A Novel Sentinel Lymph Node Approach in Oral Squamous Cell Carcinoma

BACKGROUND

Occult metastases are common in patients with oral squamous cell carcinoma (OSCC) which is why elective neck dissection, adjuvant radiotherapy or watchful waiting have been treatment options after surgical removal of the primary tumour. Sentinel lymph node biopsy (SLNB) has lately emerged as a novel possibility in treatment planning.

OBJECTIVES

To establish a reliable and clinically useful protocol for SLNB in staging/elective neck dissection in oral cancer.

METHODS

Fourteen consecutive patients with T1-T2 N0 oral cancer were enrolled when scheduled for elective neck dissection.

RESULTS

This study outlines various techniques for improving SLNB in head and neck cancer. After evaluation, a combination of techniques was found to constitute a reliable, clinically adaptable work concept. The suggested procedure starts with the pre-surgical injection of radioactive technetium 99Tcm carried on tilmanocept (Lymphoseek ®) at the tumour site. The radioactivity in the lymph node is then visualized preoperatively with Single Photon Emission Computed Tomography (SPECT/CT). Intraoperatively, indocyanine green (ICG) is injected and a sentinel node is visualized with near-infrared light. To support the sentinel node detection, the surgeon uses a hand-held gamma detection probe. This approach results in a reproducible and reliable detection of sentinel nodes.

CONCLUSION

This paper presents a novel protocol for the identification of the sentinel node in the head and neck region. The protocol additionally enables the use of flow cytometry analysis of resected lymph nodes.

Complete and long-lasting clinical responses in immune checkpoint inhibitor-resistant, metastasized melanoma treated with adoptive T cell transfer combined with DC vaccination

Development of T cell-directed immune checkpoint inhibitors (ICI) has revolutionized metastatic melanoma (MM) therapy, but <50% of treated patients experience durable responses. This phase I trial (NCT01946373) investigates the safety/feasibility of tumor-infiltrating lymphocyte (TIL) adoptive cell therapy (ACT) combined with dendritic cell (DC) vaccination in MM patients progressing on ICI. An initial cohort (5 patients) received TIL therapy alone to evaluate safety and allow for optimization of TIL expansion protocols. A second cohort (first-in-man, 5 patients) received TIL combined with autologous tumor lysate-loaded DC vaccination. All patients received cyclophosphamide/fludarabine preconditioning prior to, and intravenous (i.v.) IL-2 after, TIL transfer. The DC vaccine was given as five intradermal injections after TIL and IL-2 administration. [¹⁸F]-FDG PET/CT radiology was performed to evaluate clinical response, according to RECIST 1.1 (on the CT part). Immunological monitoring was performed by flow cytometry and T-cell receptor (TCR) sequencing. In the safety/optimization cohort, all patients had a mixed response or stable disease, but none durable. In the combination cohort, two patients experienced complete responses (CR) that are still ongoing (>36 and >18 months, respectively). In addition, two patients had partial responses (PR), one still ongoing (>42 months) with only a small bone-lesion remaining, and one of short duration (<4 months). One patient died early during treatment and did not receive DC. Long-lasting persistency of the injected TILs was demonstrated in blood. In summary, we report clinical responses by TIL therapy combined with DC vaccination in 4 out of 4 treated MM patients who previously failed ICI.

Increase of Intra-Abdominal Fat in Patients Treated with Continuous Ambulatory Peritoneal Dialysis

Objective

To evaluate changes in amount and distribution of body fat in patients treated with continuous ambulatory peritoneal dialysis (CAPD).

Design

Prospective study. Computed tomography (CT) and dual energy x-ray absorptiometry (DEXA) were used for determination of body composition at commencement of CAPD, and after a mean of 7.2 months of dialysis treatment.

Setting

CAPD unit at an academic teaching hospital.

Patients

The study included 19 consecutive patients who started CAPD during a 15-month time frame. Of these 19 patients, 12 (8 males) with a mean initial age of 60 years completed the study.

Main Outcome Measures

Siemens Somatom HiQ (Erlangen, Germany) was used for CT of the abdomen and of the right thigh. Fat and muscle areas were expressed as square centimeters. The proportion of total fat mass was determined by body composition analysis using DEXA (DPX-L densitometer) (Lunar, Madison, WI, U.S.A.) and expressed as percentage of total body weight (FAT%).

Results

Body weight changed from 67.1 to 68.4 kg (p = 0.20), and the intra-abdominal fat area increased 22.8% (p = 0.02). This increase was predominantly seen in male patients (p = 0.007). The FAT% changed from 27.8% to 30.9% (p = 0.25), without difference between sexes.

Conclusion

The increase of intra-abdominal fat found in this study may suggest a mechanism by which the established risk for CAPD patients to develop cardiovascular morbidity and mortality may be at least partially explained.

Gastric Emptying and Electrogastrography in Patients on Capd

Objective

To evaluate if impaired gastric emptying of digestible solids can explain the disturbed eating behavior in continuous ambulatory peritoneal dialysis (CAPD) patients, and if predialytic and dialytic (CAPD and hemodialysis) patients with impaired gastric emptying have a higher prevalence of electrogastrographic (EGG) abnormalities.

Design

Cross-sectional study. After ingestion of a 99mTc-labeled test meal, anterior and posterior 1-minute scintigraphic acquisitions were collected every 5 minutes during the first 50 minutes and thereafter every 10 minutes until 2 hours had elapsed. Simultaneously, cutaneous EGG recorded gastric myoelectric activity.

Setting

The Division of Nephrology and the Department of Nuclear Medicine at the same academic teaching hospital.

Participants

Thirty outpatients participated in both the gastric emptying and the EGG studies. Dialysis patients should have been on dialysis for more than 3 months. For comparison, 160 healthy control subjects participated in the gastric emptying study.

Main Outcome Measures

The following parameters were used to describe gastric emptying: lag phase 90%, half-emptying time ( T50), gastric retention at 90 and 120 minutes (Ret 90/120) and gastric emptying rate (GER, %/min). Electrogastrographic measurements were expressed as percentages of normal slow waves [2.4 – 3.6 cycles/min (cpm)], bradygastria (1.5 – 2.4 cpm), and tachygastria (3.6 – 10 cpm).

Results

T50 was prolonged, Ret 90 and Ret 120 were higher, and GER was slower in male CAPD patients compared to male controls. No significant differences were found in postprandial EGG.

Conclusion

Gastric emptying is impaired in male non-diabetic CAPD patients. However, abnormalities in postprandial EGG cannot explain this finding.

Gastroparesis versus dyspepsia by intragastric meal distribution: new diagnostics and definitions ahead

Gastroparesis often presents a challenge to the practicing gastroenterologist. Postprandial symptoms with nausea and vomiting may not only lead to nutritional and metabolic consequences, but also significant disruption of social activities that often center around food. The treatment options that affect gastric function are limited and often disappointing. The female predominance, the mostly idiopathic and idiosyncratic nature of the illness, often with some common psychiatric co-morbidity, parallels other functional disorders of the gastrointestinal tract. These parallels have provided the rationale for studies investigating alternative diagnostic features of the gastric emptying test as employed in the clinical setting. Hence, not only the regular cut-offs of 60% or 10% gastric retention of a meal at 2 and 4 h, but also a new concept, the intragastric meal distribution at time 0 (IMD⁰) is now introduced as a plausible diagnostic feature that should be more aligned with the patients' symptoms as they appear in close connection with the meal. Impaired gastric accommodation with absence of fundic relaxation followed by dumping of the meal into antrum is suggested to be diagnostic for functional dyspepsia and gastroparesis. The diagnostic cut-off is considered when more than 57% of the meal is distributed to the distal part of the stomach immediately on food intake. This new diagnostic feature of the gastric emptying profile lend support to better understanding of the patients' symptoms and provides a new basis for pharmacological treatment options in gastroparesis that may provide an improved quality of life in affected individuals.

