International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Apr 1991
Clinical Trial Controlled Clinical TrialDecreasing gastrointestinal morbidity with the use of small bowel contrast during treatment planning for pelvic irradiation.
Small bowel tolerance is a major dose-limiting factor in treating the pelvis with radiation therapy (RT). The use of small bowel contrast during RT simulation is one technique used to localize the bowel and identify the treatment plan that would exclude the greatest volume. To determine the influence of treatment planning with oral contrast on gastrointestinal injury, acute and chronic small bowel morbidity was analyzed in 115 patients with endometrial and rectal carcinoma who received postoperative radiation therapy at the Fox Chase Cancer Center. ⋯ Multivariate analysis revealed that both the use of oral contrast (p = .026) and a lower superior border of the treatment field (p = .007) were predictive for fewer sequelae to RT, indicating that planning with contrast leads to changes in the technical delivery of RT other than field placement (e.g., block placement). The reduced incidence and duration of small bowel morbidity may be in part caused by alterations of the treatment plan made when the small bowel is visualized at the time of simulation. It is therefore recommended that oral small bowel contrast be used during treatment planning for pelvic irradiation.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 1991
The effect of lonidamine (LND) on radiation and thermal responses of human and rodent cell lines.
Rodent and human cells were tested for response to Lonidamine (LND) (1-(2,4 dichlorobenzyl) 1-indazol-3-carboxylic acid) combined with radiation or hyperthermia. Lonidamine exposure before, during, and after irradiation caused varying degrees of inhibition of potentially lethal damage (PLD) repair which was cell line dependent. In human glioma, melanoma, squamous cell carcinoma, and fibroblasts, LND exposure did not inhibit or only partially inhibited repair of potentially lethal damage. ⋯ In human glioma cells, LND treatment alone did not inhibit PLD repair, but when combined with hyperthermia treatment at moderate levels easily achievable in the clinic, there was complete inhibition of potentially lethal damage repair. These data suggest that LND effectiveness is cell type dependent. Combinations of LND, hyperthermia, and radiation may be effective in cancer therapy especially in tumors such as glioma in which repair of potentially lethal damage may be extensive.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 1991
Pre-treatment prognostic factors in stage III non-small cell lung cancer patients receiving combined modality treatment.
Approximately one-third of non-small cell lung cancer (NSCLC) patients present with locally advanced disease. Increasing numbers of clinical trials are being conducted in this group of patients and recently a new international staging system has been introduced, resulting in the sub-division of Stage III into IIIa (potentially operable disease) and IIIb (inoperable disease). Kaplan-Meier survival analyses and Cox regression analyses were used to analyze data from 129 Stage III NSCLC patients who had been treated on two consecutive Phase II trials testing combined modality treatment. ⋯ Kaplan-Meier statistics revealed significantly longer survival for PS 0-1 versus 2-3 (p = .001), for eligible versus ineligible for surgery (p = .003), for Stage-IIIa versus IIIb (p = .004), and for Stage-IIIa T3N0 versus IIIa N2 versus IIIb (p = .004). The best model developed from Cox regression analyses included stage (IIIa T3 N0 vs IIIa N2 vs IIIb), PS, and sex. These observations appear to have implications for clinical research in Stage III NSCLC.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 1991
Conditions for the equivalence of continuous to pulsed low dose rate brachytherapy.
Low dose rate interstitial brachytherapy is extremely useful for those tumors that are accessible for an implant, while the introduction of remote afterloaders has eliminated exposure to nursing personnel. Currently, such machines require an inventory of many sources which are loaded into catheters implanted in the tumor and kept in place during treatment. A significant simplification of such machines would be possible in a pulsed mode, with a single source moving under computer control through the catheters. ⋯ For a regimen of 30 Gy in 60 hr, a pulse width of 10 min with a period between pulses of 1 hr would be appropriate for all the cell lines considered. Similar results were found for other possible time/dose combinations. For late effects, a 1-hr period between 10-min pulses might produce up to a 2% increase in late-effect probability, which is probably acceptable for the small volumes irradiated in interstitial brachytherapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Dec 1990
Randomized Controlled Trial Comparative Study Clinical TrialTwo or six hyperthermia treatments as an adjunct to radiation therapy yield similar tumor responses: results of a randomized trial.
From March 1984 to February 1988, 70 patients with 179 separate treatment fields containing superficially located (less than 3 cm from surface) recurrent or metastatic malignancies were stratified based on tumor size, histology, and prior radiation therapy and enrolled in prospective randomized trials comparing two versus six hyperthermia treatments as an adjunct to standardized courses of radiation therapy. A total of 165 fields completed the combined hyperthermia-radiation therapy protocols and were evaluable for response. No statistically significant differences were observed between the two treatment arms with respect to tumor location; histology; initial tumor volume; patient age and pretreatment performance status; extent of prior radiation therapy, chemotherapy, hormonal therapy, or immunotherapy; or concurrent radiation therapy. ⋯ The mean of the minimum intratumoral temperatures (less than 41 degrees C vs. greater than or equal to 41 degrees C) was of borderline prognostic significance in the univariate analysis, and added to the power of the best three covariate model. Neither the actual number of hyperthermia treatments administered nor the hyperthermia protocol group (two versus six treatments) correlated with duration of local control. The development of thermotolerance is postulated to be, at least in part, responsible for limiting the effectiveness of multiple closely spaced hyperthermia treatments.