Erik Vegt

Optimisation of Fluorescence Guidance During Robot-assisted Laparoscopic Sentinel Node Biopsy for Prostate Cancer

BACKGROUND The hybrid tracer was introduced to complement intraoperative radiotracing towards the sentinel nodes (SNs) with fluorescence guidance. OBJECTIVE Improve in vivo fluorescence-based SN identification for prostate cancer by optimising hybrid tracer preparation, injection technique, and fluorescence imaging hardware. DESIGN, SETTING, AND PARTICIPANTS Forty patients with a Briganti nomogram-based risk >10% of lymph node (LN) metastases were included. After intraprostatic tracer injection, SN mapping was performed (lymphoscintigraphy and single-photon emission computed tomography with computed tomography (SPECT-CT)). In groups 1 and 2, SNs were pursued intraoperatively using a laparoscopic gamma probe followed by fluorescence imaging (FI). In group 3, SNs were initially located via FI. Compared with group 1, in groups 2 and 3, a new tracer formulation was introduced that had a reduced total injected volume (2.0 ml vs. 3.2 ml) but increased particle concentration. For groups 1 and 2, the Tricam SLII with D-Light C laparoscopic FI (LFI) system was used. In group 3, the LFI system was upgraded to an Image 1 HUB HD with D-Light P system. INTERVENTION Hybrid tracer-based SN biopsy, extended pelvic lymph node dissection, and robot-assisted radical prostatectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Number and location of the preoperatively identified SNs, in vivo fluorescence-based SN identification rate, tumour status of SNs and LNs, postoperative complications, and biochemical recurrence (BCR). RESULTS AND LIMITATIONS Mean fluorescence-based SN identification improved from 63.7% (group 1) to 85.2% and 93.5% for groups 2 and 3, respectively (p=0.012). No differences in postoperative complications were found. BCR occurred in three pN0 patients. CONCLUSIONS Stepwise optimisation of the hybrid tracer formulation and the LFI system led to a significant improvement in fluorescence-assisted SN identification. Preoperative SPECT-CT remained essential for guiding intraoperative SN localisation. PATIENT SUMMARY Intraoperative fluorescence-based SN visualisation can be improved by enhancing the hybrid tracer formulation and laparoscopic fluorescence imaging system.

Impact of 18F‐fluorodeoxyglucose (FDG)‐positron‐emission tomography/computed tomography (PET/CT) on management of patients with carcinoma invading bladder muscle

To evaluate the clinical impact of 18F‐fluorodeoxyglucose (FDG)‐positron‐emission tomography/computed tomography (PET/CT) scanning, compared with conventional staging with contrast‐enhanced CT imaging (CECT).

Multimodal surgical guidance towards the sentinel node in vulvar cancer

INTRODUCTION Conventional sentinel node (SN) mapping is performed by injecting a radiocolloid followed by lymphoscintigraphy (and SPECT/CT imaging). An extra intraoperative injection with blue dye can then allow for optical identification of the SN. In order to improve the current clinical standard, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was introduced, a tracer that is both radioactive and fluorescent. This feasibility study aimed to evaluate the value of a multimodal-based SN biopsy in vulvar cancer. MATERIALS AND METHODS Fifteen patients with vulvar cancer (29 groins) scheduled for SN biopsy were peritumorally injected with ICG-(99m)Tc-nanocolloid followed by lymphoscintigraphy and SPECT/CT imaging to identify the SNs. In thirteen patients, shortly before the start of the operation, blue dye was intradermally injected around the lesion. SNs were harvested using a combination of radiotracing, fluorescence imaging, and optical blue dye detection. A portable gamma camera was used before and after SN excision to confirm excision of the preoperatively defined SNs. RESULTS Preoperative lymphoscintigraphy and SPECT/CT imaging visualized drainage to 39 SNs in 28 groins. During the operation, 98% (ex vivo 100%) of the SNs were radioactive. With fluorescence imaging 96% of the SNs (ex vivo 100%) could be visualized. Only 65% of the SNs had stained blue at the time of excision. CONCLUSION ICG-(99m)Tc-nanocolloid can be used for preoperative SN identification and enables multimodal (radioactive and fluorescent) surgical guidance in patients with vulvar cancer. The addition of fluorescence-based optical guidance offers more effective SN visualization compared to blue dye.

FDG-Positron Emission Tomography/Computerized Tomography for Monitoring the Response of Pelvic Lymph Node Metastasis to Neoadjuvant Chemotherapy for Bladder Cancer

