Marcello Rodari

Early Response Evaluation in Malignant Pleural Mesothelioma by Positron Emission Tomography With [18F]Fluorodeoxyglucose

Purpose Response evaluation with conventional criteria based on computed tomography (CT) is particularly challenging in malignant pleural mesothelioma (MPM) due to its diffuse pattern of growth. There is growing evidence that therapy-induced changes in tumor [18F]fluorodeoxyglucose (FDG) uptake as measured by positron emission tomography (PET) may predict response and patient outcome early in the course of treatment. Patients and Methods Patients with histologically proven MPM, not candidates to curative surgery, scheduled to undergo palliative chemotherapy with a pemetrexed-based regimen were eligible for this study. Patients were evaluated by FDG-PET and CT at baseline and after two cycles of therapy. A decrease of 25% or more in tumor FDG uptake as measured by standardized uptake value was defined as a metabolic response (MR). Best overall response from CT scans was determined according to previously published criteria. Results Twenty-two patients were included in the study, and 20 were assessable for ...

Outcome predictors and impact of central node dissection and radiometabolic treatments in papillary thyroid cancers ≤2 cm

The incidence of papillary thyroid cancer (PTC) is rapidly growing, the recorded increase being mainly related to tumors < or =2 cm. The re-classification of tumors >1 and < or =2 cm limited to the thyroid from the T2 to the T1 category triggered some concerns about their best management. In order to identify possible predictors of disease outcome, several clinico-pathological features were analyzed by uni- and multivariate analyses in a retrospective consecutive series of 251 PTCs < or =2 cm. Moreover, since 37% of cases were submitted to prophylactic central compartment node dissection (CLND, VI-VII levels) and radioiodine ablation was performed only when the tumor had an extrathyroidal extension, the impact of these therapeutic tools on the final outcome was evaluated. Among all outcome predictors analyzed, only lymph node metastases and extracapsular invasion were strongly associated with persistence/recurrence. It is worth noting that neither age nor tumor size was a significant indicator of the outcome. Interestingly, as far as the therapeutic interventions are concerned, CLND was strongly associated with remission, whereas radioiodine ablation did not influence the outcome. In conclusion, present results confirm the prognostic influence of node metastases and extra-thyroidal invasion, indicating the need for aggressive treatment in tumors extending beyond the capsule. On the contrary, all pT1N0 tumors, regardless of the diameter, the number of intrathyroidal foci, and the age can be effectively treated only by surgery. The major impact of prophylactic CLND on prognosis suggests to routinely associate it to total thyroidectomy in cases with a preoperative diagnosis of malignancy.

Predictive value of early 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) during salvage chemotherapy in relapsing/refractory Hodgkin lymphoma (HL) treated with high‐dose chemotherapy

This retrospective study evaluated whether early 2‐[fluorine‐18]fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET) after two cycles of salvage chemotherapy (PET2) could predict survival after high‐dose chemotherapy (HDC). Twenty‐four Hodgkin lymphoma (HL) patients were included. PET2 was negative in 58% and positive in 42% of patients. Ninety per cent of patients (9/10) with positive PET2 relapsed after HDC while all but one patient with negative PET2 maintained a complete remission. The 2‐year progression‐free survival was 93% vs. 10% for patients with negative and positive PET2, respectively (P < 0.001). This study shows that interim PET can predict the outcome after high‐dose chemotherapy in HL patients.

Detection of somatostatin receptor subtypes 2 and 5 by somatostatin receptor scintigraphy and immunohistochemistry: clinical implications in the diagnostic and therapeutic management of gastroenteropancreatic neuroendocrine tumors.

