Prognostic value of total metabolic tumour volume and therapy-response assessment by [18F]FDG PET/CT in patients with metastatic melanoma treated with BRAF/MEK inhibitors.

OBJECTIVES: Target therapy with BRAF/MEK inhibitors in metastatic melanoma is characterised by a high response rate; however, acquired resistance to treatment develops in many cases. We aimed to investigate if baseline total metabolic tumour volume (TMTV) and therapy-response assessment by [18F]FDG PET/CT have a prognostic role on progression-free survival (PFS) and overall survival (OS) in patients with metastatic melanoma receiving BRAF ± MEK inhibitors. METHODS: Fifty-seven patients who performed an [18F]FDG PET/CT at baseline and on treatment were retrospectively evaluated. A Cox proportional-hazard model was used to examine associations between OS and PFS with baseline clinical/PET parameters as well as for PET response. RESULTS: According to EORTC criteria, 34 patients were classified as responders (partial/complete metabolic response [PMR/CMR]) and 23 as non-responders (progressive/stable metabolic disease [PMD/SMD]). Baseline characteristics associated with a shorter PFS were more than two metastatic organ sites and TMTV > 56 cm3; the latter was the only independent feature at multivariate analysis. Patients achieving a CMR were associated with a prolonged PFS compared with those with PMR (median PFS 42.9 vs 8.8 months; p = 0.009). Disease progression occurred in new-onset disease sites in 87.5% of CMR, 7.1% of PMR and 34.8% of PMD/SMD (p < 0.001). High baseline TMTV and lack of treatment response were independent prognostic factors for OS, stratifying patients in three different prognostic classes (median OS 6.7, 18.3 and 102.2 months, respectively). CONCLUSIONS: Baseline TMTV and metabolic response may be useful prognostic indicators for PFS and OS in patients with advanced melanoma treated with BRAF/MEK inhibitors. KEY POINTS: • In a retrospective cohort of 57 metastatic melanoma patients treated with BRAF/MEK inhibitors, a TMTV > 56 cm3 at baseline [18F]FDG PET/CT was significantly correlated with a shorter PFS and OS. • The combined use of baseline TMTV along with PET response during treatment allowed for the identification of three groups of patients with very different median OS.

Significant increase in detection of prostate cancer recurrence following radical prostatectomy with an early imaging acquisition protocol with ¹8F-fluorocholine positron emission tomography/computed tomography.

PURPOSE: To highlight a new imaging acquisition protocol during (18)F-fluorocholine PET/CT in patients with biochemical recurrence after RP. METHODS: A total of 146 patients with PSA levels between 0.2 and 1 ng/ml with negative conventional imaging who did not receive salvage treatment were prospectively enrolled. Imaging acquisition protocol included an early dynamic phase (1-8 min), a conventional whole body (10-20 min), and a late phase (30-40 min). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were measured. Univariable and multivariable analyses were performed to identify independent predictors of positive PET/CT. RESULTS: The median trigger PSA was 0.6 ng/ml (IQR 0.43-0.76). Median PSA doubling time (PSA DT) was 7.91 months (IQR 4.42-11.3); median PSA velocity (PSAV) was 0.02 ng/ml per month (IQR 0.02-0.04). Overall, (18)F-fluorocholine PET/CT was positive in 111 of 146 patients (76 %). Out of 111 positive examinations, 80 (72.1 %) were positive only in the early dynamic phase. Sensitivity, specificity, PPV, NPV, and accuracy were 78.9, 76.9, 97.2, 26.3, and 78.7 %, respectively. At multivariable logistic regression, trigger PSA ≥ 0.6 ng/ml [odds ratio (OR) 3.13; p = 0.001] and PSAV ≥ 0.04 ng/ml per month (OR 4.95; p = 0.004) were independent predictors of positive PET/CT. The low NPV remains the main limitation of PET/CT in this setting of patients. CONCLUSIONS: The increased sensitivity, thanks to the early imaging acquisition protocol, makes (18)F-fluorocholine PET/CT an attractive tool to detect prostate cancer recurrences in patients with a PSA level <1 ng/ml.

Prognostic value of [18F]-FDG PET/CT in patients with meta-static breast cancer treated with cyclin-dependent inhibitors.

