Positron emission tomography in the evaluation of stage III and IV head and neck cancer.

BACKGROUND: Detection of metastatic disease in head and neck cancer patients is critical to preoperative planning, because patients with distant metastasis will not benefit from surgical therapy. Conventional radiographic modalities, such as CT and MR, give excellent anatomic detail but poorly identify unenlarged lymph nodes harboring metastatic disease. OBJECTIVE: A pilot study was conducted to evaluate the usefulness of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) detection of metastatic disease in patients with advanced-stage head and neck cancer. METHODS: Total body FDG-PET imaging was performed in a prospective manner on 12 consecutive patients with a new diagnosis of stage III or IV mucosal squamous cell carcinoma of the head and neck. Chest CT was also performed on all 12 patients. Patients found to have metastatic disease on either CT or PET imaging underwent procedures to obtain histopathologic confirmation of disease. RESULTS: Three patients (25%) had FDG-PET scans demonstrating metastatic disease. Two of these patients had no evidence of disease on chest radiograph or chest CT but were noted to have positive FDG-PET imaging within the mediastinal lymphatics. Mediastinoscopy was performed confirming metastatic disease in these patients. The third patient had a peripheral lung lesion detected on chest radiograph, CT, and FDG-PET. This nodule was diagnosed by CT-guided biopsy as squamous cell carcinoma. CONCLUSION: FDG-PET scanning detected mediastinal disease in two patients (17%) with advanced-stage head and neck squamous cell carcinoma that was not identified with conventional imaging techniques. PET imaging seems to have significant potential in the detection of occult metastatic disease, particularly in the mediastinal lymphatics.     

Evaluation of minimally invasive surgical staging for esophageal cancer

BACKGROUND: Conventional imaging studies (computed tomography and endoscopic esophageal ultrasonography) used for preoperative evaluation of patients with esophageal cancer can be inaccurate for detection of small metastatic deposits. We evaluated the efficacy of minimally invasive surgical (MIS) staging as an additional modality for evaluation of patients with esophageal cancer. METHODS: Between December 1998 and February 2001, 33 patients with esophageal cancer were evaluated for surgical resection. Conventional imaging studies demonstrated operable disease in 31 patients and equivocal findings in 2 patients. All patients then underwent MIS staging (laparoscopy, bronchoscopy, and ultrasonography of the liver). We compared the results from surgical resection and MIS staging with those from conventional imaging. RESULTS: MIS staging altered the treatment plan in 12 (36%) of 33 patients; MIS staging upstaged 10 patients with operable disease and downstaged 2 patients with equivocal findings. MIS staging accurately determined resectability in 97% of patients compared with 61% of patients staged by conventional imaging. The specificity and negative predictive value for detection of unsuspected metastatic disease in MIS staging were 100% and 96%, respectively, compared with 91% and 65%, respectively, for conventional imaging studies. CONCLUSION: In addition to conventional imaging studies, MIS staging should be included routinely in the preoperative work-up of patients with esophageal cancer.     

Fluorodeoxyglucose positron emission tomography for detection of recurrent or metastatic breast cancer

Fluorodeoxyglucose-positron emission tomography (FDG-PET) is a noninvasive imaging technique capable of identifying primary tumors and metastases with high sensitivity and accuracy. The aim of this study was to evaluate the diagnostic accuracy of whole-body FDG-PET imaging for the detection of recurrent or metastatic breast cancer after surgery. Whole-body FDG-PET imaging was performed on 27 patients with suspected recurrent breast carcinoma. PET images were evaluated qualitatively for each patient and lesion. FDG-PET scans showed that there were 61 reference sites of malignant or benign lesions in 27 patients. In a patient-based analysis, FDG-PET scans correctly identified 16 of 17 patients with recurrent or metastatic disease and 8 of 10 without recurrence, resulting in a sensitivity, specificity, and accuracy of 94%, 80%, and 89%, respectively. In a lesion-based analysis, FDG-PET scans correctly identified 46 of 48 lesion sites with recurrent or metastatic disease and 11 of 13 without recurrence. The overall sensitivity, specificity, and accuracy for all lesion sites were 96%, 85%, and 93%, respectively. FDG-PET scans revealed unsuspected recurrent or metastatic diseases in 8 of 27 (30%) of patients and 11 of 20 (55%) distant metastatic lesions. In 13 patients treatment was altered by the outcome of the PET scan. We concluded that whole-body FDG-PET scan is a useful diagnostic imaging modality for detecting recurrent or metastatic breast carcinoma in patients suspected of having recurrent disease after primary surgery.     

