| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nuclear Medicine |
1 From the Departments of Nuclear Medicine (E.E.S., Y.P., H.L., U.M.), Radiology (C.L.), Surgery "C" (M.R.), and Oncology (A.F.), Tel Aviv Sourasky Medical Center, 6 Weizman St, Tel Aviv 64239, Israel; and Department of Surgery "A," Sapir Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Israel (M.G.). Received July 8, 2003; revision requested September 25; final revision received December 23; accepted January 15, 2004. Address correspondence to E.E.S. (e-mail: evensap@tasmc.health.gov.il).
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
MATERIALS AND METHODS: Sixty-two patients were enrolled; 37 were men, and 25 were women. Seventeen patients underwent abdominoperineal resection and 45 underwent anterior resection with an anastomosis in the pelvic region before referral for PET/CT. Pelvic sites of fluorine 18 (18F) fluorodeoxyglucose (FDG) uptake were rated separately on PET and PET/CT images as benign or malignant on the basis of shape, location, and intensity of 18F FDG uptake (1–2 = benign and/or physiologic, 3 = equivocal, 4–5 = malignant). Two readers interpreted images in consensus. Altered pelvic anatomy and presence of presacral abnormalities were assessed with CT. Pelvic recurrence was confirmed with histologic analysis or clinical and imaging follow-up. Sensitivity, specificity, positive and negative predictive values, and accuracy of PET and PET/CT in the detection of pelvic recurrence were compared with lesion- and patient-based analyses by using the 
2 test. Clinical relevance of PET/CT assessment was determined.
RESULTS: Of 81 pelvic sites with increased 18F FDG uptake, 44 were malignant. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for differentiating malignant from benign 18F FDG uptake in the pelvis were 98%, 96%, 90%, 97%, and 93% for PET/CT and 82%, 65%, 73%, 75%, and 74% for PET, respectively. The most common cause for false-positive interpretation of PET findings was physiologic 18F FDG uptake in displaced pelvic organs. Presacral CT abnormalities were present in 30 (48%) of 62 patients, and seven (23%) abnormalities were malignant. PET/CT was used to distinguish benign and malignant presacral abnormalities with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 96%, 88%, and 100%, respectively. PET/CT findings were clinically relevant in 29 (47%) of 62 patients.
CONCLUSION: PET/CT is an accurate technique in the detection of pelvic recurrence after surgical removal of rectal cancer.
© RSNA, 2004
Index terms: Computed tomography (CT), technology, 757.12163, 757.12166 • Positron emission tomography (PET), technology, 757.12163, 757.12166 • Radionuclide imaging, comparative studies, 757.12163, 757.12166 • Rectum, neoplasms, 757.31
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
The functional data of fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET) have been reported to have an important complementary role in the detection of distant metastases and local recurrence and in the differentiation of tumoral and nontumoral masses in patients with colorectal cancer (5–7). As in the case of anatomic imaging modalities, however, the altered pelvic anatomy associated with surgical removal of primary rectal tumors may also have an effect on the interpretation of 18F FDG PET images, especially in the differentiation between tumoral 18F FDG uptake and physiologic 18F FDG uptake in the gastrointestinal or genitourinary tracts. In assessing the role of 18F FDG PET in the detection of local recurrence in 18 patients with rectal cancer who underwent abdominoperineal resection, Keogan et al (8) reported displaced bladder activity as a potential reason for incorrect interpretation of recurrent disease in the presacral region. They suggested appropriate hydration and prescan voiding, bladder catheterization, and registration of anatomic and metabolic images as ways to overcome this problem (8).