Abstract P2-06-11: Sortilin targeted therapy in breast cancer with elevated progranulin expression

Background: A major challenge concerning breast cancer therapy is the occasional lack of effects using drugs that target cancer cells unspecifically. One possible explanation for this treatment failure is the existence of the small subpopulation of breast cancer stem cells that are believed to be more resistant towards conventional therapy and possesses the ability to drive tumor formation and disease progression. Cytokines secreted by nearby cells and other factors in the surrounding tumor microenvironment further stimulate the cancer cells, contributing to a heterogeneous and potentially more treatment resistant tumor. Thus, a more specific treatment approach targeting the breast cancer stem cell niche is crucial in preventing disease recurrences. In a cytokine screen, we identified progranulin as one of the main compounds secreted from cells exposed to hypoxia, leading to cancer stem cell propagation. Progranulin is involved in biological processes such as wound healing, inflammation and cancer progression. Progranulin and its receptor sortilin are known to be highly expressed in subgroups of breast cancer and are further associated with a clinically aggressive phenotype.

Methods/Results: By carrying out a number of in vitro and in vivo like screening assays, we demonstrate that progranulin influences the stem cell population in breast cancer and is responsible for spreading a cancer stem cell promoting signal to normoxic tumor areas. In breast cancer, progranulin induces a dedifferentiation process in the receiving cancer cells and expression of cancer stem cell markers together with an EMT-associated gene expression profile, leading to cancer stem cell expansion. By using siRNA and pharmacological inhibition of sortilin, we show that sortilin is a functional receptor of progranulin and is responsible for driving progranulin induced breast cancer stem cell propagation. Supporting the role of progranulin in cancer progression, administration of progranulin in immunocompromised mice induce lung metastasis in our breast cancer xenograft models. The use of different approaches for blocking sortilin, such as sortilin inhibitors, down-modulators or sortilin-targeted antibodies can prevent this dedifferentiation process, both in vitro and in vivo, making the tumor cells less aggressive and metastatic.

Conclusion: Targeting progranulin through its associated receptors is a potential therapeutic strategy for the treatment of patients with breast tumors having elevated progranulin or sortilin expression. By inhibiting the secretion based breast cancer progression, we could possibly block the formation of metastasis and cancer cell infiltration.

Citation Format: Berger K, Rhost S, Hughes E, Harrison H, Rafnsdottir S, Jacobsson H, Gregersson P, Magnusson Y, Fitzpatrick P, Andersson D, Ståhlberg A, Landberg G. Sortilin targeted therapy in breast cancer with elevated progranulin expression [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-11.

Clinical response of the novel activating ALK-I1171T mutation in neuroblastoma to the ALK inhibitor ceritinib

Tumors with anaplastic lymphoma kinase (ALK) fusion rearrangements, including non-small-cell lung cancer and anaplastic large cell lymphoma, are highly sensitive to ALK tyrosine kinase inhibitors (TKIs), underscoring the notion that such cancers are addicted to ALK activity. Although mutations in ALK are heavily implicated in childhood neuroblastoma, response to the ALK TKI crizotinib has been disappointing. Embryonal tumors in patients with DNA repair defects such as Fanconi anemia (FA) often have a poor prognosis, because of lack of therapeutic options. Here we report a child with underlying FA and ALK mutant high-risk neuroblastoma responding strongly to precision therapy with the ALK TKI ceritinib. Conventional chemotherapy treatment caused severe, life-threatening toxicity. Genomic analysis of the initial biopsy identified germline FANCA mutations as well as a novel ALK-I1171T variant. ALK-I1171T generates a potent gain-of-function mutant, as measured in PC12 cell neurite outgrowth and NIH3T3 transformation. Pharmacological inhibition profiling of ALK-I1171T in response to various ALK TKIs identified an 11-fold improved inhibition of ALK-I1171T with ceritinib when compared with crizotinib. Immunoaffinity-coupled LC-MS/MS phosphoproteomics analysis indicated a decrease in ALK signaling in response to ceritinib. Ceritinib was therefore selected for treatment in this child. Monotherapy with ceritinib was well tolerated and resulted in normalized catecholamine markers and tumor shrinkage. After 7.5 mo treatment, the residual primary tumor shrunk, was surgically removed, and exhibited hallmarks of differentiation together with reduced Ki67 levels. Clinical follow-up after 21 mo treatment revealed complete clinical remission including all metastatic sites. Therefore, ceritinib presents a viable therapeutic option for ALK-positive neuroblastoma.

Abstract CT032: Adoptive T cell transfer combined with DC vaccination in patients with metastatic melanoma

Background and aim: Although several drugs have been approved that improve overall survival in patients with metastatic melanoma, there is still a need for additional treatments when the approved ones are exhausted. Adoptive T-cell therapy (ACT) has been reported to induce clinical responses in up to 70% of stage IV melanoma patients. The aim of the MAT02 trial is to investigate the toxicity and feasibility of a combined treatment with adoptive transfer of autologous, tumor-derived T cells with or without autologous dendritic cell (DC) vaccination in patients with stage III/IV melanoma.

Method: This study is a single centre, open-label, two-armed, phase I trial. Five patients are assigned to each cohort (A or B) and receive ACT of autologous tumor infiltrating lymphocytes (TIL) without (A) or with (B) autologous tumor loaded DC i.c. Prior to TIL cell transfer, all patients are pre-treated with a precondition regimen. Administration of TIL cells is followed by IL-2 administration (100000 U/Kg q8hx14). Radiological evaluation is performed four weeks after the last DC administration. The primary objective is to evaluate the toxicity and feasibility. The secondary objectives are to generate large numbers of T cells, boost tumor-reactive T cells by DC vaccination, characterize the T cell population used for adoptive transfer with regard to phenotype and functionality, and generate an objective anti-tumour response.

Results: Cohort A in which patients received only TIL has been completed and the treatment was feasible with limited expected toxicity. All treated patients showed a mixed response or stable disease. However, these responses were not durable. The overall survival ranged between 4-17 months. For cohort B which received the combined treatment of TIL and DC vaccine, three patients have completed the treatment that has been feasible with limited expected toxicity. The number of cells transfused in this cohort ranged between 29 and 33 billion and all patients have been administered five DC-vaccinations. All 3 patients responded; one with a complete response which is still ongoing (&gt; 12 mo). Two patients showed a partial response, one with a long lasting response (&gt; 18 mo) and one with a short response (&lt; 4 mo). The accrual continues and we expect to include another two patients before the summer of 2018.

Conclusions: Adoptive T cell therapy combined with DC vaccination is safe with tolerable toxicity profiles and can result in complete clinical response in patients who have failed on checkpoint therapy.

Citation Format: stina L. wickström, Tanja Lövgren, Maria Wolodarski, Ulrika Edbäck, Eva Martell, Karin Markland, Maria Nyström, Andreas Lundqvist, Hans Jacobsson, Johan Hansson, Giuseppe Masucci, Roger Tell, Isabel Poschke, Lars Adamson, Jonas Mattsson, Rolf Kiessling. Adoptive T cell transfer combined with DC vaccination in patients with metastatic melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT032.

Vaccination against hepatitis B virus among people who inject drugs - A 20year experience from a Swedish needle exchange program

BACKGROUND

People who inject drugs (PWID) are at particular risk of hepatitis B virus (HBV) acquisition, but often have poor access or adherence to HBV vaccination. Vaccination against HBV has been offered at a major Swedish needle exchange program (NEP) since 1994. The aim of this study was to evaluate vaccine completion and response rates, and the effect of sequential booster doses to non-responders to the standard vaccination schedule.

METHODS

PWID enrolled in the NEP 1994-2013, without serological markers for HBV at baseline (negative for HBsAg/anti-HBc/anti-HBs), were offered a three-dose standard intramuscular vaccination schedule (Engerix®-B, GSK, 20μg/mL, intended to be received at months 0, 1 and 6). Vaccination response was defined as protective levels of anti-HBs (⩾10mIU/mL). Up to three booster doses were then offered for non-responders, each followed by anti-HBs testing.

