Early Timing of Thyroidectomy for Hyperthyroidism in Graves' Disease Improves Biochemical Recovery.

BACKGROUND: The role of thyroidectomy as an early treatment for hyperthyroidism has been poorly investigated. Our aim was to examine its success rates, particularly focusing on thyroidectomy as an early treatment. METHODS: Patients with thyroidectomy for hyperthyroidism between February 2008 and October 2014 were included. They were divided into two groups (early and delayed thyroidectomy), and patient characteristics, treatment indications, complications and time to biochemical recovery were analyzed. RESULTS: Ninety-nine patients met the inclusion criteria, of whom 65 (66%) suffered from Graves' disease, 25 (25%) from toxic goiters and 9 (9%) from amiodarone-induced hyperthyroidism. Structural abnormalities of the thyroid (39 patients, 39%) represented the most frequent indications for thyroidectomy. Forty-six patients (46%) underwent an early and 53 (54%) a delayed surgical approach. Patients with Graves' disease undergoing early thyroidectomy did not suffer more often from complications but had a significantly faster biochemical recovery after surgery than those with a delayed thyroidectomy, as judged by a shorter time to reach TSH (121 ± 24 vs. 240 ± 31 days, p = 0.007) and fT4 (91 ± 29 vs. 183 ± 31 days p = 0.015) levels in the normal range. As expected, there were no recurrences of hyperthyroidism. CONCLUSIONS: Early thyroidectomy was neither associated with permanent complications nor thyroid storm, but with a significantly improved biochemical recovery and therefore has to be recommended early in patients with Graves' disease.

Limited value of 18F-FDG PET/CT and S-100B tumour marker in the detection of liver metastases from uveal melanoma compared to liver metastases from cutaneous melanoma.

PURPOSE: The objective of this study was to evaluate the value of (18)F-FDG PET/CT and S-100B tumour marker for the detection of liver metastases from uveal melanoma in comparison to liver metastases from cutaneous melanoma. METHODS: A retrospective evaluation was conducted of 27 liver metastases in 13 patients with uveal melanoma (UM) (mean age: 56.8, range: 30-77) and 43 liver metastases in 14 patients (mean age: 57.9, range: 40-82) with cutaneous melanoma (CM) regarding size and FDG uptake by measuring the maximum standardized uptake value (SUV(max)). S-100B serum tumour markers were available in 20 patients. Cytology, histology, additional morphological imaging and follow-up served as reference standard. In nine patients liver metastases were further evaluated histologically regarding GLUT-1 and S-100 receptor expression and regarding epithelial or spindle cell growth pattern. RESULTS: Of 27 liver metastases in 6 of 13 patients (46%) with UM, 16 (59%) were FDG negative, whereas all liver metastases from CM were positive. Liver metastases from UM showed significantly (p < 0.001) lower SUV(max) (mean: 3.5, range: 1.5-13.4) compared with liver metastases from CM (mean: 6.6, range: 2.3-15.3). In four of six (66.7%) patients with UM and liver metastases S-100B was normal and in two (33.3%) increased. All PET-negative liver metastases were detectable by morphological imaging (CT or MRI). S-100B was abnormal in 13 of 14 patients with liver metastases from CM. S-100B values were significantly higher (p = 0.007) in the CM patient group (mean S-100B: 10.9 microg/l, range: 0.1-115 microg/l) compared with the UM patients (mean: 0.2 microg/l, range: 0.0-0.5 microg/l). Histological work-up of the liver metastases showed no obvious difference in GLUT-1 or S-100 expression between UM and CM liver metastases. The minority (36%) of patients with UM had extrahepatic metastases and the majority (86%) of patients with CM had extrahepatic metastases, respectively. There was a close to significant trend to better survival of UM patients compared with CM patients (p = 0.06). CONCLUSION: FDG PET/CT and serum S-100B are not sensitive enough for the detection of liver metastases from UM, whereas liver metastases from cutaneous melanoma are reliably FDG positive and lead regularly to increased S-100B tumour markers. The reason for the lower FDG uptake in UM liver metastases remains unclear. We recommend to perform combined contrast-enhanced PET/CT in order to detect FDG-negative liver metastases from UM.

