Long-Term Outcomes of Cervical Cancer Patients Treated With Definitive Chemoradiation Following a Complete Metabolic Response.

AIMS: A complete metabolic response (CMR) on early post-treatment 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a positive prognostic factor for cervical cancer patients treated with definitive chemoradiation, but long-term outcomes of this group of patients are unknown. Patterns of failure and risk subgroups are identified. MATERIALS AND METHODS: Patients who received curative-intent chemoradiation from 1998 to 2018 for International Federation of Gynecology and Obstetrics (FIGO) stage IB1-IVA cervical cancer and had a CMR on post-treatment FDG-PET within 5 months of treatment completion were included. Cox proportional hazards models determined factors associated with locoregional and distant failure. Kaplan-Meier estimates of freedom from any recurrence (FFR) of patient subgroups were compared with Log-rank tests. RESULTS: There were 402 patients with a CMR after chemoradiation on FDG-PET. Initial T stage was T1 (38%)/T2 (40%)/T3 (20%)/T4 (2%); initial FDG-avid nodal status was no nodes (50%)/pelvic lymph nodes (40%)/pelvic and para-aortic lymph nodes (10%). After a median follow-up of 6 years, 109 (27%) recurred. The pattern of recurrence was locoregional (27%), distant (61%) or both (12%). No factors were associated with locoregional failure. Distant recurrence was more likely in patients with T3-4 lesions (hazard ratio = 2.4, 95% confidence interval 1.5-3.8) and involvement of pelvic (hazard ratio = 1.6, 95% confidence interval 1.0-2.7) or para-aortic lymph nodes (hazard ratio = 2.7, 95% confidence interval 1.4-5.0) at diagnosis. The 5-year FFR rates for T1-2 patients with no nodes, pelvic nodes alone or para-aortic nodes at diagnosis were 85, 76 and 62%, respectively (P = 0.04, none versus para-aortic nodes). The 5-year FFR for T3-4 patients with no nodes, pelvic nodes alone or para-aortic nodes at diagnosis were 68, 56 and 25%, respectively (P = 0.09, none versus para-aortic nodes). CONCLUSIONS: T3-4 tumours and para-aortic nodal involvement at diagnosis are poor prognostic factors, even after a CMR following chemoradiation.

Lymph node staging by positron emission tomography in patients with carcinoma of the cervix.

PURPOSE: The aim of this study was to compare the results of computed tomography (CT) and positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG) for lymph node staging in patients with carcinoma of the cervix and to evaluate the relationship of the imaging findings to prognosis. PATIENTS AND METHODS: We retrospectively compared the results of CT lymph node staging and whole-body FDG-PET in 101 consecutive patients with carcinoma of the cervix. Patients were treated with standard irradiation and chemotherapy (as clinically indicated) and observed at 3-month intervals for a median of 15.4 months (range, 2.5 to 30 months). Progression-free survival was evaluated by the Kaplan-Meier method. RESULTS: CT demonstrated abnormally enlarged pelvic lymph nodes in 20 (20%) and para-aortic lymph nodes in seven (7%) of the 101 patients. PET demonstrated abnormal FDG uptake in pelvic lymph nodes in 67 (67%), in para-aortic lymph nodes in 21 (21%), and in supraclavicular lymph node in eight (8%). The 2-year progression-free survival, based solely on para-aortic lymph node status, was 64% in CT-negative and PET-negative patients, 18% in CT-negative and PET-positive patients, and 14% in CT-positive and PET-positive patients (P <.0001). A multivariate analysis demonstrated that the most significant prognostic factor for progression-free survival was the presence of positive para-aortic lymph nodes as detected by PET imaging (P =.025). CONCLUSION: This study demonstrates that FDG-PET detects abnormal lymph node regions more often than does CT and that the findings on PET are a better predictor of survival than those of CT in patients with carcinoma of the cervix.

Metabolic flare: indicator of hormone responsiveness in advanced breast cancer.