Systems that enable PET and CT data acquisition without changing patient positioning have recently been introduced for use in clinical practice (9–14). Lesions are characterized on PET/CT images by their metabolic status and anatomic details. Such fusion can also assist in the differentiation between physiologic and tumoral sites of 18F FDG uptake. Thus, the purpose of our study was to assess the role of PET/CT in the detection of pelvic recurrence in patients with colorectal cancer who underwent abdominoperineal or anterior resection.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
PET/CT Scanning
The patients fasted at least 4 hours prior to intravenous injection of 370–666 MBq (10–18 mCi) of 18F FDG. The administration of oral contrast material was added to the protocol after the study was already under way. Thus, the first 20 patients were assessed with PET/CT without oral contrast material, and the remaining 42 patients were assessed with iodinated oral contrast material, which allowed better discrimination between physiologic bowel activity and abdominal tumors (15). Blood glucose levels were checked in patients with diabetes and patients who were not certain about their blood glucose levels prior to the injection of 18F FDG. A PET/CT examination was performed only when blood glucose levels did not exceed 150 mg/dL (8.3 mmol/L). Scanning from the base of the skull through the midthigh was performed with the Discovery LS PET/CT system (GE Medical Systems, Milwaukee, Wis). Low-dose CT scanning was performed first (140kV, 80 mA, 0.8 seconds per CT rotation, pitch of 6, and table speed of 22.5 mm/sec) (11), without any specific breath-holding instructions. PET scanning was performed immediately after acquisition of the CT images, without changing the patient position. Between five and eight bed positions were used for imaging, with an acquisition time of 5 minutes for each position. PET images were reconstructed by using an ordered set expectation maximization algorithm. CT data were used for attenuation correction.
PET/CT Image Interpretation
Images were interpreted at a workstation (eNTEGRA; Elgems, Haifa, Israel) equipped with fusion software that enables the display of PET images with and without attenuation correction, CT images, and PET/CT images.
For the purpose of this study, PET and PET/CT images were interpreted in two sequential steps on separate days, at least 1 week apart, in a consensus reading by two readers (E.E.S. and U.M.) with experience in interpretation of PET/CT images. With regard to reader experience, a PET/CT system was installed in the department in May 2002, and, on average, these two readers interpret 16 studies daily in a consensus reading. The patients’ names were removed from the reports, and images were presented in a different order for the second step of interpretation. In keeping with the purpose of the study, interpretation was focused on pelvic findings; however, extrapelvic lesions with 18F FDG uptake were also recorded to determine overall clinical relevance of PET/CT in this patient population.
The interpretation sheet was divided into the following three sections: findings on PET images, findings on PET/CT images, and relevant CT anatomic data. Uptake sites were interpreted as benign or malignant on the basis of shape, location, and intensity. Each lesion was assessed on transverse, coronal-sagittal, and three-dimensional maximum intensity projection images, and its 18F FDG uptake was expressed as the maximal standard uptake value. The latter semiquantitative parameter was automatically obtained on the patient’s final report and was calculated as the ratio of activity in tissue per milliliter to the activity in the injected dose per patient body weight in kilograms. 18F FDG uptake in the urinary bladder along the ureters or elongated uptake that followed the shape of the bowel when traced along the three-dimensional images was considered to be clear physiologic uptake. These sites were recorded, but they were not included in analysis of the results. Uptake sites in stomas or recent surgical incisions were not included, either.
Other sites of increased 18F FDG uptake in the pelvis were categorized as follows: A score of 1 indicated that the lesion was nontumoral (benign or physiologic); a score of 2, that the lesion was probably nontumoral; a score of 3, that the lesion was equivocal; a score of 4, that the lesion was probably malignant; and a score of 5, that the lesion was malignant (16). A lesion was categorized as 1 or 2 if it did not follow the previously described physiologic 18F FDG uptake patterns and was not thought to represent a tumor site. These lesions were of low intensity and/or were located at the anatomic location of organs or structures that may be associated with nontumoral 18F FDG uptake, such as the blood vessels, endometrium or functional ovarian cysts, rectal stump or levator ani, or field of recent surgery or radiation therapy (17). Lesions categorized as 4 or 5 were lesions with focal intense 18F FDG uptake and/or lesions in the anatomic location of pelvic lymph nodes, anastomotic site, abdominal wall (not the incision or colostomy), presacral region, or peritoneal cavity. Categorizing a suspected benign lesion as 1 or 2 and a suspected malignant lesion as 4 or 5 indicates the degree of certainty in the interpretation. If readers could not decide whether a lesion was benign or malignant on the basis of the previous criteria, the lesion was categorized as 3.
