Non-invasive measurement of hemodynamic response to postural stress using inert gas rebreathing.

In postural stress, an increased preload volume leads to higher stroke volume (SV) according to the Frank-Starling law of the heart. The present study aimed to evaluate the hemodynamic response to postural stress using non-invasive inert gas rebreathing (IGR) in patients with normal as well as impaired left ventricular function. Hemodynamic measurements were performed in 91 patients undergoing cardiac magnetic resonance imaging (CMR). Mean cardiac output and SV determined by IGR were 4.4±1.3 l/min and 60±19 ml in the upright position, which increased significantly to 5.0±1.2 l/min and 75±23 ml in the supine position (P<0.01). Left ventricular systolic function was normal [ejection fraction (EF) ≥55%] in 42 patients as determined by CMR. In 21 patients, EF was mildly abnormal (45-54%), in 16 patients moderately abnormal (30-44%) and in 12 patients severely abnormal (<30%). An overall trend for a lower percentage change in SV (%ΔSV) was indicated with increasing impairment of ejection fraction. In patients with abnormal EF in comparison to those with normal EF, the %ΔSV was significantly lower (13% vs. 22%; P=0.03). Non-invasive measurement of cardiac function using IGR during postural changes may be feasible and detected significant difference in %ΔSV in patients with normal and impaired EF according to the Frank-Starling law of the heart. Several clinical scenarios including cases of heart rhythm disturbances or pulmonary or congenital heart disease are worthy of further investigation.

Value of Additional Digital Breast Tomosynthesis for Preoperative Staging of Breast Cancer in Dense Breasts.

AIM: This retrospective study was initiated to determine the diagnostic value of additional preoperative breast tomosynthesis (DBT) for breast cancer staging in dense breasts. PATIENTS AND METHODS: Sixty-six patients (69 breasts) with findings of American College of Radiology category 3 or 4 with Breast Imaging Reporting and Data System 5, 6 or 0 were included. All patients underwent digital mammography and additional DBT. RESULTS: A total of 40/69 (58%) cancers were detected on both mammography and DBT, 23 (33.3%) were only seen on DBT (p=0.0001); 6/69 (8.7%) carcinomas were not detected by either method, of which three were invasive lobular carcinomas. Sensitivity for multifocal/multicentric disease was significantly higher on DBT (12/19, 63.2%) compared to mammography (4/19, 21.1%) (p=0.02), specificity was comparable (96.0% vs. 90.0%). Multifocal/multicentric disease was not detected on mammography nor DBT in 7/19 (36.8%) patients, including three invasive lobular carcinomas. CONCLUSION: DBT may significantly improve preoperative breast cancer staging in patients with dense breasts compared to conventional mammography alone. Nevertheless, limitations have to be expected in the case of invasive lobular carcinoma.

Impact of Tumor Localization and Method of Preoperative Biopsy on Sentinel Lymph Node Mapping After Periareolar Nuclide Injection.

BACKGROUND: To evaluate whether tumor localization and method of preoperative biopsy affect sentinel lymph node (SLN) detection after periareolar nuclide injection in breast cancer patients. METHODS AND FINDINGS: 767 breast cancer patients were retrospectively included. For lymphscintigraphy periareolar nuclide injection was performed and the SLN was located by gamma camera. Patient and tumor characteristics were correlated to the success rate of SLN mapping. SLN marking failed in 9/61 (14.7%) patients with prior vacuum-assisted biopsy and 80/706 (11.3%) patients with prior core needle biopsy. Individually evaluated, biopsy method (p = 0.4) and tumor localization (p = 0.9) did not significantly affect the SLN detection rate. Patients with a vacuum-assisted biopsy of a tumor in the upper outer quadrant had a higher odds ratio of failing in SLN mapping (OR 3.8, p = 0.09) compared to core needle biopsy in the same localization (OR 0.9, p = 0.5). CONCLUSIONS: Tumor localization and preoperative biopsy method do not significantly impact SLN mapping with periareolar nuclide injection. However, the failure risk tends to rise if vacuum-assisted biopsy of a tumor in the upper outer quadrant is performed.

