| 1. |
- Latifi, Ali, et al.
(författare)
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The accuracy of focused abdominal CT in patients presenting to the emergency department
- 2009
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Ingår i: Emergency Radiology. - : Springer Science and Business Media LLC. - 1070-3004 .- 1438-1435. ; 16:3, s. 209-215
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Tidskriftsartikel (refereegranskat)abstract
- Focused computed tomography(CT) examination (FCT) is CT limited to a specific abdominal area in an attempt to reduce radiation exposure. We wanted to evaluate FCT on the basis of information from the request form and thus reduce radiation dose to the patient without missing relevant findings. We retrospectively analyzed 189 consecutive acute abdominal CT, dividing the findings as localized in the upper or lower abdomen. Another researcher blindly determined where the CT should be focused to, based only on information provided in the request form. The sensitivity and specificity of FCT in patients with symptoms from only upper abdomen was 100%. Sensitivity, specificity, and accuracy of FCT in patients with symptom from only lower abdomen were 79%, 100%, and 92%, respectively. Our study suggests that among patients with symptoms from the lower abdomen, not examining the upper abdomen would lead to missing relevant findings.
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| 2. |
- Darkeh, M. H. S. E., et al.
(författare)
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The minimum number of target lesions that need to be measured to be representative of the total number of target lesions (according to RECIST)
- 2009
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Ingår i: British Journal of Radiology. - : British Institute of Radiology. - 0007-1285 .- 1748-880X. ; 82:980, s. 681-6
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Tidskriftsartikel (refereegranskat)abstract
- Response evaluation criteria in solid tumours (RECIST) were introduced as a means to classify tumour response with no definition of the minimum number of lesions. This study was conducted in order to evaluate discrepancies between full assessments based on either all target lesions or fewer lesions. RECIST evaluation was performed on separate occasions based on between one and seven of the target lesions, with simultaneous assessment of non-target lesions. 99 patients were included. 38 patients demonstrated progressive disease, in 61% of whom it was a result of the appearance of new lesions or unequivocal progress in non-target lesions. 32 patients showed stable disease, with 8 having results that differed when 1-3 target lesions were measured. 22 cases were considered as having partial regression, with only 1 case differing when performing 1-3 target lesion assessments. Seven cases demonstrated complete response. The number of discordant cases increased gradually from measuring three lesions to one target lesion. The average number of available target lesions among those with discrepancies was 7.1, which was significantly higher than those demonstrating concordance (4.1 lesions; p<0.05). In conclusion, measuring fewer than four target lesions might cause discrepancies when more than five target lesions are present.
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| 3. |
- Suzuki, Chikako, et al.
(författare)
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Radiologic measurements of tumor response to treatment : practical approaches and limitations
- 2008
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Ingår i: Radiographics. - : Radiological Society of North America (RSNA). - 0271-5333 .- 1527-1323. ; 28:2, s. 329-44
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Tidskriftsartikel (refereegranskat)abstract
- Objective response assessment is important to describe the treatment effect of anticancer drugs. Standardization by using a "common language" is also important for comparison of results from different trials. In contrast to clinical results, which can be subjective, diagnostic imaging provides a greater opportunity for objectivity and standardization. It was generally accepted that a decrease in tumor size correlated with treatment effect; as a result, imaging was adopted for lesion measurement in the World Health Organization (WHO) criteria in 1979. However, because of some limitations of the WHO criteria, the Response Evaluation Criteria in Solid Tumors (RECIST) were introduced in 2000. In RECIST, imaging was recognized as indispensable for response evaluation of solid tumors. Nevertheless, the widespread use of multidetector computed tomography and other imaging innovations have made RECIST outdated, with a concomitant need for modifications. Meanwhile, newer anticancer agents with targeted mechanisms of action have demonstrated an inherent limitation and unsuitability of anatomic tumor evaluation that assesses only lesion size. In addition, the effect of these new drugs changes the paradigm according to which tumor response or response rate is measured. Complete and partial responses cannot be the end points in all clinical trials; in some cases, disease control or progression-free survival may be the more relevant end point.
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| 4. |
- Suzuki, Chikako, et al.
