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Esophageal cancer is relatively infrequent, with 14,000 new cases reported in the United States in 2003. The 5-year survival rate is not more than 14%.72 The incidence of the disease is much higher in Asia and Northern France and in some regions of the world where esophageal cancer is endemic.

FDG-PET in Staging Esophageal Carcinoma

The accuracy of endoscopic ultrasonography (EUS) is lower for evaluation of T1 and T2 tumor than for T3 and T4, and the CT scan is inaccurate for identifying nonbulky lymph-adenopathy. Neither EUS nor CT is able to distinguish tumor from inflammation. The introduction of FDG-PET has greatly improved the staging of esophageal carcinoma. Squamous cell and adenocarcinomas of the esophagus are both generally characterized by high FDG uptake.73,74 FDG uptake in esophageal cancer is greater than that in the normal unin-flamed esophagus, and the primary tumor can be distinguished easily from background activity in most cases.75

FDG-PET false-positive results in the esophagus and nearby tissues can be caused by inflammation (reflux esophagitis), radiation-induced esophagitis, benign tumors, skeletal and adipose tissue uptake, and heterogeneous uptake in the primary, simulating periesophageal nodal metastases.

FDG-PET false-negative results are the result of small tumor volume, well-differentiated tumor, and close proximity to the primary tumor. Histologic confirmation of PET findings is necessary before a patient is denied potentially curative surgery. PET is very useful in identifying a site suitable for biopsy.

FDG-PET has been shown to detect primary esophageal cancer with a higher sensitivity than that of CT (95% to 100% versus 81% to 92%).73,76-78 Himeno et al.79 reported that FDG-PET has a sensitivity of 100% for the detection of primary tumors extending to the submucosa (TIb) or deeper, but cannot detect lesions confined to the mucosa (Tis or T1a). Kato et al.80 described that there is a significant relationship between FDG uptake and the depth of tumor invasion; this is most likely a relationship between tumor volume and invasion (Figure 33.3).

Although PET detects most primary esophageal cancers, it is not as sensitive for nodal metastases. Yoon et al.81 evaluated 82 patients with squamous cell carcinoma and 677 lesions and found the sensitivity for PET was 30% and that for CT was 11%. This result shows the extent of the problem of nodal staging with both methods. Although PET was more sensitive than CT, both techniques failed to detect small nodal metastases that are often under 1 cm in size. There is considerable variability in the literature concerning nodal staging in esophageal cancer.

The 5-year survival without lymph node involvement is 42% to 72% versus only 10% to 12%82 for patients with disease that has spread to the lymph nodes. Metastatic lymph node size was the strongest independent predictor of survival among several prognostic factors, such as primary tumor size, histopathologic type, number of metastatic lymph nodes.83

The combined accuracy of EUS and CT (70% to 90%) in the detection of mediastinal nodal metastases was reported to be greater than that of each modality alone,84 but limitations remained because of inability to detect tumor involvement in normal-sized lymph nodes and to differentiate metastatic from inflammatory disease.

Kim et al.74 compared FDG-PET with CT and histopathologic results from esophagectomy and extensive lymph node dissection. The sensitivity, specificity, and accuracy for FDG-PET to detect metastatic lymph nodes were 52%, 94%, and 84%, respectively, and those for CT were 15%, 97%, and 77%, respectively. That study showed that FDG-PET had greater sensitivity and accuracy than CT, with equal specificity in nodal staging.

Flamen et al.73 compared FDG-PET (attenuation corrected with spiral CT) and EUS in 74 patients with potentially resectable esophageal cancer and showed that EUS was more sensitive (81% versus 33%) but less specific (67% versus 89%) than PET for detection of regional nodal metastases. Combined EUS and CT were more sensitive (62% versus 33%) and less specific (67% versus 89%) in the same setting. The findings from PET resulted in upstaging in 15% of patients and in downstaging in 7% of patients. PET is a better method for detection of distant metastatic disease than any other method available, but it is not as robust for locoregional disease. PET is routinely recommended before surgery for esophageal carcinoma.

A curative surgical approach is not appropriate in patients with metastases to distant foci. Distant metastatic disease most commonly occurs in distant lymph nodes, liver, and lung. FDG-PET is superior to CT and MRI for detection of distant metastatic disease.73,74,85-89 FDG-PET uncovered 3% to 37% of findings that were unsuspected. Kinkel et al.87 reported that at the specificity level of 85% the mean sensitivities of FDG-PET, ultrasound, CT, and MRI were 90%, 55%, 63%, and 76%, respectively.

Flamen et al.73 demonstrated that the accuracy of FDG-PET in 74 patients with stage IV disease was 82%, whereas it was only 64% for a combination of CT and EUS (P less than 0.01). The sensitivity and specificity were 74% and 90% for FDG-PET, 41% and 83% for CT, and 42% and 94% for EUS.

Luketich et al.88 found, in 35 patients with potentially resectable esophageal cancer, that distant metastatic disease was identified by PET in 20% with an accuracy of 91%. The same group89 found that the sensitivity and specificity of FDG-PET for detection of distant disease were 69% and 93% for FDG-PET and 46% and 74% for CT.

PET prevents ineffective radical therapies by detection of occult stage IV disease and identification of the local or distant metastases that are most accessible to confirmation by directed tissue sampling using minimally invasive procedures. Wallace et al.90 found that the combination of PET and EUS with fine-needle aspiration biopsy is the most effective strategy for staging.

Table 33.4 summarizes the results of studies evaluating the sensitivity, specificity, and accuracy of CT, EUS, and FDG-PET for detecting local tumor extension (T and N stages) and systemic disease (M).73,74,81,89,91-93

figure 33.3. Coronal PET/CT images obtained from a middle-aged male with a history of gastroesophageal reflux and biopsy-proven esophageal carcinoma. These images show intense tracer uptake in the primary lesion located at the gas-troesophageal junction and extending downward into the stomach. No metastatic disease is identified. (A) CT scan. (B) Fused PET/CT image. (C) Attenuation corrected PET image. (D) Nonat-tenuation corrected PET image.

figure 33.3. Coronal PET/CT images obtained from a middle-aged male with a history of gastroesophageal reflux and biopsy-proven esophageal carcinoma. These images show intense tracer uptake in the primary lesion located at the gas-troesophageal junction and extending downward into the stomach. No metastatic disease is identified. (A) CT scan. (B) Fused PET/CT image. (C) Attenuation corrected PET image. (D) Nonat-tenuation corrected PET image.

TABLE 33.4. Comparison of various modalities (CT/EUS with PET) for initial staging of esophageal cancer.

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Herbal Remedies For Acid Reflux

Herbal Remedies For Acid Reflux

Gastroesophageal reflux disease is the medical term for what we know as acid reflux. Acid reflux occurs when the stomach releases its liquid back into the esophagus, causing inflammation and damage to the esophageal lining. The regurgitated acid most often consists of a few compoundsbr acid, bile, and pepsin.

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