Analysis of Gene Expression and Ultrastructure of Stifle Menisci from Juvenile and Adult Pigs.

The origin of the age-associated degenerative processes in meniscal tissue is poorly understood and may be related to an imbalance of anabolic and catabolic metabolism. The aim of the current study was to compare medial menisci isolated from juvenile pigs and degenerated medial menisci from adult pigs in terms of gene expression profile and ultrastructure. Medial menisci were isolated from the knee joints of juvenile and adult pigs (n = 8 for each group). Degeneration was determined histologically according to a scoring system. In addition, the gene expression profiles of 14 genes encoding extracellular matrix proteins, catabolic matrix metalloproteinases and mediators of inflammation were analyzed. Changes in the ultrastructure of the collagen network of the meniscal tissue were analyzed by using transmission electron microscopy. The histologic analysis of menisci showed significantly higher grade of degeneration in tissue isolated from adult porcine knee joints compared with menisci isolated from juvenile knee joints. In particular, destruction of the collagen network was greater in adult menisci than in juvenile menisci. Degenerated menisci showed significantly decreased gene expression of COL1A1 and increased expression of MMP2, MMP13, and IL8. The menisci from adult porcine knee joints can serve as a model for meniscal degeneration. Degenerative changes were manifested as differences in histopathology, gene expression and ultrastructure of collagen network.

Instruments for reproducible setting of defects in cartilage and harvesting of osteochondral plugs for standardisation of preclinical tests for articular cartilage regeneration.

BACKGROUND: Standardisation is required in research, so are approval procedures for advanced therapy medical products and other procedures for articular cartilage therapies. The process of creating samples needs to be reproducible. The aim of this study was to design, create and validate instruments (1) to create reproducible and accurate defects and (2) to isolate samples in the shape of osteochondral cylinders in a quick, reliable and sterile manner. METHODS: Adjustable instruments were created: a crown mill with a resolution of 0.05 mm and a front mill to create defects in articular cartilage and subchondral bone. The instruments were tested on knee joints of pigs from the slaughterhouse; 48 defects were created and evaluated. A punching machine was designed to harvest osteochondral plugs. These were validated in an in vivo animal study. RESULTS: The instruments respect the desired depth of 0.5 and 1.5 mm when creating the defects, depending on whether the person using the instrument is highly experienced (0.451 mm; confidence interval (CI): 0.390 mm; 0.512 mm and 1.403 mm; CI: 1.305 mm; 1.502 mm) or less so (0.369 mm; CI: 0.297 mm; 0.440 mm and 1.241 mm; CI: 1.141 mm; 1.341 mm). Eighty samples were taken from knee joints of Göttingen Minipigs with this punching technique. The time needed for the harvesting of the samples was 7.52 min (±2.18 min), the parallelism of the sides of the cylinders deviated by -0.63° (CI: -1.33°; 0.08°) and the surface of the cartilage deviated from the perpendicularity by 4.86° (CI: 4.154°; 5.573°). In all assessed cases, a sterile procedure was observed. CONCLUSIONS: Instruments and procedures for standardised creation and validation of defects in articular cartilage and subchondral bone were designed. Harvesting of samples in the shape of osteochondral cylinders can now be performed in a quick, reliable and sterile manner. The presented instruments and procedures can serve as helpful steps towards standardised operating procedures in the field of regenerative therapies of articular cartilage in research and for regulatory requirements.

Topical anaesthetic patches for postoperative wound pain in laparoscopic gynaecological surgery: a prospective, blinded and randomised trial.

