| 1. |
|
|
| 2. |
- Adell, Gunnar, 1953-, et al.
(författare)
-
Decreased tumor cell proliferation as an indicator of the effect of preoperative radiotherapy of rectal cancer
- 2001
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - 0360-3016 .- 1879-355X. ; 50:3, s. 659-663
-
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.
|
|
| 3. |
- Adjeiwaah, Mary, 1980-, et al.
(författare)
-
Dosimetric Impact of MRI Distortions : A Study on Head and Neck Cancers
- 2019
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 103:4, s. 994-1003
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the effect of magnetic resonance (MR) imaging (MRI) geometric distortions on head and neck radiation therapy treatment planning (RTP) for an MRI-only RTP. We also assessed the potential benefits of patient-specific shimming to reduce the magnitude of MR distortions for a 3-T scanner.Methods and Materials: Using an in-house Matlab algorithm, shimming within entire imaging volumes and user-defined regions of interest were simulated. We deformed 21 patient computed tomography (CT) images with MR distortion fields (gradient nonlinearity and patient-induced susceptibility effects) to create distorted CT (dCT) images using bandwidths of 122 and 488 Hz/mm at 3 T. Field parameters from volumetric modulated arc therapy plans initially optimized on dCT data sets were transferred to CT data to compute a new plan. Both plans were compared to determine the impact of distortions on dose distributions.Results: Shimming across entire patient volumes decreased the percentage of voxels with distortions of more than 2 mm from 15.4% to 2.0%. Using the user-defined region of interest (ROI) shimming strategy, (here the Planning target volume (PTV) was the chosen ROI volume) led to increased geometric for volumes outside the PTV, as such voxels within the spinal cord with geometric shifts above 2 mm increased from 11.5% to 32.3%. The worst phantom-measured residual system distortions after 3-dimensional gradient nonlinearity correction within a radial distance of 200 mm from the isocenter was 2.17 mm. For all patients, voxels with distortion shifts of more than 2 mm resulting from patient-induced susceptibility effects were 15.4% and 0.0% using bandwidths of 122 Hz/mm and 488 Hz/mm at 3 T. Dose differences between dCT and CT treatment plans in D-50 at the planning target volume were 0.4% +/- 0.6% and 0.3% +/- 0.5% at 122 and 488 Hz/mm, respectively.Conclusions: The overall effect of MRI geometric distortions on data used for RTP was minimal. Shimming over entire imaging volumes decreased distortions, but user-defined subvolume shimming introduced significant errors in nearby organs and should probably be avoided.
|
|
| 4. |
- Adjeiwaah, Mary, et al.
(författare)
-
Quantifying the Effect of 3T Magnetic Resonance Imaging Residual System Distortions and Patient-Induced Susceptibility Distortions on Radiation Therapy Treatment Planning for Prostate Cancer
- 2018
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 100:2, s. 317-324
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the effect of magnetic resonance system- and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers.Methods and Materials: Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution.Results: Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of <0.5% between distorted and undistorted treatment plans. The 90% confidence intervals of the mean difference between the dCT and CT treatment plans were all within an equivalence interval of (−0.5, 0.5) for all investigated plan quality measures.Conclusions: Patient-induced susceptibility distortions at high field strengths in closed bore magnetic resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%.
|
|
| 5. |
- Adra, Jamila, et al.
(författare)
-
Distribution of locoregional breast cancer recurrence in relation to postoperative radiation fields and biological subtypes.