(författare)
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The importance of rectal cancer MRI protocols on interpretation accuracy
- 2008
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Ingår i: World Journal of Surgical Oncology. - : Springer Science and Business Media LLC. - 1477-7819. ; 6, s. 89-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Magnetic resonance imaging (MRI) is used for preoperative local staging in patients with rectal cancer. Our aim was to retrospectively study the effects of the imaging protocol on the staging accuracy. PATIENTS AND METHODS: MR-examinations of 37 patients with locally advanced disease were divided into two groups; compliant and noncompliant, based on the imaging protocol, without knowledge of the histopathological results. A compliant rectal cancer imaging protocol was defined as including T2-weighted imaging in the sagittal and axial planes with supplementary coronal in low rectal tumors, alongside a high-resolution plane perpendicular to the rectum at the level of the primary tumor. Protocols not complying with these criteria were defined as noncompliant. Histopathological results were used as gold standard. RESULTS: Compliant rectal imaging protocols showed significantly better correlation with histopathological results regarding assessment of anterior organ involvement (sensitivity and specificity rates in compliant group were 86% and 94%, respectively vs. 50% and 33% in the noncompliant group). Compliant imaging protocols also used statistically significantly smaller voxel sizes and fewer number of MR sequences than the noncompliant protocols CONCLUSION: Appropriate MR imaging protocols enable more accurate local staging of locally advanced rectal tumors with less number of sequences and without intravenous gadolinium contrast agents.
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| 5. |
- Syk, Erik, et al.
(författare)
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Local recurrence in rectal cancer : anatomic localization and effect on radiation target
- 2008
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 72:3, s. 658-64
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To determine the sites of local recurrence after total mesorectal excision for rectal cancer in an effort to optimize the radiation target. METHODS AND MATERIALS: A total of 155 patients with recurrence after abdominal resection for rectal cancer were identified from a population-based consecutive cohort of 2,315 patients who had undergone surgery by surgeons trained in the total mesorectal excision procedure. A total of 99 cross-sectional imaging studies were retrieved and re-examined by one radiologist. The clinical records were examined for the remaining patients. RESULTS: Evidence of residual mesorectal fat was identified in 50 of the 99 patients. In 83 patients, local recurrence was identified on the imaging studies. All recurrences were within the irradiated volume if the patients had undergone preoperative radiotherapy or within the same volume if they had not. The site of recurrence was in the lower 75% of the pelvis, anatomically below the S1-S2 interspace for all patients. Only 5 of the 44 recurrences in patients with primary tumors >5 cm from the anal verge were in the lowest 20% of the pelvis. Six recurrences involved the lateral lymph nodes. CONCLUSION: These data suggest that a lowering of the upper limit of the clinical target volume could be introduced. The anal sphincter complex with surrounding tissue could also be excluded in patients with primary tumors >5 cm from the anal verge.
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| 6. |
- Syk, Erik, et al.
(författare)
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Radiological findings do not support lateral residual tumour as a major cause of local recurrence of rectal cancer
- 2006
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Ingår i: British Journal of Surgery. - West Sussex, United Kingdom : Oxford University Press (OUP). - 0007-1323 .- 1365-2168. ; 93:1, s. 113-119
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: The aim of this study was to determine the sites of local recurrence following radical (R0) total mesorectal excision (TME) for rectal cancer in an effort to elucidate the reasons for recurrence. METHODS: Thirty-seven patients with recurrence following curative resection for rectal cancer were identified from a population of 880 patients operated on by surgeons trained in the TME procedure. Two radiologists independently examined 33 available computed tomograms and magnetic resonance images taken when the recurrence was detected. RESULTS: Twenty-nine of the 33 recurrences were found in the lower two-thirds of the pelvis. Two recurrent tumours appeared to originate from lateral pelvic lymph nodes. Evidence of residual mesorectal fat was identified in 15 patients. Fourteen of the recurrent tumours originated from primary tumours in the upper rectum; all of these tumours recurred at the anastomosis and 12 of the 14 patients had evidence of residual mesorectal fat. CONCLUSION: Lateral pelvic lymph node metastases are not a major cause of local recurrence after TME. Partial mesorectal excision may be associated with an increased risk of local recurrence from tumours in the upper rectum.
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| 7. |
- Torkzad, Michael R., et al.