PURPOSE: Aim of this prospective study was to investigate the effectiveness of eutectic mixture of local anaesthetic (EMLA) patches on every abdominal incision for pain relief after gynaecologic laparoscopic surgery. METHODS: A total of 121 women were prospectively randomised to receive either placebo (control group) or EMLA (study group) patches on all abdominal incisions. Postoperative pain was assessed 24 and 48 h after surgery using the short form of the McGill Pain Questionnaire (SF-MPQ). The amount of analgesic pain medication on demand was assessed in both groups. RESULTS: Sixty women were allocated to the study group and 61 patients to the control group before laparoscopic surgery. There were no statistically significant differences regarding age, body mass index (BMI), duration of surgery and blood loss comparing both groups. There were no statistically significant differences between both groups with regard to postoperative total pain scores 24 h (McGill total score: 31.77 ± 27.95 vs. 36.80 ± 31.39, p = 0.3535) and 48 h (McGill total score: 19.18 ± 20.09 vs. 26.61 ± 27.70, p = 0.0942) after surgery. Time to mobilisation after surgery (hours) was significantly shorter in the study group (5.01 ± 3.72 vs. 5.78 ± 3.04, p = 0.0423). CONCLUSION: Despite of a significant reduction of time for mobilisation transdermal anaesthetic patches after gynaecologic laparoscopic surgery did not lead to decreased postoperative pain scores.

Right ventricular function quantification in Takotsubo cardiomyopathy using two-dimensional strain echocardiography.

AIMS: This study sought to characterize global and regional right ventricular (RV) myocardial function in patients with Takotsubo cardiomyopathy (TC) using 2D strain imaging. METHODS: We compared various parameters of RV and left ventricular (LV) systolic function between 2 groups of consecutive patients with TC at initial presentation and upon follow-up. Group 1 had RV involvement and group 2 did not have RV involvement. RESULTS: At initial presentation, RV peak systolic longitudinal strain (RVPSS) and RV fractional area change (RVFAC) were significantly lower in group 1 (-13.2±8.6% vs. -21.8±5.4%, p = 0.001; 30.7±9.3% vs. 43.5±6.3%, p = 0.001) and improved significantly upon follow-up. Tricuspid annular plane systolic excursion (TAPSE) did not differ significantly at initial presentation between both groups (14.8±4.1 mm vs. 17.9±3.5 mm, p = 0.050). Differences in regional systolic RV strain were only observed in the mid and apical segments. LV ejection fraction (LVEF) and LV global strain were significantly lower in group 1 (36±8% vs. 46±10%, p = 0.006 and -5.5±4.8% vs. -10.2±6.2%, p = 0.040) at initial presentation. None of the parameters were significantly different between the 2 groups upon follow-up. A RVPSS cut-off value of >-19.1% had a sensitivity of 85% and a specificity of 71% to discriminate between the 2 groups. CONCLUSION: In TC, RVFAC, RVPSS, LVEF and LV global strain differed significantly between patients with and without RV dysfunction, whereas TAPSE did not. 2 D strain imaging was feasible for the assessment of RV dysfunction in TC and could discriminate between patients with and without RV involvement in a clinically meaningful way.

The risk of infections in hematologic patients treated with rituximab is not influenced by cumulative rituximab dosage - a single center experience.

BACKGROUND: Rituximab, a monoclonal antibody directed against CD20, is approved for the treatment of CD20-positive B-cell Non-Hodgkin's lymphoma and rheumatologic disorders. Due to its potent activity in depleting CD20-positive lymphocytes, the influence on opportunistic infections is still under discussion. Thus, we analyzed the impact of rituximab either as monotherapy or in combination with other chemotherapeutic regimens to elucidate its role in contributing to infectious complications. METHODS: The records of consecutive patients (n = 125, 141 treatment episodes) treated with rituximab alone or in combination with chemotherapy and corticosteroids were analyzed retrospectively for the incidence, spectrum and outcome of infections during treatment and 6 months after the last course of rituximab. Univariate analysis of cofactors such as steroid medication, antiinfective prophylaxis, underlying disease and remission status were performed. RESULTS: Altogether 80 therapy episodes were associated with infections, the median number of infections per patient being 1 (range 1-7). The number of infectious complications was significantly higher in patients receiving a combination of rituximab and chemotherapy compared to rituximab monotherapy (p < 0.001). There was no statistically significant difference regarding number of rituximab courses or cumulative rituximab dosage between episodes with and without infections, respectively.Mean cumulative prednisone dosage between the cohort with infections and the one without infections showed a trend towards higher dosage of prednisone in the patients with infections (mean difference 441 mg, p > 0.14). CONCLUSIONS: Rituximab in induction treatment, either as monotherapy or combined with chemotherapy by itself does not increase the incidence or change the spectrum of infections in hematologic patients. However the possible influence of higher dosages of concomitant steroid medication on frequency of infections suggests that a heightened awareness of the potential for infectious complications should be applied to patients receiving higher doses of glucocorticoids in combination with other therapeutic regimens.