AIMS AND BACKGROUND Somatostatin receptor scintigraphy (SRS) is the standard method for the detection of somatostatin receptors (SSTRs). It is commonly used in gastroenteropancreatic neuroendocrine tumor (GEP-NET) staging, and represents the criterion of choice for treatment with somatostatin (SST) analogs. Immunohistochemistry (IHC) was reported as a reliable method for the detection of SSTRs with theoretically superior sensitivity over SRS. METHODS AND STUDY DESIGN We retrospectively analyzed the sensitivity and specificity of IHC in the detection of SSTRs in a cohort of consecutive patients with GEP-NETs attending our Institute from 1997 to 2007. IHC analysis was restricted to SSTR2 and SSTR5, and the results were interpreted according to two different scoring systems. SRS was used as the gold standard. Results. Forty-four patients were enrolled; 24 (55%) had foregut carcinoids, 9 (20%) midgut carcinoids, 2 (5%) hindgut carcinoids, and 9 (20%) had GEP-NETs of unknown primary sites. A high concordance rate between IHC and SRS was shown, irrespective of the IHC scoring system applied (73% and 70%). The sensitivity of IHC was 89.3% and 78.6% and the specificity 43.8% and 50%, depending on the scoring system used. CONCLUSIONS Although SSTR2 was shown to be expressed by IHC in up to 50% of tumors not visualized by SRS, SRS still remains the method of choice in the diagnostic and therapeutic management of GEP-NETs. More pathological and clinical data are needed to properly understand the clinical relevance of immunohistochemical detection of SSTR expression in the absence of tumor uptake at SRS.

[11C]Choline PET/CT Impacts Treatment Decision Making in Patients With Prostate Cancer Referred for Radiotherapy

BACKGROUND The purpose of our study was to analyze the role of [(11)C]choline-positron emission tomography/computed tomography (cho-PET/CT) in the management of patients with prostate cancer referred for radiotherapy. PATIENTS AND METHODS Inclusion criteria for this retrospective study were (1) presence of prostate cancer, (2) referral for first radiotherapy course (for primary or recurrent tumor) between February 2007 and July 2010, and (3) performance of cho-PET/CT. All cho-PET/CT scans were classified according to whether they were positive in the prostate/prostate bed (T), pelvic lymph nodes (N), and distant metastases (M) or negative. Therapeutic strategy based on the cho-PET/CT evaluation was compared with the strategy that would have been proposed had cho-PET/CT imaging not been available, following international and national prostate cancer guidelines. RESULTS Eighty-two cho-PET/CT scans performed in 74 patients were analyzed. Cho-PET/CT was positive in 49 studies (60%): T only in 22 (45% of all positive studies); N only in 4 (8%); T in combination with N in 3 (6%); and M in combination with T or N, or both, in 16 (33%). Treatment after positive cho-PET/CT examination included radiotherapy ± androgen deprivation (29 patients), surgery ± radiotherapy (6 patients), androgen deprivation only (8 patients), and other treatment (6 patients). In 22 cases, cho-PET/CT (27%) altered the treatment approach compared with the treatment that would have been adopted in the absence of cho-PET/CT analysis. CONCLUSION Cho-PET/CT is valuable in defining the extent of disease and supporting therapeutic decisions in the management of prostate cancer. The therapeutic strategy turned out to be influenced by cho-PET/CT imaging in about one third of the patients included in this study.

Impact of 11C-methionine positron emission tomography/computed tomography on radiation therapy planning and prognosis in patients with primary brain tumors.

