Molecular image-guided surgery in gynaecological cancer: where do we stand?

PURPOSE: The aim of this review is to give an overview of the current status of molecular image-guided surgery in gynaecological malignancies, from both clinical and technological points of view. METHODS: A narrative approach was taken to describe the relevant literature, focusing on clinical applications of molecular image-guided surgery in gynaecology, preoperative imaging as surgical roadmap, and intraoperative devices. RESULTS: The most common clinical application in gynaecology is sentinel node biopsy (SNB). Other promising approaches are receptor-target modalities and occult lesion localisation. Preoperative SPECT/CT and PET/CT permit a roadmap for adequate surgical planning. Intraoperative detection modalities span from 1D probes to 2D portable cameras and 3D freehand imaging. CONCLUSION: After successful application of radio-guided SNB and SPECT, innovation is leaning towards hybrid modalities, such as hybrid tracer and fusion of imaging approaches including SPECT/CT and PET/CT. Robotic surgery, as well as augmented reality and virtual reality techniques, is leading to application of these innovative technologies to the clinical setting, guiding surgeons towards a precise, personalised, and minimally invasive approach.

Setting-up a training programme for intraoperative molecular imaging and sentinel node mapping: how to teach? How to learn?

BACKGROUND: The current expansion of image-guided surgery is closely related to the role played by radio-guided surgery in supporting the sentinel node (SN) procedure during more than three decades. The so-called triple approach (lymphoscintigraphy, gamma probe detection and blue dye) was not only essential in the seminal validation of the SN procedure but also a first collective learning effort based on skill transfer and outcome-related evaluation which laid the fundaments to delineate the field of intraoperative molecular imaging (IMI) based on a similar multimodality approach and multidisciplinary practice. METHODS: These elements are also becoming valid in the current incorporation of SPECT/CT and PET/CT to existing and new protocols of IMI procedures and SN mapping concerning other clinical applications. On the other hand, there is a growing tendency to combine novel modern technologies in an allied role with gamma guidance in the operating room following the development of hybrid tracers and multimodal detection approaches. Against this background, learning initiatives are required for professionals working in this area. RESULTS: This objective has led to a group of European practitioners with large experience in SN mapping and IMI applications to give shape to a programme made up out of specific learning modules aimed to be used as a conductive thread in peripherical or centralised training instances concerning the topic. CONCLUSION: The presented work, written as a tutorial review, is placed in an available prior-art context and is primarily aimed at medical and paramedical practitioners as well as at hardware and software developers.

Delphi consensus project on prostate-specific membrane antigen (PSMA)-targeted surgery-outcomes from an international multidisciplinary panel.

PURPOSE: Prostate-specific membrane antigen (PSMA) is increasingly considered as a molecular target to achieve precision surgery for prostate cancer. A Delphi consensus was conducted to explore expert views in this emerging field and to identify knowledge and evidence gaps as well as unmet research needs that may help change practice and improve oncological outcomes for patients. METHODS: One hundred and five statements (scored by a 9-point Likert scale) were distributed through SurveyMonkey®. Following evaluation, a consecutive second round was performed to evaluate consensus (16 statements; 89% response rate). Consensus was defined using the disagreement index, assessed by the research and development project/University of California, Los Angeles appropriateness method. RESULTS: Eighty-six panel participants (72.1% clinician, 8.1% industry, 15.1% scientists, and 4.7% other) participated, most with a urological background (57.0%), followed by nuclear medicine (22.1%). Consensus was obtained on the following: (1) The diagnostic PSMA-ligand PET/CT should ideally be taken < 1 month before surgery, 1-3 months is acceptable; (2) a 16-20-h interval between injection of the tracer and surgery seems to be preferred; (3) PSMA targeting is most valuable for identification of nodal metastases; (4) gamma, fluorescence, and hybrid imaging are the preferred guidance technologies; and (5) randomized controlled clinical trials are required to define oncological value. Regarding surgical margin assessment, the view on the value of PSMA-targeted surgery was neutral or inconclusive. A high rate of "cannot answer" responses indicates further study is necessary to address knowledge gaps (e.g., Cerenkov or beta-emissions). CONCLUSIONS: This Delphi consensus provides guidance for clinicians and researchers that implement or develop PSMA-targeted surgery technologies. Ultimately, however, the consensus should be backed by randomized clinical trial data before it may be implemented within the guidelines.