Improved Staging With Pretreatment Positron Emission Tomography/Computed Tomography in Low Rectal Cancer

Background ¹⁸F-Fluorodeoxyglucose (FDG)-positron emission tomography (PET) and computed tomography (CT) are widely accepted in the evaluation for metastatic or recurrent rectal cancer. Only spiral CT and transrectal ultrasonography (TRUS) are routinely used in the initial evaluation of primary rectal cancer. We wished to determine whether PET/CT could provide additional information in patients undergoing standard evaluation for primary rectal cancer. Methods Thirty-seven patients (mean age, 58 years; range, 26–90 years) with a previously untreated rectal cancer underwent TRUS or magnetic resonance imaging, spiral CT, and FDG-PET/CT. The tumor location (low, ≤6 cm; mid, 7–10 cm; or high, ≥10 cm) and carcinoembryonic antigen level were recorded. Discordant findings between spiral CT and FDG-PET/CT were confirmed by histological analysis or imaging follow-up. Results FDG-PET/CT identified discordant findings in 14 patients (38%), and this resulted in upstaging of 7 patients (50%) and downstaging of 3 patients (21%). Although node-positive disease on TRUS/magnetic resonance imaging was associated with discordant FDG-PET/CT findings, this was not statistically significant. Discordant PET/CT findings were significantly more common in patients with a low rectal cancer than in those with mid or high rectal cancer (13 vs. 1; P = .0027). The most common discordant finding was lymph node metastasis (n = 7; 50%). Histological confirmation of discordant FDG-PET/CT findings was performed in seven patients, and in no case did FDG-PET/CT prove to be inaccurate. Discordant PET/CT findings resulted in a deviation in the proposed treatment plan in 27% of patients (n = 10). Conclusions FDG-PET/CT frequently yields additional staging information in patients with low rectal cancer. Improved accuracy of pretreatment imaging with FDG-PET/CT will allow for more appropriate stage-specific therapy. Presented at the Annual Meeting of the Society of Surgical Oncology, Atlanta, Georgia, March 3–6, 2005.     

The role of [<Superscript>18</Superscript>F] FDG-PET,CT/MRI and tumor marker kinetics in the evaluation of postchemotherapy residual masses in metastatic germ cell tumors—prospects for management

The purpose of this study was to assess the ability of [¹⁸F]FDG-PET, CT/MRI and serum tumor marker (TM) to predict the viability of residual masses after high-dose chemotherapy (HD-Ctx) in patients with metastatic germ cell tumors (GCT). In a prospective study, 60 residual tumors in 28 GCT patients were classified as viable/nonviable by FDG-PET, CT/MRI and TM levels. The results were validated either by histological examination of a resected mass and/or biopsy or by clinical/radiological follow-up for at least 6 months. There were no significant differences among the sensitivities observed with PET, CT/MRI and TM, but PET was significantly more specific than CT/MRI in predicting residual mass viability. TM showed the highest specificity. The highest accuracy in classification of residual tumors was achieved by a combination of PET, CT/MRI and TM (area under the ROC curve =0.91). All mature teratomas showed false-negative PET results with SUVs in the same range as necrosis. For classification of residual masses after HD-Ctx of metastatic GCT, [¹⁸F]FDG-PET is a valuable diagnostic method to complement the established procedures CT and TM. Positive PET results are highly correlated with the presence of viable tumor, but residual masses with negative PET findings still require resection. In cases of tumor progression diagnosed by CT and elevated TM, additional PET examinations are without benefit. PET seems useful in patients with stable disease or partial remission in CT/MRI and normalized TM as well as in marker-negative disease.     