- 2019
-
Ingår i: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 105:2, s. 285-295
-
Tidskriftsartikel (refereegranskat)abstract
- and purpose: To investigate incidence and location of locoregional recurrence (LRR) in patients who have received postoperative locoregional radiotherapy (LRRT) for primary breast cancer. LRR-position in relation to applied radiotherapy and the primary tumours biological subtype were analysed with the aim to evaluate current target guidelines and RT techniques in relation to tumour biology.Medical records were reviewed for all patients who received postoperative LRRT for primary BC in southwestern Sweden from 2004-2008 (N=923). Patients with LRR as a first event were identified (N=57, distant failure and death were considered competing risks). CT images identifying LRR were used to compare LRR locations to postoperative LRRT fields. LRR risk and distribution were then related to the primary BC biological subtype and to current target guidelines.Cumulative LRR incidence after 10 years was 7.1% (95%CI 5.5-9.1). Fifty-seven of the 923 patients in the cohort developed LRR (30 local recurrences (LR), 30 regional recurrences (RR), of which 3 cases of simultaneous LR/RR). Most cases of LRR developed fully (56%) or partially (26%) within postoperatively irradiated areas. The most common location for out-of-field RR was cranial to RT fields in the supraclavicular fossa. Patients with an ER- (HR 4.6, p<0.001, 95%CI 2.5-8.4) or HER2+ (HR 2.4, p=0.007, 95%CI 1.3-4.7) primary BC presented higher risks of LRR compared to those with ER+ tumours. ER-/HER2+ tumours more frequently recurred in-field (68%) rather than marginal/out-of-field (32%). In addition, 75% of in-field recurrences derived from an ER-/HER+ tumour, compared to 45% of marginal/out-of-field recurrences. A complete pathological response in the axilla after neoadjuvant treatment was associated with a lower degree of LRR risk (p=0.022).Incidence and locations of LRR seems to be related to the primary BC biological subtype. Individualized LRRT according to tumour biology may be applied to improve outcomes.
|
|
| 6. |
- Aksnessaether, Bjorg Y., et al.
(författare)
-
In Reply to Sari et al
- 2020
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 107:2, s. 388-389
-
Tidskriftsartikel (refereegranskat)
|
|
| 7. |
- Aksnessaether, Bjorg Y., et al.
(författare)
-
Second Cancers in Patients With Locally Advanced Prostate Cancer Randomized to Lifelong Endocrine Treatment With or Without Radical Radiation Therapy : Long-Term Follow-up of the Scandinavian Prostate Cancer Group-7 Trial
- 2020
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 106:4, s. 706-714
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Curative radiation therapy (RT) constitutes a cornerstone in prostate cancer (PC) treatment. We present long-term follow-up estimates for second cancer (SC) risk and overall survival (OS) in patients randomized to hormone therapy (ET) alone or combined with 70 Gy prostatic RT in the Scandinavian Prostate Cancer Group-7 (SPCG-7) study. We explored the effect of salvage RT (≥60 Gy to the ET group) and reported causes of death.Methods and Materials: The SPCG-7 study (1996-2002) was a randomized controlled trial that included 875 men with locally advanced nonmetastatic PC. In this analysis, including data from the Norwegian and Swedish Cancer and Cause of Death registries for 651 Norwegian and 209 Swedish study patients, we estimated hazard ratios (HRs) for SC and death, and cumulative incidences of SC.Results: Median follow-up of the 860 (431 ET and 429) ET + RT patients was 12.2 years for SC risk analysis and 12.6 years for the OS analysis. Eighty-three of the Norwegian ET patients received salvage RT, and median time to salvage RT was 5.9 years. We found 125 and 168 SCs in the ET and ET + RT patients, respectively. With ET alone as reference, ET + RT patients had an HR of 1.19 (95% confidence interval [CI], 0.92-1.54) for all SCs and 2.54 (95% CI, 1.14-5.69) for urinary bladder cancer (UBC). The total number of UBC was 31 (23 in ET + RT; 8 in ET), and the vast majority (85%) were superficial. The HR for SC in salvage RT patients was 0.48 (95% CI, 0.24-0.94). Median OS was 12.8 (95% CI, 11.8-13.8) and 15.3 (95%, CI 14.3-16.4) years in the ET and ET + RT groups, respectively. Compared with ET alone, the risk of death was reduced in ET + RT patients (HR, 0.73; 95% CI, 0.62-0.86) and in ET patients receiving salvage RT (HR, 0.44; 95% CI, 0.30-0.65).Conclusions: Although the risk of UBC was increased in PC patients who received RT in addition to ET, this disadvantage is outweighed by the OS benefit of RT confirmed in our study. The risk of SC, and especially UBC, should be discussed with patients and be reflected in follow-up programs.
|
|
| 8. |
- Al-Ubaidi, Firas L. T., et al.