PURPOSE: The purpose of this study was to investigate whether positron emission tomography (PET) with the glucose analog [(18)F]fluorodeoxyglucose (FDG) and the estrogen analog 16 alpha-[(18)F]fluoroestradiol-17 beta (FES), performed before and after treatment with tamoxifen, could be used to detect hormone-induced changes in tumor metabolism (metabolic flare) and changes in available levels of estrogen receptor (ER). In addition, we investigated whether these PET findings would predict hormonally responsive breast cancer. PATIENTS AND METHODS: Forty women with biopsy-proved advanced ER-positive (ER(+)) breast cancer underwent PET with FDG and FES before and 7 to 10 days after initiation of tamoxifen therapy; 70 lesions were evaluated. Tumor FDG and FES uptake were assessed semiquantitatively by the standardized uptake value (SUV) method. The PET results were correlated with response to hormonal therapy. RESULTS: In the responders, the tumor FDG uptake increased after tamoxifen by 28.4% +/- 23.3% (mean +/- SD); only five of these patients had evidence of a clinical flare reaction. In nonresponders, there was no significant change in tumor FDG uptake from baseline (mean change, 10.1% +/- 16.2%; P =.0002 v responders). Lesions of responders had higher baseline FES uptake (SUV, 4.3 +/- 2.4) than those of nonresponders (SUV, 1.8 +/- 1.3; P =.0007). All patients had evidence of blockade of the tumor ERs 7 to 10 days after initiation of tamoxifen therapy; however, the degree of ER blockade was greater in the responders (mean percentage decrease, 54.8% +/- 14.2%) than in the nonresponders (mean percentage decrease, 19.4% +/- 17.3%; P =.0003). CONCLUSION: The functional status of tumor ERs can be characterized in vivo by PET with FDG and FES. The results of PET are predictive of responsiveness to tamoxifen therapy in patients with advanced ER(+) breast cancer.

Survival of patients evaluated by FDG-PET before hepatic resection for metastatic colorectal carcinoma: a prospective database study.

OBJECTIVE: To present the survival results for patients with colorectal carcinoma metastases who have undergone liver resection after being staged by [(18)F] fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET). SUMMARY BACKGROUND DATA: Hepatic resection is standard therapy for colorectal metastases confined to the liver, but recurrence is common because of the presence of undetected cancer at the time of surgery. FDG-PET is a sensitive diagnostic tool that identifies tumors based on the increased uptake of glucose by tumor cells. To date, no survival results have been reported for patients who have actually had liver resection after being staged by FDG-PET. METHODS: Forty-three patients with metastatic colorectal cancer were referred for hepatic resection after conventional tumor staging with computed tomography. FDG-PET was performed on all patients. Laparotomy was performed on patients not staged out by PET. Resection was performed at the time of laparotomy unless extrahepatic disease or unresectable hepatic tumors were found. Patients were examined at intervals in the preoperative period. RESULTS: FDG-PET identified additional cancer not seen on computed tomography in 10 patients. Surgery was contraindicated in six of these patients because of the findings on FDG-PET. Laparotomy was performed in 37 patients. In all but two, liver resection was performed. Median follow-up in the 35 patients undergoing resection was 24 months. The Kaplan-Meier estimate of overall survival at 3 years was 77% and the lower 95% confidence limit of this estimate of survival was 60%. This figure is higher than 3-year estimate of survival found in previously published series. The 3-year disease-free survival rate was 40%. CONCLUSIONS: Preoperative FDG-PET lessens the recurrence rate in patients undergoing hepatic resection for colorectal metastases to the liver by detection of disease not found on conventional imaging.

Usefulness of FDG-PET scan in the assessment of suspected metastatic or recurrent adenocarcinoma of the colon and rectum.

PURPOSE: The purpose of this study was to evaluate the clinical efficacy of positron emission tomography with 2-[18F] fluoro-2-deoxy-D-glucose compared with computed tomography plus other conventional diagnostic studies in patients suspected of having metastatic or recurrent colorectal adenocarcinoma. METHODS: The records of 105 patients who underwent 101 computed tomography and 109 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography scans for suspected metastatic or recurrent colorectal adenocarcinoma were reviewed. Clinical correlation was confirmed at time of operation, histopathologically, or by clinical course. RESULTS: The overall sensitivity and specificity of 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography in detection of clinically relevant tumor were higher (87 and 68 percent) than for computed tomography plus other conventional diagnostic studies (66 and 59 percent). The sensitivity of 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography in detecting mucinous cancer was lower (58 percent; n = 16) than for nonmucinous cancer (92 percent; n = 93). The sensitivity of 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography in detecting locoregional recurrence (n = 70) was higher than for computed tomography plus colonoscopy (90 vs. 71 percent, respectively). The sensitivity of 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography in detecting hepatic metastasis (n = 101) was higher than for computed tomography (89 vs. 71 percent). The sensitivity of 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography in detecting extrahepatic metastases exclusive of locoregional recurrence (n = 101) was higher than for computed tomography plus other conventional diagnostic studies (94 vs. 67 percent). 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography altered clinical management in a beneficial manner in 26 percent of cases (26/101) when compared with evaluation by computed tomography plus other conventional diagnostic studies. CONCLUSION: 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography is more sensitive than computed tomography for the detection of metastatic or recurrent colorectal cancer and may improve clinical management in one-quarter of cases. However, 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography is not as sensitive in detecting mucinous adenocarcinoma, possibly because of the relative hypocellularity of these tumors.

