Large cell carcinoma of the lung metastatic to nuchal muscle

Abstract Clinically apparent hematogenous skeletal muscle metastases from lung cancer are extremely rare. We present a 72-year-old man with a large cell lung carcinoma metastatic to nuchal muscle. Cervical computed tomography (CT) and magnetic resonance imaging (MRI) revealed the presence of a well-defined mass in the left splenius capitis muscle. A percutaneous needle biopsy was performed to establish a diagnosis. Localized skeletal muscle swelling may rarely prove to be metastases in patients with lung cancer, but should be investigated in the case of muscle swelling.     

Skeletal muscle metastasis from esophageal cancer: a report of two cases and a review of the literature

Skeletal muscle metastases from carcinoma are very rare. This report describes two cases of skeletal muscle metastasis from esophageal cancer as the first distant metastasis. Case 1, a 58-year-old man with stage IVa upper thoracic esophageal squamous cell carcinoma (SqCC), underwent chemoradiotherapy (CRT) and a subtotal esophagectomy with a three-field lymph node dissection. After the operation, he complained of a painful mass in his forearm, which was diagnosed to be metastatic SqCC by a biopsy. Local radiation therapy and systemic chemotherapy were performed, but he died 7 months after the first CRT. Case 2, a 61-year-old woman with stage IVa middle thoracic SqCC, underwent CRT. ¹⁸F-Fluorodeoxyglucose positron emission tomography (FDG-PET) after the CRT showed a hot spot in the right gluteus maximus muscle, and it was diagnosed to be metastatic SqCC by a biopsy. Although additional treatment was performed, she died 6 months after the first visit. A short review of the literature concerning skeletal muscle metastasis from esophageal cancer was conducted.     

Comparison of the diagnostic value of 3-deoxy-3-18F-fluorothymidine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of regional lymph node in thoracic esophageal squamous cell carcinoma: a pilot study

We used pathological examination as golden standard to determine whether 3-deoxy-3-(18)F-fluorothymidine positron emission tomography/computed tomography (FLT PET/CT) can detect regional lymph node metastasis in untreated thoracic esophageal squamous cell carcinoma and additionally performed (18)F-fluorodeoxyglucose (FDG) PET/CT for direct comparison with that of FLT. Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing CT images and side-by-side FDG PET and FLT PET images for the diagnosis of locoregional lymph node metastasis were compared prospectively in relation to pathologic findings. All patients underwent esophagectomy and lymphadenectomy. Pathologic examination confirmed nodes positive for metastasis in 16 patients and 47 of 424 excised nodes. The uptake of FDG (median SUVmax, 5.4; range, 2.4-10.6) in locoregional lymph nodes metastases was significantly higher than that of FLT (median SUVmax, 2.8; range, 1.3-4.6). There were 14 false-positive nodes in FDG PET/CT and only 3 in FLT PET/CT; 8 false-negative nodes in FDG PET/CT, while there were 12 false negative nodes in FLT PET/CT. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 74.47%, 99.20%, 96.46%, 92.11%, and 96.89%, respectively, whereas those of FDG PET/CT were 82.98%, 96.29%, 94.81%, 82.98%, and 96.29%, respectively. P-values were 0.450, 0.014, 0.313, 0.050, and 0.555, respectively. FLT uptake in regional lymph nodes of esophageal carcinoma is significantly lower compared with FDG uptake. FLT PET/CT has fewer false-positive findings and higher specificity compared with FDG PET/CT.     

Value of fusing PET plus CT images in hepatocellular carcinoma and combined hepatocellular and cholangiocarcinoma patients with extrahepatic metastases: preliminary findings.

BACKGROUND/AIMS: This study aimed to evaluate the usefulness of (18)F-fluoro-2-deoxy-d-glucose positron emission tomography (PET) and PET plus computed tomography (CT) fusion images for the detection of extrahepatic metastases of hepatocellular carcinoma (HCC) and combined hepatocellular and cholangiocarcinoma (combined HCC/CC). METHODS: Twenty-one patients with HCC and combined HCC/CC were enrolled in the study from December 2004 to February 2005. In all patients, PET and CT of the chest to pelvis region were performed. The sensitivity of PET plus CT fusion images was compared with the sensitivity of PET, CT, and bone scintigraphy. RESULTS: In 14 patients, a total of 58 extrahepatic metastases were diagnosed. The detection rate of PET plus CT fusion images, PET, CT, and bone scintigraphy was 98.2% (57 of 58 metastases), 89.6% (52 of 58 metastases), 91.2% (52 of 57 metastases), and 68.7% (11 of 16 bone metastases), respectively. No extrahepatic metastases were detected in the other seven patients. The detection rate of PET was 10/18 (55.6%) for intrahepatic lesions of HCC and combined HCC/CC. CONCLUSIONS: The fusion of PET plus CT images is useful in detecting extrahepatic metastases in HCC and combined HCC/CC patients.     