Objective: The addition of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) to endocrine therapy impressively improved the outcome of patients with hormone receptor-positive metastatic breast cancer. Despite their great efficacy, not all patients respond to treatment and many of them develop acquired resistance. The aim of this retrospective study was to assess the role of [18F]-FDG PET/CT in predicting PFS and OS in breast cancer patients treated with CDK4/6i. Methods: 114 patients who performed an [18F]-FDG PET/CT scan before (PET1) and 2-6 months (PET2) after starting treatment were retrospectively enrolled. Metabolic response was evaluated by EORTC, PERCIST and Deauville Score and correlated to PFS and OS. Results: In patients who did not progress at PET2 (n = 90), PFS rates were not significantly different between classes of response by EORTC and PERCIST. Conversely, patients showing a Deauville score ≤3 had a longer PFS (median PFS 42 vs 21.0 months; p = 0.008). A higher total metabolic tumor volume at PET1 (TMTV1) was also associated with a shorter PFS (median 18 vs 42 months; p = 0.0026). TMTV1 and Deauville score were the only independent prognostic factors for PFS at multivariate analysis and their combination stratified the population in four definite classes of relapse risk. Conversely, the above parameters did not affect OS which was only influenced by a progressive metabolic disease at PET2 (3-years survival rate 29.8 vs 84.9%; p<0.0001). Conclusion: TMTV and metabolic response by Deauville score were significant prognostic factors for PFS in patients with breast cancer treated with CDK4/6i. Their determination could help physicians to select patients who may need a closer follow up.

Thrombosis of the Iliac Vein Detected by 64Cu-Prostate-Specific Membrane Antigen (PSMA) PET/CT.

An 82-year-old man had a diagnosis of prostate cancer and underwent curative radiotherapy. During the oncological follow-up, the patient showed biochemical relapse and underwent whole-body Cu-prostate-specific membrane antigen PET/CT for restaging purpose. Cu-prostate-specific membrane antigen PET/CT showed a pathological uptake in left iliac venous axis, subsequently confirmed as venous thrombosis.

The role of dosimetry and biological effects in metastatic castration-resistant prostate cancer (mCRPC) patients treated with 223Ra: first in human study.

BACKGROUND: 223Ra is currently used for treatment of metastatic castration resistant prostate cancer patients (mCRPC) bone metastases with fixed standard activity. Individualized treatments, based on adsorbed dose (AD) in target and non-target tissue, are absolutely needed to optimize efficacy while reducing toxicity of α-emitter targeted therapy. This is a pilot first in human clinical trial aimed to correlate dosimetry, clinical response and biological side effects to personalize 223Ra treatment. METHODS: Out of 20 mCRPC patients who underwent standard 223Ra treatment and dosimetry, in a subset of 5 patients the AD to target and non-target tissues was correlated with clinical effects and radiation-induced chromosome damages. Before each 223Ra administrations, haematological parameters, PSA and ALP values were evaluated. Additional blood samples were obtained baseline (T0), at 7 days (T7), 30 days (T30) and 180 days (T180) to evaluate chromosome damage. After administration WB planar 223Ra images were obtained at 2-4 and 18-24 h. Treatment response and toxicity were monitored with clinical evaluation, bone scan, 18F-choline-PET/CT, PSA value and ALP while haematological parameters were evaluated weekly after 223Ra injection and 2 months after last cycle. RESULTS: 1. a correlation between AD to target and clinical response was evidenced with threshold of 20 Gy as a cut-off to obtain tumor control; 2. the AD to red marrow was lower than 2 Gy in all the patients with no apparently correlation between dosimetry and clinical toxicity. 3. a high dose dependent increase of the number of dicentrics and micronuclei during the course of 223Ra therapy was observed and a linear correlation has been found between blood AD (BAD) and number of dicentrics. CONCLUSIONS: This study provides some interesting preliminary evidence to be further investigated: dosimetry may be useful to identify a more appropriate 223Ra administered activity predicting AD to target tissue; a dose dependent complex chromosome damage occurs during 223Ra administration and this injury is more evident in heavily pre-treated patients; dosimetry could be used for radioprotection purpose. TRIAL REGISTRATION: The pilot study has been approved from the Ethics Committee of Regina Elena National Cancer Institute (N:RS1083/18-2111).

A Prospective Study Assessing the Post-Prostatectomy Detection Rate of a Presumed Local Failure at mpMR with Either 64CuCl2 or 64CuPSMA PET/CT.