Contemporary update of SPECT tracers and novelties in radioguided surgery: a perspective based on urology.

Recent technical advances and implementation of novel radiotracers have further increased the potential of radioguided surgery for a broad variety of malignancies. Indeed, the possibilities for future applications of novel radiotracers in diverse oncological strategies has become more promising than ever. This literature review aims to provide a contemporary update on a selected group of radiotracers and evaluates the usability of radioguided surgery and sentinel node procedures, focusing on most promising advances. For example, the impact of targeted radiotracers on prostate specific membrane antigen (PSMA), CD206 receptor-targeted agents (99mTc-tilmanocept), and hybrid tracers adding fluorescence to radioguidance (ICG-99mTc-nanocolloid) as well as targeting hypoxia-induced carbonic anhydrase IX (CAIX) will be covered. Furthermore, future outlooks on the implementation of gold nanoparticles (AuNP's), but also technical advances in improved radiotracer detection by hybrid gamma devices will be discussed.

Interventional nuclear medicine: a focus on radioguided intervention and surgery.

Within interventional nuclear medicine (iNM) a prominent role is allocated for the sub-discipline of radioguided surgery. Unique for this discipline is the fact that an increasing number of clinical indications (e.g. lymphatic mapping, local tumor demarcation and/or tumor receptor targeted applications) have been adopted into routine care. The clinical integration is further strengthened by technical innovations in chemistry and engineering that enhance the translational potential of radioguided procedures in iNM. Together, these features not only ensure ongoing expansion of iNM but also warrant a lasting clinical impact for the sub-discipline of radioguided surgery.

Lymphoscintigraphy and sentinel lymph node biopsy in vulvar carcinoma: update from a European expert panel.

PURPOSE: This study aimed to update the clinical practice applications and technical procedures of sentinel lymph node (SLN) biopsy in vulvar cancer from European experts. METHODS: A systematic data search using PubMed/MEDLINE database was performed up to May 29, 2019. Only original studies focused on SLN biopsy in vulvar cancer, published in the English language and with a minimum of nine patients were selected. RESULTS: Among 280 citations, 65 studies fulfilled the inclusion criteria. On the basis of the published evidences and consensus of European experts, this study provides an updated overview on clinical applications and technical procedures of SLN biopsy in vulvar cancer. CONCLUSIONS: SLN biopsy is nowadays the standard treatment for well-selected women with clinically negative lymph nodes. Negative SLN is associated with a low groin recurrence rate and a good 5-year disease-specific survival rate. SLN biopsy is the most cost-effective approach than lymphadenectomy in early-stage vulvar cancer. However, future trials should focus on the safe extension of the indication of SLN biopsy in vulvar cancer. Although radiotracers and optical agents are widely used in the clinical routine, there is an increasing interest for hybrid tracers like indocyanine-99mTc-nanocolloid. Finally, it is essential to standardise the acquisition protocol including SPECT/CT images, and due to the low incidence of this type of malignancy to centralise this procedure in experienced centres for personalised approach.

The EANM practical guidelines for sentinel lymph node localisation in oral cavity squamous cell carcinoma.

PURPOSE: Sentinel lymph node biopsy is an essential staging tool in patients with clinically localized oral cavity squamous cell carcinoma. The harvesting of a sentinel lymph node entails a sequence of procedures with participation of specialists in nuclear medicine, radiology, surgery, and pathology. The aim of this document is to provide guidelines for nuclear medicine physicians performing lymphoscintigraphy for sentinel lymph node detection in patients with early N0 oral cavity squamous cell carcinoma. METHODS: These practice guidelines were written and have been approved by the European Association of Nuclear Medicine (EANM) and the International Atomic Energy Agency (IAEA) to promote high-quality lymphoscintigraphy. The final result has been discussed by distinguished experts from the EANM Oncology Committee, and national nuclear medicine societies. The document has been endorsed by the Society of Nuclear Medicine and Molecular Imaging (SNMMI). These guidelines, together with another two focused on Surgery and Pathology (and published in specialised journals), are part of the synergistic efforts developed in preparation for the "2018 Sentinel Node Biopsy in Head and Neck Consensus Conference". CONCLUSION: The present practice guidelines will help nuclear medicine practitioners play their essential role in providing high-quality lymphatic mapping for the care of early N0 oral cavity squamous cell carcinoma patients.

The clinical impact of molecular breast imaging in women with proven invasive breast cancer scheduled for breast-conserving surgery.