Positron emission tomography scanning in the evaluation of hepatocellular carcinoma

BACKGROUND/AIMS: 18F-fluorodeoxyglucose uptake allows estimation of glucose metabolism by tumor cells using positron emission tomography (PET). We evaluated the role of PET imaging in the diagnosis of hepatocellular carcinoma. METHODS: PET images were collected after intravenous injection of 8-12 mCi of 18F-FDG in 20 patients with hepatocellular carcinoma (HCC). PET tumor activity level was assessed on a scale of 1 to 4 compared to normal liver tissue. The PET score was compared with abdominal computerized tomography (CT) scan results and between tumors of different grades and differentiation. RESULTS: Of the 20 patients studied, 11 (55%) had positive PET scans (PET score: 3 or 4) while nine (45%) were negative (PET score: 1 or 2). CT scan was positive in 18 patients (90%) and negative in two (10%). PET, however, revealed metastases in three patients that were not seen on CT. On pathological review, well-differentiated and low-grade tumors had lower PET scores. Comparison of the well-differentiated with the moderately- and poorly-differentiated tumors revealed a statistically significant difference. No statistical significance was observed between the moderately- and poorly-differentiated tumors or between different tumor grades and PET scores. CONCLUSIONS: The sensitivity of PET in diagnosis of HCC was 55% compared to 90% for CT scanning, although only PET detected some tumors (including distant metastases). Well-differentiated and low tumor grades had lower activity on PET and correspondingly lower PET scores. PET imaging may help assess tumor differentiation and may be useful in the diagnosis and staging and prognostication of HCC as an adjunct to CT.     

Clinical role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in post-operative follow up of gastric cancer： Initial results

AIM： To evaluate the clinical role of 18F-fluorodeo-xyglucose positron emission and computed tomography （18F-FDG PET/CT） in detection of gastric cancer recurrence after initial surgical resection. METHODS： In the period from January 2007 to May 2008, 23 patients who had previous surgical resection of histopathologically diagnosed gastric cancer underwent a total of 25 18F-FDG PET/CT scans as follow-up visits in our center. The standard of reference for tumor recurrence consisted of histopathologic confirmation or clinical follow-up information for at least 5 mo after PET/CT examinations. RESULTS： PET/CT was positive in 14 patients （61%） and negative in 9 （39%）. When correlated with final diagnosis, which was confirmed by histopathologic evidence of tumor recurrence in 8 of the 23 patients （35%） and by clinical follow-up in 15 （65%）, PET/CT was true positive in 12 patients, false positive in 2, true negative in 8 and false negative in 2. Overall, the accuracy of PET/CT was 82.6%, the negative predictive value （NPV） was 77.7%, and the positive predictive value （PPV） was 85.7%. The 2 false positive PET/CT findings were actually chronic inflammatory tissue lesions. For the two patients with false negativePET/CT, the f inal diagnosis was recurrence of mucinous adenocarcinoma in the anastomosis in one patient and abdominal wall metastasis in the other. Importantly, PET/CT revealed true-positive findings in 11 （47.8%） patients who had negative or no definite findings by CT. PET/CT revealed extra-abdominal metastases in 7 patients and additional esophageal carcinoma in one patient. Clinical treatment decisions were changed in 7 （30.4%） patients after introducing PET/CT into their conventional post-operative follow-up program. CONCLUSION： Whole body 18F-FDG PET/CT was highly effective in discriminating true recurrence in post-operative patients with gastric cancer and had important impacts on clinical decisions in a considerable portion of patients.     

Follicular thyroid carcinoma metastasis to the esophagus detected by 18FDG PET/CT.