Baseline staging of melanoma with unknown primary site: the value of serum s100 protein and positron emission tomography.

BACKGROUND: Baseline staging is important in all melanoma types, including melanoma with unknown primary site (MUP). Staging includes different examination strategies, each with different accuracy. OBJECTIVE: To determine the value of serum S100 protein levels and positron emission tomography (PET) in the baseline staging of MUP. METHODS: Twenty patients with MUP were evaluable for the analysis between 1996 and 2007 with both S100 assessment and PET performed for baseline staging. RESULTS: Serum S100 was elevated in 7 patients (35%). The PET scan detected the metastases in 6 of 7 patients with elevated serum S100 protein showing a strong correlation (p = 0.005). Patients with metastases had significantly higher serum S100 levels (p = 0.01) than the ones without. Serum S100 protein was shown to be discriminative between patients with and without metastases (receiver-operating characteristic, p = 0.012) with 75% sensitivity and 92% specificity. CONCLUSION: Serum S100 protein appears to be a sensitive as well as specific marker to detect metastases. We therefore might recommend serum S100 assessment to be included in the baseline staging of MUP.

Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography.

BACKGROUND: We compared the diagnostic accuracy of integrated positron-emission tomography (PET) and computed tomography (CT) with that of CT alone, that of PET alone, and that of conventional visual correlation of PET and CT in determining the stage of disease in non-small-cell lung cancer. METHODS: In a prospective study, integrated PET-CT was performed in 50 patients with proven or suspected non-small-cell lung cancer. CT and PET alone, visually correlated PET and CT, and integrated PET-CT were evaluated separately, and a tumor-node-metastasis (TNM) stage was assigned on the basis of image analysis. Nodal stations were identified according to the mapping system of the American Thoracic Society. The standard of reference was histopathological assessment of tumor stage and node stage. Extrathoracic metastases were confirmed histopathologically or by at least one other imaging method. A paired sign test was used to compare integrated PET-CT with the other imaging methods. RESULTS: Integrated PET-CT provided additional information in 20 of 49 patients (41 percent), beyond that provided by conventional visual correlation of PET and CT. Integrated PET-CT had better diagnostic accuracy than the other imaging methods. Tumor staging was significantly more accurate with integrated PET-CT than with CT alone (P=0.001), PET alone (P<0.001), or visual correlation of PET and CT (P=0.013); node staging was also significantly more accurate with integrated PET-CT than with PET alone (P=0.013). In metastasis staging, integrated PET-CT increased the diagnostic certainty in two of eight patients. CONCLUSIONS: Integrated PET-CT improves the diagnostic accuracy of the staging of non-small-cell lung cancer.

Single-photon emission computed tomography/computed tomographyfor sentinel node mapping in breast cancer.

Accurate lymph node staging is essential for the prognosis and treatment in patients with cancer. The sentinel lymph node is the first node to which lymphatic drainage and metastasis from the primary tumor occurs. In malignant melanoma and breast cancer, the sentinel lymph node detection and biopsy already have been implemented into clinical practice. Currently, 2 techniques are used to identify the sentinel lymph nodes: technetium-99m-labeled colloid and blue dye. After peritumoral injection, the material migrates through the lymphatics to the first lymph nodes draining the tumor. The precise anatomic localization of the sentinel lymph nodes is important for minimal invasive surgery and to avoid incomplete removal of the sentinel lymph nodes. All sentinel lymph nodes should be resected to achieve a complete nodal staging. In the inguinal or low-axillary nodal stations, planar scintigraphic images mostly are adequate for the localization of the sentinel lymph nodes. However, in the regions of the head and neck, the chest, and the pelvis, an imaging method for the more precise anatomic localization of the sentinel lymph nodes preoperatively is highly desired. Recently, integrated single-photon emission computed tomography and computed tomography (SPECT/CT) scanners have become available. Initial reports suggest that integrated SPECT/CT might have an additional value in sentinel lymph node scintigraphy in head and neck tumors and tumors draining to the pelvic lymph nodes. We evaluated the clinical use of integrated SPECT/CT in the identification of the sentinel lymph nodes in patients with operable breast cancer. In our experience, localization and identification of sentinel lymph nodes was more accurate by integrated SPECT/CT imaging in comparison with planar images and SPECT images, respectively. In this report, the experiences of sentinel lymph node imaging with SPECT/CT are summarized.