PURPOSE: To investigate the clinical utility of molecular breast imaging (MBI) in patients with proven invasive breast cancer scheduled for breast-conserving surgery (BCS). METHODS: Following approval by the institutional review board and written informed consent, records of patients with newly diagnosed breast cancer scheduled for BCS who had undergone MBI for local staging in the period from March 2012 till December 2014 were retrospectively reviewed. RESULTS: A total of 287 women (aged 30-88 years) were evaluated. MBI showed T stage migration in 26 patients (9%), with frequent detection of in situ carcinoma around the tumor. Surgical management was adjusted in 14 of these patients (54%). In 17 of 287 patients (6%), MBI revealed 21 proven additional lesions in the ipsilateral, contralateral breast or both. In 18 of these additional foci (86%), detected in 15 patients, malignancy was found. Thirteen of these 15 patients had ipsilateral cancer and 2 patients bilateral malignancy. In total, MBI revealed a larger tumor extent, additional tumor foci or both in 40 patients (14%), leading to treatment adjustment in 25 patients (9%). CONCLUSION: MBI seems to be a useful imaging modality with a high predictive value in revealing ipsilateral and bilateral disease not visualized by mammography and ultrasound. It may play an important role in delineating the extent of the index lesion during preoperative planning. Incorporation of MBI in the clinical work-up as an adjunct modality to mammography and ultrasound may lead to better selection of patients who could benefit from BCS.

Lymphatic Drainage from Renal Tumors In Vivo: A Prospective Sentinel Node Study Using SPECT/CT Imaging.

PURPOSE: Lymphatic drainage from renal tumors is unpredictable. In vivo drainage studies of primary lymphatic landing sites may reveal the variability and dynamics of lymphatic connections. The purpose of this study was to investigate the lymphatic drainage pattern of renal tumors in vivo with single photon emission/computerized tomography after intratumor radiotracer injection. MATERIALS AND METHODS: We performed a phase II, prospective, single arm study to investigate the distribution of sentinel nodes from renal tumors on single photon emission/computerized tomography. Patients with cT1-3 (less than 10 cm) cN0M0 renal tumors of any subtype were enrolled in analysis. After intratumor ultrasound guided injection of 0.4 ml 99mTc-nanocolloid we performed preoperative imaging of sentinel nodes with lymphoscintigraphy and single photon emission/computerized tomography. Sentinel and locoregional nonsentinel nodes were resected with a γ probe combined with a mobile γ camera. The primary study end point was the location of sentinel nodes outside the locoregional retroperitoneal templates on single photon emission/computerized tomography. Using a Simon minimax 2-stage design to detect a 25% extralocoregional retroperitoneal template location of sentinel nodes on imaging at α = 0.05 and 80% power at least 40 patients with sentinel node imaging on single photon emission/computerized tomography were needed. RESULTS: Of the 68 patients 40 underwent preoperative single photon emission/computerized tomography of sentinel nodes and were included in primary end point analysis. Lymphatic drainage outside the locoregional retroperitoneal templates was observed in 14 patients (35%). Eight patients (20%) had supradiaphragmatic sentinel nodes. CONCLUSIONS: Sentinel nodes from renal tumors were mainly located in the respective locoregional retroperitoneal templates. Simultaneous sentinel nodes were located outside the suggested lymph node dissection templates, including supradiaphragmatic sentinel nodes in more than a third of the patients.

Contribution of SPECT/CT for sentinel node localization in patients with ipsilateral breast cancer relapse.