Feasibility and perioperative morbidity of minilaparoscopic hysterectomy.

AIM: To analyze the feasibility and perioperative morbidity of minilaparoscopy compared to conventional laparoscopy (CL) in patients undergoing laparoscopic hysterectomy. PATIENTS AND METHODS: Between 04/2012 and 04/2013, 31 patients were prospectively enrolled to undergo hysterectomy via minilaparoscopy with 3.5-mm instruments. A cohort of 108 matched patients who underwent hysterectomy via CL performed by the same surgeon between 08/2011 and 12/2012 served as the control group. RESULTS: There were no statistically significant differences concerning duration of surgery, overall hospital stay and perioperative haemoglobin drop between groups. However, in the study group, the registered blood loss via suction tube was higher (p-value=0.0216) and in two women, intraoperative complications occurred in the form of thermal damage of the ureter via bipolar coagulation. CONCLUSION: Hysterectomy via minilaparoscopy is a feasible laparoscopic approach. Nevertheless, the use of minilaparoscopy should be considered carefully as the reduced diameter of the instruments might impede certain surgical procedures, such as vessel sealing.

Solo surgery--early results of robot-assisted three-dimensional laparoscopic hysterectomy.

OBJECTIVE: Report of our initial experience in laparoscopic hysterectomy by a solo surgeon using a robotic camera system with three-dimensional visualisation. MATERIAL AND METHODS: This novel device (Einstein Vision®, B. Braun, Aesculap AG, Tuttlingen, Germany) (EV) was used for laparoscopic supracervical hysterectomy (LASH) performed by one surgeon. Demographic data, clinical and surgical parameters were evaluated. Our first 22 cases, performed between June and November 2012, were compared with a cohort of 22 age-matched controls who underwent two-dimensional LASH performed by the same surgeon with a second surgeon assisting. RESULTS: Compared to standard two-dimensional laparoscopic hysterectomy, there were no significant differences regarding duration of surgery, hospital stay, blood loss or incidence of complications. The number of trocars used was significantly higher in the control group (p <.0001). All hysterectomies in the treatment group were performed without assistance of a second physician. CONCLUSION: Robot-assisted solo surgery laparoscopic hysterectomy is a feasible and safe procedure. Duration of surgery, hospital stay, blood loss, and complication rates are comparable to a conventional laparoscopic hysterectomy.

Full High-definition three-dimensional gynaecological laparoscopy--clinical assessment of a new robot-assisted device.

AIM: To investigate the clinical assessment of a full high-definition (HD) three-dimensional robot-assisted laparoscopic device in gynaecological surgery. PATIENTS AND METHODS: This study included 70 women who underwent gynaecological laparoscopic procedures. Demographic parameters, type and duration of surgery and perioperative complications were analyzed. Fifteen surgeons were postoperatively interviewed regarding their assessment of this new system with a standardized questionnaire. RESULTS: The clinical assessment revealed that three-dimensional full-HD visualisation is comfortable and improves spatial orientation and hand-to-eye coordination. The majority of the surgeons stated they would prefer a three-dimensional system to a conventional two-dimensional device and stated that the robotic camera arm led to more relaxed working conditions. CONCLUSION: Three-dimensional laparoscopy is feasible, comfortable and well-accepted in daily routine. The three-dimensional visualisation improves surgeons' hand-to-eye coordination, intracorporeal suturing and fine dissection. The combination of full-HD three-dimensional visualisation with the robotic camera arm results in very high image quality and stability.

Diagnostic accuracy of 18F choline PET/CT using time-of-flight reconstruction algorithm in prostate cancer patients with biochemical recurrence.

