International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2004
Randomized Controlled Trial Clinical TrialEffects of amifostine on acute toxicity from concurrent chemotherapy and radiotherapy for inoperable non-small-cell lung cancer: report of a randomized comparative trial.
To determine the ability of amifostine to reduce the severity and/or incidence of the acute toxicities of concurrent chemotherapy and radiotherapy (RT) for non-small-cell lung cancer. ⋯ Amifostine reduced the severity and incidence of acute esophageal, pulmonary, and hematologic toxicity resulting from concurrent cisplatin-based chemotherapy and RT. Amifostine had no apparent effect on survival in these patients with unresectable non-small-cell lung cancer, suggesting that it does not have a tumor-protective effect.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2004
Interval between surgery and radiotherapy: effect on local control of soft tissue sarcoma.
To evaluate the clinical significance of the interval between surgery and postoperative radiotherapy (RT) for patients with soft tissue sarcoma. ⋯ The interval between surgery and RT did not significantly impact the 10-year LC rate. These findings indicate that an RT delay should not be viewed as an independent adverse factor for LC and that treatment intensification may not be necessary for patients in whom a treatment delay has already occurred.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2004
Necessity for adjuvant neck dissection in setting of concurrent chemoradiation for advanced head-and-neck cancer.
Neck dissection has traditionally played an important role in the treatment of patients with squamous cell carcinoma of the head and neck who present with regionally advanced neck disease (N2-N3). Radiotherapy and concurrent chemotherapy improves overall survival in advanced head-and-neck cancer compared with radiotherapy alone. The necessity for postchemoradiation neck dissection is controversial. The intent of this report was to define the value of neck dissection in this patient population better. ⋯ The clinical and pathologic responses in the neck correlated poorly with one another for patients with N2-N3 neck disease undergoing concurrent chemoradiation for advanced head-and-neck cancer. MND still appears to confer a disease-free survival and overall survival advantage with acceptably low morbidity. Tumor oxygenation assessment may be useful in selecting patients who are especially prone to have residual disease. Better tools need to be developed to determine prospectively whether this procedure is required for individual patients.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2004
Dose-volume conundrum for response of prostate cancer to brachytherapy: summary dosimetric measures and their relationship to tumor control probability.
Although it is known that brachytherapy dose distributions are highly heterogeneous, the effect of particular dose distribution patterns on tumor control probability (TCP) is unknown. It is unlikely that clinical results will throw light on the question in the near future, given the long follow-up and detailed dosimetry required for each patient. We used detailed dose distribution data from 50 patients combined with radiobiologic parameters consistent with what is known about TCP curves for prostate cancer to study the changes in TCP that accompany gross dosimetric measures and particular dosing irregularities (e.g., moderate underdosing of large volumes vs. extreme underdosing of small volumes). ⋯ The work described here was an hypothesis-generating study. Our results showed that even if the V100 and D90 are nearly identical for 2 patients, there can be (and frequently are) significant differences in the dose distributions in the subvolumes of the prostate. Under simulated dose-response conditions (i.e., with variations in the dose distribution), the D90 and minimal dose significantly affected the TCP but the V100 and the volumes moderately or severely underdosed did not. In general, one must consider the totality of the dose distribution to evaluate the dosimetric quality of a low-dose-rate prostate implant. TCP is not a monotonic function of extreme or moderate underdosing. In some instances, extreme underdosing of relatively small volumes may result in a greater TCP than moderate underdosing of relatively large volumes and vice versa.
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 2004
A treatment planning comparison of intensity modulated photon and proton therapy for paraspinal sarcomas.
A comparative treatment planning study has been undertaken between intensity modulated (IM) photon therapy and IM proton therapy (IMPT) in paraspinal sarcomas, so as to assess the potential benefits and limitations of these treatment modalities. In the case of IM proton therapy, plans were compared also for two different sizes of the pencil beam. Finally, a 10% and 20% dose escalation with IM protons was planned, and the consequential organ at risk (OAR) irradiation was evaluated. ⋯ These results suggest that the use of IM photon therapy, when compared to IM protons, can result in similar levels of tumor conformation. IM proton therapy, however, reduces the OAR integral dose substantially, compared to IM photon radiation therapy. As a result, tumor dose escalation was always possible with IM proton planning, within the maximal OAR dose constraints. In IM proton planning, reducing the size of the proton pencil beam (using the "mini-beam") improved the dose homogeneity, but it did not have a significant effect on the dose conformity.