BACKGROUND: We aimed assess the detection rate (DR) of positron emission tomography/computed tomography with two novel tracers in patients referred for salvage radiotherapy (sRT) with a presumed local recurrence at multiparametric magnetic resonance (mpMR) after radical prostatectomy (RP). METHODS: The present prospective study was conducted at a single institution between August 2017 and June 2020. Eligibility criteria were undetectable PSA after RP; subsequent biochemical recurrence (two consecutive PSA rises to 0.2 ng/mL or greater); a presumed local failure at mpMR; no distant metastases at 18F-fluorocholine PET/CT (CH/PET); no previous history of androgen deprivation therapy. Patients were offered both 64CuCl2 PET/CT (CU/PET) and 64Cu-PSMA PET/CT (PSMA/PET) before sRT. After image co-registration, PET findings were compared to mpMR ones in terms of DR and independent predictors of DR investigated at logistic regression. RESULTS: A total of 62 patients with 72 nodules at mpMR were accrued. Compared to mpMR (DR = 100%, 95%CI: 94.9-100%), DRs were 47.2% (95%CI: 36.1-58.6%) and 54.4% (95%CI: 42.7-65.7%) for CU/PET and PSMA/PET, respectively (p < 0.001 for both). Both experimental PET/CT performed particularly poorly at PSA levels consistent with early sRT. CONCLUSIONS: The two novel radiotracers are inferior to mpMR in restaging the prostatic fossa for sRT planning purposes, particularly in the context of early salvage radiotherapy.

Bone density and genomic analysis unfold cold adaptation mechanisms of ancient inhabitants of Tierra del Fuego.

The Fuegians, ancient inhabitants of Tierra del Fuego, are an exemplary case of a cold-adapted population, since they were capable of living in extreme climatic conditions without any adequate clothing. However, the mechanisms of their extraordinary resistance to cold remain enigmatic. Brown adipose tissue (BAT) plays a crucial role in this kind of adaptation, besides having a protective role on the detrimental effect of low temperatures on bone structure. Skeletal remains of 12 adult Fuegians, collected in the second half of XIX century, were analyzed for bone mineral density and structure. We show that, despite the unfavorable climate, bone mineral density of Fuegians was close to that seen in modern humans living in temperate zones. Furthermore, we report significant differences between Fuegians and other cold-adapted populations in the frequency of the Homeobox protein Hox-C4 (HOXC4) rs190771160 variant, a gene involved in BAT differentiation, whose identified variant is predicted to upregulate HOXC4 expression. Greater BAT accumulation might therefore explain the Fuegians extreme cold-resistance and the protection against major cold-related damage. These results increase our understanding of how ecological challenges have been important drivers of human-environment interactions during Humankind history.

Diagnostic and Clinical Impact of 18F-FDG PET/CT in Staging and Restaging Soft-Tissue Sarcomas of the Extremities and Trunk: Mono-Institutional Retrospective Study of a Sarcoma Referral Center.

BACKGROUND: Soft-tissue sarcomas (STS) represent a wide heterogeneous class of rare tumors. The exact role 18F-fluorodeoxyglucose positron emission/computed tomography (18F-FDG PET/CT) in the evaluation of STS is not well established. The aim of the present study was to evaluate how the use of 18F-FDG PET/CT in STS could influence patient therapy planning, looking for a possible added value over computed tomography and magnetic resonance imaging-the most used modalities in the study of STS. Differences in SUVmax according to histologic subtype and tumor grade were also considered. METHODS: a total of 345 consecutive 18F-FDG PET/CT scans performed for initial staging (n = 171) or for suspected disease relapse (n = 174) in 282 patients with STS extracted from the local Information System database were retrospectively reviewed. RESULTS: 18F-FDG PET/CT altered therapy planning in 80 cases (16.4% for staging and 29.9% in restaging), both for disease upstaging (58.8%) and downstaging (41.2%) Conclusions: 18F-FDG PET/CT could significantly influence management of patients with STS, particularly for restaging.

Dual-time 18F-FDG PET/CT for the detection of liver metastases in breast cancer.

OBJECTIVE: The aim was to investigate the diagnostic potential of dual-time-point F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in patients with breast cancer with known or suspected liver metastases and to assess its clinical value on clinical management. PATIENTS AND METHODS: A total of 151 consecutive patients with breast cancer who underwent F-FDG PET/CT scan for staging or restaging, in whom an additional delayed scan of the liver was performed, were retrospectively evaluated. RESULTS: Overall, F-FDG PET/CT showed the presence of 146 liver metastases in 57 patients. Overall, 54 of these lesions were clearly identified at standard whole-body acquisition, 49 were suspected and 43 were missed in early acquisition. Only 59.6% of patients with liver involvement were clearly identified at the first scan. A high percentage of patients (48.3%) showed at least one liver lesion suspected on standard acquisition which was not more confirmed in late scan. Maximum tumour standardized uptake value of liver metastases was significantly higher in delayed as compared with standard acquisition (6.5±2.4 vs. 5.3±1.6; P<0.0001). The higher detection rate in late acquisition altered patient management in a relative low number of cases in the whole series (15.8%) and in a higher proportion (28.6%) in the group of patients with exclusive liver involvement. CONCLUSION: The results of the study revealed the potential usefulness of late liver acquisition in patients with breast cancer with suspected or known liver metastases. Its use should be advocated in case of inconclusive results on standard acquisition to improve the study interpretation confidence or to increase the accuracy in specific clinical settings.