PURPOSE We evaluated FDG-positron emission tomography/computerized tomography for monitoring the response of pelvic lymph node metastasis to neoadjuvant chemotherapy for bladder cancer. We compared this to contrast enhanced computerized tomography. MATERIALS AND METHODS Included in study were 19 consecutive patients with lymph node positive bladder cancer who underwent FDG-positron emission tomography/computerized tomography and contrast enhanced computerized tomography before and after a median of 4 cycles (range 2 to 4) of neoadjuvant chemotherapy between September 2011 and April 2012. Metabolic response was assessed according to EORTC (European Organisation for Research and Treatment of Cancer) recommendations based on the change in FDG uptake on FDG-positron emission tomography/computerized tomography. Radiological response was assessed on contrast enhanced computerized tomography according to RECIST (Response Evaluation Criteria in Solid Tumors) 1.1. All patients underwent pelvic lymph node dissection. Histopathological evaluation served as the gold standard for the nodal response. RESULTS Before neoadjuvant chemotherapy, hypermetabolic FDG uptake was seen in all 19 patients, which matched the lymph node metastasis. Evaluating the nodal response with positron emission tomography/computerized tomography was feasible in all patients. On histopathology 16 patients were responders, including 14 with a complete pathological response of the lymph nodes. Positron emission tomography/computerized tomography and contrast enhanced computerized tomography correctly distinguished responders from nonresponders (18 of 19 patients or 94.7% and 15 of 19 or 78.9%) and complete responders from patients with residual disease (13 of 19 or 68.4% and 12 of 19 or 63.2%, respectively). CONCLUSIONS Although no definitive conclusions can be drawn from these preliminary data, positron emission tomography/computerized tomography appears feasible for evaluating the nodal response to neoadjuvant chemotherapy and distinguishing responders from nonresponders.

18F-fluorodeoxyglucose–Positron Emission Tomography/Computed Tomography Aids Staging and Predicts Mortality in Patients With Muscle-invasive Bladder Cancer

OBJECTIVE To investigate the association between extravesical (18)F-fluorodeoxyglucose (FDG) avid lesions on FDG-positron emission tomography/computed tomography (PET/CT) and mortality in patients with muscle-invasive bladder cancer. METHODS An international, bi-institutional cohort study of 211 patients with muscle-invasive bladder cancer who underwent staging CT and FDG-PET/CT imaging. On the basis of the presence of extravesical FDG-avid lesions suspicious for malignancy on PET/CT images, patients were divided into a PET/CT-positive and PET/CT-negative group. Data on staging and mortality were retrospectively analyzed from prospective databases. Kaplan-Meier analyses were performed to compare overall (OS) and disease-specific survival (DSS) between the groups. Multivariable Cox regression models were used to investigate the association between extravesical PET/CT lesions and mortality. Extravesical lesions suspicious for malignancy on conventional CT were included in the models. RESULTS Of the 211 patients, 98 (46.4%) had 1 or more extravesical lesions on PET/CT, 113 (53.5%) had a negative PET/CT. Conventional CT revealed extravesical lesions in 51 patients (24.4%). Median follow-up was 18 months. Patients with a positive PET/CT had a significantly shorter OS and DSS (median OS: 14 vs 50 months, P = .001; DSS: 16 vs 50 months, P <.001). In multivariable analysis, the presence of extravesical lesions on PET/CT was an independent prognostic indicator of mortality (OS: hazard ratio = 3.0, confidence interval 95% 1.7-5.1). This association was not statistically significant for conventional CT (hazard ratio = 1.6 (95% confidence interval 0.9-2.7). CONCLUSION On the basis of our results, the presence of extravesical FDG-avid lesions on PET/CT might be considered an independent indicator of mortality.

FDG-avid sclerotic bone metastases in breast cancer patients : a PET/CT case series

Distant metastases from breast cancer most frequently occur in the skeleton. Although 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), with or without computed tomography (CT), is superior to bone scintigraphy for the detection of osteolytic bone metastases, it has been reported that sclerotic bone metastases frequently show no or only a low degree of FDG uptake on PET and PET/CT. Since both lytic and sclerotic metastases can occur in breast cancer patients, bone scintigraphy may remain of additional value in these patients. In this case series, we describe four breast cancer patients in whom FDG PET/CT has clearly visualized sclerotic bone metastases because of increased FDG uptake. Not so much the type of metastasis (sclerotic or lytic), but possibly the characteristics of the primary tumor or treatments prior to the FDG PET/CT scan might influence the degree of FDG uptake of bone metastases. The ability to detect sclerotic bone metastases based on increased FDG uptake supports the use of FDG PET/CT as a staging procedure in breast cancer patients, but knowledge of factors determining the visibility of bone metastases with FDG PET/CT is crucial.

Neoadjuvant Taxane-Based Combination Chemotherapy in Patients With Advanced Penile Cancer