Diagnosis, treatment and long-term outcome of solitary fibrous tumours of the pleura.

OBJECTIVE: Solitary fibrous tumours of the pleura (SFTP) are rare and can histologically be differentiated into benign and malignant forms. The aim of this study is to present new cases, and discuss up-to-date preoperative examinations, the role of video-assisted thoracic surgery and long-term outcome. METHODS: Between 1993 and 2006, 27 SFTPs were diagnosed (14 females, mean age+/-SD, 62.3+/-9.6 years) at our institution. Medical records were reviewed, and follow-up was obtained by repeated examinations or contact with general practitioners. RESULTS: SFTPs were associated with symptoms in 63% of all cases. In the six patients in which positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) was performed preoperatively, malignant lesions were all found to be positive. Complete resection was achieved by video-assisted thoracic surgery in 15 and anterolateral thoracotomy in 12 patients. Mean hospital stay was shorter for patients operated by video-assisted thoracic surgery compared to thoracotomy, 4.5 (range 3-6) versus 7.5 (range 4-25) days, respectively (p<0.01). Histology revealed 17 benign and 10 malignant SFTP. Mean+/-SD tumour diameter of malignant SFTPs was larger than in benign forms, 11.9+/-7.1 versus 6.1+/-3.5 cm, respectively (p<0.01). Tumour recurrence was recognised in four patients with malignant SFTPs at a median time interval after surgery of 38 (range 6-122) months, two late deaths occurred resulting from tumour recurrences. CONCLUSIONS: SFTPs can be treated minimally invasively by video-assisted thoracic surgery with short hospital stay. Large SFTPs with increased FDG-uptake have a high likelihood for malignancy. Long-term follow-up is mandatory in malignant SFTPs because of late recurrences associated with death.

S-100B and FDG-PET/CT in therapy response assessment of melanoma patients.

OBJECTIVE: To compare the value of the tumor marker S-100B protein and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in patients treated for melanoma metastases. METHODS: In 41 patients with proven melanoma metastases, S-100B measurements and FDG-PET/CT were performed before and after therapy. The change of S-100B levels (DeltaS-100B) was assessed. In all patients, therapy response was assessed with PET/CT using visual criteria and change of maximal standard uptake value (DeltaSUV(max.)) or total lesion glycolysis (DeltaTLG). RESULTS: In 15 of 41 patients (37%), S-100B values were not suitable because they were normal before and after therapy. In 26 patients, S-100B was suitable for therapy response assessment. PET/CT was suitable for response assessment in all patients. Correlations between DeltaS-100B and DeltaTLG (r = 0.850, p < 0.001) and between DeltaS-100B and DeltaSUV(max.) (r = 0.818, p < 0.001) were both excellent. A complete agreement between S-100B and PET/CT response assessment was achieved in 22 of 26 patients. In 4 patients, therapy response differed between the S-100B and PET/CT findings, but subsequent S-100B measurements realigned the S-100B results with the later PET/CT findings. CONCLUSION: In a third of our patients with metastases, the S-100B tumor marker was not suitable for therapy assessment. In these patients, imaging techniques remain necessary, and FDG-PET/CT can be used for response assessment.

Etiology of solitary extrapulmonary positron emission tomography and computed tomography findings in patients with lung cancer.

