Comparison of Patient Skin Dose Evaluated Using Radiochromic Film and Dose Calculation Software.

PURPOSE: To compare, in an interventional radiology setting, peak skin doses (PSDs) delivered as calculated using a dedicated software tool and as measured using radiochromic film. To assess the utility of this dose calculation software tool in routine clinical practice. MATERIALS AND METHODS: First, radiochromic films were positioned on the examination table in the back of an adult anthropomorphic phantom to measure PSD, and X-ray examinations were simulated. Then, films were again positioned in the patient's back for 59 thoracic or abdominopelvic endovascular interventions. The results obtained with the radiochromic films were taken as a reference and were statistically compared with those of the software. RESULTS: With measured PSDs ranging from 100 to 7000 mGy, the median software-film difference was 8.5%. Lin's concordance coefficient was 0.98 [0.97; 0.99] (p < 0.001), meaning that concordance was excellent between the two methods. For the films where PSD exceeded 1000 mGy, the median difference in the measured value was 8.7% [- 1.3; 21.1], with a maximum discrepancy of 34%. Lin's concordance coefficient was 0.98 [0.96; 1] (p < 0.001), meaning that concordance was excellent between the two methods. CONCLUSION: Comparison between radiochromic films and the software tool showed that the software is a suitable tool for a simple and reliable estimation of PSD. The software seems to be a good alternative to films, whose use remains complex.

Role of FDG-PET in the implementation of involved-node radiation therapy for Hodgkin lymphoma patients.

PURPOSE: This study examines the role of (18)F-labeled fluorodeoxyglucose positron emission tomography (FDG-PET) in the implementation of involved-node radiation therapy (INRT) in patients treated for clinical stages (CS) I/II supradiaphragmatic Hodgkin lymphoma (HL). METHODS AND MATERIAL: Patients with untreated CS I/II HL enrolled in the randomized EORTC/LYSA/FIL Intergroup H10 trial and participating in a real-time prospective quality assurance program were prospectively included in this study. Data were electronically obtained from 18 French cancer centers. All patients underwent APET-computed tomography (PET-CT) and a post-chemotherapy planning CT scanning. The pre-chemotherapy gross tumor volume (GTV) and the postchemotherapy clinical target volume (CTV) were first delineated on CT only by the radiation oncologist. The planning PET was then co-registered, and the delineated volumes were jointly analyzed by the radiation oncologist and the nuclear medicine physician. Lymph nodes undetected on CT but FDG-avid were recorded, and the previously determined GTV and CTV were modified according to FDG-PET results. RESULTS: From March 2007 to February 2010, 135 patients were included in the study. PET-CT identified at least 1 additional FDG-avid lymph node in 95 of 135 patients (70.4%; 95% confidence interval [CI]: 61.9%-77.9%) and 1 additional lymph node area in 55 of 135 patients (40.7%; 95% CI: 32.4%-49.5%). The mean increases in the GTV and CTV were 8.8% and 7.1%, respectively. The systematic addition of PET to CT led to a CTV increase in 60% of the patients. CONCLUSIONS: Pre-chemotherapy FDG-PET leads to significantly better INRT delineation without necessarily increasing radiation volumes.

Hyperthermic pelvic perfusion with tumor necrosis factor-α for locally advanced cancers: encouraging results of a phase II study.

PURPOSE: To assess the efficacy of isolated pelvic perfusion (IPP) with tumor necrosis factor (TNF)-α and melphalan in patients with locally advanced cancers in the pelvic and groin area requiring mutilating surgery. METHODS: A total of 27 patients were enrolled (carcinoma, n = 17; sarcoma/melanoma, n = 4; and endocrine tumor, n = 6). They were candidates for exarticulation (n = 3) or exenteration (n = 11) or were judged unresectable (n = 13). In installing IPP, tourniquets were positioned around both thighs, and an inflated pressure suit was placed at a subthoracic position. Tumor necrosis factor-α (300 µg) was injected in the perfusate, followed 5 minutes later by melphalan at 1.5 mg/kg. After 30 minutes, the remaining drugs were washed out. Leakage was assessed with technetium Tc 99m radiolabeled human serum albumin, and a pharmacokinetic study was performed. Efficacy was based on the complete response rate observed on magnetic resonance imaging. RESULTS: Pelvic/systemic ratios of melphalan/TNF/technetium Tc 99m were 14.2/7/3.6. Responses on magnetic resonance imaging were as follows: 30% complete, 30% partial, 19% no change, and 15% progression. Two patients were not evaluable because they did not receive the treatment. Pre-IPP/post-IPP median percentage of necrosis on magnetic resonance imaging was 10%/70%. Median follow-up was 43 months. Median overall survival was 17 months. Twelve-month survival rate, disease-free survival, and local and metastatic recurrence rates were 67%, 30%, 57%, and 26%, respectively. CONCLUSIONS: Isolated pelvic perfusion with TNF-α compares favorably with historical data, as it was observed in limb perfusion and could provide a chance to translate its successful combination with chemotherapy into treatment of locally advanced pelvic cancers.