Interpretation of PET/CT images also included the anatomic localization of 18F FDG uptake sites. On the CT part of the integrated PET/CT image, the two main features assessed were displacement of pelvic organs from their normal anatomic location and the presence of CT abnormalities, especially in the presacral region.
Data Analysis
The clinical follow-up and final diagnosis of the scintigraphic lesions were investigated together by two physicians (Y.P. and H.L.) who did not participate in the image interpretation part of this study. The medical records of all the study patients were reviewed. Reports of diagnostic CT performed within 6 weeks of the PET/CT examination were available for all patients. The final diagnosis was based on histologic findings and imaging and clinical follow-up data for at least 6 months (mean, 8 months ± 2.6). Follow-up with other imaging modalities included diagnostic full-dose CT (n = 38), ultrasonography (US) (n = 4), magnetic resonance (MR) imaging (n = 5), transrectal US (n = 5), colonoscopy (n = 11), and repeat PET/CT (n = 9). These PET/CT images were used only for validation of the early PET/CT findings and were not included in the results analysis.
A lesion that was depicted with PET or PET/CT was considered to be true-positive if histologic findings were positive or if the lesion was depicted with other imaging modalities and showed either improvement after successful treatment or progression at follow-up imaging after unsuccessful therapy. A lesion that was depicted with other imaging modalities but not with PET or PET/CT was considered to be true-negative if histologic findings were negative or the lesion disappeared or remained unchanged without treatment at follow-up imaging, without clinical deterioration for at least 6 months (18).
The clinical relevance of assessment with PET/CT was determined. Findings were clinically relevant when PET/CT excluded the presence of disease that was suspected before PET/CT assessment and depicted tumor sites in patients with unexplained rising carcinoembryonic antigen levels, a more extensive local-regional pelvic disease than was previously suspected, and unexpected remote tumor sites. PET/CT findings were also correlated with surgical findings in patients with proved pelvic recurrence.
Statistical Analysis
Comparison of the standard uptake value in malignant versus benign lesions was performed by using the mixed model, which allows for analysis of an unequal number of lesions per patient. In this hierarchical model, metastases are considered to be a random effect in patients. The individual intercept was also introduced into the model as a random effect. This statistical analysis was performed by using the SAS system for Windows, version 8.01 (SAS Institute, Cary, NC). The degree of certainty in differentiating benign and malignant lesions was expressed as the mean rate for benign and malignant lesions. Mean rate values of PET and PET/CT were compared by using the unpaired t test.
The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of PET and PET/CT in the diagnosis of pelvic malignancy were assessed with lesion- and patient-based analyses. The McNemar test (2 test) was used for comparison of the sensitivity and specificity of PET and PET/CT. A P value of less than .05 was considered to indicate a statistically significant difference (10,14). Statistical analysis was performed by using the SSPS for Windows package (version 11; SPSS, Chicago, Ill).
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
Assessment of Pelvic Recurrence
A total of 88 foci of increased 18F FDG uptake, which were not clear physiologic sites of uptake, were detected in the region of the pelvis. In 81 of these lesions, the standard of reference for the final diagnosis was either histologic analysis (n = 30) or correlation with clinical and imaging follow-up (n = 51). The exact diagnosis could not be determined in the remaining seven lesions, and they were not included in the analysis of the results. These seven sites of 18F FDG uptake were lesions for which further validation was not clinically indicated because the patients had proved malignancy in other locations, and the therapeutic approach was already determined. Of the 81 pelvic lesions, 44 were tumor sites, and 37 were nontumoral sites of 18F FDG uptake.
Tumor sites were located in the region of anastomosis (n = 6), colorectum or rectal stump (n = 6), metastatic lymph nodes (n = 16), peritoneal or presacral soft-tissue masses (n = 11 [one patient had adjacent sacral neural foramen involvement; this finding was further validated with MR imaging]), abdominal wall (n = 2), adnexal metastasis (n = 1), and pelvic side walls (n = 1).