PURPOSE: The aim of this prospective study was to assess the incidence and the nature of solitary extrapulmonary [18F] fluorodeoxyglucose (FDG) accumulations in patients with non-small-cell lung cancer (NSCLC) staged with integrated positron emission tomography and computed tomography (PET/CT) and to evaluate the impact on management. PATIENTS AND METHODS: A total of 350 patients with NSCLC underwent whole-body PET/CT imaging. All solitary extrapulmonary FDG accumulations were evaluated by histopathology, further imaging, or clinical follow-up. RESULTS: PET/CT imaging revealed extrapulmonary lesions in 110 patients. In 72 patients (21%), solitary lesions were present. A diagnosis was obtained in 69 of these patients, including 37 (54%) with solitary metastases and 32 (46%) with lesions unrelated to the lung primary. Histopathologic examinations of these 32 lesions revealed a second clinically unsuspected malignancy or a recurrence of a previous diagnosed carcinoma in six patients (19%) and a benign tumor or inflammatory lesion in 26 patients (81%). The six malignancies consisted of carcinoma of the breast in two patients, and carcinoma of the orbit, esophagus, prostate, and non-Hodgkin's lymphoma in one patient each. Benign tumors and inflammatory lesions included eight colon adenomas, four Warthin's tumors, one granuloma of the lower jaw, one adenoma of the thyroid gland, one compensatory muscle activity due to vocal chord palsy, two occurrences of arthritis, three occurrences of reflux esophagitis, two occurrences of pancreatitis, two occurrences of diverticulitis, one hemorrhoidal inflammation, and one rib fracture. CONCLUSION: Solitary extrapulmonary FDG accumulations in patients with newly diagnosed lung cancer should be analyzed critically for correct staging and optimal therapy, given that up to half of the lesions may represent unrelated malignancies or benign disease.

[CME: Radioactive iodine therapy in thyroid cancer]. / CME: Radiojodbehandlung des Schilddrüsenkarzinoms.

Differentiated thyroid carcinomas represent about 90% of all thyroid tumors and are divided in papillary and follicular carcinomas. Their prognosis is good, however, recurrences are not rare. Their ability to accumulate iodine is used for the radioactive iodine treatment. The aim of the postoperative radioactive iodine ablation therapy is the complete elimination of remnant thyroid cells and sensitive staging (Fig. 1). The recurrence rate decreases after a complete thyroid ablation. Furthermore, thyroglobulin can be used as a sensitive tumor marker. Radioactive iodine treatment by itself describes the therapy of metastases. An exception is the papillary microcarcinoma, which in general is treated by a lobectomy alone.

Radiation treatment planning with an integrated positron emission and computer tomography (PET/CT): a feasibility study.

PURPOSE: To investigate the usefulness of hardware coregistered PET/CT images for target volume definition. METHODS AND MATERIALS: Thirty-nine patients presenting with various solid tumors were investigated. CT and a FDG-PET were obtained in treatment position in an integrated PET/CT scanner, and coregistered images were used for treatment planning. First, volume delineation was performed on the CT data. In a second step, the corresponding PET data were used as an overlay to the CT data to define the target volume. Delineation was done independently by two investigators. RESULTS: Coregistered PET/CT showed good fusion accuracy. The GTV increased by 25% or more because of PET in 17% of cases with head-and-neck (2/12) and lung cancer (1/6), and in 33% (7/21) in cancer of the pelvis. The GTV was reduced > or =25% in 33% of patients with head-and-neck cancer (4/12), in 67% with lung cancer (4/6), and 19% with cancer of the pelvis (4/21). Overall, in 56% (22/39) of cases, GTV delineation was changed significantly if information from metabolic imaging was used in the planning process. The modification of the GTV translated into altered PTV changes exceeding >20% in 46% (18/39) of cases. With PET, volume delineation variability between two independent oncologists decreased from a mean volume difference of 25.7 cm(3) to 9.2 cm(3) associated with a reduction of the standard deviation from 38.3 cm(3) to 13.3 cm(3) (p = 0.02). In 16% of cases, PET/CT revealed distant metastasies, changing the treatment strategy from curative to palliative. CONCLUSION: Integrated PET/CT for treatment planning for three-dimensional conformal radiation therapy improves the standardization of volume delineation compared with that of CT alone. PET/CT has the potential for reducing the risk for geographic misses, to minimize the dose of ionizing radiation applied to non-target organs, and to change the current practice to three-dimensional conformal radiation therapy planning by taking into account the metabolic and biologic features of cancer. The impact on treatment outcome remains to be demonstrated.

Why most PET of lung and head-and-neck cancer will be PET/CT.