PURPOSE: Image quality (IQ) of PET in voluminous body regions can be limited, which impairs the assessment of small metastatic lesions. Time-of-flight (TOF) reconstruction algorithm may deliver an increase of spatial resolution. The purpose of this study was to evaluate the impact of TOF on IQ, lesion detection rate, lesion volume (V) and SUVmax in F choline PET/CT of prostate cancer patients with biochemical recurrence compared to standard PET/CT reconstruction (standard). PATIENTS AND MATERIALS: During a period of 9 months, 32 patients with prostate cancer (mean [SD] age, 71 [7.8] years) and biochemical recurrence were included in this prospective institutional review board-approved study. Each patient underwent a state-of-the-art 3-dimensional F choline PET/CT. A total of 76 lesions were assessed by 2 board-certified nuclear medicine physicians and a third-year resident. Lesion volume and SUVmax of local recurrence, lymph nodes, and organ metastases were compared between TOF and standard. Image quality and lesion demarcation were rated according to a 5-point Likert-type scale. Interobserver agreement was assessed. RESULTS: Eight additional lesions were detected using TOF (SUVmax, 3.64 [0.95]; V, 0.58 cm [0.50]). Image quality was reduced (IQ standard, 1.28; TOF, 1.77; P < 0.01) in calculated TOF images, although quality of lesion demarcation was improved (lesion demarcation: standard, 1.66; TOF, 1.26; P < 0.01). SUVmax was significantly increased in TOF images (SUVmax standard, 6.9 [4.1]; TOF, 8.1 [4.1]; P < 0.01), whereas V did not show significant differences (V standard, 5.3 [10.4] cm; TOF, 5.4 [10.3] cm; P = 0.41). Interobserver agreement was good for combined ratings (1 + 2 and 3 + 4). CONCLUSIONS: Application of TOF seems to be of additional value to detect small metastatic lesions in patients with prostate cancer and biochemical recurrence, which may have further clinical implications for secondary treatment.

Whole-body bioelectrical impedance analysis in assessing upper-limb lymphedema after breast cancer therapy.

AIM: The purpose of this prospective study was to evaluate single-frequency whole-body bioelectrical impedance analysis (BIA) as a predictor for the onset of edema of the upper limb in patients undergoing treatment for breast cancer. MATERIALS AND METHODS: Whole-body BIA was performed before surgery, as well as at two days, and one, three, six and twelve months after surgery. RESULTS: Sixty women undergoing breast cancer surgery were examined, with loss of follow-up of 18 patients. Seven patients (14.3%) developed an edema of the upper limb within the first 12 months after surgery. Resistance (R) using whole-body BIA showed a fairly good performance in terms of sensitivity (85.71%) and specificity (97.4%) at predicting edema. The positive predictive value of 54.6% was unsatisfactory, whereas the negative predictive value was 97.4%. CONCLUSION: Resistance in whole-body BIA can be used to rule-out a developing edema of the upper limb.

Effectiveness of nitrous oxide for postpartum perineal repair: a randomised controlled trial.

OBJECTIVE: To compare the effectiveness of self-administered 50% nitrous oxide and conventional infiltrative anaesthesia with 1% prilocaine hydrochloride in postpartum perineal repair. STUDY DESIGN: A total of 100 women were prospectively enrolled and randomised to receive either infiltrative anaesthesia or a self-administered nitrous oxide mixture (Livopan(©)) for pain relief during postpartum perineal suturing. Besides data concerning anaesthesia, characteristics of patients and labour were documented for statistical analysis. Pain experienced during perineal repair was assessed using the short form of the McGill Pain Questionnaire (SF-MPQ). RESULTS: Forty-eight women received nitrous oxide and 52 underwent perineal suturing after infiltrative anaesthesia. There were no statistically significant differences regarding maternal age, body mass index (BMI), duration of pregnancy and suturing time between the groups. The most frequent birth injury was second-degree perineal laceration in the study group [22/48; 46%] and episiotomy in the control group [18/52; 35%]. Pain experienced during genital tract suturing and patients' satisfaction showed no statistically significant differences between the groups. Thirty-seven women in the study group and 47 in the control group were satisfied with the anaesthesia during perineal repair and would recommend it to other parturients [37/48, 77% vs. 47/52, 90%; p=0.0699). CONCLUSION: Nitrous oxide self-administration during genital tract suturing after vaginal childbirth is a satisfactory and effective alternative to infiltrative anaesthesia.