BACKGROUND: In recent years repeat sentinel node (SN) biopsy has been proven to be feasible in local breast cancer recurrence (LBCR). However, in these patients SNs outside the ipsilateral axilla are frequently observed. This study evaluates the contribution of SPECT/CT for SN localization and surgical adjustment in LBCR patients. METHODS: SN biopsy was performed in 122 LBCR patients (median age 60.5 years, range 24-87), enrolled from August 2006 to July 2015. Median disease-free time lapse was 109.5 months (range 9-365). Axillary lymph node dissection (ALND) had previously been performed in 55 patients, SN biopsy in 44, both techniques in 13 and fine-needle aspiration in 10. Primary breast cancer treatment included radiotherapy in 104 patients (85.3 %) and chemotherapy in 40 (32.8 %). Preoperative lymphatic mapping, using planar scintigraphy (PS) and SPECT/CT included report of SN location according to lymph node territory. In case of a territorial PS-SPECT/CT mismatch, surgery was adjusted according to SPECT/CT findings. RESULTS: SPECT/CT SN visualization rate was higher than PS (53.3 % vs. 43.4 %, p n.s.) with, in total, 19 additional SN (118 vs. 99, p n.s.). PS-SPECT/CT territory mismatch, found in 60 % (39/65) of patients with SN visualization, led to surgical adjustment in 21.3 % (26/122) of patients. The SN procedure was finally performed in 104 patients resulting in a 65.7 % surgical retrieval rate with a total of 132 removed SNs (1.86/patient). SN metastases were found in 17/71 patients (23.9 %), in 16 of them (94 %) in ipsilateral basins outside the axilla or in the contralateral axilla. CONCLUSION: Using SPECT/CT there is a trend to visualize more SNs in LBCR, providing at the same time important anatomical information to adjust intraoperative SN procedures. The addition of SPECT/CT to the standard imaging protocol may lead to better staging mainly in patients presenting drainage outside the ipsilateral axilla.

Sentinel node biopsy for prostate cancer: report from a consensus panel meeting.

OBJECTIVE: To explore the evidence and knowledge gaps in sentinel node biopsy (SNB) in prostate cancer through a consensus panel of experts. METHODS: A two-round Delphi survey among experts was followed by a consensus panel meeting of 16 experts in February 2016. Agreement voting was performed using the research and development project/University of California, Los Angeles Appropriateness Methodology on 150 statements in nine domains. The disagreement index based on the interpercentile range, adjusted for symmetry score, was used to assess consensus and non-consensus among panel members. RESULTS: Consensus was obtained on 91 of 150 statements (61%). The main outcomes were: (1) the results from an extended lymph node dissection (eLND) are still considered the 'gold standard', and sentinel node (SN) detection should be combined with eLND, at least in patients with intermediate- and high-risk prostate cancer; (2) the role of SN detection in low-risk prostate cancer is unclear; and (3) future studies should contain oncological endpoints as number of positive nodes outside the eLND template, false-negative and false-positive SN procedures, and recurrence-free survival. A high rate of consensus was obtained regarding outcome measures of future clinical trials on SNB (89%). Consensus on tracer technology was only obtained in 47% of statements, reflecting a need for further research and standardization in this area. The low-level evidence in the available literature and the composition of mainly SNB users in the panel constitute the major limitations of the study. CONCLUSIONS: Consensus on a majority of elementary statements on SN detection in prostate cancer was obtained.; therefore, the results from this consensus report will provide a basis for the design of further studies in the field. A group of experts identified evidence and knowledge gaps on SN detection in prostate cancer and its application in daily practice. Information from the consensus statements can be used to direct further studies.

Advances in radioguided surgery in oncology.

The sentinel lymph node (SLN) biopsy is probably the most well-known radioguided technique in surgical oncology. Today SLN biopsy reduces the morbidity associated with lymphadenectomy and increases the identification rate of occult lymphatic metastases by offering the pathologist the lymph nodes with the highest probability of containing metastatic cells. These advantages may result in a change in clinical management both in melanoma and breast cancer patients. The SLN evaluation by pathology currently implies tumor burden stratification for further prognostic information. The concept of SLN biopsy includes pre-surgical lymphoscintigraphy as a "roadmap" to guide the surgeon toward the SLNs and to localize unpredictable lymphatic drainage patterns. In addition to planar images, SPECT/CT improves SLN detection, especially in sites closer to the injection site, providing anatomic landmarks which are helpful in localizing SLNs in difficult to interpret studies. The use of intraoperative imaging devices allows a better surgical approach and SLN localization. Several studies report the value of such devices for excision of additional sentinel nodes and for monitoring the whole procedure. The combination of preoperative imaging and radioguided localization constitutes the basis for a whole spectrum of basic and advanced nuclear medicine procedures, which recently have been encompassed under the term "guided intraoperative scintigraphic tumor targeting" (GOSTT). Excepting SLN biopsy, GOSTT includes procedures based on the detection of target lesions with visible uptake of tumor-seeking radiotracers on SPECT/CT or PET/CT enabling their subsequent radioguided excisional biopsy for diagnostic of therapeutic purposes. The incorporation of new PET-tracers into nuclear medicine has reinforced this field delineating new strategies for radioguided excision. In cases with insufficient lesion uptake after systemic radiotracer administration, intralesional injection of a tracer without migration may enable subsequent excision of the targeted tissue. This approach has been helpful in non-palpable breast cancer and in solitary pulmonary nodules. The introduction of allied technologies like fluorescence constitutes a recent advance aimed to refine the search for SLNs and tracer-avid lesions in the operation theatre in combination with radioguidance.