Experience in our and other institutions with PET/CT imaging of lung and head and neck cancers has shown that this new modality has higher specificity and sensitivity than PET alone and in certain settings even when compared to PET and CT viewed side by side. The largest experience exists with non-small cell lung cancer (NSCLC), in which it has been demonstrated that PET/CT is superior to PET and CT in T and in N staging. Superiority in M staging has yet to be demonstrated. CT contrast media enhancement is probably only necessary when a substantial mediastinal tumor component is present. In such cases, delineation of tumor from vascular structures is relevant. In ENT tumors, PET/CT also appears to be superior to PET, and probably also to PET and CT viewed side by side. Early information suggests that contrast media enhancement for staging may not be required, but the data available is still limited. In both settings, it is interesting to note that in a number of patients, second metachronous tumors are discovered with PET/CT, mainly localized in the GI tract.

Impact of whole-body 18F-FDG PET on staging and managing patients for radiation therapy.

UNLABELLED: Whole-body PET with (18)F-FDG has proven to be a very effective imaging modality for staging of malignant tumors. This study was performed to evaluate the impact of (18)F-FDG PET on staging and managing patients for radiation therapy. METHODS: The treatment records of 202 consecutive patients (98 male, 104 female; mean age, 56.9 y; age range, 8-91 y) with different malignant tumors were reviewed. Radiation therapy was intended for all patients. The diagnoses were head and neck tumors (n = 55), gynecologic tumors (n = 28), breast cancer (n = 28), lung cancer (n = 26), malignant lymphomas (n = 24), tumors of the gastrointestinal tract (n = 18), and others (n = 23). Whole-body PET was performed before radiation therapy. The alteration of PET on each patient's staging and management decisions for radiation therapy were determined. RESULTS: For 55 of 202 patients (27%), PET results changed the patients' management in radiation therapy. In 18 cases (9%), PET resulted in a cancellation of radiation therapy because of the detection of previously unknown distant metastases (8 patients), additional lymph node metastases (9 patients), residual tumor (6 patients), or the exclusion of active disease (2 patients). In 6 patients, >1 incremental reason was found for cancellation. In 21 PET examinations (10%), PET results changed the intention of radiation treatment (curative or palliative). The radiation dose was changed in 25 cases (12%). A change of radiation volume was necessary in 12 patients (6%). CONCLUSION: The results of this study show that (18)F-FDG PET has a major impact on the management of patients for radiation therapy, influencing both the stage and the management in 27% of patients.

Whole-body (18)F-FDG PET improves the management of patients with small cell lung cancer.

UNLABELLED: The aim of this study was to evaluate the impact of whole-body (18)F-FDG PET on staging and managing patients with small cell lung cancer (SCLC). METHODS: The treatment records of 42 consecutive patients (27 men, 15 women; mean age, 62 y; age range, 45-83 y) with SCLC were reviewed. Whole-body (18)F-FDG PET was performed for initial staging in 24 patients and for restaging after chemotherapy or radiation treatment in 20 patients. Two patients of the initial staging group were restaged with PET after therapy. PET findings were correlated with clinical and radiologic findings (CT of the chest and abdomen, bone scan, and CT or MRI of the brain). The impact of PET on staging and management decisions was determined. RESULTS: For 12 of 42 patients (29%), PET results changed the patient's management. In 8 patients (19%), PET resulted in a change of radiation therapy because of the detection of previously unknown tumor foci. Adjuvant radiation therapy was cancelled in 3 patients. A change of radiation field and volume was necessary in 5 patients. In 1 patient, PET results excluded extensive disease, which permitted surgical resection of the tumor. Chemotherapy was discontinued in 2 patients and restarted in 1 patient on the basis of the PET findings. In 5 patients (12%), PET excluded malignancy as the suspicious lesions found with conventional cross-sectional imaging did not take up (18)F-FDG. CONCLUSION: The results of this study show that (18)F-FDG PET has a major impact on the management of patients with SCLC, influencing both the stage and the management in 29% of patients. PET is a highly valuable tool for accurate target definition of radiation treatment by reducing the probability of overlooking involved areas.

Detection of extramedullary infiltrates in acute myelogenous leukemia with whole-body positron emission tomography and 2-deoxy-2-[18F]-fluoro-D-glucose.