We report an unusual case of an esophageal metastasis demonstrated on integrated 18F-fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT) scanning. A 55-year-old male with treated well-differentiated follicular thyroid carcinoma (FTC) had persistently raised thyroglobulin levels despite both negative whole-body CT scan and 131I scans. An initial 18FDG PET/CT scan showed moderate focal uptake in the esophagus, which was initially thought to be physiological. A subsequent comparative 18FDG PET/CT scan showed more intense uptake. A diagnostic endoscopy revealed a pedunculated esophageal polyp, which histological examination confirmed to be metastatic FTC. Such a case has not previously been reported.     

Resection of skeletal muscle metastases from squamous cell carcinoma of the esophagus: case report and literature review

Skeletal muscle metastasis from esophageal squamous cell carcinoma is an unusual entity. A 72-year-old man underwent a subtotal esophagectomy for advanced esophageal squamous cell carcinoma. Mediastinal lymph node metastases developed 36 months after operation, and the patient received chemoradiotherapy. He complained about two painful, subcutaneous masses in the upper part of the left arm at 3 months after the end of chemoradiotherapy. Histopathological examination of tissue specimens obtained by explorative surgery showed skeletal muscle metastases from poorly differentiated squamous cell carcinoma. The patient died of multiple metastases 7 months after chemoradiotherapy. This is considered a very rare case of metastasis from squamous cell carcinoma of the esophagus to the triceps muscle of the left arm.     

Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIM To compare the value of contrast-enhanced abdominal computed tomography(CT) and fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT) for detecting gastric carcinoma recurrence.METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group(P 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Fortyfour patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities(P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT(96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT(98% vs 80%, P = 0.035).CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.     

Advantages of positron emission tomography‐computed tomography imaging in esophageal squamous cell carcinoma

To explore the value of positron emission tomography‐computed tomography (PET‐CT) scan in esophageal squamous cell carcinoma (ESCC), we retrospectively summarize the results of PET‐CT scan from 118 patients, with ESCC who underwent PET‐CT scan in the different courses during treatment. Then, the results of PET‐CT scan plus other conventional methods were analyzed to identify the value of PET‐CT scan in diagnosis, staging, response evaluation, monitoring recurrence, and metastasis following treatment. It is suggested that PET‐CT scan possess high value in diagnosis and gives more favorable indication in N and M staging. PET‐CT scan should be translated into routine surveillance for postoperation follow up and is one of more helpful evaluators of response to chemoradiotherapy or chemotherapy.     

Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

AIM: To evaluated the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.METHODS: A total of 138 patients with HCC who had both conventional imaging modalities and ¹⁸F-FDG PET/CT scan done between November 2006 and March 2011 were enrolled. Diagnostic value of each imaging modality for detection of extrahepatic metastases was evaluated. Clinical factors and tumor characteristics including PET imaging were analyzed as indicative factors for metastases by univariate and multivariate methods.RESULTS: The accuracy of chest CT was significantly superior compared with the accuracy of PET imaging for detecting lung metastases. The detection rate of metastatic pulmonary nodule ≥ 1 cm was 12/13 (92.3%), when < 1 cm was 2/10 (20%) in PET imaging. The accuracy of PET imaging was significantly superior compared with the accuracy of bone scan for detecting bone metastases. In multivariate analysis, increased tumor size (≥ 5 cm) (P = 0.042) and increased average standardized uptake value (SUV) uptake (P = 0.028) were predictive factors for extrahepatic metastases. Isometabolic HCC in PET imaging was inversely correlated in multivariate analysis (P = 0.035). According to the receiver operating characteristic curve, the optimal cutoff of average SUV to predict extrahepatic metastases was 3.4.CONCLUSION: ¹⁸F-FDG PET/CT scan is invaluable for detection of lung metastases larger than 1 cm and bone metastases. Primary HCC having larger than 5 cm and increased average SUV uptake more than 3.4 should be considered for extrahepatic metastases.     

Positron emission tomography/computed tomography and endobronchial ultrasound-guided transbronchial needle aspiration to evaluate the status of N2 in preoperative non-small cell lung cancer: a diagnostic test