Evaluation of a Hanging-Breast PET System for Primary Tumor Visualization in Patients With Stage I-III Breast Cancer: Comparison With Standard PET/CT.

OBJECTIVE: The purposes of this study were to evaluate the performance of a mammography with molecular imaging PET (MAMMI-PET) system for breast imaging in the hanging-breast position for the visualization of primary breast cancer lesions and to compare this method with whole-body PET/CT. SUBJECTS AND METHODS: Between March 2011 and March 2014, a prospective evaluation included women with one or more histologically confirmed primary breast cancer lesions (index lesions). After injection of 180-240 MBq of (18)F-FDG, whole-body PET/CT and MAMMI-PET acquisitions were performed, index lesions were scored 0, 1, or 2 for FDG uptake relative to background. Detection and FDG uptake were compared by breast length, maximal tumor diameter, affected breast quadrants, tumor grade, and histologic and immunologic sub-types. Finally, the two PET modalities were compared for detection of index lesions. RESULTS: For 234 index lesions (diameter, 5-170 mm), the overall sensitivity was 88.9% for MAMMI-PET and 91% for PET/CT (p = 0.61). Twenty-three (9.8%) index lesions located too close to the pectoral muscle were missed with MAMMI-PET, and 20 index lesions were missed with PET/CT. Lesion visibility on MAMMI-PET images was influenced by tumor grade (p = 0.034) but not by cancer subtype (p = 0.65). CONCLUSION: Although in an overall evaluation MAMMI-PET was not superior to PET/CT, MAMMI-PET does have higher sensitivity for primary breast cancer lesions within the scanning range of the device. Optimization of the positioning device may increase visualization of the most dorsal lesions.

Multimodal Surgical Guidance during Sentinel Node Biopsy for Melanoma: Combined Gamma Tracing and Fluorescence Imaging of the Sentinel Node through Use of the Hybrid Tracer Indocyanine Green-(99m)Tc-Nanocolloid.

Purpose To evaluate the hybrid approach in a large population of patients with melanoma in the head and neck, on the trunk, or on an extremity who were scheduled for sentinel node (SN) biopsy. Materials and Methods This prospective study was approved by the institutional review board. Between March 2010 and March 2013, 104 patients with a melanoma, including 48 women (average age, 54.3 years; range, 18.5-87.4 years) and 56 men (average age, 55.2 years; range, 22.4-77.4 years) (P = .76) were enrolled after obtaining written informed consent. Following intradermal hybrid tracer administration, lymphoscintigraphy and single photon emission computed tomography/computed tomography were performed. Blue dye was intradermally injected prior to the start of the surgical operation (excluding patients with a facial melanoma). Intraoperatively, SNs were initially pursued by using gamma tracing followed by fluorescence imaging (FI) and, when applicable, blue-dye detection. A portable gamma camera was used to confirm SN removal. Collected data included number and location of the preoperatively and intraoperatively identified SNs and the intraoperative number of SNs that were radioactive, fluorescent, and blue. A two-sample test for equality of proportions was performed to evaluate differences in intraoperative SN visualization through FI and blue-dye detection. Results Preoperative imaging revealed 2.4 SNs (range, 1-6) per patient. Intraoperatively, 93.8% (286 of 305) of the SNs were radioactive, 96.7% (295 of 305) of the SNs were fluorescent, while only 61.7% (116 of 188) of the SNs stained blue (P < .0001). FI was of value for identification of near-injection-site SNs (two patients), SNs located in complex anatomic areas (head and neck [28 patients]), and SNs that failed to accumulate blue dye (19 patients). Conclusion The hybrid tracer enables both preoperative SN mapping and intraoperative SN identification in melanoma patients. In the setup of this study, optical identification of the SNs through the fluorescent signature of the hybrid tracer was superior compared with blue dye-based SN visualization.

The use of SPECT/CT for anatomical mapping of lymphatic drainage in vulvar cancer: possible implications for the extent of inguinal lymph node dissection.