Radiation exposure from outpatient radioactive iodine (131I) therapy for thyroid carcinoma.

CONTEXT: In May 1997, the US Nuclear Regulatory Commission (NRC) revised its patient release regulations, allowing for outpatient administration of larger activities of sodium iodide 131I than previously permitted. OBJECTIVE: To measure the radiation exposure to household members from patients receiving outpatient 131I therapy for thyroid carcinoma in accordance with the new regulations. DESIGN: Consecutive case series from October 1998 to June 1999. SETTING AND PATIENTS: Thirty patients who received outpatient 131I therapy following thyroidectomy for differentiated thyroid carcinoma were enrolled, along with their 65 household members and 17 household pets. MAIN OUTCOME MEASURE: Radiation exposure to household members and 4 rooms in each home, as monitored with dosimeters for 10 days following 131I administration. RESULTS: The patients received 131I doses ranging from 2.8 to 5.6 GBq (mean, 4.3 GBq). The radiation dose to 65 household members ranged from 0.01 mSv to 1.09 mSv (mean, 0.24 mSv). The dose to 17 household pets ranged from 0.02 mSv to 1.11 mSv (mean, 0.37 mSv). The mean dose to the 4 rooms ranged from 0.17 mSv (kitchen) to 0.58 mSv (bedroom). CONCLUSION: In our study, 131I doses to household members of patients receiving outpatient 131I therapy were well below the limit (5.0 mSv) mandated by current NRC regulations.

FDG PET evaluation of mucinous neoplasms: correlation of FDG uptake with histopathologic features.

OBJECTIVE: Our goal was to assess the sensitivity of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) for the detection of mucinous carcinoma and to determine the histologic features of these tumors that may affect lesion detectability. MATERIALS AND METHODS: A retrospective review of all patients with mucinous carcinoma who had undergone FDG PET at our institution from 1995 through 1998 identified 25 patients with new or recurrent mucinous carcinoma at the time of PET. In 22 of these patients, tissue specimens available from either core biopsy or surgical resection allowed detailed histologic analysis. RESULTS: FDG PET revealed mucinous carcinoma in only 13 (59%) of 22 patients, resulting in an unusually high percentage (41%) of false-negative results. Two histologic features were found to be predictive of FDG PET results: tumor cellularity (p = 0.011) and the amount of mucin within the tumor mass (p = 0.009). There was a positive correlation between tumor FDG uptake and cellularity but a negative correlation with the amount of mucin. CONCLUSION: FDG PET is limited in the evaluation of mucinous tumors, particularly in hypocellular lesions with abundant mucin.

Tc-99m sulfur colloid scintigraphy for detecting perigraft flow following endovascular aortic aneurysm repair: A feasibility study.

PURPOSE: To determine if scintigraphy with Tc-99m sulfur colloid can be used to detect perigraft flow after stent-graft repair of abdominal aortic aneurysm (AAA). METHODS: Twenty-three men and two women aged 56-84 years (mean 71 years) underwent endoluminal AAA repair as part of the EVT Phase II trial [EVT = Endovascular Technologies (Menlo Park, CA, USA)]. Aneurysm size averaged 5.4 cm (range 3-8 cm). Sixteen bifurcated, seven tube, and two aorto-uniiliac grafts were placed. Two days after stent-graft placement, patients underwent both contrast-enhanced computed tomography (CT), including delayed views, and Tc-99m sulfur colloid scintigraphy. RESULTS: Perigraft flow was found in only one patient at completion of angiography. Four additional patients had perigraft flow, discovered during their postoperative follow-up CT. Four patients had leaks at an attachment site and one had retrograde branch flow. Tc-99m sulfur colloid scintigraphy failed to diagnose any of the five leaks prospectively. In two of these patients, however, some abnormal paraaortic activity was noted in retrospect. CONCLUSION: Tc-99m sulfur colloid scintigraphy was unable to demonstrate endoleak with either rapid flow (attachment site leak) or slow filling (branch flow).