Evaluation of 18F-2-deoxy-2-fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography for Gastric Cancer

Positron emission tomography (PET) with ¹⁸F-2-deoxy-2-fluoro-d-glucose (FDG) has been investigated as a means of detecting certain primary tumors and their metastatic disease in recent years. The aim of this study was to compare the performance of FDG-PET and operative assessment with formal pathologic staging. Altogether, 85 patients had undergone surgical treatment for gastric cancer with curative intent, with FDG-PET preoperatively. The results using FDG-PET were compared with those using computed tomography (CT); they were also correlated with the pathologic findings. For quantitative analysis, the regional tumor uptake was measured by the standard uptake value (SUV) using a region of interest technique. Using FDG-PET, the primary tumor was visualized in 75.2% of patients. A comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between FDG uptake and the depth of invasion, the size of the tumor, and lymph node metastasis. FDG-PET scans had less accuracy for diagnosing locoregional lymph nodes than CT because of a significant lack of sensitivity (23.3% vs. 65.0%). The survival rate for patients with high FDG uptake (SUV > 4) was significantly lower than that for those with low FDG uptake (SUV < 4) (p < 0.05). FDG-PET was successful in detecting the primary gastric cancer lesion but not for finding early-stage gastric cancers. Detection of nodal metastasis also was not possible by FDG-PET. However, FDG-PET appears to provide important additional information concerning the aggressiveness of the tumor and the prognosis in patients with gastric cancer.     

Expanding role of 18F-fluoro-d-deoxyglucose PET and PET/CT in spinal infections

¹⁸F-fluoro-d-deoxyglucose positron emission tomography ([¹⁸F]-FDG PET) is successfully employed as a molecular imaging technique in oncology, and has become a promising imaging modality in the field of infection. The non-invasive diagnosis of spinal infections (SI) has been a challenge for physicians for many years. Morphological imaging modalities such as conventional radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are techniques frequently used in patients with SI. However, these methods are sometimes non-specific, and difficulties in differentiating infectious from degenerative end-plate abnormalities or postoperative changes can occur. Moreover, in contrast to CT and MRI, FDG uptake in PET is not hampered by metallic implant-associated artifacts. Conventional radionuclide imaging tests, such as bone scintigraphy, labeled leukocyte, and gallium scanning, suffer from relatively poor spatial resolution and lack sensitivity, specificity, or both. Initial data show that [¹⁸F]-FDG PET is an emerging imaging technique for diagnosing SI. [¹⁸F]-FDG PET appears to be especially helpful in those cases in which MRI cannot be performed or is non-diagnostic, and as an adjunct in patients in whom the diagnosis is inconclusive. The article reviews the currently available literature on [¹⁸F]-FDG PET and PET/CT in the diagnosis of SI.     

Positron emission tomography (PET) in the urooncological evaluation of the small pelvis

Positron emission tomography (PET) with the use of (¹⁸F)2-fluoro-d-2-desoxyglucose (FDG) has been investigated to be a highly sensitive and specific imaging modality in the diagnostic of primary and recurrent tumors and in the control of therapies in numerous non-urologic cancers. The aim of this review is to validate the significance of PET as a diagnostic tool in malignant urological tumors of the small pelvis. A systematic review of the current literature concerning the role of PET for malignant prostate, testicular and bladder tumors was carried out. The data indicate no additional role for PET in comparison with conventional imaging in tumor detection and local staging for prostate, bladder or testicular cancer. Tumor recurrence in prostate cancer seems to be more effectively identified with acetate and choline than with FDG, but this effect is more pronounced with higher PSA values. The value of PET in the identification of metastatic disease in either tumor entity can not be finally outlined as the clinical data are partly missing, controversial or in the process of evaluation. FDG-PET can be regarded as accepted imaging modality in the restaging of seminomatous germ cell tumors after chemotherapy.     