BackgroundAs a minimally invasive method, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was more accurate than non-invasive methods such as positron emission tomography (PET) and computed tomography (CT) to evaluate the lymph nodes in preoperative non-small cell lung cancer (NSCLC). PET/CT has more anatomical advantages than PET scanning and is more accurate in lung cancer staging. However, no relevant studies have comparatively evaluated PET/CT and EBUS-TBNA for NSCLC patients.MethodsA total of 112 patients were included in this retrospective analysis. The golden diagnosis of N2 status was postoperative pathological results. In EBUS-TBNA puncture specimens, if clear malignant tumor cells could be seen, the results were taken as positive. In PET/CT image analysis, the CT values, short diameter, and maximum standardized uptake value (SUVmax) of each lymph node were recorded to evaluate N2 status. The results of PET/CT and EBUS-TBNA were compared with the final pathological results, and respective sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. - Then, the patients were divided into adenocarcinoma group and squamous cell carcinoma group -and the results were calculated and compared with the above method.ResultsThe results showed that EBUS-TBNA had a higher diagnostic value for mediastinal lymph nodes than PET/CT, and the difference was statistically significant (P<0.001). In NSCLC patients, the results showed that the sensitivity (P=0.013), specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.954 and 0.636, respectively). In adenocarcinoma cases, specificity (P<0.001), PPV (P<0.001), NPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than that of PET/CT (AUC =0.957 and 0.596, respectively).In cases with squamous cell carcinoma, specificity (P=0.003), PPV (P<0.001), and accuracy (P<0.001) of EBUS-TBNA were higher than PET/CT (AUC =0.952 and 0.657, respectively).ConclusionsFor preoperative diagnosis of mediastinal lymph node metastases in NSCLC, EBUS-TBNA is more accurate than PET/CT. For those patients with suspected mediastinal lymph node metastasis, EBUS-TBNA should be preferred method to evaluate the status of mediastinal lymph nodes.     

Unusual adrenal metastasis and abdominal carcinomatosis secondary to Hurthle cell carcinoma of the thyroid.

Hurthle cell carcinoma (HCC) of the thyroid is an uncommon and relatively rare differentiated thyroid neoplasm. To our knowledge, no reported case of adrenal metastases with abdominal carcinomatosis secondary to HCC of the thyroid has been demonstrated by F-18 FDG PET/CT imaging. One report of adrenal uptake on I-131 whole-body scan with HCC exists. In this case report, we describe a patient with HCC who had a left adrenal metastasis with abdominal carcinomatosis that was discovered using F-18 FDG PET/CT imaging.     

External ultrasonography of the neck does not add diagnostic value to integrated positron emission tomography-computed tomography (PET-CT) scanning in the diagnosis of cervical lymph node metastases in patients with esophageal carcinoma

One of the objectives of preoperative imaging in esophageal cancer patients is the detection of cervical lymph node metastases. Traditionally, external ultrasonography of the neck has been combined with computed tomography (CT) in order to improve the detection of cervical metastases. In general, integrated positron emission tomography-computed tomography (PET-CT) has been shown to be superior to CT or PET regarding staging and therefore may limit the role of external ultrasonography of the neck. The objective of this study was to determine the additional value of external ultrasonography of the neck to PET-CT. This study included all patients referred our center for treatment of esophageal carcinoma. Diagnostic staging was performed to determine treatment plan. Cervical lymph nodes were evaluated by external ultrasonography of the neck and PET-CT. In case of suspect lymph nodes on external ultrasonography or PET-CT, fine needle aspiration (FNA) was performed. Between 2008 and 2010, 170 out of 195 referred patients underwent both external ultrasonography of the neck and PET-CT. Of all patients, 84% were diagnosed with a tumor at or below the distal esophagus. In 140 of 170 patients, the cervical region was not suspect; no FNA was performed. Seven out of 170 patients had suspect nodes on both PET-CT and external ultrasonography. Five out of seven patients had cytologically confirmed malignant lymph nodes, one of seven had benign nodes, in one patient FNA was not performed; exclusion from esophagectomy was based on intra-abdominal metastases. In one out of 170 patients, PET-CT showed suspect nodes combined with a negative external ultrasonography; cytology of these nodes was benign. Twenty-two out of 170 patients had a negative PET-CT with suspect nodes on external ultrasonography. In 18 of 22 patients, cervical lymph nodes were cytologically confirmed benign; in four patients, FNA was not possible or inconclusive. At a median postoperative follow-up of 15 months, only 1% of patients developed cervical lymph node metastases. This study shows no additional value of external ultrasonography to a negative PET-CT. According to our results, it can be omitted in the primary workup. However, suspect lymph nodes on PET-CT should be confirmed by FNA to exclude false positives if it would change treatment plan.     