Surveillance of patients to detect recurrent thyroid carcinoma.

BACKGROUND: The purpose of this study was to evaluate the utility of surveillance with annual whole-body iodine-131 (131I) scintigraphy for patients with recurrent thyroid carcinoma. METHODS: The records of patients with thyroid carcinoma were reviewed. The 76 patients included in this study had undergone thyroidectomy and postoperative 131I therapy, and had at least 1 negative whole-body 131I scintigraphy 1 year after 131I therapy. There were 59 females and 17 males (age range, 12-74 years). Surgery consisted of a total thyroidectomy for 84% of patients and a subtotal thyroidectomy for 16%. 131I was administered within 1 month of thyroidectomy and annually thereafter until complete ablation of remaining thyroid tissue occurred. Annual follow-up diagnostic whole-body 131I scintigraphy was performed at Years 1 and 2, and then every 3-5 years. Some patients also had scintigraphy performed in Years 3, 4, and 5. RESULTS: Patients received 1-4 annual administrations of 131I (median, 1). The administered activity per treatment was 30-211 mCi, and the total activity administered that was necessary to achieve complete ablation of functioning thyroid tissue ranged from 30 to 514 mCi (median, 100 mCi). The relapse free survival at both 5 and 10 years was 88%. By definition, all of these patients had a negative 131I scintigraphy at 1 year after their last therapeutic 131I administration. Seven patients had a positive 131I scintigraphy 1 year after the first negative scintigraphy. Two other patients had positive 131I images after 2 consecutive negative annual 131I scintigraphic studies. The predictive value for relapse free survival of 1 negative diagnostic 131I study of these patients was 91% (+/- 0.02), and for 2 consecutive annual negative 131I studies the value was 97% (+/- 0.02); these results were significantly different (P = 0.0197). A stepwise logistic regression analysis was performed in an effort to identify risk factors for disease recurrence after complete ablation. None of the variables assessed--age, gender, tumor histology, tumor size, vascular invasion, capsular invasion, surgical margin status, or lymph node status--was predictive of recurrence after complete ablation. CONCLUSIONS: A single negative 131I scintigraphic study after complete ablation has a lower predictive value for relapse free survival than do two consecutive annual negative studies. Annual 131I imaging is recommended for surveillance until 2 consecutive annual negative studies are obtained, after which repeat imaging at 3-5 years appears to be satisfactory.

Positron emission tomographic assessment of "metabolic flare" to predict response of metastatic breast cancer to antiestrogen therapy.

We have investigated whether increased tumor uptake of fluorine-18 fluorodeoxyglucose (FDG) detected with positron emission tomography (PET) early after initiating tamoxifen therapy ("metabolic flare") predicts a hormonally responsive breast cancer. Eleven postmenopausal women with biopsy-proved estrogen receptor-positive (ER+) metastatic breast cancer were studied by PET with FDG and 16alpha[18F]fluoro-17beta-estradiol (FES) before and 7-10 days after initiation of tamoxifen therapy. FDG and FES uptake was evaluated semiquantitatively in 21 lesions. The PET results were correlated with follow-up evaluation, continued until the patient became unresponsive to hormone therapy (3-24 months). There were seven responders and four nonresponders based on clinical follow-up. None of the responders had a clinical flare reaction, but all demonstrated metabolic flare, with a mean +/- standard deviation increase in tumor standardized uptake value (SUV) for FDG of 1.4+/-0. 7. No evidence for flare was noted in the nonresponders (change in SUV for FDG -0.1+/-0.4; P = 0.008 vs. responders). The degree of ER blockade by tamoxifen was greater in responders (mean decrease in SUV 2.7+/-1.7) than in nonresponders (mean decrease 0.8+/-0.5) (P = 0.04). The lesions of responders had higher baseline SUVs for FES than did those of three of four nonresponders (>/=2.2 vs

Prospective study of the utility of somatostatin-receptor scintigraphy in the evaluation of patients with multiple endocrine neoplasia type 1.