PURPOSE: To determine the lymphatic drainage pattern using SPECT/CT in clinically node-negative (cN0) patients with vulvar cancer, and to evaluate the possible implications for the extent of inguinal lymph node dissection. METHODS: A total of 83 patients with vulvar cancer scheduled for sentinel node (SN) biopsy were injected peritumorally with radioactive nanocolloid particles followed by lymphoscintigraphy and SPECT/CT for anatomical localization. The SN and higher-echelon nodes on SPECT/CT were located in different zones in the groin and pelvic region. The groin was divided into five zones according to Daseler et al.: four zones obtained by drawing two perpendicular lines over the saphenofemoral junction and one zone directly overlying this junction. The nodes in the pelvic region were classified into three zones: external iliac/obturator, the common iliac and the paraaortic zones. RESULTS: A total of 217 SNs and 202 higher-echelon nodes were localized on SPECT/CT. All SNs were located in the five zones according to Daseler et al.: 149 (69%) in the medial superior region, 31 (14%) in the medial inferior region, 22 (10%) in the central region, 14 (6.5%) in the lateral superior region and only 1 (0.5%) in the lateral inferior region. The higher-echelon nodes were located both in the groin (15%) and in the pelvic region (85%). CONCLUSION: In patients with cN0 vulvar cancer, lymphatic drainage occurs predominantly to the medial regions of the groin. Drainage to the lateral inferior region of the groin is only incidental and in SN-positive patients this zone might be spared in subsequent extended lymph node dissection. This may lead to a decrease in the morbidity associated with this procedure. SPECT/CT is able to personalize lymphatic mapping, providing detailed information about the number and anatomical location of SNs for adequate surgical planning in the groin.

Heading toward radioactive seed localization in non-palpable breast cancer surgery? A meta-analysis.

Wire-guided localization is the most commonly used technique for intraoperative localization of non-palpable breast cancer. Radioactive seed localization (RSL) is becoming more popular and seems to be a reliable alternative for intraoperative lesion localization. The purpose of the present meta-analysis was to evaluate the use of RSL. Primary study outcomes were irradicality and re-excision rates. In total 3168 patients were included. The clinical adaptation shows growing confidence in RSL and further growth is expected.

Contemporary management of regional nodes in penile cancer-improvement of survival?

PURPOSE: The management of regional nodes of penile squamous cell carcinoma has changed with time due to improved knowledge about diagnosis and treatment. To determine whether changes in the treatment of regional nodes have improved survival, we compared contemporary 5-year cancer specific survival of patients with squamous cell carcinoma of the penis with that of patients in previous cohorts. MATERIALS AND METHODS: In an observational cohort study of 1,000 patients treated during 56 years 944 were eligible for analysis. Tumors were staged according to the 2009 TNM classification, and patients were divided into 4 cohorts of 1956 to 1987, 1988 to 1993, 1994 to 2000 and 2001 to 2012, reflecting changes in clinical practice regarding regional nodes. Kaplan-Meier survival curves with the log rank test and Cox proportional hazards modeling were used to examine trends in 5-year cancer specific survival. RESULTS: The 5-year cancer specific survival of patients with cN0 disease treated between 2001 and 2012 was 92% compared to 89% (1994 to 2000), 78% (1988 to 1993) and 85% (1956 to 1987). The 5-year cancer specific survival improved significantly since 1994, the year dynamic sentinel node biopsy was introduced, at 91% (1994 to 2012) vs 82% (1956 to 1993) (p = 0.021). This conclusion still holds after adjustment for pathological T stage and grade of differentiation (HR 2.46, p = 0.01). Extranodal extension, number of tumor positive nodes and pelvic involvement in node positive (pN+) cases were associated with worse 5-year cancer specific survival. CONCLUSIONS: Despite less surgery being performed on regional nodes, 5-year cancer specific survival has improved in patients with cN0 disease. The number of tumor positive nodes, extranodal extension and pelvic involvement were highly associated with worse cancer specific survival in patients with pN+ disease. In this group other treatment strategies are needed as no improvement was observed.

Feasibility of intraoperative navigation to the sentinel node in the groin using preoperatively acquired single photon emission computerized tomography data: transferring functional imaging to the operating room.