Comparative study between endoscopic ultrasonography and positron emission tomography‐computed tomography in staging patients with esophageal squamous cell carcinoma

Treatment strategy of esophageal cancer mainly depends on accurate staging. At present, no single ideal staging modality is superior to another in preoperative tumor‐node‐metastasis (TNM) staging of patients with esophageal cancer. We aimed to investigate the efficacy of endoscopic ultrasonography (EUS) and positron emission tomography‐computed tomography (PET‐CT) for staging of esophageal cancer. We retrospectively studied 118 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy with or without neoadjuvant chemoradiotherapy (CRT) over a near 3‐year period between January 2005 and November 2008 at a tertiary hospital in Taiwan. Patients were separated into two groups: without neoadjuvant CRT (group 1, n= 28) and with CRT (group 2, n= 90). Medical records of demographic data and reports of EUS and PET‐CT of patients before surgery were reviewed. A database of clinical staging by EUS and PET‐CT was compared with one of pathological staging. The accuracies of T staging by EUS in groups 1 and 2 were 85.2% and 34.9%. The accuracies of N staging by EUS in groups 1 and 2 were 55.6% and 39.8%. The accuracies of T and N staging by means of PET‐CT scan were 100% and 54.5% in group 1, and were 69.4% and 86.1% in group 2, respectively. In group 2, 38 of 90 patients (42.2%) achieved pathologic complete remission. Among them, two of 34 (5.9%) and 12 of 17 (70.6%) patients were identified as tumor‐free by post‐CRT EUS and PET‐CT, respectively. EUS is useful for initial staging of esophageal cancer. PET‐CT is a more reliable modality for monitoring treatment response and restaging. Furthermore, the accuracy of PET‐CT with regard to N staging is higher in patients who have undergone CRT than those who have not.     

Extensive Invasive Extramammary Paget Disease Evaluated by F-18 FDG PET/CT: A Case Report

Extramammary Paget disease (EMPD) is a rare cutaneous, intraepithelial adenocarcinoma. Because of its rarity, little is known about the value of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in evaluating this disease. Our case report aims to increase current knowledge of FDG PET/CT in EMPD as a noninvasive imaging tool for assessing the extension of the disease and detecting distant metastases.We reported a 64-year-old Chinese man who presented with a slowly progressive, ill-margined erythematous lesion with a crusted, eroded, and scaly surface involving multiple sites of penis, scrotum, left pelvic wall, hip, groin, and thigh for >4 years, which became extensive in the past 1 year. He was referred for an FDG PET/CT examination to further evaluate the lesions. A following skin biopsy was performed to obtain a definitive histological diagnosis.FDG PET/CT imaging revealed mild FDG uptake at the extensive cutaneous lesion with subcutaneous invasion, involvement of lymph nodes, and multiple intense FDG-avid of skeletal metastases. According to the appearance of FDG PET/CT, a provisional diagnosis of advanced cutaneous malignancy was made. Histopathology findings indicated characteristic of EMPD. The patient was treated with radiation therapy and died from complications 2 months after the last dose of radiotherapy.Our case highlighted that a whole-body FDG PET/CT should be incorporated into the diagnostic algorithm of EMPD to give a comprehensive assessment of this disease.     

Metabolic restaging of hepatocellular carcinoma using whole-body 18F-FDG PET/CT

AIM: To evaluate the ability of ¹⁸F-fluorodeoxyglucose positron emission and computed tomography (¹⁸F-FDG PET/CT) in restaging of hepatocellular carcinoma (HCC) after treatment.METHODS: We reviewed a database of the diagnostic performance of ¹⁸F-FDG PET/CT scan for patients with HCC following local or regional treatment. The database consisted of ¹⁸F-FDG PET/CT information of 21 male and 4 female (age range, 27-81 years; mean age, 51.6 years) patients who had received surgical resection and/or interventional treatments and then underwent ¹⁸F-FDG PET/CT scan. All patients had received enhanced CT scan of the liver two weeks before or after the ¹⁸F-FDG PET/CT scan. Intrahepatic recurrence and/or extrahepatic metastases were confirmed by histological analysis or clinical and imaging follow-up. The accuracy of ¹⁸F-FDG PET/CT study was determined by histopathological results or by clinical and imaging follow-up.RESULTS: ¹⁸F-FDG PET/CT was abnormal in 19 of the 25 (76.0%) patients. In detecting HCC recurrence, ¹⁸F-FDG PET/CT scored 17 true positives, 5 true negatives, 2 false positives and 1 false negative. The sensitivity, specificity and accuracy of ¹⁸F-FDG PET/CT in detecting HCC recurrence was 89.5%, 83.3% and 88%, respectively. ¹⁸F-FDG PET/CT had an impact on management of these patients by settling the problem of an unexplained increase in alpha-fetoprotein after treatment (14 patients), by monitoring response to the treatment and guiding additional regional therapy (12 patients), by identifying extrahepatic metastases (10 patients), by identifying tumor growth or thrombosis in the portal vein (6 patients), or by guiding surgical resection of extrahepatic metastases (2 patients).CONCLUSION: Our results suggest that whole body ¹⁸F-FDG PET/CT may be useful in the early evaluation of residual, intrahepatic recurrent or extrahepatic metastatic lesions and able to provide valuable information for the management of HCC recurrence.     