RESULTS

HBV data was available for 2352 identifiable individuals at NEP enrolment, of whom 1516 (64.5%) had no markers for previous HBV exposure or vaccination. Vaccination was initiated for 1142 (75.3%) individuals and 898 (59.2%) completed the standard vaccination schedule. Post-vaccination anti-HBs levels were available from 800 individuals, with 598 (74.8%) responding to the basic vaccination schedule. After up to three booster doses a total of 676 (84.5%) individuals achieved protective anti-HBs levels. Non-response to vaccination was associated with higher age and anti-HCV positivity (p<0.001). Eighteen incident cases of HBV infection were observed among vaccine non-responders, as well as 30 cases among those who had not completed vaccination.

CONCLUSION

We demonstrate the feasibility of including HBV vaccination in the services offered by a NEP, with completion of vaccination in a majority of HBV-susceptible PWID. The response to HBV vaccination among PWID was relatively low; however, the addition of up to three booster doses improved the response rate from 74.8 to 84.5%.

Early assessment of neoadjuvant chemotherapy by FEC-courses of locally advanced breast cancer using 99mTc-MIBI

Purpose: Response assessment at neoadjuvant (preoperative) chemotherapy of locally advanced breast cancer using clinical examination and mammography is insensitive. Mammoscintigraphy with 99mTc-MIBI was studied for the prediction of response at such therapy before finishing the chemotherapy cycles.

Material and Methods: Chemotherapy was given as repeated courses of 5-fluorouracil, epirubicin and cyclophosphamide (FEC). In 1 patient group ( n = 23), the tumor uptake relative to surrounding breast tissue and lung tissue at SPECT examination after finishing neoadjuvant chemotherapy was compared with the examination made before chemotherapy. In another group ( n = 30), a similar comparison after the first therapy cycle (mean 19 days) with a baseline examination was made. Histologic examination of the resected tumors was made.

Results: After finishing chemotherapy, there was a strong reduction of the relative tumor activity, while there was no correlation with therapy effect as assessed by histology. After one therapy course, there was no significant reduction of the relative tumor uptake.

Conclusion: Scintigraphy with 99mTc-MIBI demonstrated the response after finished neoadjuvant chemotherapy of breast cancer using FEC-courses. It cannot be used to predict a therapy response after one therapy course.

Hyperostosis Cranii

The bone scintigrams of 52 women with radiographically proven hyperostosis cranii were examined specifically with regard to the endosteal lesions. It was confirmed that hyperostosis cranii exhibits a characteristic appearance at bone scintigraphy that is usually easy to recognize. By scoring the degree of hyperostotic changes and their scintigraphic activity according to a semiquantitative scale, an inverse relation between radiographic changes and scintigraphic activity was observed but could not be statistically proven. A tendency of more pronounced radiographic changes and a tendency of decreasing activity at bone scintigraphy with increasing age were also found. It is suggested that hyperostosis cranii starts in younger women and that the initial osseous turnover of the lesions is high. Successively, the metabolic activity decreases while the endosteal lesions increase, tending towards a stabilization of the process with increasing age.

Added value of cea scintigraphy in the detection of recurrence of rectal carcinoma

Purpose: To explore the diagnostic value of immunoscintigraphy compared to CT and/or MR imaging in the diagnosis of local recurrence (LR) of rectal cancer.

Material and Methods: Forty-six patients suspected of having LR of rectal cancer were retrospectively studied. Carcinoembryonic antigen (CEA) scintigraphy findings were compared to CT and/or MR in all patients, and with data from surgery and morphology (31 patients), biopsy (7 cases) and follow-up (8 patients).

Results: CEA scintigraphy was not complementary to CT and/or MR in the detection of LR. Two false-positive and 14 false-negative diagnoses of LR occurred with CEA scintigraphy. Distant metastases including metastatic lymph nodes were found by this method in only 7 of 27 patients with proven metastases. CT/MR were able to demonstrate these metastases in 21 of 27 patients.

Conclusion: Accuracy and sensitivity of CEA scintigraphy in the detection of LR and distant metastases is lower than that of CT and/or MR. However, CEA scintigraphy seems to have a high specificity and could therefore be used in patients with a strong clinical suspicion of LR but negative CT/MR investigations. Available diagnostic methods have limitations in differentiating between benign, post-treatment changes and LR of rectal cancer and in staging of malignant disease.

A 3-D Method for Delineation of Activity Distributions and Assessment of Functional Organ Volumes with Spect

The distribution volume of an organ may have a clinical impact in many cases and various methods have been designed to make volume assessments. In this paper, we describe a new method for delineation of the distribution outline and volume determination. The method is based on smoothing, differentiation, image relaxation and voxel counting of single photon emission computer tomography (SPECT) image sets with 3-D operators. A special routine corrects for the inherent thickness of the voxel-based outline. Phantom experiments, using a SPECT system with LEGP-collimator and a 64×64 acquisition matrix with 6.3×6.3 mm2 pixel size, demonstrated good correlation between the measured and the true volumes. For volumes larger than 120 cc the correlation coefficient was 0.9999 with SE 1.0 cc and an average relative deviation of 0.49%. For volumes below 120 cc, the accuracy was impaired due to low resolution power. By improving the system spatial resolution with an LEHR-collimator and a smaller pixel-size (4.1×4.1 mm2), good accuracy was achieved also for volumes in the range from 3 to 120 cc. Measurements of 15 differently shaped phantoms of volumes between 3 and 104 cc demonstrated high correlation between measured and true volumes: R=0.9921 and SE=0.74 cc (5.3%). For volumes as small as 3 and 5 cc, the difference between the true and the assessed volume was 0.6 cc. The reproducibility of the method was within 3% for volumes above 120 cc and within 7% for volumes below. Due to this accuracy, we conclude that the method can be applied for various clinical routine and research applications using SPECT.

Quantitative Single Photon Emission Computed Tomography Applied to a Comparison of Propanetetraphosphonate and Albumin Colloid for Liver and Spleen Scintigraphy

A clinical application of a previously developed technique for absolute quantitation of organ uptake of radioactivity is presented. The method, which is based on single photon emission computed tomography involving correction for scattering and attenuation of photons, enables an accurate in vivo determination of the amount of administered activity taken up in a specific organ. The technique was applied to a comparative clinical trial between propanetetraphosphonate and albumin colloid for liver and spleen scintigraphy. The mean uptake of the liver was 73±9 per cent using propanetetraphosphonate and 63±10 per cent using albumin colloid. The corresponding figures for the spleen were 6±3 and 9±4 per cent, respectively. The activity concentration of the different lobes of the liver, bone marrow and soft tissue was also estimated. Phantom studies showed that the total uptake in the liver could be determined with an accuracy of about 6 per cent. The accuracy of the clinical examinations was estimated to about 10 per cent.

Risk of recurrent laryngeal nerve palsy in patients undergoing thyroidectomy with and without intraoperative nerve monitoring

BACKGROUND

Vocal cord palsy occurs in 3-5 per cent of patients after thyroidectomy. To reduce this complication, intraoperative nerve monitoring (IONM) has been introduced, although its use remains controversial. This study investigated the risk of postoperative vocal cord palsy with and without the use of intermittent IONM.

METHODS

Patients registered in the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery, 2009-2013, were included. Early palsy of the recurrent laryngeal nerve was diagnosed within 6 weeks after surgery. Permanent palsy was defined as that persisting after 6 months. Univariable and multivariable logistic regression analyses were used to examine risk factors for vocal cord palsy.