(författare)
-
CASTRATION THERAPY OF PROSTATE CANCER RESULTS IN DOWNREGULATION OF HIF-1 alpha LEVELS
- 2012
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 82:3, s. 1243-1248
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Neoadjuvant androgen deprivation in combination with radiotherapy of prostate cancer is used to improve radioresponsiveness and local tumor control. Currently, the underlying mechanism is not well understood. Because hypoxia causes resistance to radiotherapy, we wanted to test whether castration affects the degree of hypoxia in prostate cancer. Methods and Materials: In 14 patients with locally advanced prostate cancer, six to 12 prostatic needle core biopsy specimens were taken prior to castration therapy. Bilateral orchidectomy was performed in 7 patients, and 7 were treated with a GnRH-agonist (leuprorelin). After castrationm two to four prostatic core biopsy specimens were taken, and the level of hypoxia-inducible factor-1 alpha (HIF-1 alpha) in cancer was determined by immunofluorescence. Results: Among biopsy specimens taken before castration, strong HIF-1 alpha expression (mean intensity above 30) was shown in 5 patients, weak expression (mean intensity 10-30) in 3 patients, and background levels of HIF-1 alpha (mean intensity 0-10) in 6 patients. Downregulation of HIF-1 alpha expression after castration was observed in all 5 patients with strong HIF-1 alpha precastration expression. HIF-1 alpha expression was also reduced in 2 of 3 patients with weak HIF-1 alpha precastration expression. Conclusions: Our data suggest that neoadjuvant castration decreases tumor cell hypoxia in prostate cancer, which may explain increased radiosensitivity after castration.
|
|
| 9. |
|
|
| 10. |
- Alsadius, David, 1975, et al.
(författare)
-
Mean Absorbed Dose to the Anal-Sphincter Region and Fecal Leakage among Irradiated Prostate Cancer Survivors.
- 2012
-
Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 84:2
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To supplement previous findings that the absorbed dose of ionizing radiation to the anal sphincter or lower rectum affects the occurrence of fecal leakage among irradiated prostate-cancer survivors. We also wanted to determine whether anatomically defining the anal-sphincter region as the organ at risk could increase the degree of evidence underlying clinical guidelines for restriction doses to eliminate this excess risk. METHODS AND MATERIALS: We identified 985 men irradiated for prostate cancer between 1993 and 2006. In 2008, we assessed long-term gastrointestinal symptoms among these men using a study-specific questionnaire. We restrict the analysis to the 414 men who had been treated with external beam radiation therapy only (no brachytherapy) to a total dose of 70 Gy in 2-Gy daily fractions to the prostate or postoperative prostatic region. On reconstructed original radiation therapy dose plans, we delineated the anal-sphincter region as an organ at risk. RESULTS: We found that the prevalence of long-term fecal leakage at least once per month was strongly correlated with the mean dose to the anal-sphincter region. Examining different dose intervals, we found a large increase at 40 Gy; ≥40 Gy compared with <40 Gy gave a prevalence ratio of 3.8 (95% confidence interval 1.6-8.6). CONCLUSIONS: This long-term study shows that mean absorbed dose to the anal-sphincter region is associated with the occurrence of long-term fecal leakage among irradiated prostate-cancer survivors; delineating the anal-sphincter region separately from the rectum and applying a restriction of a mean dose <40 Gy will, according to our data, reduce the risk considerably.
|
|