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.     

Value of fluorodeoxyglucose positron emission tomography in women with breast cancer

BACKGROUND: The aim of this prospective study was to evaluate the role of fluorodeoxyglucose positron emission tomography (FDG-PET) in the staging of high-risk women with primary or recurrent breast cancer. METHODS: FDG-PET was performed in 42 women with a primary breast cancer and unfavourable characteristics, or who had a suspected relapse. FDG-PET and conventional staging methods were compared. In case of abnormality on FDG-PET, confirmation was always attempted. RESULTS: Increased uptake was found in five of 17 women with a primary cancer. In the 25 women with a suspected relapse, FDG-PET showed increased uptake in 43 areas, 22 correctly confirming the area of suspected relapse and 21 indicating other sites of metastases. Compared with conventional imaging, FDG-PET revealed additional (confirmed) lesions in two women with primary cancers and three with relapse. Patient management was changed for five women. CONCLUSION: FDG-PET is a sensitive diagnostic method for the detection of distant metastatic disease. Its exact role in women with breast cancer remains to be defined.     

Clinical role of F-18 fluorodeoxyglucose positron emission tomography for detection and management of renal cell carcinoma

PURPOSE: We evaluate the accuracy of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) for staging and management of renal cell carcinoma. MATERIALS AND METHODS: FDG-PET was performed in 25 patients with known or suspected primary renal tumors and/or metastatic disease and compared with conventional imaging techniques, including computerized tomography (CT). Histopathological confirmation was obtained in 18 patients and confirmation of the disease was by followup in the remainder. The impact of FDG-PET on disease management was also assessed. RESULTS: Of the 17 patients with known or suspected primary tumors FDG-PET was true positive in 15, true negative in 1 and false-negative in 1. Comparative CT was true positive in 16 patients and false-positive in 1. The accuracy of FDG-PET and CT was similar (94%). All patients would have undergone radical nephrectomy after conventional imaging findings but FDG-PET results altered treatment decisions for 6 (35%), of whom 3 underwent partial nephrectomy and 3 avoided surgery due to confirmation of benign pathology or detection of unsuspected metastatic disease. Of the 8 cases referred for evaluation of local recurrence and/or metastatic disease FDG-PET changed treatment decisions in 4 (50%), with disease up staged in 3 and recurrence excluded in 1. Compared with CT, FDG-PET was able to detect local recurrence and distant metastases more accurately and differentiated recurrence from radiation necrosis. CONCLUSIONS: FDG-PET accurately detected local disease spread and metastatic disease in patients with renal cell carcinoma and altered treatment in 40%. FDG-PET may have a role in the diagnostic evaluation of patients with renal cell carcinoma preoperatively and staging of metastatic disease.     

The predictive value of incidental PET/CT findings suspicious for breast cancer in women with non-breast malignancies

Background

On occasion, patients followed with positron emission tomographic (PET)/computed tomographic (CT) imaging for nonbreast malignancies will have incidental breast findings concerning for second primary breast cancers. The aim of this study was to determine the predictive value of PET/CT imaging to identify breast cancers in these patients.

Methods

Patients with primary nonbreast malignancies and findings concerning for second primary breast cancers were identified from a prospectively acquired nuclear medicine database from January 2005 to July 2008. Chart reviews were then performed.

Results

Nine hundred two women underwent PET/CT imaging to evaluate nonbreast malignancies. Nine women (1%) had concerning breast findings, and 5 (56%) had subsequent breast cancer diagnoses. The positive predictive value of PET/CT imaging in these patients was 63%. Evidence of compliance with current screening guidelines was present in only 22% of these patients.