RESULTS

The cohort consisted of 5252 patients undergoing thyroidectomy. IONM was used in 3277 operations (62·4 per cent); postoperative laryngoscopy was performed in 1757 patients (33·5 per cent). Early vocal cord palsy occurred in 217 patients (4·1 per cent), of which three were bilateral, all in the group without IONM. Permanent vocal cord palsy occurred in 62 patients (1·2 per cent). In the multivariable analysis of 1757 patients who had postoperative laryngoscopy, the use of IONM was not associated with a decreased risk of early vocal cord palsy (odds ratio (OR) 0·67, 95 per cent c.i. 0·44 to 1·01), but decreased the risk of permanent vocal cord palsy (OR 0·43, 0·19 to 0·93). [Correction added on 11 November 2016 after first publication: the word 'routine' has been removed from this section.] CONCLUSION: IONM reduced the risk of permanent vocal cord palsy. No bilateral recurrent laryngeal nerve injury occurred following IONM.

Progression-free and overall survival in metastatic castration-resistant prostate cancer treated with abiraterone acetate can be predicted with serial C11-acetate PET/CT

In this retrospective study, we evaluated the benefit of repeated carbon 11 (C11)-acetate positron emission tomography/computed tomography (PET/CT) to assess response in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone acetate (AA).A total of 30 patients with mCRPC were monitored with C11-acetate PET/CT and PSA levels during their treatment with AA. Retrospective evaluation of their response was made after 102 days (median; range 70-155) of treatment. Statistical analyses were employed to detect predictors of progression-free survival (PFS) and overall survival (OS), and potential correlation between serum levels of PSA, standardized uptake values (SUVpeak), and bone lesion index measured from PET were investigated.At follow-up 10 patients exhibited partial response (PR), 10 progressive disease (PD), and 10 stable disease (SD), as assessed by PET/CT. In survival analysis, both PR and PD were significantly associated with PFS and OS. CT response was also associated with OS, but only 19/30 patients demonstrated a lesion meeting target lesion criteria according to RECIST 1.1. No PET/CT baseline characteristic was significantly associated with PFS or OS. A PSA response (reduction in the level by >50%) could also predict PFS and OS. In the subgroup lacking a PSA response, those with PD had significantly shorter OS than those with PR or SD.PFS and OS in patients with mCRPC treated with AA can be predicted from repeated C11-acetate PET/CT. This may be of particular clinical value in patients who do not exhibit a PSA response to treatment.

Pharmacokinetics and Toxicity of Sodium Selenite in the Treatment of Patients with Carcinoma in a Phase I Clinical Trial: The SECAR Study

Background: Sodium selenite at high dose exerts antitumor effects and increases efficacy of cytostatic drugs in multiple preclinical malignancy models. We assessed the safety and efficacy of intravenous administered sodium selenite in cancer patients’ refractory to cytostatic drugs in a phase I trial. Patients received first line of chemotherapy following selenite treatment to investigate altered sensitivity to these drugs and preliminary assessment of any clinical benefits. Materials and Methods: Thirty-four patients with different therapy resistant tumors received iv sodium selenite daily for consecutive five days either for two weeks or four weeks. Each cohort consisted of at least three patients who received the same daily dose of selenite throughout the whole treatment. If 0/3 patients had dose-limiting toxicities (DLTs), the study proceeded to the next dose-level. If 2/3 had DLT, the dose was considered too high and if 1/3 had DLT, three more patients were included. Dose-escalation continued until the maximum tolerated dose (MTD) was reached. MTD was defined as the highest dose-level on which 0/3 or 1/6 patients experienced DLT. The primary endpoint was safety, dose-limiting toxic effects and the MTD of sodium selenite. The secondary endpoint was primary response evaluation. Results and Conclusion: MTD was defined as 10.2 mg/m², with a calculated median plasma half-life of 18.25 h. The maximum plasma concentration of selenium from a single dose of selenite increased in a nonlinear pattern. The most common adverse events were fatigue, nausea, and cramps in fingers and legs. DLTs were acute, of short duration and reversible. Biomarkers for organ functions indicated no major systemic toxicity. In conclusion, sodium selenite is safe and tolerable when administered up to 10.2 mg/m² under current protocol. Further development of the study is underway to determine if prolonged infusions might be a more effective treatment strategy.

Gene expression profiling of sequential metastatic biopsies for biomarker discovery in breast cancer

The feasibility of longitudinal metastatic biopsies for gene expression profiling in breast cancer is unexplored. Dynamic changes in gene expression can potentially predict efficacy of targeted cancer drugs. Patients enrolled in a phase III trial of metastatic breast cancer with docetaxel monotherapy versus combination of docetaxel + sunitinib were offered to participate in a translational substudy comprising longitudinal fine needle aspiration biopsies and Positron Emission Tomography imaging before (T1) and two weeks after start of treatment (T2). Aspirated tumor material was used for microarray analysis, and treatment-induced changes (T2 versus T1) in gene expression and standardized uptake values (SUV) were investigated and correlated to clinical outcome measures. Gene expression profiling yielded high-quality data at both time points in 14/18 patients. Unsupervised clustering revealed specific patterns of changes caused by monotherapy vs. combination therapy (p = 0.021, Fisher's exact test). A therapy-induced reduction of known proliferation and hypoxia metagene scores was prominent in the combination arm. Changes in a previously reported hypoxia metagene score were strongly correlated to the objective responses seen by conventional radiology assessments after 6 weeks in the combination arm, Spearman's ρ = 1 (p = 0.017) but not in monotherapy, ρ = -0.029 (p = 1). Similarly, the Predictor Analysis of Microarrays 50 (PAM50) proliferation metagene correlated to tumor changes merely in the combination arm at 6 and 12 weeks (ρ = 0.900, p = 0.083 and ρ = 1, p = 0.017 respectively). Reductions in mean SUV were a reliable early predictor of objective response in monotherapy, ρ = 0.833 (p = 0.008), but not in the combination arm ρ = -0.029 (p = 1). Gene expression profiling of longitudinal metastatic aspiration biopsies was feasible, demonstrated biological validity and provided predictive information.

Neurobiology of Sleep Disturbances in PTSD Patients and Traumatized Controls: MRI and SPECT Findings

OBJECTIVE

Sleep disturbances such as insomnia and nightmares are core components of post-traumatic stress disorder (PTSD), yet their neurobiological relationship is still largely unknown. We investigated brain alterations related to sleep disturbances in PTSD patients and controls by using both structural and functional neuroimaging techniques.

METHOD

Thirty-nine subjects either developing (n = 21) or not developing (n = 18) PTSD underwent magnetic resonance imaging and a symptom-provocation protocol followed by the injection of 99mTc-hexamethylpropyleneamineoxime. Subjects were also tested with diagnostic and self-rating scales on the basis of which a Sleep Disturbances Score (SDS; i.e., amount of insomnia/nightmares) was computed.

RESULTS

Correlations between SDS and gray matter volume (GMV)/regional cerebral blood flow (rCBF) were computed in the whole sample and separately in the PTSD and control groups. In the whole sample, higher sleep disturbances were associated with significantly reduced GMV in amygdala, hippocampus, anterior cingulate, and insula; increased rCBF in midbrain, precuneus, and insula; and decreased rCBF in anterior cingulate. This pattern was substantially confirmed in the PTSD group, but not in controls.

CONCLUSION

Sleep disturbances are associated with GMV loss in anterior limbic/paralimbic, PTSD-sensitive structures and with functional alterations in regions implicated in rapid eye movement-sleep control, supporting the existence of a link between PTSD and sleep disturbance.

Effects on the FDG distribution by a high uptake of brown adipose tissue at PET examination

Background

At fluorodeoxyglucose/positron emission tomography (FDG/PET) examinations, a generally increased uptake of the skeletal muscles is sometimes encountered. As the tracer distribution constitutes a ‘zero-sum-game’, the uptake of lesions as well as of normal tissues is reduced in these patients. This has to be considered at calculation of standardised uptake values (SUVs), especially at longitudinal examinations in the same patient. In the current study, a possible similar influence on the FDG distribution by a high uptake of brown adipose tissue (BAT) was studied.