Nontumoral 18F FDG uptake sites were located in the gastrointestinal tract (n = 22, including nine in small bowel loops, five in the colon, four in the rectum or rectal stump, and four in the anus), urinary bladder or ureter (n = 3), seminal vesicles (n = 1), uterus (n = 1), abdominal wall (n = 3 [an abscess was diagnosed with needle aspiration biopsy in one patient]), reactive inguinal lymph node (n = 1), and site of a recent anastomosis (n = 1).
Of the 62 study patients, 16 did not have any suspected pelvic sites of uptake. Of the remaining 46 patients, 17 had pelvic metastases (a solitary lesion in six patients and multiple lesions in 11), six had pelvic metastases and nontumoral pelvic sites of 18F FDG uptake, and 23 had nontumoral pelvic lesions (a solitary lesion in 17 and multiple lesions in six). Comparison of the standard uptake value in malignant versus benign lesions was performed by using the mixed model, which allows for analysis of an unequal number of lesions per patient. The average standard 18F FDG uptake value of malignant metastases was 5.5 ± 3.7, and the average standard uptake value of benign lesions was 4.9 ± 3.4. This difference was not significant (F = 1.29, P = .307).
By using the previously described rating scale to separate benign from malignant lesions, the mean rate in the interpretation of 44 malignant lesions was 4.77 ± 0.6 (95% confidence interval: 4.60, 4.95) with PET/CT and 4.34 ± 1.17 (95% confidence interval: 4.00, 4.69) with PET (P < .05). The mean rate in the interpretation of 37 benign lesions was 1.32 ± 0.74 (95% confidence interval: 1.09, 1.56) with PET/CT and 2.49 ± 1.31 (95% confidence interval: 2.07, –2.92) with PET (P < .001).
Comparison between PET and PET/CT in the assessment of pelvic recurrence.—Table 1 summarizes the comparison of interpretations of pelvic lesions with PET and PET/CT. In the 44 pelvic tumor sites, PET interpretation was true-positive in 36 lesions, false-negative in five, and equivocal in three. PET/CT interpretation was true-positive in 43 lesions and false-negative in one. The single false-negative PET/CT pelvic lesion was an intraluminal recurrence. In the 37 nontumoral sites of uptake, PET interpretation was true-negative in 24 lesions, false-positive in 10, and equivocal in three. PET/CT interpretation was true-negative in 32 lesions, false-positive in one, and equivocal in four. The five pelvic lesions interpreted as false-positive or equivocal with PET/ CT were located in the gastrointestinal tract (n = 3), prostate (n = 1), and uterus (n = 1).
|
2 test to compare PET and PET/CT image interpretation of pelvic recurrence; PET/CT was more sensitive (2, 9.14; P < .01) and more specific (2, 10.13; P < .01) than PET for assessment of pelvic disease. PET/CT was more accurate in the assessment of the nature of pelvic sites of uptake in 15 (19%) of the 81 detected lesions, including seven tumor sites and eight nontumoral sites. Seven tumoral lesions that were interpreted as true-positive at PET/CT were interpreted as false-negative or equivocal at PET. Four of these lesions were soft-tissue peritoneal masses (Fig 1), two were metastatic lymph nodes, and one was an intraluminal recurrence. These lesions were validated as tumor sites on the basis of histologic findings in five patients and as disease progression at imaging follow-up in two. In eight nontumoral sites of uptake interpreted as true-negative at PET/CT, the PET interpretation was false-positive or equivocal as a result of physiologic uptake in the gastrointestinal (n = 6) or genitourinary (n = 2) tract. All the latter lesions were located in organs that were displaced from their normal anatomic location as a result of previous pelvic surgery and/or radiation therapy. These findings were validated as nonmalignant on the basis of clinical and imaging follow-up. Displacement of pelvic organs, including the small and large bowel, prostate, seminal vesicles, uterus, and vagina, from their normal anatomic locations was recorded when CT images were interpreted in 20 (32%) of the 62 patients. The urinary bladder showed either funneling or posterior displacement (Fig 2).