INTRODUCTION/BACKGROUND Neoadjuvant taxane-based combination chemotherapy has shown promising results in unresectable squamous cell carcinoma of the head and neck area, and the penis. Our primary aim was to assess the objective response in penile cancer patients neoadjuvantly treated with taxane-based combination chemotherapy. Secondary outcomes were progression-free survival (PFS), disease-specific survival (DSS), and toxicity. PATIENTS AND METHODS Twenty-six patients were treated within the framework of a nonrandomized institutional registration study with 4 courses of TPF (docetaxel, cisplatin, and 5-fluorouracil) for advanced penile cancer between 2008 and 2012. Response was measured using computed tomography (CT) and/or fluorodeoxyglucose positron emission tomography/CT according to Response Evaluation Criteria in Solid Tumours 1.1 criteria and European Organisation for Research and Treatment of Cancer recommendations, respectively. Toxicity, PFS, and DSS were analyzed using either the Common Toxicity Criteria of Adverse Events version 4.0 or the Kaplan-Meier methods. To analyze possible association with survival, univariable and multivariable Cox regression analyses were performed for tumor differentiation, N-category, recurrent disease, tumor margins, and administration of radiotherapy. RESULTS During a median follow-up of 30 months, an imaging-based response was obtained in 60% (95% confidence interval [CI], 39%-79%) (15/25) of patients. However, pathologic complete response was observed in 1 of 25 evaluable patients (4%; 95% CI, 0%-20%). Toxicity was considerable with registered toxicity in every patient. The 2-year PFS and DSS probability were 12% and 28%, respectively. Patients responsive to chemotherapy had significantly better survival than nonresponsive patients. CONCLUSION Despite a fairly good response percentage, TPF chemotherapy was poorly tolerated with disappointing survival rates. Therefore, other treatment options should be considered.

Detecting primary bladder cancer using delayed (18)F-2-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography imaging after forced diuresis.

Objective: The aim of this study was to evaluate the use of delayed pelvic 18F-2-fluoro-2-deoxy-D-glucose-positron emission tomography combined with the computed tomography (FDG-PET/CT) imaging, according to a standardized protocol including, pre-hydration and forced diuresis, for the detection of primary bladder cancer. Materials and Methods: We evaluated 38 consecutive patients with primary cT1-4 bladder cancer. They underwent standard FDG-PET/CT followed by delayed pelvic imaging after administration of 20 mg furosemide intravenously and extra oral water intake of 0.5 L. Two observers, blinded for patient data, scored both image sets for tumor visibility using a 3-point ordinal scale: (1) negative; (2) indeterminate; (3) positive. FDG-PET/CT findings were compared with histopathology and/or follow-up imaging. Results: The procedure was completed successfully in 37/38 patients and the reference standard revealed a bladder tumor in 26/37 patients. Delayed PET/CT images showed reduction of urinary bladder activity to (near) background levels in 17 of 37 cases (45.9%). Standard PET/CT detected hyper-metabolic bladder lesions in 15/37 patients (40.5%) of which 8 were indeterminate. Delayed FDG-PET/CT showed hyper-metabolic bladder lesions in 30/37 (81.1%) patients, of which 5 were indeterminate. When indeterminate lesions were considered positive, the sensitivity of standard and delayed PET/CT was 46% versus 88%, respectively. The specificity was 72% versus 36%. When indeterminate lesions were considered negative, the sensitivity of standard and delayed PET/CT was 23% and 85%. The specificity was 93% versus 73%. Conclusions: Our data suggest that delayed pelvic FDG-PET/CT imaging after forced detects more primary bladder tumors than standard FDG-PET/CT protocols. However, indeterminate bladder lesions on delayed PET/CT remain a problem and should be interpreted cautiously in order to avoid false positive results.

Dynamic Sentinel Node Biopsy and FDG-PET/CT for Lymph Node Staging in Penile Cancer

Staging of inguinal nodes is pivotal for prognostication and determination of the optimal treatment in penile cancer. Current noninvasive staging tools (such as palpation, ultrasound, CT, and MRI) are not sensitive enough to detect small occult lymph node metastases in intermediate to high-risk patients, who have a chance of approximately 20 % of harboring inguinal nodal metastases. Dynamic lymphoscintigraphy with sentinel node biopsy can detect microscopic metastases, while avoiding the morbidity associated with an inguinal lymphadenectomy. If dynamic sentinel node biopsy is preceded by ultrasound with fine needle aspiration cytology for the identification of macroscopic metastases, the overall sensitivity for inguinal nodes is >90 %. If metastases are found, an inguinal lymphadenectomy should be performed. The risks of false negative results and their implications on prognosis should be discussed with the patient before deciding on which method to use (i.e., dynamic sentinel node biopsy or direct inguinal lymphadenectomy). Newer imaging modalities, such as FDG-PET/CT, are of limited use for inguinal staging but are promising for pelvic and distant staging.

The role of PET/CT imaging in penile cancer

Positron emission tomography (PET) imaging with 18F-fluorodeoxyglucose (FDG) combined with computed tomography (CT) provides functional imaging combined with anatomic information, improving diagnostic accuracy and confidence. Although virtually all primary penile tumors are FDG-avid, PET/CT is not recommended for primary tumor staging as it has limited spatial resolution and is hampered by urinary FDG excretion. The accuracy of PET/CT for lymph node staging seems to improve with the pretest likelihood of metastatic nodes. In groins with normal physical examination, sensitivity is only 57%. In groins with palpably enlarged lymph nodes, sensitivity of PET/CT reaches 96%. For pelvic lymph nodes and distant metastases, PET/CT is more accurate if inguinal metastases are present. However, these results are based on a very limited number of studies. Overall, the role of PET/CT imaging in penile cancer remains ambiguous, especially in inguinal lymph nodes. During staging and follow-up, it may be particularly useful in detecting pelvic lymph node metastases and occult distant metastases prior to systemic chemotherapy and/or extensive surgery, improving selection of patients that are most likely to benefit from such therapies.