Methods

Twelve patients with strongly increased BAT uptake were examined twice with a mean of 5 days (study group). In six of these patients, there was at least one pathological lesion with increased uptake. The BAT uptake was normalised at the second examination after pretreatment with propranolol. SUVs of the pathological lesions and of the liver, spleen, lung, blood, skeletal muscles, bone marrow, gluteal fat, abdomen and heart were assessed. In order to control the effects of propranolol on normal organs/tissues, which could interfere with the findings, 25 age and gender matched normal controls were also studied (control subjects).

Results

In the study group, there was only a lower bone marrow uptake after propranolol administration. Comparing the study group with the control subjects, the bone marrow activity was higher at examination before propranolol treatment compared to the control subjects. There was also a higher uptake of the spleen in the study group before propranolol treatment compared to the control subjects. There were no differences between the study group after propranolol administration and the control subjects.

Conclusions

The differences found are small and cannot be explained, why they could be random phenomena. Together with, there were no differences between the study group after propranolol administration and the control subjects; it is concluded that an effect on the FDG distribution in patients with a strong BAT uptake by can be disregarded in clinical praxis. This is important at longitudinal examinations of patients undergoing tailored tumour therapy and in contrast to examinations in patients with a generally increased uptake of the skeletal muscles which significantly affects the distribution of the radiopharmaceutical.

Towards mapping the brain connectome in depression: functional connectivity by perfusion SPECT

Several studies have demonstrated altered brain functional connectivity in the resting state in depression. However, no study has investigated interregional networking in patients with persistent depressive disorder (PDD). The aim of this study was to assess differences in brain perfusion distribution and connectivity between large groups of patients and healthy controls. Participants comprised 91 patients with PDD and 65 age- and sex-matched healthy controls. Resting state perfusion was investigated by single photon emission computed tomography, and group differences were assessed by Statistical Parametric Mapping. Brain connectivity was explored through a voxel-wise interregional correlation analysis using as covariate of interest the normalized values of clusters of voxels in which perfusion differences were found in group analysis. Significantly increased regional brain perfusion distribution covering a large part of the cerebellum was observed in patients as compared with controls. Patients showed a significant negative functional connectivity between the cerebellar cluster and caudate, bilaterally. This study demonstrated inverse relative perfusion between the cerebellum and the caudate in PDD. Functional uncoupling may be associated with a dysregulation between the role of the cerebellum in action control and of the caudate in action selection, initiation and decision making in the patients. The potential impact of the resting state condition and the possibility of mitochondrial impairment are discussed.

[11C]Acetate positron emission tomography-computed tomography imaging of prostate cancer lymph-node metastases correlated with histopathological findings after extended lymphadenectomy

OBJECTIVE

The aim of this study was to determine the efficacy of combined [(11)C]acetate positron emission tomography and computed tomography ([(11)C]acetate-PET/CT) in regional lymph-node staging in patients with prostate cancer (PCa).

MATERIAL AND METHODS

[(11)C]Acetate-PET/CT was performed in 19 PCa patients who subsequently underwent extended pelvic lymph-node dissection (ePLND). The [(11)C]acetate-PET/CT results were compared with the surgical and histopathological findings from 13 defined lymph-node regions.

RESULTS

[(11)C]Acetate-PET/CT was true-positive for lymph-node metastases in nine patients, false-positive in three, false-negative in one patient and true-negative in six. The patient-by-patient-based sensitivity was 90% and the specificity 67%, the positive predictive value (PPV) was 75% and the negative predictive value (NPV) 86%. From a total of 114 nodal regions (mean 5.9 regions per patient), 484 lymph nodes (mean 25.5 nodes per patient) were removed and evaluated histopathologically. Forty-six lymph nodes from 24 out of 114 (21%) nodal regions were positive for PCa metastasis. The nodal-region-based sensitivity of [(11)C]acetate-PET/CT was 62%, specificity was 89%, PPV 62% and NPV 89%.

CONCLUSION

[(11)C]Acetate-PET/CT detects PCa lymph-node metastases with high patient-by-patient-based sensitivity but low specificity, and low nodal-region-based sensitivity but high specificity. Its limited ability to detect microscopic lymph-node involvement makes ePLND essential in all patients diagnosed with positive nodes on [(11)C]acetate-PET/CT.

Repeatability of the Maximum Standard Uptake Value (SUVmax) in FDG PET

Objective: SUV_max is often calculated at FDG PET examinations in systematic studies as well as at clinical examinations. Since SUV_max represents a very small portion of a lesion it may be questioned how statistically reliable the figure is. This was studied by assessing the repeatability of SUV_max between two FDG acquisitions acquired immediately upon each other in patients with chest lesions.

Methods: In 100 clinical patients with a known chest lesion, two identical 3 min PET registrations (PET1 and PET2, respectively) were initiated within 224±31 sec of each other. The difference in SUV_max between the lesion for the two PET scans (ΔSUVmax) was calculated and the uncertainty expressed as the coefficient of variation, CV (%). The correlation between ΔSUV_max and the lowest SUV_max from PET1 or PET2, the approximate metabolic lesion volume, the time from FDG injection to PET1 and the time between PET1 and PET2, respectively, was also assessed.

Results: In 56 patients SUV_max increased at the second acquisition and in 44 patients it decreased. Mean of SUV_max was 7.8±6.1 and 7.8±6.2 for PET1 and PET2, respectively. The mean percentage difference was 0.9±7.8. The difference was not significant (p=0.20). CV gave an uncertainty of 4.3% between the two measurements which is a strong indicator of equivalence. There was no correlation between ΔSUV_max and any of the assessed four parameters. The difference between the acquisitions, 0.9%, was much lower compared to the 3 previous published similar, but more restricted studies where the difference was 2.5-8.2%.

Conclusion: From camera and computational perspectives, SUV_max is a stable parameter

Conflict of interest:None declared.

Technical requirements for Na¹⁸F PET bone imaging of patients being treated using a Taylor spatial frame

Diagnosis of new bone growth in patients with compound tibia fractures or deformities treated using a Taylor spatial frame is difficult with conventional radiography because the frame obstructs the images and creates artifacts. The use of Na(18)F PET studies may help to eliminate this difficulty.

METHODS

Patients were positioned on the pallet of a clinical PET/CT scanner and made as comfortable as possible with their legs immobilized. One bed position covering the site of the fracture, including the Taylor spatial frame, was chosen for the study. A topogram was performed, as well as diagnostic and attenuation correction CT. The patients were given 2 MBq of Na(18)F per kilogram of body weight. A 45-min list-mode acquisition was performed starting at the time of injection, followed by a 5-min static acquisition 60 min after injection. The patients were examined 6 wk after the Taylor spatial frame had been applied and again at 3 mo to assess new bone growth.

RESULTS

A list-mode reconstruction sequence of 1 × 1,800 and 1 × 2,700 s, as well as the 5-min static scan, allowed visualization of regional bone turnover.

CONCLUSION

With Na(18)F PET/CT, it was possible to confirm regional bone turnover as a means of visualizing bone remodeling without the interference of artifacts from the Taylor spatial frame. Furthermore, dynamic list-mode acquisition allowed different sequences to be performed, enabling, for example, visualization of tracer transport from blood to the fracture site.

Abstract OT1-2-03: A prospective randomized phase II study to identify predictive biomarkers and mechanisms of resistance in patients with HER2-negative metastatic breast cancer treated with the combination of bevacizumab and paclitaxel

Background

Several phase III trials have evaluated the combination of bevacizumab and chemotherapy in patients with metastatic breast cancer (MBC). These individual studies as well as a meta-analysis indicate high response rates (RR) and increased progression-free survival (PFS), however no significant gain of overall survival (OS) by the addition of bevacizumab to chemotherapy. To date, there are no methods to reliably select patients with MBC that benefit from treatment with bevacizumab.