|
|
|
|
2 test was used to compare PET and PET/CT interpretation of pelvic recurrence on a patient-based analysis, and PET/CT was found to be more specific than PET in the assessment of pelvic disease. The 2 value was 0.5 for sensitivity and 4.17 for specificity (P < .05). Table 2 summarizes the calculated sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET and PET/CT in the differentiation of malignant and nonmalignant sites of 18F FDG uptake in the pelvis with lesion- and patient-based analyses.
|
|
|
|
Patients with unexplained rising carcinoembryonic antigen levels.—PET/CT depicted tumor sites in 13 (81%) of the 16 patients referred for PET/CT as a result of unexplained rising carcinoembryonic antigen levels. Pelvic recurrence was depicted in five of these 13 patients, and extrapelvic metastases were depicted in nine. One patient had both pelvic recurrence and extrapelvic metastases. Extrapelvic tumor sites were located in the lymph nodes (n = 2), liver (n = 6), and lung (n = 3), and two patients had intraperitoneal masses. Of the 13 patients, nine were referred for chemotherapy, and four were referred for surgery. Two of the three patients with negative PET/CT findings remained disease free, and the third had intraluminal recurrent disease at repeat colonoscopy.
Patients suspected of having pelvic recurrence at diagnostic CT and/or colonoscopy prior to PET/CT.—Only 13 of the 22 patients referred for 18F FDG assessment because of suspected pelvic recurrence at diagnostic CT and/or colonoscopy had evidence of pelvic tumor at histopathologic analysis, imaging, and clinical follow-up. PET/CT was true-positive for pelvic recurrence in all 13 patients. Surgery was performed in eight of these patients and was not performed in the other five because of advanced locoregional disease and/or an unsuspected lymph node or distant metastases (Fig 4). Nine patients suspected of having pelvic recurrence at CT did not have pelvic tumors. PET/CT findings were true-negative, and the presence of a viable tumor tissue in the pelvis was excluded in eight patients. PET/CT findings were false-positive in one patient. PET/CT was used to correctly exclude pelvic disease but depicted unsuspected extrapelvic metastases in two patients. These patients were referred for systemic therapy.
Correlation between PET/CT results and surgery in patients with proved pelvic recurrence.—Sixteen of the study patients had proved pelvic recurrence, and eight had both pelvic and extrapelvic recurrence. Thirteen of the 24 patients with pelvic recurrence were referred for surgery. PET/CT depicted pelvic recurrence in 23 of these 24 patients, and 12 were referred for surgery. In one patient referred for surgery for pelvic recurrence, the results of PET/CT were false-negative. The anatomic location of pelvic tumor sites, as indicated by PET/CT images, was correct in all 12 patients that underwent surgery. On the basis of the local extension of disease on PET/CT images, two patients underwent pelvic exenteration.
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
The diagnosis of pelvic recurrence and the differentiation of tumor recurrence and changes associated with previous surgery and/or radiation therapy in the pelvic region constitute a diagnostic challenge for CT, MR imaging, and PET (20–25). Most patients undergoing abdominoperineal resection develop a fibrotic mass in the presacral operative bed. Radiation therapy causes an inflammatory reaction in the pelvic tissues and induces thickening of the perirectal fascia; these changes may appear on CT images for many years and be indistinguishable from tumor recurrence (21).
It has been reported that PET has an additional diagnostic value in the detection of pelvic tumor recurrence in 56% of patients if only CT findings are considered and in 20% of patients if both CT and transrectal US findings are considered (1). In the current investigation, presacral CT abnormalities were detected in 30 (48%) of 62 patients. These findings were due to tumor recurrence in seven (23%) of the patients with a presacral CT abnormality and a benign finding in the remaining 23 (77%). PET/CT allowed us to differentiate a benign lesion from a tumorous presacral abnormality with a sensitivity of 100% and a specificity of 96%.
Occasionally, 18F FDG uptake in the presacral region was nonhomogeneous and depicted only parts of the presacral mass, probably indicating active tumor tissue and benign portions of the mass. PET/CT images also provided data that pertained to the involvement of pelvic structures; this information was clinically relevant in selecting an appropriate treatment approach. The anatomic definition of pelvic tumor sites was correct in all patients that were referred for surgery. The PET/CT findings indicated the need for an extended resection, and a pelvic exenteration was performed accordingly in two patients.