18F-fluorodeoxyglucose positron emission tomography and computed tomography in anaplastic thyroid cancer.

PURPOSE: Our aim was to evaluate in anaplastic thyroid carcinoma (ATC) patients the value of 18F-FDG PET/CT compared with total body computed tomography (CT) using intravenous contrast material for initial staging, prognostic assessment, therapeutic monitoring and follow-up. METHODS: Twenty consecutive ATC patients underwent PET/CT for initial staging. PET/CT was performed again during follow-up. The gold standard was progression on imaging follow-up (CT or PET/CT) or confirmation with another imaging modality. RESULTS: A total of 265 lesions in 63 organs were depicted in 18 patients. Thirty-five per cent of involved organs were demonstrated only with PET/CT and one involved organ only with CT. In three patients, the extent of disease was significantly changed with PET/CT that demonstrated unknown metastases. Initial treatment modalities were modified by PET/CT findings in 25% of cases. The volume of FDG uptake (≥300 ml) and the intensity of FDG uptake (SUVmax≥18) were significant prognostic factors for survival. PET/CT permitted an earlier assessment of tumour response to treatment than CT in 4 of the 11 patients in whom both examinations were performed. After treatment with combined radiotherapy and chemotherapy, only the two patients with a negative control PET/CT had a confirmed complete remission at 14 and 38 months; all eight patients who had persistent FDG uptake during treatment had a clinical recurrence and died. CONCLUSION: FDG PET/CT appears to be the reference imaging modality for ATC at initial staging and seems promising in the early evaluation of treatment response and follow-up.

The conundrum of Hodgkin lymphoma nodes: to be or not to be included in the involved node radiation fields. The EORTC-GELA lymphoma group guidelines.

PURPOSE: To develop easily applicable guidelines for the determination of initially involved lymph nodes to be included in the radiation fields. PATIENTS AND METHODS: Patients with supra-diaphragmatic Hodgkin lymphoma. All the imaging procedures were carried out with patients in the treatment position. The prechemotherapy PET/CT was coregistered with the postchemotherapy CT simulation for planning purposes. Initially involved lymph nodes were determined on fused prechemotherapy CT and FDG-PET imaging data. The initial assessment was verified with the postchemotherapy CT scan. RESULTS: The classic guidelines for determining the involvement of lymph nodes were not easily applicable and did not seem to reflect the exact extent of Hodgkin lymphoma. Three simple steps were used to pinpoint involved lymph nodes. First, FDG-PET scans were meticulously analysed to detect lymph nodes that were overlooked on CT imaging. Second, any morphological and/or functional asymmetry was sought on CT and FDG-PET scans. Third, a decrease in size or the disappearance of initially visible lymph nodes on the prechemotherapy CT scan as compared to the postchemotherapy CT scan was considered as surrogate proof of initial involvement. CONCLUSIONS: All the radiological procedures should be performed on patients in the treatment position for proper coregistration. It is highly advisable that all CT and/or CT/PET scans be performed with IV contrast. Using the above-mentioned three simple guidelines, initially involved lymph nodes can be detected with very satisfactory accuracy. It is also emphasized that the classic guidelines (2, 3, 4) can always be used when deemed necessary.

Prospective study of bone marrow infiltration in aggressive lymphoma by three independent methods: whole-body MRI, PET/CT and bone marrow biopsy.