Trial design

This project is a prospective, randomized, 2-arm, open-label, single-center, phase II trial aiming to identify predictive markers and mechanisms of resistance to bevacizumab in MBC by longitudinal biopsies and functional imaging. The study will be initiated with a non-randomized, feasibility stage including ten patients who will be treated with bevacizumab and paclitaxel, in order to determine the safety of metastatic tumor biopsies during therapy with bevacizumab. In a second phase, 20 patients will be randomized (1:1) between two treatment arms: Paclitaxel 80 mg / m2 weekly with or without bevacizumab 15 mg / kg every 3 weeks.

Mandatory, repeated peripheral blood sampling and fine needle aspiration biopsies (FNAB) will be collected at baseline, at day 4 after the first cycle and at progression. At baseline, a core biopsy will be obtained as well. Patients will also undergo two 18F]-fluoro-L-thymidine (FLT) Positron Emission Tomography (PET)/CT scans (18F-FLT PET/CT), at baseline and at day 4 after the first cycle.

Eligibility criteria

Eligible are patients aged 18-70 years, with newly diagnosed HER2-negative MBC (stage IV or recurrent) that are candidates for chemotherapy (ECOG 0-2), with measurable disease and at least one lesion that is accessible for biopsy. Adequate bone marrow, hepatic and renal function are required, as well as absence of thromboembolic disease, bleeding diathesis or second concurrent malignancy. No previous systemic treatment for MBC is allowed.

Specific aims

1. To assess early therapeutic response to bevacizumab in MBC by whole-exome sequencing and gene expression of serial metastatic biopsies and functional imaging.

2. To identify potential biomarkers present in plasma that can be used for patient selection or for monitoring therapy with bevacizumab in MBC.

3. To explore mutations and gene expression alterations as mechanisms of resistance to bevacizumab in MBC.

Statistical methods

The main objective of the study is exploratory. For most of the planned analyses, each patient will serve as her own control and baseline values of potential biomarkers will be compared in pairs with intra-patient, longitudinal samples, which significantly increases the statistical power.

For the identification of biomarkers, the results of the molecular analyses will be correlated with clinical outcome measurements including RR, PFS, and OS.

Present accrual and target accrual.

The trial was opened for inclusion in May 2013 and one patient has been accrued by June 1st 2013. A total of 30 patients will be included during a period of 2 years.

Contact:

Principal Investigator: Theodoros.Foukakis@ki.se; Study Director: Jonas.Bergh@ki.se.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-2-03.

Dynamic gadoxetate-enhanced MRI for the assessment of total and segmental liver function and volume in primary sclerosing cholangitis

PURPOSE

To evaluate dynamic hepatocyte-specific contrast-enhanced MRI (DHCE-MRI) for the assessment of global and segmental liver volume and function in patients with primary sclerosing cholangitis (PSC), and to explore the heterogeneous distribution of liver function in this patient group.

MATERIALS AND METHODS

Twelve patients with primary sclerosing cholangitis (PSC) and 20 healthy volunteers were examined using DHCE-MRI with Gd-EOB-DTPA. Segmental and total liver volume were calculated, and functional parameters (hepatic extraction fraction [HEF], input relative blood-flow [irBF], and mean transit time [MTT]) were calculated in each liver voxel using deconvolutional analysis. In each study subject, and incongruence score (IS) was constructed to describe the mismatch between segmental function and volume. Among patients, the liver function parameters were correlated to bile duct obstruction and to established scoring models for liver disease.

RESULTS

Liver function was significantly more heterogeneously distributed in the patient group (IS 1.0 versus 0.4). There were significant correlations between biliary obstruction and segmental functional parameters (HEF rho -0.24; irBF rho -0.45), and the Mayo risk score correlated significantly with the total liver extraction capacity of Gd-EOB-DTPA (rho -0.85).

CONCLUSION

The study demonstrates a new method to quantify total and segmental liver function using DHCE-MRI in patients with PSC.

Neurobiological insight into hyperbaric hyperoxia

AIM

Hyperbaric hyperoxia (HBO) is known to modulate aerobic metabolism, vasoreactivity and blood flow in the brain. Nevertheless, mechanisms underlying its therapeutic effects, especially in traumatic brain injury (TBI) and stroke patients, are debated. The present study aimed at investigating regional cerebral blood flow (rCBF) distribution during acute HBO exposure.

METHODS

Regional cerebral blood flow response was investigated in seven healthy subjects exposed to either normobaric normoxia or HBO with ambient pressure/inspired oxygen pressure of 101/21 and 250/250 kPa respectively. After 40 min at the desired pressure, they were injected a perfusion tracer and subsequently underwent brain single photon emission computed tomography. rCBF distribution changes in the whole brain were assessed by Statistical Parametric Mapping.

RESULTS

During HBO, an increased relative rCBF distribution was found in sensory-motor, premotor, visual and posterior cingulate cortices as well as in superior frontal gyrus, middle/inferior temporal and angular gyrus and cerebellum, mainly in the dominant hemisphere. During normobaric normoxia, a higher (99m) Tc-HMPAO distribution in the right insula and subcortical structures as well as in bilateral hippocampi and anterior cingulated cortex was found.

CONCLUSIONS

The present study firstly confirmed the rCBF distribution increase during HBO in sensory-motor and visual cortices, and it showed for the first time a higher perfusion tracer distribution in areas encompassed in dorsal attention system and in default mode network. These findings unfold both the externally directed cognition performance improvement related to the HBO and the internally directed cognition states during resting-state conditions, suggesting possible beneficial effects in TBI and stroke patients.

Gray matter volume alterations related to trait dissociation in PTSD and traumatized controls

OBJECTIVE

This study used voxel-based morphometry (VBM) to investigate brain structural alterations related to trait dissociation and its relationship with post-traumatic stress disorder (PTSD).

METHOD

Thirty-two subjects either developing (N = 15) or non-developing (N = 17) PTSD underwent MRI scanning and were assessed with the Dissociative Experience Scale (DES), subscales for pathological (DES-T) and non-pathological trait (DES-A) dissociation, and other clinical measures. Gray matter volume (GMV) was analyzed using VBM as implemented in SPM. PTSD and non-PTSD subjects were compared to assess brain alterations related to PTSD pathology, whereas correlation analyses between dissociation measures and GMV were performed on the whole sample (N = 32), irrespective of PTSD diagnosis, to identify alterations related to trait dissociation.

RESULTS

As compared to traumatized controls, PTSD subjects showed reduced GMV in the prefrontal cortex, hippocampus and lingual gyrus. Correlations with dissociation measures (DES, DES-T, and DES-A) consistently showed increased GMV in the medial and lateral prefrontal, orbitofrontal, parahippocampal, temporal polar, and inferior parietal cortices.

CONCLUSION

PTSD and dissociation seem to be associated with opposite volumetric patterns in the prefrontal cortex. Trait dissociation appears to involve increased GMV in prefrontal, paralimbic, and parietal cortices, with negligible differences between pathological and non-pathological dissociation.

Development of a bioactive implant for repair and potential healing of cranial defects

The repair of complex craniofacial bone defects is challenging and a successful result is dependent on the size of the defect, quality of the soft tissue covering the defect, and choice of reconstruction method. The objective of this study was to develop a bioactive cranial implant that could provide a permanent reconstructive solution to the patient by stimulating bone healing of the defect. In this paper the authors report on the feasibility and clinical results of using such a newly developed device for the repair of a large traumatic and therapy-resistant cranial bone defect. The patient had undergone numerous attempts at repair, in which established methods had been tried without success. A mosaic-designed device was manufactured and implanted, comprising interconnected ceramic tiles with a defined calcium phosphate composition. The clinical outcome 30 months after surgery revealed a restored cranial vault without postoperative complications. Computed tomography demonstrated signs of bone ingrowth. Examination with combined (18)F-fluoride PET and CT provided further evidence of bone healing of the cranial defect.