This work reports on a female patient with acute myelogenous leukemia (AML) FAB M 5a with initial extramedullary leukemia (EML) in skin, breast, and synovia. A year after diagnosis she developed a histologically proven isolated recurrence of the EML in the right upper ankle. The bone marrow was still in complete remission. Conventional x-ray, magnetic resonance imaging (MRI), bone scintigraphy, and 2-deoxy-2-[18F]-fluoro-D-glucose whole-body positron emission tomography (FDG-PET) were performed. All images showed alterations in the lower leg. Shortly after, an isolated relapse of the AML was diagnosed in the right elbow. FDG-PET demonstrated this lesion as well as an unknown lesion in the subcutis due to EML. In the course of her illness, the patient underwent one more PET examination for therapy control. The present observations suggest that whole-body FDG-PET may be valuable for the detection of EML and for the assessment of chemotherapeutic effects on identified lesions.

Management and costs of treating lung cancer patients in a university hospital.

BACKGROUND: New diagnostic tools and emerging medications have significantly changed the existing medical treatment options for lung cancer over the last 5 years. However, the increase in healthcare costs in all developed societies has put the more economical treatments on centre stage. OBJECTIVE: To examine the patterns and costs of lung cancer management at a Swiss University hospital at which there is a focus on interdisciplinary treatment. PATIENTS AND METHODS: All patients encountered during 1998 at the University Hospital of Zurich (USZ) with any diagnosis of lung cancer were selected for this retrospective study. Medical and sociodemographic data were collected by medical chart review for a period beginning with the first contact and ending with the last follow-up examination up to 30 months afterwards. Costs were calculated by assessing all resources used by each patient, multiplied by a uniform average cost factor. Results are in euros at 1999 prices. RESULTS: The sample included 118 patients (72% male) with a mean age of 64.2 years (SD 9.8, range 34-85 years) and a mean smoking history of 45 pack-years (SD 31.8, range 0-13 pack-years). Eighty-nine percent of all patients showed histology of non-small cell lung cancer (NSCLC), whereas 11% showed small cell lung cancer (SCLC). Of the NSCLC patients, 27% were classified as stage I, 14% as stage II, 19% as stage IIIA, 11% as stage IIIB and 26% as stage IV disease. The overall survival rate after 1 year was 55% and after 2 years was 29%. Gender and health insurance status were not associated with overall survival. The median length of hospitalisation during the first year of treatment was 14 days (range 0-112 days). For the entire patient sample, the mean cost per patient was 19,408 euros (median 14,691 euros, range 1821-80,020 euros), 71% of which was due to the hospitalisation costs. The mean cost per NSCLC patient was 19,212 euros (median 14,511 euros, range 1821-80,020 euros) and for SCLC patients it was 20,992 euros (median 15,367 euros, range 5282-51,840 euros). CONCLUSION: This is the first study attempting to estimate the hospital cost of treatment for lung cancer patients in Switzerland and central Europe. The major part of the total cost was due to hospitalisation costs. Patients with advanced stages of lung cancer show the highest cost, mainly due to the costs of chemotherapy. We found that the distribution of total cost is asymmetric: a small number of patients with an excessively long hospital stay cause very high costs.

FDG PET for mucosal malignant melanoma of the head and neck.

OBJECTIVES/HYPOTHESIS: To evaluate imaging findings using positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG) in mucosal malignant melanoma (MMM) of the head and neck. STUDY DESIGN: Retrospective evaluation. METHODS: Eighteen PET examinations were performed for initial staging and/or follow-up in 10 patients with MMM. Medical records of 6 male and 4 female patients (age range, 43--81 y; mean, 67 y) were reviewed retrospectively with regard to the patients' history, symptoms, and clinical course. Primary melanoma elsewhere in the body was excluded at the time of diagnosis. RESULTS: All MMM were visible in staging PET examinations, but FDG uptake depended on lesion size and anatomic site. Big lesions with a nodular growth, as seen in pathologic specimens, were better visible compared with lesions with a more superficial spread within the mucous membranes. Lesions in the anterior part of the nasal cavity were more difficult to detect than those in the posterior sinonasal complex because of possible interference with nonspecific uptake in muscles of the mouth and pronounced appearance of the skin when imaging was performed using filtered back projection without attenuation correction. CONCLUSION: We found that MMM of the head and neck can be visualized using FDG PET. Furthermore, locoregional and distant metastases can be evaluated much like those of cutaneous malignant melanoma. Therefore, PET may be suitable for the staging and/or restaging of these patients. Further studies have to elucidate the potential role of FDG PET in patient management.