Conclusions

The data suggest that findings concerning for an additional primary breast cancer should be evaluated and that age-appropriate screening tools should not be abandoned.     

The utility of positron emission tomography for the diagnosis and staging of recurrent esophageal cancer

OBJECTIVE: To study the utility of whole-body positron emission tomography with (18)F-fluoro-deoxy-D -glucose (FDG-PET) for the evaluation of recurrence after curative resection of cancer of the esophagus or gastroesophageal junction. METHODS: Forty-one patients with a clinical or radiologic suspicion of recurrent disease underwent conventional diagnostic work-up, including a spiral computed tomographic scan, an endoscopic ultrasound, and a dedicated whole-body FDG-PET. PET lesions were classified as equivocal or suspicious recurrence. The conventional diagnostic work-up and PET findings were correlated with pathology or with radiologic and clinical follow-up. Equivocal lesions were classified as positive. RESULTS: Forty recurrences were found in 33 patients. The lesions were perianastomotic (n = 9), regional (n = 12), and at distant sites (n = 19). For the diagnosis of a perianastomotic recurrence, the sensitivity, specificity, and accuracy of FDG-PET were 100%, 57%, and 74%, versus 100%, 93%, and 96% for conventional diagnostic work-up, respectively (P = not significant). False-positive PET lesions were found in patients with a progressive anastomotic stenosis requiring repetitive endoscopic dilatation. For the diagnosis of regional and distant recurrences, the sensitivity, specificity, and accuracy of PET were 94%, 82%, and 87%, versus 81% (P = not significant), 82% (P = not significant), and 81% (P =.0771) for conventional diagnostic work-up. All false-positive PET lesions (n = 4) had been reported as equivocal. On a patient base, PET provided additional information in 11 of 41 (27%) patients. A major impact on diagnosis was found in 5 patients with equivocal or negative findings on complete diagnostic work-up in whom PET provided a true-positive diagnosis. In 5 other patients the diagnosis was staged upward from localized to extended recurrent disease, and in 1 patient with an equivocal complete diagnostic work-up, PET correctly excluded malignancy. CONCLUSION: FDG-PET allows a highly sensitive diagnosis and accurate whole-body staging of symptomatic recurrent esophageal cancer. Further studies in asymptomatic patients are needed to assess the potential benefit on survival.     

MRI and <Superscript>18</Superscript>FDG-PET in the assessment of bone marrow infiltration of the spine in cancer patients

The aim of this study was to evaluate the diagnostic value of MRI and ¹⁸FDG-PET in bone marrow infiltration of the spine due to metastases of solid tumours and lymphoma in cancer patients. In 35 cancer patients (solid tumours n = 26, lymphoma n = 9) MRI of the spine and ¹⁸FDG-PET were reviewed and the detectability of metastases, infiltration of the spine, extent of disease, and therapeutic implications were compared. In 8/35 cases (23%) imaging technique showed concordantly no bone marrow infiltration. In 19/35 patients (54%), both MRI and ¹⁸FDG-PET revealed bone marrow infiltration of the axial skeleton. In 12/19 patients (63%), MRI showed more extensive disease which lead to subsequent therapy. The imaging findings of MRI and ¹⁸FDG-PET were discordant in 8/35 cases (23%). ¹⁸FDG-PET was false positive in two patients. In six patients, ¹⁸FDG-PET failed to detect bone metastases and bone marrow infiltration of the spine, which was detected by MRI and proven by clinical follow-up with subsequent therapy in two cases. MRI is more sensitive and specific than ¹⁸FDG-PET detecting bone marrow metastases and infiltration of the spine and has a great impact in staging cancer patients.     