Whole-body versus segmental bioelectrical impedance analysis in patients with edema of the upper limb after breast cancer treatment.

AIM: The purpose of this study was to compare whole-body (50 kHz alternating current) and segmental (5 kHz alternating current) bioelectrical impedance analysis (BIA) in the assessment of manifested edema of the upper limbs. PATIENTS AND METHODS: Whole-body and segmental BIA were performed in 30 patients with edema of the upper limb following breast cancer treatment. RESULTS: Pearson correlation coefficient comparing both measurements was 0.8891 (p-value <0.0001) with corresponding least squares (r(2)) of 0.7904. CONCLUSION: Whole-body BIA seems to be a suitable method in the assessment of manifested edema of the upper limbs.

Influence of bag volume on reproducibility of inert gas rebreathing pulmonary blood flow measurements in patients with pulmonary diseases.

PURPOSE: Non-invasive inert gas rebreathing (IGR) has shown promising results in the determination of pulmonary blood flow. The volume of the rebreathing bag (V bag) is proposed by the system. However, elderly patients or those with severe pulmonary disease may be unable to rebreathe this volume entirely. We evaluated the effect of adapting V bag on the reproducibility of IGR. METHODS: A total of 270 valid measurements were obtained from 45 patients with obstruction (group A), restriction (group B), and in healthy controls (group C). Two measurements for each of three different V bag of 1,200, 1,700, and 2,200 ml were conducted in the supine position. RESULTS: We found no statistically significant difference of the repeated measurements neither between the different V bag in groups A to C nor between the three groups for identical V bag. There was a weak yet significantly worse coefficient of variation between a V bag of 2,200 ml in group A compared with group C with 2,200 and 1,200 ml, respectively. Intraclass correlation coefficient and repeatability coefficient yielded significantly worse values in group A for a V bag of 2,200 ml compared with healthy controls and lower bag volumes. No difference could be found intraclass nor interclass in groups B and C. CONCLUSIONS: V bag can be altered between 1,200 and 2,200 ml in most situations without affecting the reproducibility. Attention has to be paid to extreme volumes in obstructive patients. Nevertheless, V bag should be chosen as large as possible and therefore has to be carefully adapted, particularly in patients with obstruction or restriction.

Laparoscopic supracervical hysterectomy with concomitant bilateral salpingectomy--why not?

AIM: The aim of this investigation was to analyze the feasibility and postoperative outcome of laparoscopic supracervical hysterectomy (LASH) with and without bilateral salpingectomy. PATIENTS AND METHODS: Between February and October 2012, a total of 25 patients were prospectively enrolled to undergo LASH with bilateral salpingectomy. A retrospective cohort of 25 matched patients who underwent LASH without bilateral salpingectomy at our Institution, performed by the same surgeon, served as the control collective. RESULTS: Comparing both collectives, there were no statistically significant differences concerning overall hospital stay, duration of surgery and blood loss. CONCLUSION: LASH with bilateral salpingectomy is a fast and safe procedure.

Influence of acetic acid on a pap smear of dysplastic lesion.

BACKGROUND: Cervical cancer prevention is performed by taking Pap smears. The correct execution of the smear is crucial as an inadequate smear might result in underdiagnosis. The second means of cervical cancer prevention is visual inspection of the cervix uteri with acetic acid, while often both methods are combined. We investigated whether the application of acetic acid compromises the Pap smear. PATIENTS AND METHODS: A total of 100 patients with dysplasia were prospectively included; Pap smears were obtained before and after the application of acetic acid. RESULTS: We observed an alteration of the result of the Pap smear after acetic acid application in 41%. However, these alterations did not result in a dysplastic case being classed as a normal smear or vice versa. CONCLUSION: The application of acetic acid to the transformation zone of the cervix uteri may enhance changes of the Pap smear in dysplasia, however, the changes affect subgroups of dysplasia and thus do not change therapeutic management.