Long term efficacy and safety of Fludarabine, Cyclophosphamide and Rituximab regimen followed by (90)Y-ibritumomab tiuxetan consolidation for the treatment of relapsed grades 1 and 2 follicular lymphoma.

BACKGROUND: In this retrospective study, we investigated the efficacy and safety of radioimmunotherapy with (90)Yttrium- ibritumomab tiuxetan ((90)Y-RIT) in 9 patients with recurrent follicular lymphoma (FL) who were treated in a consolidation setting after having achieved complete (CR) or partial remission (PR) with Fludarabine, Cyclophosphamide and Rituximab (FCR). METHODS: The median age was 63 years (range 46-77). All patients were relapsed with histologically confirmed CD20-positive (grade 1 or 2) FL, at relapse they received FCR every 28 days: F (25 mg/m(2)x 3 days), C (1 gr/m(2) day 1) and R (375 mg/m(2) day 4) for 4 cycles. Those who achieved at least a PR with <25 % bone marrow involvement were treated with (90)Y-RIT 11.1 or 14.8 MBq/Kg, at 3 months after completing FCR. Patients underwent a further restaging at 12 weeks after (90)Y-RIT with a total body CT scan, FDG-PET/CT and bilateral bone marrow biopsy. RESULTS: Nine patients completed the treatment: FCR followed by (90)Y-RIT (6 patients at 14.8 MBq/Kg, 3 patients at 11.1 MBq/Kg). After FCR, 7 patients obtained CR and 2 PR; after (90)Y-RIT 2 patients in PR converted to CR 12 weeks later. With a median follow up of 95 months (range 20-114) since FCR and 88 months (range 13-104) since (90)Y-RIT 3 deaths were not related to lymphoma; all 3 deceased patients obtained CR before (90)Y-RIT and died still in CR. The median overall (OS) and progression free survival (PFS) have not been reached, in this analysis both OS or PFS are 67 % at 7.5 year. The most common grade 3 or 4 adverse events were hematologic. CONCLUSIONS: These results confirm the long term efficacy and safety of 4 cycles of FCR followed by (90)Y-RIT in relapsed grades 1 and 2 FL and suggest that this regimen could be a therapeutic option for this setting of patients, specially at age of 60-75 with no unexpected toxicities.

Effects of low-dose cisplatin on 89Sr therapy for painful bone metastases from prostate cancer: a randomized clinical trial.

UNLABELLED: This study evaluated the effects of low-dose cisplatin plus 89Sr versus 89Sr alone in the treatment of painful bone metastases from prostate cancer, addressing both pain palliation and cytostatic effects. METHODS: Seventy patients with metastatic hormone-refractory prostate cancer were randomized into 2 groups: One group (arm A) received 148 MBq 89Sr plus 50 mg/m(2) cisplatin, and the other group (arm B) received 148 MBq 89Sr plus placebo. After treatment, the patients were followed up until death to evaluate the outcome variables: grade and duration of pain palliation, onset of new painful sites, changes in bone disease, global survival, serum prostate-specific antigen and alkaline phosphatase changes, and hematologic toxicity. RESULTS: Overall pain relief occurred in 91% of patients in arm A and 63% of patients in arm B (P < 0.01), with a median duration of 120 d in arm A and 60 d in arm B (P = 0.002). New painful sites on previously asymptomatic bone metastases appeared in 14% of patients in arm A and in 30% of patients in arm B (P = 0.18). The median survival without new painful sites was 4 mo in arm A and 2 mo in arm B (P = 0.04). Bone disease progression was observed in 27% of patients in arm A and in 64% of patients in arm B (P = 0.01). Median global survival after therapy was 9 mo in arm A and 6 mo in arm B (P = 0.30). Transient and moderate hematologic toxicity, as determined by World Health Organization criteria, was apparent in both arms without significant differences. CONCLUSION: The addition of a low dose of cisplatin enhances the effect of a standard dose of 89Sr without significant side effects, producing a significant improvement in pain palliation and a cytostatic effect on bone disease.