CT staging for breast cancer patients with poor prognostic tumours

The aim of this study was to assess the value of computed tomography (CT) staging of the chest, abdomen and pelvis in patients with poor prognostic tumours and no symptoms of metastatic disease in those who have undergone primary surgical management for the treatment of breast cancer.Patients who had primary operable invasive breast cancer treated by surgery over a 2-year period were retrospectively identified. Pathological data from the surgical resection were used to calculate the Nottingham Prognostic Index. Patients with no symptoms of distant metastases who underwent CT staging of the chest, abdomen and pelvis as a result of being placed in the poor prognostic group were identified. The presence and sites of metastatic disease or any indeterminate finding were documented. Additional investigations generated as a result of the staging CT and the outcome were also recorded.Sixty-seven patients (80%) in the poor prognostic group underwent a staging CT. Forty-seven patients (70%) had no signs of metastatic disease on the staging CT. Two patients (3%) were diagnosed with metastatic disease, on the basis of the initial CT scan. Eighteen patients (27%) had an indeterminate finding requiring further investigation, generating 21 additional imaging tests – following this only one additional patient was diagnosed with metastatic disease. Seventeen patients with an initially indeterminate finding did not have metastatic disease, giving a false-positive rate of 25%. In total, three patients (4%) had a final diagnosis of metastatic disease.The routine use of CT staging in patients with no symptoms of distant metastases with primary operable breast cancer even when in a poor prognostic group is of limited value, with a low pick-up rate of metastatic disease and considerable risk of false-positive findings.     

PET和CT对结直肠癌复发、转移诊断价值的评估

目的：评价PET和CT诊断复发转移性结直肠癌的价值。方法：结直肠癌病人94例行PET检查，其中67例同时行CT检查。以病理或随访为最后诊断，平均随访时间为21个月。^18F-FDG-PET的诊断结果基于医师的肉眼判断、SUV值（the standard uptake value）和CT图像三者结果而得出的。结果：PET和CT检查真阳性分别为46例和32例，真阴性25例和14例，假阳性5例和7例，假阴性4例和10例。PET和CT的符合率88．75％和73．02％、灵敏度92．00％和76．19％，特异性83．33％和66．67％，阳性预测值90．20％和82．05％，阴性预测值86．21％和58.33％。两者诊断符合率和灵敏度差异具有统计学意义P值分别为0．015和0．034。PET对临床处理的影响率为12．5％（n=10）。结论：PET结合常规诊断方法可有效地提高结直肠癌复发转移病灶诊断的准确性。     

Utility of Preoperative [(18)]F Fluorodeoxyglucose–Positron Emission Tomography Scanning in High-Risk Melanoma Patients

Background [(18)]F Fluorodeoxyglucose-positron emission tomography (PET) scanning provides functional imaging based on glucose uptake by tumors. Melanoma is a glucose-avid malignancy, and preoperative PET scanning in melanoma patients has the potential to guide appropriate treatment. Methods We performed a prospective trial to evaluate the clinical utility of whole-body fluorine 18–labeled deoxyglucose-PET scanning used in addition to standard imaging (contrast-enhanced computed tomographic [CT] imaging of the chest, abdomen, and pelvis) in preoperative stage IIC (T4N0M0), III (any T, N1 to N3, M0), and IV (any T, any N, M1) melanoma patients. Pathologic or clinical follow-up within 4 to 6 months of the imaging studies was used to determine the accuracy of preoperative PET and CT scan findings. Results Preoperative imaging findings led to a change in clinical management in 36 (35%) of 103 patients. In 32 (89%) of these patients, the information was accurate. Findings on PET scan alone (14 of 36; 39%) or in combination with CT (20 of 36; 56%) resulted in a treatment change in most patients (34 of 36; 94%). The most common decision was to cancel the operation (19 of 36; 53%). PET scanning was more sensitive than CT scanning in detecting occult disease (68% vs. 48%; P = .05), but both tests were highly specific (92% vs. 95%; P = .7, PET vs. CT). Conclusions PET scanning facilitates the appropriate management of high-risk melanoma patients being considered for operative intervention. PET imaging in addition to CT scanning should be strongly considered before operation in patients at high risk for occult metastatic disease. Presented in part at the Annual Meeting of the American Society of Clinical Oncology, New Orleans, Louisiana, June 7, 2004.     