Alteration in the normal pelvic anatomy is a consequence of the surgical removal of the primary rectal tumor, and it was present on CT images in one-third of our patients. The remaining pelvic contents, including the bladder, small-bowel loops, and seminal vesicles or uterus, are primarily redistributed by posterior displacement (3,22,26,27). Posterior displacement of pelvic organs is a major concern if radiation therapy is planned. A trained PET reader expects displaced pelvic organs in patients who underwent abdominoperineal or anterior resection and traces the increased activity along the three-dimensional images by looking for the characteristic curvilinear pattern of physiologic uptake along the gastrointestinal or genitourinary tracts. On the other hand, pelvic recurrence sites and physiologic uptake in displaced pelvic organs may be adjacent to and/or located in the same anatomic region and, as shown by our measurements, do not differ in their intensity. In the current study, we found that physiologic sites of 18F FDG uptake may occasionally be focal, while recurrence sites may be elongated, particularly when located in the gastrointestinal tract. Thirteen (35%) of the 37 pelvic nontumoral sites of 18F FDG uptake were either false-positive or equivocal at PET alone, although transverse, coronal-sagittal, and maximum intensity projection images were interpreted. Physiologic 18F FDG uptake in displaced pelvic organs was the main cause for the relatively high number of false-positive interpretations of PET images. Although this rate was reduced when PET/CT images were interpreted, findings were still incorrect in five (14%) sites.
The detection of distant metastases on PET images has a positive effect on the diagnosis of recurrence in patients with colorectal cancer (1,2,7). Extrapelvic metastases were found in 27 patients included in this study. PET/CT images led to the identification of extrapelvic metastases in nine (56%) of the 16 patients referred with unexplained increasing carcinoembryonic antigen levels. PET/CT was used to identify unsuspected distant metastases in five (23%) of 22 patients referred for suspected pelvic disease. We did not compare the extrapelvic findings at PET with findings at PET/CT, since the scope of this study was limited to pelvic recurrence.
The relatively recent introduction of integrated PET/CT has already succeeded in provoking questions (9,28). Some authors feel that its use is justified only if it is found to be more accurate than a side-by-side interpretation of PET and CT images obtained separately. Others consider PET/CT a modality that may eliminate the need to perform a full-dose diagnostic CT examination for the sake of fusion with PET and emerge as an easy registration technique. This modality may, for instance, overcome registration challenges presented by repositioning of mobile organs or the localization of small abdominal sites of disease. In the current study, PET alone failed to depict eight (18%) of the 44 tumor lesions, seven of which were identified on PET/CT images as peritoneal metastases with lymph node involvement and an intraluminal recurrence.
There are several limitations to the study. The enrolled patients represent a select group of patients who had a high likelihood of recurrent disease, as indicated by initial CT findings and clinical and laboratory analysis. As often occurs in studies in which tumor detection is assessed, histologic diagnosis was possible in only 30 of 81 analyzed lesions (29). We did not have diagnostic CT images that were obtained shortly before or after the PET/CT examination; thus, we could not conduct a side-by-side reading to compare CT images obtained shortly before or after PET/CT with PET/CT images obtained with an integrated system.
In conclusion, the results of this study suggest an important role of integrated PET/low-dose CT in the assessment of pelvic recurrence in patients who underwent surgical removal of rectal cancer. The method overcomes the difficulties of PET image interpretation associated with the distorted pelvic anatomy in a relatively easy way, and it does so without necessitating additional imaging for correlation purposes. It is also used to differentiate between viable tumor tissue and fibrosis in residual masses seen on CT images and identify peritoneal metastases and normal-sized lymph node involvement.