(författare)
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Enterclysis versus enterography : the unsettled issue
- 2009
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 19:1, s. 90-91; discussion 92
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Torkzad, Michael R
(författare)
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Magnetic resonance imaging of rectum : diagnostic and therapy related aspects
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Papers I-II: The purpose of paper 1 was to assess the size and configuration of the perirectal fatty tissues (PF) using magnetic resonance imaging (MRI). In 25 subjects the volume and cross-sectional parameters based on the amount of PF to different sides of die rectum, and the total area occupied were retrospectively measured on MRI. There was a good correlation between anteroposterior diameter of the PF at four centimeter below S 1-2 (and the left-to-right diameter seven centimeter below S 1-2), and mesorectal volume (NW). Furthermore, the form of PF differed significantly between male and female subjects. In paper II, we analyzed the influence of MV on the accuracy of the first preoperative MRI. 267 patients with rectal cancer had their MV measured without knowledge of the prospective evaluations by the radiologist or the pathologist, and the discrepancies in the results were correlated to the MV and clinical data. T- or N-staging accuracy by MRI did not significantly correlate to MV. The difference between assessment by radiologist and pathologist did not differ based on MV. Finally patients with larger MV did not have fewer cases with involvement of mesorectal fascia (MF) or involvement of neighboring organs. Thus, MV does not appear to affect the locoregional prognostic factors, nor is it able to explain the difference in evaluation between the radiologist and pathologist. Papers III-IV: In paper III we tried to find out if the tumor size on MRI in patients without preoperative radiotherapy correlates to the corresponding pathologic findings. 18 patients were included. The tumor size was measured on MR and histopathologic specimen. Regression curves showed best correlations for area (r2=0.75) and volume (r2=0.65-0.82). With the formula proposed from this material, we assume that rectal tumors can be measured on MR images using a metric model, and then extrapolated to what we would expect from pathology, hence providing us with a tool where we could measure tumor response after neoadjuvant therapy. In paper IV, we used these tools to evaluate changes after radiotherapy and correlation between MRI and histopathology. RVs was defined as the residual pathologic tumor volume while RVm was similarly defined as the residual MRI tumor volume at 2 nd MRI. 25 patients with MRI before and after radiotherapy were included. The second MRI was not more accurate than the initial MRI for assessment of the T-stage or distance to circumferential resection margin (CRM). RVm showed significant correlation to RVs and pathologic T-stage. A 2 nd MRI alone after radiotherapy with delay before surgery has limited value in understanding the individual response to therapy, but followup volumetry can be helpful to understand which tumors have responded. Paper V: The aim of this study was to determine the sites of local recurrence (LR) following radical total mesorectal excision (TME) for rectal cancer in an effort to elucidate the reasons for recurrence. 33 CT and MRI of 37 patients with LR were examined. 29 LR were found in the lower two-thirds of the pelvis, with two appearing to originate from lateral pelvic lymph nodes (LN). Evidence of residual PF was identified in 15 patients. 14 of the LR originated from primary tumors in the upper rectum and 12 of them with evidence of residual PF. Lateral pelvic LN metastases are not a major cause of LR after TME. Partial mesorectal excision may be associated with an increased risk of LR from tumors in the upper rectum.
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| 9. |
- Torkzad, Michael R., 1968-, et al.
(författare)
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Morphological assessment of the interface between tumor and neighboring tissues, by magnetic resonance imaging, before and after radiotherapy in patients with locally advanced rectal cancer
- 2008
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 49:10, s. 1099-103
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Magnetic resonance imaging (MRI) in rectal cancer is sometimes performed after radiotherapy (MRI 2) to evaluate tumor response and to choose alternative forms of surgery. The accuracy of MRI 2 in distinguishing tumor delineation might be difficult due to fibrosis. PURPOSE: To evaluate the morphological changes in the interface between the tumor and neighboring organs on MRI 2 performed after radiotherapy, and to assess the accuracies of MRI before and after radiotherapy compared to histopathology after surgery. MATERIAL AND METHODS: Sixteen patients with locally advanced primary rectal cancer, with MRI before and after radiotherapy, were retrospectively studied, concerning the interface between the tumor and neighboring structures. The accuracies of MRI before and after radiotherapy were compared based on histopathology as a reference. RESULTS: The accuracies of both MRI before and after radiotherapy were moderate, with no additional value of MRI after radiotherapy compared to MRI before radiotherapy. The most predictive form of interface for involvement of a neighboring organ after radiotherapy was nodular growth of the tumor into a neighboring structure. CONCLUSION: The morphological assessment of pelvic MRI after preoperative radiotherapy does not provide any significant new information about tumor extent in patients with locally advanced rectal cancer.
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| 10. |
- Torkzad, Michael R., et al.
(författare)
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MRI after preoperative radiotherapy for rectal cancer; correlation with histopathology and the role of volumetry.
- 2007
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 17:6, s. 1566-1573
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Tidskriftsartikel (refereegranskat)abstract
- The objective is to assess if tumor size after radiotherapy in patients with rectal cancer can be assessed by a second magnetic resonance imaging (MRI), after radiotherapy prior to surgery and to correlate changes observed on MRI with findings at histopathology at surgery. Twenty-five patients with MRI before and after radiotherapy were included. Variables studied were changes in tumor size, T-staging and distance to the circumferential resection margin (CRM). RVs was measured as tumor volume at surgery (Vs) divided by tumor volume at the initial MRI (Vi) in percent. RVm was defined as the tumor volume at the second MRI (Vm) divided by Vi in percent. The ypT-stage was the same or more favorable than the initial MRI T-stage in 24 of 25 patients. The second MRI was not more accurately predictive than the initial MRI for ypT-staging or distance to CRM (p > 0.05). Vm correlated significantly to Vs, as did RVs to RVm, although the former was always smaller than the latter. Vm and RVm correlated well with ypT-stage (p < 0.001). Volumetry seems to correlate with ypT-stage after preoperative radiotherapy for resectable rectal cancer. The value of a second MRI after radiotherapy for assessment of distance to CRM and ypT-staging is, however, not apparent.
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