BACKGROUND: Neuroendocrine tumors (NETs) are a potentially lethal component of multiple endocrine neoplasia type 1 (MEN 1). Somatostatin receptor scintigraphy (SRS) can be used to localize NETs and evaluate patients for extraduodenopancreatic disease; its utility in managing MEN 1 is undefined. METHODS: All patients with MEN 1 evaluated by SRS from April 1994 to November 1997 are reported. SRS findings were correlated with other imaging studies and operative findings. RESULTS: Thirty-seven SRS studies were performed in 29 patients with MEN 1. SRS identified occult tumor in 36% (4/11) of patients with only biochemical evidence of NET; 2 patients went on to resection. SRS showed tumor in 79% (15/19) of patients with computed tomography (CT)-demonstrated tumor; 30% (6/20) of the SRS lesions were occult on CT. Conversely, 55% (16/29) of CT-identified lesions were occult on SRS. SRS found distant disease in 21% (6/29) of patients. In patients who had previous operations, SRS found tumor in 40% (4/10) of patients, again with both new positive and false-negative results compared with other imaging. SRS also had 3 important false-positive results, including 1 patient who had laparotomy with no tumor identified. CONCLUSIONS: SRS is useful in identifying otherwise occult NETs in patients with MEN 1 and can substantially alter management. However, SRS also has significant false-positive and false-negative results that demand correlation with other studies.

PET in breast cancer.

Over the past decade, the role of radiology in breast cancer has changed significantly because of the technical advances in mammography, greater use of ultrasonography, and the emergence of magnetic resonance imaging (MRI), as well as development of functional imaging techniques that add new dimensions to the noninvasive evaluation of patients with breast cancer. Currently, radiological evaluation of breast cancer is important not only for early detection of this disease, but also for staging, assessing certain prognostic factors, and monitoring response to treatment. This review focuses on the potential applications and limitations of positron emission tomography (PET) as a functional imaging method in breast cancer. PET with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) has been used successfully in an increasing number of oncological applications and is considered a valuable adjunct to anatomical imaging methods, providing unique functional information for better characterization of disease. The contributions of PET to breast cancer imaging can be considered in two main categories. First, by providing qualitative and/or quantitative information, FDG-PET can aid in detection and discrimination of breast cancer in its primary location. Although, FDG-PET is certainly not necessary in every potential case of breast cancer, it can be very useful in clinically and radiologically "difficult-to-examine breasts," eg, following breast surgery. Qualitative assessment of the extent of the tumor spread provides prognostic information and allows for selection of appropriate therapy. The identification of tumor spread to the axillary nodes or to more remote nodal groups, i.e., internal mammary, or supraclavicular nodes, is probably the most practical information that qualitative FDG-PET can offer. Although it is still too early to formulate definite clinical recommendations, it appears likely that FDG-PET has the potential to reduce the number of patients requiring nodal dissection. Second, PET imaging can provide an assessment of the biological behavior of breast cancer. Quantitative and/or semi-quantitative FDG-PET yields valuable information regarding prognosis and response to therapy in a timely fashion. Preliminary studies have indicated that serial assessment of tumor metabolism by FDG-PET early during effective chemohormonotherapy may predict subsequent response to such therapy. The use of PET with the estrogen analogue 16 alpha-[18F]fluoro-17 beta-estradiol (FES) to monitor receptor function and response to hormonal therapy opens up intriguing new ways to monitor patients with breast cancer at a cellular level.

Utility of FDG-PET for investigating unexplained plasma CEA elevation in patients with colorectal cancer.

OBJECTIVE: To assess the potential role of positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) in patients with unexplained rising carcinoembryonic antigen (CEA) levels after the treatment of colorectal cancer. BACKGROUND: A rising CEA level after the resection of colorectal cancer is an early indicator of tumor recurrence. However, conventional imaging techniques have limited sensitivity for detecting recurrent disease in such patients. Especially after surgical intervention, FDG-PET is rapidly gaining an important role in establishing the extent of disease in the oncology patient. METHODS: Twenty-two patients with abnormal CEA levels and normal results of conventional methods of tumor detection were studied with FDG-PET. The PET results were compared with pathologic findings (n = 9) and long-term radiologic and clinical follow-up (n = 13). RESULTS: FDG-PET was abnormal in 17 of 22 patients. Tissue sampling was available in 7 of these 17 patients; all of these had recurrent disease. Definitive curative surgical intervention was performed in four patients. Subsequent dedicated imaging findings and clinical course confirmed the presence of extensive disease in 8 of the remaining 10 patients; the PET results in the other 2 patients were considered falsely positive. FDG-PET was negative in 5 of 22 patients. No disease was found by tissue sampling (n = 2) and clinical follow-up (n = 3). Overall, the positive-predictive value for PET was 89%, (15 of 17) and the negative-predictive value was 100% (5 of 5). CONCLUSIONS: When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have a rising CEA level after colorectal surgery.