Results of radio frequency ablation of primary and secondary liver tumors: long-term follow-up with computed tomography and positron emission tomography-18F-deoxyfluoroglucose scanning

BACKGROUND: In the literature, promising results have been obtained with radiofrequency ablation (RFA) of primary liver malignancies (e.g. hepatocellular carcinoma, HCC) and secondary liver malignancies (e.g. metastases of colorectal tumors). In our center, positron emission tomography with FDG (FDG-PET) and computed tomography (CT) were used for follow-up. Patient outcome was compared with that in the literature, and PET and CT were analyzed regarding positive and negative predictive values for early detection of tumor recurrence. METHODS: The data were analyzed of patients who were treated with RFA for primary or secondary liver tumors between January 1999 and December 2002. Indications for treatment with RFA were liver tumors that could not be resected owing to size, number, or tumor location. In all patients, a CT scan was performed before RFA, and follow-up was performed with a CT scan in all patients and with an additional PET scan at various intervals in 11 patients. At evaluation with PET, tumor recurrence was defined as positive uptake of tracer either at the previous RFA lesion or at a new site in the liver. RESULTS: In total, 15 patients (8 M, 7 F) were treated in 21 sessions with RFA. The mean follow-up period was 16.8 months (range: 7-42). Average age of the patients was 63 years (range: 40-74). One patient had a primary liver tumor; all other patients had metastases of the breast (1), ovary (1), renal cells (1), and colorectal carcinoma (11 patients). The mean number of tumors per patient was 2.7 (range: 1-5). No treatment-related morbidity or mortality occurred. In 4 of 11 patients evaluated with PET at a mean period of 6.8 months, positive uptake of tracer was noted. At CT evaluation, tumor recurrence was observed in 4 of these patients, at a mean time of 9.8 months. Two patients (13.3%) died of cancer recurrence during follow-up. CONCLUSIONS: Tumor recurrence is comparable with that in other studies. Centrally located tumors showed more recurrence than peripheral tumors. The use of PET in combination with CT scan at follow-up may lead to earlier detection of tumor recurrence than contrast-enhanced CT alone.     

Original article: Impact of 18‐fluorodeoxyglucose positron emission tomography on computed tomography defined target volumes in radiation treatment planning of esophageal cancer: reduction in geographic misses with equal inter‐observer variability

Target volume definition in modern radiotherapy is based on planning computed tomography (CT). So far, 18‐fluorodeoxyglucose positron emission tomography (FDG‐PET) has not been included in planning modality in volume definition of esophageal cancer. This study evaluates fusion of FDG‐PET and CT in patients with esophageal cancer in terms of geographic misses and inter‐observer variability in volume definition. In 28 esophageal cancer patients, gross, clinical and planning tumor volumes (GTV; CTV; PTV) were defined on planning CT by three radiation oncologists. After software‐based emission tomography and computed tomography (PET/CT) fusion, tumor delineations were redefined by the same radiation‐oncologists. Concordance indexes (CCI's) for CT and PET/CT based GTV, CTV and PTV were calculated for each pair of observers. Incorporation of PET/CT modified tumor delineation in 17/28 subjects (61%) in cranial and/or caudal direction. Mean concordance indexes for CT‐based CTV and PTV were 72 (55–86)% and 77 (61–88)%, respectively, vs. 72 (47–99)% and 76 (54–87)% for PET/CT‐based CTV and PTV. Paired analyses showed no significant difference in CCI between CT and PET/CT. Combining FDG‐PET and CT may improve target volume definition with less geographic misses, but without significant effects on inter‐observer variability in esophageal cancer.