Aims and background There is limited evidence regarding the impact of 11C-methionine positron emission tomography/computed tomography (MET-PET/CT) on radiation therapy planning of primary brain tumors. Our aim was to assess the effect of this imaging modality on treatment volumes and clinical outcome of patients eligible for radiation therapy in this oncologic setting. Methods and study design Between November 2009 and May 2012, 31 consecutive patients (male:female, 20:11; mean age, 53.0 years) with pathologically proven primary/relapsed glioma were treated with radiation therapy at the Humanitas Research Hospital. All patients were submitted to the same multi-imaging protocol including MET-PET/CT for biological target volume (PET) and contrast-enhanced magnetic resonance imaging/CT for gross tumor volume, in order to define the clinical target volume. Different volumes were compared and analyzed with respect to treatment planning modification after MET-PET/CT and impact on disease outcome. In 19/31 cases, patients were re-evaluated after completing radiotherapy, and in these cases, progression-free survival and overall survival were determined. The study was submitted to and data collection was approved by the local ethics committee. Results All patients completed the treatment. In 29 of 31 patients, a biological target volume was defined (mean volume, 18.3 cc), which in 20 cases (65%) resulted in a modification of the clinical target volume (mean, 65.9 cc; range, 8.5–165.6). In the other two cases, PET was negative and did not influence treatment planning. The mean percentage of added volume was 9.2%, ranging between -29% and 38%. With a mean follow-up of 5.4 months, treatment modification according to MET-PET/CT was the only predictor demonstrating a significant correlation with both progression-free survival (P = 0.018) and overall survival (P = 0.003). None of the other factors evaluated in the analyses, including age, tumor histology, previous treatment, and tumor uptake, was correlated with the outcome. Conclusions Despite the limited study population, our data indicate that MET-PET/CT can have a significant impact on radiation therapy planning in patients with primary brain tumors. Moreover, treatment modification according to PET appears to be a predictor of clinical outcome in this group of patients.

A case of atypical giant cell arteritis diagnosed by positron emission tomography (PET)

The authors describe an atypical case of a patient having giant cell arteritis presenting only with fever, diagnosed by positron emission tomography and subsequently confirmed by temporal artery biopsy.

B-IGEV (bortezomib plus IGEV) versus IGEV before high-dose chemotherapy followed by autologous stem cell transplantation in relapsed or refractory Hodgkin lymphoma: a randomized, phase II trial of the Fondazione Italiana Linfomi (FIL).

Abstract This randomized, multicenter study evaluates the addition of bortezomib (13 mg/m2) to IGEV (B-IGEV) in patients with relapsed/refractory Hodgkin Lymphoma (HL). Patients received either four courses of IGEV alone (n = 40) or B-IGEV (n = 40). The primary endpoint was the complete response (CR) proportion, evaluated by FDG-PET, after induction chemotherapy. CR proportion was 39% with B-IGEV and 53% with IGEV. PFS and OS were similar between the two groups (two-year PFS: 58% vs 56%; two-year OS: 93% vs 81%). The PET-negative status after treatment was the only variable favorably influencing both PFS (two-year PFS: 77% vs 40%; p = 0.002) and OS (two-year OS: 100% vs 76%; p < 0.001). Toxicity was overall similar with the two regimens. The addition of bortezomib to IGEV does not improve response in relapsed/refractory HL patients. However, its favorable therapeutic and safety profile, and the prognostic role of pre-transplant PET negativity in patients receiving IGEV-based regimens are confirmed.

Standardization and Quantification in PET/CT Imaging: Tracers Beyond FDG

Standardization of FDG PET-CT is becoming a reality, at least in centers that perform clinical trials. Non-FDG radiopharmaceuticals used with PET/CT are far from standard in clinical trials and in clinical use. This article only gives an example of different protocols and indications related to the availability of different radiopharmaceuticals. This scenario will be probably the reality in the near future in many centers throughout the world. Starting from the FDG experience, it will be easy to implement standards for acquisition and interpretation of PET/CT studies with other radiopharmaceuticals.

Imaging struma ovarii by means of 124I-Na PET/CT.

Struma ovarii is a rare form of ovary tumour defined as the presence of ectopic thyroid tissue in the ovarian structures. It usually presents with a benign course, although in some cases carcinoma or other malignant tumours can be found in the context of the ectopic tissue. Herein we report the case of a young patient affected by struma ovarii visualized by means of 124I-NaPET/CT. Thanks to the excellent target-to-background ratio of the tracer and the high resolution of the method, we could well identify the presence of some minimal tumour at the level of the left ovary. To our knowledge, this is the first report of its kind.