Prevalence, mass, and glucose-uptake activity of ¹8F-FDG-detected brown adipose tissue in humans living in a temperate zone of Italy.

BACKGROUND: The ¹8F-fluorodeoxyglucose (¹8F-FDG)-detected brown adipose tissue (BAT), is enhanced by cold stimulus and modulated by other factors that still have to be disentangled. We investigated the prevalence, mass, and glucose-uptake activity of ¹8F-FDG-detected BAT in a population of adults living in the temperate climatic zone of the Rome area. METHODS AND FINDINGS: We retrospectively analyzed 6454 patients who underwent ¹8F-FDG positron emission tomography/computed tomography (PET/CT) examinations. We found ¹8F-FDG BAT in 217 of the 6454 patients (3.36%). Some of them underwent more than one scan and the positive scans were 278 among 8004 (3.47%). The prevalence of patients with at least one positive scan was lower in men (1.77%; 56 of 3161) compared with women (4.88%; 161 of 3293). The BAT positive patients were most frequently younger, thinner and with lower plasma glucose levels compared with BAT negative patients. The amount of BAT in the defined region of interest, the activity of BAT and the number of positive sites of active BAT were similar in both sexes. The prevalence of patients with ¹8F-FDG positive PET/CT was highest in December-February, lower in March-May and September-November, and lowest in June-August and was positively correlated with night length and negatively correlated with ambient temperature. Changes in day length and variations of temperature, associated with the prevalence of positive BAT patients. Among the patients who had multiple scans, outdoor temperature was significantly lower and day length was shorter on the occasion when BAT was detected. CONCLUSIONS: This study identifies day length, outdoor temperature, age, sex, BMI, and plasma glucose levels as major determinants of the prevalence, mass, and activity of ¹8F-FDG-detected BAT.

Efficacy and toxicity related to treatment of hepatocellular carcinoma with 90Y-SIR spheres: radiobiologic considerations.

UNLABELLED: Radioactive (90)Y-selective internal radiation (SIR) sphere therapy is increasingly used for the treatment of nonresectable hepatocellular carcinoma (HCC). However, the maximum delivered dose is limited by severe injury to the nontarget tissue, including liver parenchyma. Our study aimed to implement radiobiologic models for both tumor control probability (TCP) and normal-tissue complication probability (NTCP) to describe more effectively local response and the liver toxicity rate, respectively. METHODS: Patients with documented HCC, adequate bone marrow parameters, and regular hepatic and pulmonary function were eligible for the study. Patients who had pulmonary shunt greater than 20% of (99m)Tc-labeled macroaggregated albumin or any uncorrectable delivery to the gastrointestinal tract, reverse blood flow out of the liver, or complete portal vein thrombosis were excluded. Patients received a planned activity of the (90)Y-SIR spheres, determined using the empiric body surface area method. The dose distribution was determined using posttreatment (3-dimensional) activity distribution and Monte Carlo dose voxel kernel calculations, and the mean doses to healthy liver and tumor were calculated for each patient. Response was defined according to Response Evaluation Criteria in Solid Tumors (RECIST) and recommendations of the European Association for the Study of the Liver (EASL). Criteria were used to assess possible liver toxicities. The parameters of TCP and NTCP models were established by direct maximization of the likelihood. RESULTS: Seventy-three patients were treated. With an average dose of 110 Gy to the tumor, complete or partial response was observed in 74% and 55% of patients according to the EASL guideline and RECIST, respectively, and the predicted TCPs were 73% and 55%, respectively. With a median liver dose of 36 Gy (range, 6-78 Gy), the >or=grade 2 (G2), >or=grade 3 (G3), and >or=grade 4 (G4) liver toxicities were observed in 32% (23/73), 21% (15/73), and 11% (8/73) of patients, respectively. The parameters describing the >or=G2 liver toxicity data using the NTCP model were a tolerance dose of the whole organ leading to a 50% complication probability of 52 Gy (95% confidence interval, 44-61 Gy) and a slope of NTCP versus dose of 0.28 (95% confidence interval, 0.18-0.60), assuming n = 1. CONCLUSION: The radiobiologic approach, based on patient-specific dosimetry, could improve the (90)Y-microsphere therapeutic approach of HCC, maintaining an acceptable liver toxicity.