma. The majority of patients with clinical Stage I UPSC are found to have extrauterine disease at the time of surgery. Most authors report survival rates of 35-50% for Stage I-II and 0-15% for Stage III and IV UPSC. Surgical treatment as the sole therapy for patients with Stage I-IV UPSC is unacceptable because of high recurrence rates. Chemotherapy, radiotherapy, or both have been added after surgery in an attempt to improve survival. However, the survival benefit to patients from such multimodality therapy remains uncertain. This study analyzes the patterns of failure in patients with FIGO Stages I-IV UPSC treated by multimodality therapy. ⋯ Our data suggest that, after multimodality therapy of FIGO Stage I-IV UPSC, most patients developed abdominopelvic (locoregional) failure, and the great majority of the failures occurred in the abdomen, vagina, and pelvis (66%). Abdominopelvic failure as a component of distant failure occurred in an additional 5 patients (17%). Distant failure alone occurred in 17% of the patients.We propose that future studies should combine whole abdominal radiotherapy (WART) with pelvic and vaginal boosts, in addition to chemotherapy for FIGO Stage I-IV UPSC, especially in patients with minimal residual disease, to attempt to improve the dismal prognosis of patients with UPSC.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2003
Use of portal images and BAT ultrasonography to measure setup error and organ motion for prostate IMRT: implications for treatment margins.
Traditionally, portal images have been used for verification of patient setup. More recently, direct prostate localization using ultrasound imaging has become available. The aim of this study was to use both modalities to measure daily setup error and prostate organ motion and their respective contributions to the overall uncertainty of prostate target localization. ⋯ Prostate organ motion appears to predominate over setup error as the major component of variation in target localization. Without the use of BAT ultrasound prostate imaging, misses of the prostate can occur in a high percentage of treatments, despite patient setup verification with portal images. Relatively large planning target volume margins in the AP and SI dimensions may be necessary to overcome this.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2003
Combination external beam radiotherapy and high-dose-rate intracavitary brachytherapy for uterine cervical cancer: analysis of dose and fractionation schedule.
To determine an appropriate dose and fractionation schedule for a combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) for uterine cervical cancer. ⋯ In view of the therapeutic ratio, cumulative BED 70-80 Gy(10) at point A is appropriate for uterine cervical cancer patients treated with a combination of EBRT and HDR-ICBT. Present results and data from other literatures suggested that cumulative BED at the rectal point should be kept below 100-120 Gy(3) to prevent late rectal complication.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 2003
Prostate localization using transabdominal ultrasound imaging.
Adding margin around a target is done in an attempt to ensure complete coverage of the target. The B-mode acquisition and targeting (BAT) system allows ultrasound imaging of the prostate in patients with a full bladder. This provides a setup tool for patients with localized prostate cancer that takes into account real-time prostate position and may make it possible to decrease tumor margins. Prostate localization using the conventional setup verification method and daily isocenter shifts recommended by the ultrasound imaging system (BAT) were compared and analyzed. ⋯ Prostate patient setup verification on the basis of bony anatomy position does not reflect the actual prostate position. BAT ultrasound target alignment provides a real-time prostate localization system that may make it possible to measure prostate position variations and reduce margins.
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Int. J. Radiat. Oncol. Biol. Phys. · Jul 2003
What hypofractionated protocols should be tested for prostate cancer?
Recent analyses of clinical results have suggested that the fractionation sensitivity of prostate tumors is remarkably high; corresponding point estimates of the alpha/beta ratio for prostate cancer are around 1.5 Gy, much lower than the typical value of 10 Gy for many other tumors. This low alpha/beta value is comparable to, and possibly even lower than, that of the surrounding late-responding normal tissue in rectal mucosa (alpha/beta nominally 3 Gy, but also likely to be in the 4-5 Gy range). This lower alpha/beta ratio for prostate cancer than for the surrounding late-responding normal tissue creates the potential for therapeutic gain. We analyze here possible high-gain/low-risk hypofractionated protocols for prostate cancer to test this suggestion. ⋯ The hypofractionated regimens that we suggest be tested for prostate-cancer radiotherapy show high potential therapeutic gain as well as economic and logistic advantages. They appear to have little potential risk as long as excessively short overall times (<5 weeks) and very small fraction numbers (<5) are avoided. The values of bNED and rectal complications presented are entirely theoretical, being related by LQ modeling to existing clinical data for approximately intermediate-risk prostate cancer patients as discussed in detail.