FDG-PET/CT in the staging of local/regional metastases in breast cancer

Breast cancer is the commonest female malignancy in the Western world and the most reliable predictor for survival is axillary lymph node metastases. Conventional staging techniques employed in breast cancer include mammography, ultrasonography, isotope bone scanning, sentinel lymph node biopsy, axillary lymph node dissection and magnetic resonance imaging. More recently FDG-PET and FDG-PET/CT have been used to complement the above methods. This review assesses the role of FDG-PET/CT in axillary staging in patients with primary breast cancer.A PubMed search was conducted and all articles containing relevant or new information were included. Relevant studies examined identified that FDG-PET/CT has a sensitivity of 60% and a specificity of 97% in detecting lymphatic metastasis.Although positive axillary FDG-PET/CT is a good predictor of axillary disease and correlates well with SLNB, the relatively poor sensitivity (60%) must be considered for treatment planning.     

Evaluation of the evidence on staging imaging for detection of asymptomatic distant metastases in newly diagnosed breast cancer

While guidelines recommend against routine use of staging imaging to detect asymptomatic distant metastases (DM) in newly diagnosed breast cancer (BC), modern imaging technologies may have improved detection capability and may have a role in some cases. We performed a systematic review of studies (1995-2011) evaluating the prevalence of DM and the accuracy of staging imaging for detection of asymptomatic DM. Twenty-two studies reporting on 14,824 BC subjects (median age 53 years) undergoing staging imaging were eligible. Median prevalence of DM was 7.0% (range 1.2-48.8%); prevalence increased with increasing BC stage. Conventional imaging studies had lower DM prevalence than studies of PET(PET/CT). Imaging median sensitivity/specificity respectively were: combined conventional imaging 78.0%/91.4%; bone scintigraphy 98.0%/93.5%; chest X-ray 100%/97.9%; liver ultrasound 100%/96.7%; CT chest/abdomen 100%/93.1%; FDG-PET 100.0%/96.5%; FDG-PET/CT 100%/98.1%. Low prevalence of DM was seen in Stage I-II BC with much higher prevalence in more advanced disease. Accuracy of PET modalities was very high however the high proportion of detected asymptomatic DM partly reflects selection bias.     

Positron emission tomography with 18F-fluorodeoxyglucose to predict pathologic response after induction chemotherapy and definitive chemoradiotherapy in head and neck cancer

BACKGROUND: Conventional imaging is limited in identifying persistent disease after organ-preserving therapy for patients with advanced squamous cell carcinoma of the head and neck (SCCHN). We studied the accuracy of positron emission tomography (PET) with (18)F-fluoro-2-deoxy-D-glucose (FDG-PET) in restaging disease in patients with SCCHN after they had undergone induction chemotherapy (ICT) followed by chemoradiotherapy (CRT). METHODS: Forty patients with advanced SCCHN were treated with ICT followed by CRT. FDG-PET imaging was performed to assess for residual cancer at the primary site and in nodal metastases. Two nuclear medicine physicians interpreted PET scans in random sequence. Test characteristics were calculated with pathologic analysis or clinical recurrence as the standard. RESULTS: After induction chemotherapy, PET imaging had a sensitivity of 100% and specificity of 65% for detecting persistent disease at the primary tumor site. After ICT and CRT were completed, the sensitivity and specificity of PET imaging were 67% and 53%, respectively, for detecting occult disease in cervical lymph nodes. CONCLUSIONS: FDG-PET imaging showed some correlation with pathologic response after ICT and CRT in patients with advanced SCCHN. The use of FDG-PET warrants further investigation in this setting.