| 1. |
- Adell, Gunnar, 1953-, et al.
(författare)
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Decreased tumor cell proliferation as an indicator of the effect of preoperative radiotherapy of rectal cancer
- 2001
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016 .- 1879-355X. ; 50:3, s. 659-663
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rectal cancer is a common malignancy, with significant local recurrence and death rates. Preoperative radiotherapy and refined surgical technique can improve local control rates and disease-free survival.PURPOSE: To investigate the relationship between the tumor growth fraction in rectal cancer measured with Ki-67 and the outcome, with and without short-term preoperative radiotherapy.Method: Ki-67 (MIB-1) immunohistochemistry was used to measure tumor cell proliferation in the preoperative biopsy and the surgical specimen.MATERIALS: Specimens from 152 patients from the Southeast Swedish Health Care region were included in the Swedish rectal cancer trial 1987-1990.RESULTS: Tumors with low proliferation treated with preoperative radiotherapy had a significantly reduced recurrence rate. The influence on death from rectal cancer was shown only in the univariate analysis. Preoperative radiotherapy of tumors with high proliferation did not significantly improve local control and disease-free survival. The interaction between Ki-67 status and the benefit of radiotherapy was significant for the reduced recurrence rate (p = 0.03), with a trend toward improved disease-free survival (p = 0.08). In the surgery-alone group, Ki-67 staining did not significantly correlate with local recurrence or survival rates.CONCLUSION: Many Ki-67 stained tumor cells in the preoperative biopsy predicts an increased treatment failure rate after preoperative radiotherapy of rectal cancer.
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| 2. |
- Dewyngaert, J. Keith, et al.
(författare)
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Procedure for unmasking localization information from ProstaScint scans for prostate radiation therapy treatment planning
- 2004
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 60:2, s. 654-662
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To demonstrate a method to extract the meaningful biologic information from In-111-radiolabeled capromab pendetide (ProstaScint) SPECT scans for use in radiation therapy treatment planning by removing that component of the In-111 SPECT images associated with normal structures. Methods and Materials: We examined 20 of more than 80 patients who underwent simultaneous Tc-99m/In-111 SPECT scans, which were subsequently registered to the corresponding CT/MRI scans. A thresholding algorithm was used to identify Tc-99m uptake associated with blood vessels and CT electron density associated with bone marrow. Corresponding voxels were removed from the In-111 image set. Results: No single threshold value was found to be associated with the Tc-99m uptake that corresponded to the blood vessels. Intensity values were normalized to a global maximum and, as such, were dependent upon the quantity of Tc-99m pooled in the bladder. The reduced ProstaScint volume sets were segmented by use of a thresholding feature of the planning system and superimposed on the CT/MRI scans. Conclusions: ProstaScint images are now closer to becoming a biologically and therapeutically useful and accurate image set. After known sources of normal intensity are stripped away, the remaining areas that demonstrate uptake may be segmented and superimposed on the treatment-planning CT/MRI volume.
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| 3. |
- Knutsen Holmqvist, Annica, et al.
(författare)
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Survivin expression is an independent prognostic factor in rectal cancer patients with and without preoperative radiotherapy
- 2004
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Ingår i: Journal of chromatography. B. - 1570-0232 .- 1873-376X. ; 60:1, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Survivin, as an inhibitor of apoptosis, is undetectable in normal tissues but expressed in tumors. Survivin expression in rectal cancer patients who have undergone preoperative radiotherapy (RT) alone has not been studied. We analyzed the relationships of survivin expression to RT, clinicopathologic variables, apoptosis, and p53 expression in rectal cancer patients who participated in a trial of preoperative RT. Methods and Materials: Survivin was immunohistochemically examined in 98 rectal tumors (74 had adjacent normal mucosa). Of 98 patients, 57 underwent surgery alone and 41 underwent RT before surgery. Results: Survivin positivity was related to worse survival, independent of Dukes' stage, local and distant recurrence, differentiation, gender, age, apoptosis, and p53 expression (p = 0.02). Survivin was not associated with survival in the patients without (p = 0.08) or with (p = 0.19) RT. After RT, survivin tended to be increased in adjacent normal mucosa (p = 0.057) but not in tumors (p = 0.71). Conclusion: Survivin was independently related to survival in rectal cancer patients who participated in a trial of preoperative RT, but not in either treatment group (surgery alone or surgery plus RT). Whether the effect of survivin on tumors is associated with RT and further related to patient survival needs to be investigated in a larger number of patients. (C) 2004 Elsevier Inc.
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| 4. |
- Areberg, Johan, et al.
(författare)
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Antitumor effect of radioactive cisplatin (191Pt) on nude mice
- 2001
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016. ; 49:3, s. 827-832
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate the effect of (191)Pt-cisplatin in vivo in terms of the antitumor effect and general toxicity on tumor-bearing nude mice. METHODS AND MATERIALS: Tumor-bearing (human squamous cell carcinoma, AB) nude mice were divided into four groups and given, i.p., physiological saline (controls), cisplatin, (191)Pt-cisplatin (80 MBq/mg), or (191)Pt-cisplatin (160 MBq/mg), respectively. Mortality and weight were used as parameters for monitoring general toxic effect, while specific growth delay (SGD) and the area under the logarithm of the relative tumor size curve (AUC-log[RTS]) were used to evaluate the antitumor effect of the treatments. RESULTS: Both SGD and AUC-log(RTS) values showed that (191)Pt-cisplatin was significantly (P < 0.05) more effective in retarding tumor growth than nonradioactive cisplatin. No differences in mortality between the different groups could be observed and no significant differences in weight change between the mice treated with cisplatin or (191)Pt-cisplatin could be seen. CONCLUSION: (191)Pt-cisplatin is a more effective drug than nonradioactive cisplatin in retarding tumor growth on nude mice without adding systemic toxic effects. We believe that radioactive cisplatin may prove to be an alternative to conventional cisplatin; however, the possible toxic effects on organs at risk have to be thoroughly investigated.
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| 5. |
- Björk, Peter, et al.
(författare)
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Design and dosimetry characteristics of a soft-docking system for intraoperative radiation therapy
- 2000
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016. ; 47:2, s. 527-533
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The design concept and the dosimetric characteristics of an applicator system for intraoperative radiation therapy (IORT) with special emphasis on alignment methods, the effect of a plastic scatterer in the beam, radiation leakage, and misalignment dosimetry, are presented in this paper. MATERIALS AND METHODS: A soft-docking system for a linear accelerator, which enables collimation of electron beams (4-22 MeV) for IORT has been developed. The system includes twenty-one circular polymethylmethacrylate (PMMA) treatment cones of different lengths, diameters and end angles. All in-water measurements are made using p-type silicon diode detectors. RESULTS: The effect of introducing a PMMA scatterer in the therapeutic beam includes increased surface dose values (above 83% for all nominal electron energies and for all cones) and improved dose homogeneity within the therapeutic range. Electrons scattered from the inside wall of the cone result in dose profile horns at depth of dose maximum always lower than 109%. The radiation leakage outside the cone is less than 13%. Large changes in the dose profiles occur if the intraoperative cone is misaligned more than 0.5. CONCLUSION: The alignment procedure of the soft-docking system is easy to handle and the applicator design provides adequate collimation of electron beams for IORT.
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