The relation between the blood glucose level and the FDG uptake of tissues at normal PET examinations

Background

The influence of the blood glucose level on the tracer uptake of normal tissues at [¹⁸F]-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) was retrospectively studied in examinations in clinical patients.

Methods

Five hundred examinations were evaluated in retrospect. The inclusion criteria were studies with a normal or near-normal FDG distribution. Patients who had been subjected to chemotherapy (including GSF treatment) or radiotherapy <4 weeks prior to the examination were excluded; we cannot exclude, however, that in a very few patients the available information might have been incomplete. Otherwise, patients were included regardless of concurrent diseases and/or therapy. In one evaluation, the mean standardized uptake value of the liver, spleen, lungs, peripheral blood, selected muscles and bone marrow of all 500 individuals was correlated to the blood glucose level. In another evaluation, a subgroup of 62 patients with increased blood glucose levels (≥7.0 mmol/l) was compared with another subgroup of 62 patients paired with regard to age and gender with blood glucose levels within normal range (≤6.0 mmol/l).

Results

There was a weak positive correlation between the blood glucose level and the muscular uptake of FDG, while there was no correlation with the tracer uptake of the liver, spleen, lungs, peripheral blood or bone marrow. The patient group with increased blood glucose levels showed a slightly, but significantly, higher muscular FDG uptake compared with the matched subgroup of patients with normal blood glucose levels. When comparing the other assessed tissues/organs, there were no differences between these two patient groups.

Conclusions

The effect of hyperglycaemia at FDG PET on the studied normal tissues is restricted to a slightly increased muscular uptake. The effect of the blood glucose level on the blood activity at the time of examination is negligible.

Dynamic PET/CT measurements of induced positron activity in a prostate cancer patient after 50-MV photon radiation therapy

Background

The purpose of this work was to reveal the research interest value of positron emission tomography (PET) imaging in visualizing the induced tissue activity post high-energy photon radiation treatment. More specifically, the focus was on the possibility of retrieving data such as tissue composition and physical half-lives from dynamic PET acquisitions, as positron-emitting radionuclides such as ¹⁵O, ¹¹C, and ¹³N are produced in vivo during radiation treatment with high-energy photons (>15 MeV). The type, amount, and distribution of induced positron-emitting radionuclides depend on the irradiated tissue cross section, the photon spectrum, and the possible perfusion-driven washout.

Methods

A 62-year-old man diagnosed with prostate cancer was referred for palliative radiation treatment of the pelvis minor. A total dose of 8 Gy was given using high-energy photon beams (50 MV) with a racetrack microtron, and 7 min after the end of irradiation, the patient was positioned in a PET/computed tomography (CT) camera, and a list-mode acquisition was performed for 30 min. Two volumes of interests (VOIs) were positioned on the dynamic PET/CT images, one in the urinary bladder and the other in the subcutaneous fat. Analysis of the measured relative count rate was performed in order to compute the tissue compositions and physical half-lives in the two regions.

Results

Dynamic analysis from the two VOIs showed that the decay constants of activated oxygen and carbon could be deduced. Calculation of tissue composition from analyzing the VOI containing subcutaneous fat only moderately agreed with that of the tabulated International Commission on Radiation Units & Measurements (ICRU) data of the adipose tissue. However, the same analysis for the bladder showed a good agreement with that of the tabulated ICRU data.

Conclusions

PET can be used in visualizing the induced activity post high-energy photon radiation treatment. Despite the very low count rate in this specific application, wherein 7 min after treatment was about 5% of that of a standard ¹⁸F-FDG PET scan, the distribution of activated tissue elements (¹⁵O and ¹¹C) could be calculated from the dynamic PET data. One possible future application of this method could possibly be to measure and determine the tumor tissue composition in order to identify any hypoxic or necrotic region, which is information that can be used in the ongoing therapy planning process.

Trial registration

The official name of the trial committee of this study is ‘Regionala etikprövningsnämnden i Stockholm’ (FE 289, Stockholm, SE-17177, Sweden). The unique identifying number is 2011/1789-31/2.

Epigenetic screen identifies genotype-specific promoter DNA methylation and oncogenic potential of CHRNB4

Genome-wide association studies have highlighted three major lung cancer susceptibility regions at 15q25.1, 5p15.33 and 6p21.33. To gain insight into the possible mechanistic relevance of the genes in these regions, we investigated the regulation of candidate susceptibility gene expression by epigenetic alterations in healthy and lung tumor tissues. For genes up- or downregulated in lung tumors the influence of genetic variants on DNA methylation was investigated and in vitro studies were performed.

We analyzed 394 CpG units within 19 CpG islands in the susceptibility regions in a screening set of 34 patients. Significant findings were validated in an independent patient set (n=50) with available DNA and RNA. The most consistent overall DNA methylation difference between tumor and adjacent normal tissue on 15q25 was tumor hypomethylation in the promoter region of CHRNB4 with a median difference of 8% (p<0.001) which resulted in overexpression of the transcript in tumors (p<0.001). Confirming previous studies we also found hypermethylation in CHRNA3 and TERT with significant expression changes. Decitabine treatment of H1299 cells resulted in reduced methylation levels in gene promoters, elevated transcript levels of CHRNB4 and CHRNA3 and a slight downregulation of TERT demonstrating epigenetic regulation of lung cancer cells. SNPs rs421629 on 5p15.33 and rs1948, rs660652, rs8040868 and rs2036527 on 15q25.1, previously identified as lung cancer risk or nicotine addiction modifiers were associated with tumor DNA methylation levels in the promoters of TERT and CHRNB4 (p<0.001) respectively in two independent sample sets (n=82; n=150). In addition, CHRNB4 knock down in two different cell lines (A549 and H1299) resulted in reduced proliferation (p_A549<0.05;p_H1299L<0.001) and propensity to form colonies in H1299 cells.

These results suggest epigenetic deregulation of nicotinic acetylcholinereceptor subunit (nAChR) genes which in the case of CHRNB4 is strongly associated with genetic lung cancer susceptibility variants and a functional impact on tumorigenic potential.

A revision of the organ radiation doses from 2-fluoro-2-deoxy-D-glucose with reference to tumour presence

Absorbed radiation doses to major human organs after intravenous bolus administration of 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG) were reviewed. Absorbed doses were calculated using the medical internal radiation dose (MIRD) formalism from experimental activity-time curves. Thirty patients (22 with macroscopic lung tumour and 8 without observable disease) were investigated using a state-of-the-art combined positron emission tomography/computer tomography system (Siemens Biograph 64). Each patient underwent a series of 10 consecutive whole-body PET scans during the first 60-min post-FDG administration. Differences were observed between organ radiation doses in this work and those reported in International Commission for Radiation Protection 106 (21 % in effective dose). The presence of tumour did not affect the FDG biodistribution. Large inter-individual variations in organ-absorbed doses were observed. This in combination with the lack of a model for bladder voiding suitable for all patients suggests the need for a more precise estimate of normal-organ radiation doses. This will be beneficial in optimising FDG administration in clinical routine.

Adding 11C-acetate to 18F-FDG at PET Examination Has an Incremental Value in the Diagnosis of Hepatocellular Carcinoma

OBJECTIVE

The sensitivity of FDG at PET examination of Hepatocellular Carcinoma (HCC) is restricted. In a few studies, all done in Oriental patients, PET-examination with (11)C-acetate has shown a higher accuracy than with FDG. In the current study, the uptake of (11)C-acetate has been compared with the uptake of FDG in the primary HCC in a cohort of Occidental patients.

MATERIAL AND METHODS

44 patients underwent PET-examination with both tracers with a mean of 9 days between the examinations. 26 patients had a microscopical diagnosis and 18 were diagnosed with multimodal radiological methods. At least one relevant radiological examination was available for comparison.