PURPOSE: Initial lymphoma staging requires bone marrow assessment in aggressive lymphomas. Bone marrow lymphoma infiltration is routinely assessed by bone marrow biopsy (BMB), considered as the "gold standard". The aim of this study was to compare the performance of BMB, whole-body MRI and PET/CT for evaluation of BM infiltration. METHODS: Patients with newly diagnosed aggressive lymphoma were evaluated by BMB, MRI and PET/CT. Two radiologists, two nuclear medicine physicians and one pathologist independently assessed the results of the three modalities. Bone was considered as involved if BM was positive or if PET/CT or MRI was positive and if there was a resolution of the abnormal image shown on PET/CT or MRI halfway or at the end of therapy. RESULTS: Both MRI and PET/CT detected bone marrow lesions in the 9/43 patients, but two patients with multiple lesions had more lesions detected by PET/CT compared to MRI. Among these nine patients, two with an iliac crest lesion detected by both MRI and PET/CT had bone marrow involvement with large-cell lymphoma on histological examination. The other seven patients had focal MRI and PET/CT lesions in areas other than the iliac crest, where the blind BMB was done. The other patients had bone marrow without large-cell lymphoma involvement. In all cases, after lymphoma therapy bone marrow involvement regressed on histological examination, PET and MRI. CONCLUSION: These preliminary results suggest that non-invasive morphological procedures could be superior to BMB for bone marrow assessment in aggressive lymphomas. Ongoing study is underway to validate these results.

Imaging medullary thyroid carcinoma with persistent elevated calcitonin levels.

PURPOSE: Because calcitonin level remains elevated after initial treatment in many medullary thyroid carcinoma (MTC) patients without evidence of disease in the usual imaging work-up, there is a need to define optimal imaging procedures. PATIENTS AND METHODS: Fifty-five consecutive elevated calcitonin level MTC patients were enrolled to undergo neck and abdomen ultrasonography (US); neck, chest, and abdomen spiral computed tomography (CT); liver and whole-body magnetic resonance imaging (MRI); bone scintigraphy; and 2-[fluorine-18]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/CT scan (PET). RESULTS: Fifty patients underwent neck US, CT, and PET, and neck recurrence was demonstrated in 56, 42, and 32%, respectively. Lung and mediastinum lymph node metastases in the 55 patients were demonstrated in 35 and 31% by CT and in 15 and 20% by PET. Liver imaging with MRI, CT, US, and PET in 41 patients showed liver in 49, 44, 41, and 27% patients, respectively. Bone metastases in 55 patients were demonstrated in 35% by PET, 40% by bone scintigraphy, and 40% by MRI; bone scintigraphy was complementary with MRI for axial lesions but superior for the detection of peripheral lesions. Ten patients had no imaged tumor site despite elevated calcitonin level (median 196 pg/ml; range 39-816). FDG uptake in neoplastic foci was higher in progressive patients but with a considerable overlap with stable ones. CONCLUSION: The most efficient imaging work-up for depicting MTC tumor sites would consist of a neck US, chest CT, liver MRI, bone scintigraphy, and axial skeleton MRI. FDG PET scan appeared to be less sensitive and of low prognostic value.

Is FDG-PET scan in patients with early stage Hodgkin lymphoma of any value in the implementation of the involved-node radiotherapy concept and dose painting?

BACKGROUND AND PURPOSE: To evaluate the input of FDG-PET data in the implementation of the involved-node radiotherapy concept and dose painting. MATERIALS AND METHODS: Patients with early-stage Hodgkin lymphoma treated with combined modality treatments. First, patients underwent a PET/CT before chemotherapy in the treatment position using a head and shoulder immobilization mask. Second, all patients had a CT simulation for treatment planning. The CT simulation was coregistered with the prechemotherapy CT and FDG-PET scan. All prechemotherapy volumes were superimposed on the CT simulation. The initially involved lymph node areas to be irradiated were delineated on the CT simulation scan. Chemotherapy-induced shrinkage rates of the tumor masses visible on CT scan and on FDG-PET were determined and compared. RESULTS: Before chemotherapy, FDG-PET-avid areas represented 25% of the total volume on CT. After chemotherapy, the influence of initial FDG-PET data on the delineation of involved-node radiotherapy fields was significant and was due to the fact that in 36% of the patients, FDG-PET helped pinpoint lymph nodes that were undetected on CT. After chemotherapy, the rates of tumor volume shrinkage on CT and FDG-PET were similar. This finding suggests similar chemosensitivity for FDG-PET-avid and non-avid areas. There was no correlation between initial FDG-PET-avid volumes and the clinical outcome. CONCLUSION: Prechemotherapy FDG-PET data are essential for correctly implementing the involved-node radiotherapy concept but seem to be of minimal value for applying the concept of dose painting.