Improvement in staging of esophageal cancer with the addition of positron emission tomography.

BACKGROUND: Positron emission tomography with the glucose analogue 2-[18F]fluoro-2-deoxy-D-glucose (FDG) has been used to detect and stage a variety of malignancies. We hypothesized that FDG-positron emission tomography would improve staging of patients with esophageal cancer and thereby facilitate selection of candidates for resection. METHODS: Fifty-eight patients (42 men and 16 women) with biopsy-proven esophageal cancer were evaluated with both FDG-positron emission tomography and computed tomography. RESULTS: In all but 2 patients, increased FDG uptake was identified at the site of the primary tumor. Six patients were not operative candidates. Seventeen patients were not candidates for resection because of metastatic disease. Positron emission tomography identified the metastatic disease in all 17 (12 of whom underwent confirmatory biopsy), whereas computed tomography was positive for metastases in only 5. The remaining 35 patients underwent surgical exploration, were judged to have resectable disease and had esophagectomy. Pathologic examination of resected specimens identified lymph node metastases in 21 patients. These nodes were detected by positron emission tomography in 11 patients and by computed tomography in 6. CONCLUSIONS: Positron emission tomography improved staging and facilitated selection of patients for operation by detecting distant disease not identified by computed tomography alone.

Staging of esophageal cancer with 18F-fluorodeoxyglucose positron emission tomography.

OBJECTIVE: The objective of this study was to assess the performance of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in the staging of cancer in patients with esophageal carcinoma. MATERIALS AND METHODS: The findings of FDG PET and of CT in the chest and upper abdomen of 36 patients with newly diagnosed esophageal carcinoma were compared with pathologic findings obtained either during a curative surgical procedure with tissue sampling (n = 29) or by tissue sampling alone (n = 7). RESULTS: Abnormal FDG uptake was identified on PET in the esophageal tumors of all patients. In 29 patients who underwent curative esophagectomy, PET and CT accurately revealed the extent of nodal disease in 76% (22/29) and 45% (13/29) of patients, respectively. In the seven patients who underwent tissue sampling instead of complete esophagectomy, PET revealed metastatic disease in five patients, all of whom avoided needless surgery. CT failed to reveal metastatic disease in these five patients. In addition, PET incidentally revealed an unsuspected primary long carcinoma in one patient. CONCLUSION: FDG PET is more sensitive than CT for revealing regional and distant metastases in patients with esophageal carcinoma. The use of PET in the staging of esophageal cancer may prove to be cost-effective by decreasing the number of unnecessary surgeries in patients with unresectable tumors.

Detection of recurrent and metastatic colorectal cancer: comparison of positron emission tomography and computed tomography.

BACKGROUND: This study evaluates the clinical value of positron emission tomography (PET) with 2-[F-18] fluoro-2-deoxy-D-glucose (FDG) as compared to computed tomography (CT) in patients with suspected recurrent or metastatic colorectal cancer (CRC). METHODS: A retrospective review of the records of 58 patients who had FDG-PET for evaluation of recurrent or advanced primary CRC was performed. FDG-PET results were compared with those of CT and correlated with operative and histopathologic findings, or with clinical course and autopsy reports. RESULTS: Recurrent or advanced primary CRC was diagnosed in 40 and 11 patients, respectively. The sensitivity and specificity of FDG-PET were 91% and 100% for detecting local pelvic recurrence, and 95% and 100% for hepatic metastases. These values were superior to CT, which had sensitivity and specificity of 52% and 80% for detecting pelvic recurrence, and 74% and 85% for hepatic metastases. FDG-PET correctly identified pelvic recurrence in 19 of 21 patients; CT was negative in 6 of these patients and equivocal in 4. FDG-PET was superior to CT in detecting multiple hepatic lesions and influenced clinical management in 10 of 23 (43%) patients. CONCLUSION: FDG-PET is more sensitive than CT in the clinical assessment of patients with recurrent or metastatic CRC, and provides an accurate means of selecting appropriate treatment for these patients.