RESULTS

At visual evaluation, 13 of the HCC's were positive at PET-examination using FDG and 34 were positive using (11)C-acetate (p<0.001). Median tumor SUVmean of (11)C-acetate was 4.7 and of FDG was 1.9 (p<0.001). There was also a higher uptake of (11)C-acetate by the surrounding liver tissue than of FDG. Median liver SUVmean of [u]11[/u]C-acetate was 3.2 and of FDG it was 1.7 (p<0.001). This corresponded to a median tumour/liver tissue ratio for (11)C-acetate of 1.4 and for FDG of 1.0 (p<0.05). Previous reports of a negative correlation between the uptake of the tracers were weakly supported. In 4 large tumors some portions being hot using one of the tracers were cold using the other tracer and vice versa.

CONCLUSION

Adding registration with (11)C-acetate to registration with FDG at PET-examination has an incremental value in the diagnosis of HCC. A higher tumor uptake of (11)C-acetate cannot be taken full advantage of because of a higher uptake also by the surrounding liver tissue.

CONFLICT OF INTEREST

None declared.

Minimal transmission of HIV despite persistently high transmission of hepatitis C virus in a Swedish needle exchange program

The aim of this study was to examine the prevalence and incidence of HIV and hepatitis B and C (HBV and HCV) among injecting drug users in a Swedish needle exchange programme (NEP) and to identify risk factors for blood-borne transmission. A series of serum samples from NEP participants enrolled from 1997 to 2005 were tested for markers of HIV, HBV and HCV (including retrospective testing for HCV RNA in the last anti-HCV-negative sample from each anti-HCV seroconverter). Prevalence and incidence were correlated with self-reported baseline characteristics. Among 831 participants available for follow-up, one was HIV positive at baseline and two seroconverted to anti-HIV during the follow-up of 2433 HIV-negative person-years [incidence 0.08 per 100 person-years at risk (pyr); compared to 0.0 in a previous assessment of the same NEP covering 1990-1993]. The corresponding values for HBV were 3.4/100 pyr (1990-1993: 11.7) and for HCV 38.3/100 pyr (1990-1993: 27.3). HCV seroconversions occurred mostly during the first year after NEP enrolment. Of the 332 cases testing anti-HCV negative at enrolment, 37 were positive for HCV RNA in the same baseline sample (adjusted HCV incidence 31.5/100 pyr). HCV seroconversion during follow-up was significantly associated with mixed injection use of amphetamine and heroin, and a history of incarceration at baseline. In this NEP setting, HIV prevalence and incidence remained low and HBV incidence declined because of vaccination, but transmission of HCV was persistently high. HCV RNA testing in anti-HCV-negative NEP participants led to more accurate identification of timepoints for transmission.

Self-rating scales assessing subjective well-being and distress correlate with rCBF in PTSD-sensitive regions

BACKGROUND

The aim of this study was to investigate the distribution of the regional cerebral blood flow (rCBF) in occupational-related post-traumatic stress disorder (PTSD) subjects and to seek possible correlations between brain perfusion and self-rating scales (SRS) in order to cross-check their diagnostic value and to look for their neural correlates.

METHOD

A total of 13 traumatized underground and long-distance train drivers developing (S) and 17 not developing (NS) PTSD who had experienced a 'person under train' accident or who had been assaulted at work underwent clinical assessment and 99mTc-HMPAO SPECT imaging during autobiographical trauma scripts. Statistical parametric mapping was applied to analyse rCBF changes in S as compared with NS and to search for correlations between rCBF and the administered SRS scores, modelling age, months to SPECT and the ratio 'grey matter/intra-cranial volume' as nuisance variables.

RESULTS

Significantly higher activity was observed during trauma script in left posterior and anterior insula, posterior cingulate, inferior parietal lobule, precuneus, caudate and putamen in PTSD subjects as compared with the trauma-exposed control group. Impact of Event Scale and World Health Organisation (10) Well-Being Index scores highly correlated with tracer uptake to a great extent in the same regions in which rCBF differences between S and NS were found.

CONCLUSIONS

These findings support the involvement of insular, cingulate and parietal cortices (as well as the basal ganglia) in the pathogenesis of PTSD and in the processing of related subjective well-being and distress.

The initial change in tumor size predicts response and survival in patients with metastatic colorectal cancer treated with combination chemotherapy

BACKGROUND

To determine whether the change in tumor diameters at the first follow-up computed tomography (CT) examination after baseline examination (first change) correlates with outcome in patients with metastatic colorectal cancer (mCRC) treated with combination chemotherapy.

PATIENTS AND METHODS

The first change was analyzed in a multicenter randomized phase III trial (Nordic VI, N = 567) comparing first-line irinotecan with either bolus or infused 5-fluorouracil. Cox proportional hazards multiple regression model and Kaplan-Meier survival analyses after correction for guarantee-time bias were carried out to evaluate correlations between first change, objective response according to RECIST 1.0, progression-free survival (PFS), and overall survival (OS).

RESULTS

The hazard ratios for PFS and OS decreased along with first change. A decrease between 10% and <30%, albeit RECIST does not regard this as a partial response, was a positive prognostic factor for PFS and OS. Patients who had new lesions or unequivocal progression of nonmeasurable lesions had a worse prognosis than those with only an increase in size of >20%.

CONCLUSIONS

The change in tumor size at the first follow-up CT is strongly prognostic for PFS and OS in mCRC.

Impact of acute hypobaric hypoxia on blood flow distribution in brain

AIM

Acute hypobaric hypoxia is well known to alter brain circulation and to cause neuropsychological impairment. However, very few studies have examined the regional changes occurring in the brain during acute exposure to extreme hypoxic conditions.

METHODS

Regional cerebral blood flow (rCBF) response to hypoxia was investigated in six healthy subjects exposed to either normobaric normoxia or hypobaric hypoxia with ambient pressure/inspired oxygen pressure of 101/21 kPa and 50/11 kPa respectively. After 40 min at the desired pressure they were injected (99m)Tc-HMPAO and subsequently underwent single photon emission computed tomography. Regional cerebral blood flow distribution changes in the whole brain were assessed by Statistical Parametric Mapping, a well established voxel-based analysis method.

RESULTS

Hypobaric hypoxia increased rCBF distribution in sensorymotor and prefrontal cortices and in central structures. PCO(2) correlated positively and SatO(2) negatively with rCBF in several temporal, parahippocampal, parietal and central structures.

CONCLUSIONS

These findings underscore the specific sensitivity of the frontal lobe to acute hypobaric hypoxia and of limbic and central structures to blood gas changes emphasizing the involvement of these brain areas in acute hypoxia.

Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion

OBJECTIVE

To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal.

MATERIAL AND METHODS

In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma concentrations of insulin, glucagon and glucose were measured during infusion of saline or the GLP-1 receptor antagonist exendin(9-39)amide (Ex(9-39)) at 300 pmol·kg(-1)·min(-1).

RESULTS

Ex(9-39) infusion had no effect on the total gastric emptying curve, but changed the intra-gastric distribution of the meal. During infusion of Ex(9-39), more content stayed in the upper stomach (79.1 ± 2.5% of total during Ex(9-39) compared to 66.6 ± 5.7% during saline at 5 min). During Ex(9-39) infusion, higher concentrations of plasma glucagon were measured both before (after 40 min of Ex(9-39) infusion the glucagon level was 15.1 ± 0.7 pmol·L(-1) compared to 5.4 ± 1.4 during saline) and after the meal, and postprandial GLP-1 levels increased. Basal insulin and glucose levels were not affected by Ex(9-39), but the postprandial rise of insulin and glucose enhanced during Ex(9-39).

CONCLUSIONS

Endogenous GLP-1 is involved in the regulation of gastric motility in relation to meal intake and also in the regulation of postprandial insulin and glucose levels. Furthermore, endogenous GLP-1 seems to tonically restrain glucagon secretion.