|
FOOTNOTES |
|---|
Abbreviation: FDG = fluorodeoxyglucose
Author contributions: Guarantor of integrity of entire study, E.E.S.; study concepts and design, E.E.S., U.M., Y.P., H.L., M.G.; literature research, Y.P., H.L., C.L.; clinical studies, E.E.S., U.M., C.L., M.G., M.R., A.F.; data acquisition, E.E.S., U.M., Y.P., H.L.; data analysis/interpretation, E.E.S., U.M., Y.P.; statistical analysis, E.E.S.; manuscript preparation, E.E.S.; manuscript definition of intellectual content, E.E.S., U.M., C.L., M.G., M.R., A.F.; manuscript editing, E.E.S., U.M., C.L., Y.P.; manuscript revision/review and final version approval, all authors
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  L.F. de Geus-Oei, H. W. M. van Laarhoven, E. P. Visser, R. Hermsen, B. A. van Hoorn, Y. J. L. Kamm, P. F. M. Krabbe, F. H. M. Corstens, C. J. A. Punt, and W. J. G. Oyen Chemotherapy response evaluation with FDG-PET in patients with colorectal cancer Ann. Onc., February 1, 2008; 19(2): 348 - 352. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. U. Gerth, K. U. Juergens, U. Dirksen, J. Gerss, O. Schober, and C. Franzius Significant Benefit of Multimodal Imaging: PET/CT Compared with PET Alone in Staging and Follow-up of Patients with Ewing Tumors J. Nucl. Med., December 1, 2007; 48(12): 1932 - 1939. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Nakamoto, S. Sakamoto, T. Okada, M. Senda, T. Higashi, T. Saga, and K. Togashi Clinical Value of Manual Fusion of PET and CT Images in Patients with Suspected Recurrent Colorectal Cancer Am. J. Roentgenol., January 1, 2007; 188(1): 257 - 267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Israel and A. Kuten Early Detection of Cancer Recurrence: 18F-FDG PET/CT Can Make a Difference in Diagnosis and Patient Care J. Nucl. Med., January 1, 2007; 48(1_suppl): 28S - 35S. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Czernin, M. Allen-Auerbach, and H. R. Schelbert Improvements in Cancer Staging with PET/CT: Literature-Based Evidence as of September 2006 J. Nucl. Med., January 1, 2007; 48(1_suppl): 78S - 88S. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Blake, A. Singh, B. N. Setty, J. Slattery, M. Kalra, M. M. Maher, D. V. Sahani, A. J. Fischman, and P. R. Mueller Pearls and Pitfalls in Interpretation of Abdominal and Pelvic PET-CT RadioGraphics, September 1, 2006; 26(5): 1335 - 1353. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Capirci, D. Rubello, F. Chierichetti, G. Crepaldi, S. Fanti, G. Mandoliti, S. Salviato, G. Boni, L. Rampin, C. Polico, et al. Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy. Am. J. Roentgenol., August 1, 2006; 187(2): W202 - W208. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. L. Gearhart, D. Frassica, R. Rosen, M. Choti, R. Schulick, and R. Wahl Improved Staging With Pretreatment Positron Emission Tomography/Computed Tomography in Low Rectal Cancer Ann. Surg. Oncol., March 1, 2006; 13(3): 397 - 404. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. E. Juweid and B. D. Cheson Positron-Emission Tomography and Assessment of Cancer Therapy N. Engl. J. Med., February 2, 2006; 354(5): 496 - 507. [Full Text] [PDF]
|
|
|
|
 |
|
 G. K. von Schulthess, H. C. Steinert, and T. F. Hany Integrated PET/CT: Current Applications and Future Directions Radiology, February 1, 2006; 238(2): 405 - 422. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P Veit, C Kuhle, T Beyer, H Kuehl, C U Herborn, G Borsch, H Stergar, J Barkhausen, A Bockisch, and G Antoch Whole body positron emission tomography/computed tomography (PET/CT) tumour staging with integrated PET/CT colonography: technical feasibility and first experiences in patients with colorectal cancer Gut, January 1, 2006; 55(1): 68 - 73. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D Tait Advances in chemoradiation therapy in rectal cancer: the impact of imaging Br. J. Radiol., October 1, 2005; 78(Special_Issue_2): S131 - S137. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| RADIOLOGY | RADIOGRAPHICS | RSNA JOURNALS ONLINE |