Significance of a new fluorodeoxyglucose-positive lesion on restaging positron emission tomography/computed tomography after induction therapy for non-small-cell lung cancer.

OBJECTIVES: Restaging of patients with locally advanced non-small-cell lung cancer (NSCLC) is of paramount importance, since only patients with down-staging after induction therapy will benefit from surgery. In this study, we assessed the aetiology of new (18)fluoro-2-deoxy-d-glucose (FDG)-positive focal abnormalities on restaging positron emission tomography/computed tomography (PET/CT) in patients with a good response after induction chemotherapy in the primary tumour and lymph nodes. METHODS: Between 2004 and 2008, 31 patients with histological proven stage III NSCLC had a PET/CT prior and after induction chemotherapy. Their medical charts were retrospectively reviewed. RESULTS: Restaging PET/CT revealed a new FDG-positive lesion in 6 of 31 (20%) patients. The initial clinical stage of the disease was IIIA N2 in four and IIIB T4 in two patients. The maximal standard uptake value in the primary tumour (P = 0.043) and in the initially involved mediastinal nodes (P = 0.068) decreased after induction treatment in all patients. The new PET/CT findings were located in an ipsilateral cervical lymph node in two patients, a contralateral mediastinal in one patient and an ipsilateral mammary internal lymph node in one patient. Two other patients had a lesion on the contralateral lung. Malignant lymph node infiltrations were excluded following fine-needle puncture, intraoperative biopsy or follow-up PET/CT. Contralateral pulmonary lesions were diagnosed as benign following mini thoracotomy and pulmonary wedge resection. CONCLUSIONS: New solitary FDG-positive lesions on restaging PET/CT after induction chemotherapy for NSCLC are not rare in good responders to chemotherapy. In our experience, all these lesions were not associated with malignancy.

Continued pemetrexed and platin-based chemotherapy in patients with malignant pleural mesothelioma (MPM): value of 18F-FDG-PET/CT.

PURPOSE: To prospectively analyze different FDG-PET/CT-parameters (modified RECIST, SUVmax, TLG, PETvol) in patients with malignant pleural mesothelioma (MPM) under continued pemetrexed and platin based treatment. METHODS: Patients with biopsy proven MPM undergoing treatment with pemetrexed and platin based treatment were prospectively included in the study. Integrated FDG-PET/CT imaging was performed within 2 weeks before therapy and after every three consecutive cycles of combined chemotherapy. All CT-images were evaluated according to the modified RECIST (modRECIST) criteria. All FDG-PET/CT images were analyzed using SUVmax (maximum Standard Uptake Value) according to the EORTC criteria, change in Total Lesion Glycolysis (TLG) and FDG volume (PETvol). Percent change in all parameters compared to the initial, pre-therapeutic and the previous FDG-PET/CT scan. ModRECIST, EORTC guidelines, increase or decrease in TLG and PETvol was correlated with overall survival (OS) using the Log Rank Test. RESULTS: 41 patients with MPM were prospectively included in this study. The median OS of the study population is 439 days (111-1128). 41 patients had initial staging, 41 patients completed 3 cycles, 28 patients completed 6 cycles, 19 patients completed 9 cycles, 11 patients completed 12 cycles, 5 patients completed 15 cycles, 4 patients completed 18 cycles and 1 patient completed 21 cycles of chemotherapy. Chemotherapy was well tolerated up to 21 cycles. SUVmax showed a high variance over time for individual patients and change in SUVmax using EORTC guidelines did not predict OS at any time point. Ongoing morphological response in CT using modRECIST had highest correlation with OS and predicted survival up to the 15th cycle of continued permetrexed and platin based treatment. The correlations of response of the volume based PET parameters (TLG and PETvol) and OS are inferior to the morphological modRECIST parameter. CONCLUSION: Permetrexed and platin based treatment in MPM patients can be given over a prolonged time with good tolerance. Therapy response should be assessed by modRECIST in CT but not with SUVmax in FDG-PET. Long term permetrexed and platin therapy should be considered in MPM patients with good tolerance of treatment and ongoing morphological response in CT.