Effect of reconstruction parameters in high-definition PET/CT on assessment of lymph node metastases in head and neck squamous cell carcinoma.

UNLABELLED: Therapy outcome and overall survival in patients with head and neck squamous cell carcinoma (HNSCC) is influenced by precise localization of the primary tumor and detection of lymph node metastasis involvement at the time of initial diagnosis. Only accurate preoperative staging can improve primary tumor response and avoid early locoregional recurrence with lymph node metastases. The purpose of this study was the optimization of reconstruction parameters in high-definition PET/CT for the improved diagnostic assessment of lymph node metastases. METHODS: In the experimental study, image contrast and signal-to-noise ratio were evaluated using a Jaszczak phantom. In the clinical study, 54 patients underwent head and neck imaging on a PET/CT scanner. Diagnostic findings were correlated with postoperative histopathology. For the 54 patients, 123 lymph nodes were evaluated on PET and histologically correlated with the neck dissection specimen. Forty-one lymph nodes were benign, and 82 findings were confirmed as being malignant. Both experimental and clinical studies were reconstructed into a 200 × 200 matrix using a 3-dimensional iterative reconstruction algorithm (ordered-subset expectation maximization [OSEM], 3 iterative steps, 24 subsets). Postfiltering with a 3-dimensional gaussian filter was applied. To study the effect of smoothing filter strength on the diagnostic accuracy of lymph node metastasis detection, 3 different cutoffs-1, 3, and 6 mm in full width at half maximum-were used to perform reconstructions. RESULTS: Phantom studies showed that images reconstructed with 3-mm gaussian postfiltering gained a higher image quality and signal-to-noise ratio. Overall sensitivities for correctly diagnosed lymph nodes were best in 3-mm postfiltered images. Best results for true-positive lymph node findings were achieved with 3-mm postfiltering. With 1-mm postfiltering, accurate lesion detection was not improved, because increasing sensitivity (95% true-positive) correlated with decreasing specificity (12% false-positive). CONCLUSION: For lymph node assessment on a high-resolution PET/CT scanner, we consider the OSEM algorithm with 3 iterations and 24 subsets, combined with 3-dimensional 3-mm gaussian postfiltering, to be optimal. The continuous application of presently established PET protocols in patients with HNSCC will prove whether current acquisition and reconstruction methods are valuable and should be maintained.

Is the assessment of the central skeleton sufficient for osseous staging in breast cancer patients? A retrospective approach using bone scans.

OBJECTIVE: By analyzing bone scans we aimed to determine whether the assessment of the central skeleton is sufficient for osseous staging in breast cancer patients. This might be of interest for future staging modalities, especially positron emission tomography/computed tomography, usually sparing the peripheral extremities, as well as the skull. MATERIALS AND METHODS: In this retrospective study, a total of 837 bone scans for initial staging or restaging of breast cancer were included. A total of 291 bone scans in 172 patients were positive for bone metastases. The localization and distribution of the metastases were re-evaluated by two readers in consensus. The extent of the central skeleton involvement was correlated to the incidence of peripheral metastases. RESULTS: In all 172 patients bone metastases were seen in the central skeleton (including the proximal third of humerus and femur). In 34 patients (19.8 %) peripheral metastases of the extremities (distally of the proximal third of humerus and femur) could be detected. Sixty-four patients (37.2 %) showed metastases of the skull. Summarizing the metastases of the distal extremities and skull, 79 patients (45.9 %) had peripheral metastases. None of the patients showed peripheral metastases without any affliction of the central skeleton. The incidence of peripheral metastases significantly correlated with the extent of central skeleton involvement (p<0.001). CONCLUSIONS: Regarding bone scans, an isolated metastatic spread to the peripheral skeleton without any manifestation in the central skeleton seems to be the exception. Thus, the assessment of the central skeleton should be sufficient in osseous breast cancer staging and restaging. However, in case of central metastases, additional imaging of the periphery should be considered for staging and restaging.