PURPOSE: We explored the clinical feasibility and accuracy of intraoperative navigation based on preoperatively acquired 3-dimensional functional imaging data. MATERIALS AND METHODS: Ten patients with penile carcinoma scheduled for sentinel node biopsy were prospectively included in study. After tracer injection preoperative single photon emission computerized tomography/computerized tomography was performed with a reference target fixed on the patient. Repositioning a sterile reference target shortly before surgery allowed 3-dimensional single photon emission computerized tomography/computerized tomography mixed reality based navigation of the γ probe (also containing a reference target) to the sentinel node. The accuracy of the declipse®SPECT navigation approach was determined in relation to the incision site indicated by the conventional γ probe in the coronal plane and the depth estimation measured on axial computerized tomography slices in the sagittal/axial plane. RESULTS: The 3-dimensional mixed reality approach enabled γ probe navigation toward the sentinel node in all 10 patients. The average ± SD navigation error in the coronal and saggital/axial planes was 5.0 ± 3.9 and 5.3 ± 3.9 mm, respectively. CONCLUSIONS: To our knowledge this is the first study demonstrating the feasibility of intraoperative navigation based on preoperatively acquired 3-dimensional single photon emission computerized tomography/computerized tomography images. Although confirmation of successful target localization (eg using γ tracing or fluorescence imaging) remains indispensable, this opens the way to translate 3-dimensional functional imaging data to the operating room.

(18)F-fluorodeoxyglucose positron emission tomography versus computed tomography in predicting histopathological response to epidermal growth factor receptor-tyrosine kinase inhibitor treatment in resectable non-small cell lung cancer.

PURPOSE: To prospectively evaluate diagnostic computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for identification of histopathologic response to neoadjuvant erlotinib, an epidermal growth factor receptor-tyrosine kinase inhibitor in patients with resectable non-small cell lung cancer (NSCLC). METHODS: This study was designed as an open-label phase 2 trial, performed in four hospitals in the Netherlands. Patients received preoperative erlotinib 150 mg once daily for 3 weeks. CT and FDG-PET/CT were performed at baseline and after 3 weeks of treatment. CT was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. FDG-PET/CT, tumor FDG uptake, and changes were measured by standardized uptake values (SUV). Radiologic and metabolic responses were compared to the histopathological response. RESULTS: Sixty patients were enrolled onto this study. In 53 patients (22 men, 31 women), the combination of CT, FDG-PET/CT, and histopathological evaluation was available for analysis. Three patients (6 %) had radiologic response. According to European Organisation for Research and Treatment of Cancer (EORTC) criteria, 15 patients (28 %) showed metabolic response. In 11 patients, histopathologic response (≥50 % necrosis) was seen. In predicting histopathologic response, relative FDG change in SUVmax showed more SUVmax decrease in the histopathologic response group (-32 %) versus the group with no pathologic response (-4 %) (p = 0.0132). Relative change in tumor size on diagnostic CT was similar in these groups with means close to 0. CONCLUSIONS: FDG-PET/CT has an advantage over CT as a predictive tool to identify histopathologic response after 3 weeks of EGFR-TKI treatment in NSCLC patients.

Sequential (18)F-FDG PET/CT for early prediction of complete pathological response in breast and axilla during neoadjuvant chemotherapy.

PURPOSE: To investigate the value of response monitoring in both the primary tumour and axillary nodes on sequential PET/CT scans during neoadjuvant chemotherapy (NAC) for predicting complete pathological response (pCR), taking the breast cancer subtype into account. METHODS: In 107 consecutive patients 290 PET/CT scans were performed at baseline (PET/CT1, 107 patients), after 2 - 3 weeks of chemotherapy (PET/CT2, 85 patients), and after 6 - 8 weeks (PET/CT3, 98 patients). The relative changes in SUVmax (from baseline) of the tumour and the lymph nodes and in both combined (after logistic regression), and the changes in the highest SUVmax between scans (either tumour or lymph node) were determined and their associations with pCR of the tumour and lymph nodes after completion of NAC were assessed using receiver operating characteristic (ROC) analysis. RESULTS: A pCR was seen in 17 HER2-positive tumours (65 %), 1 ER-positive/HER2-negative tumour (2 %), and 16 triple-negative tumours (52 %). The areas under the ROC curves (ROC-AUC) for the prediction of pCR in HER2-positive tumours after 3 weeks were 0.61 for the relative change in tumours, 0.67 for the combined change in tumour and nodes, and 0.72 for the changes in the highest SUVmax between scans. After 8 weeks equivalent values were 0.59, 0.42 and 0.64, respectively. In triple-negative tumours the ROC-AUCs were 0.76, 0.84 and 0.76 after 2 weeks, and 0.87, 0.93 and 0.88 after 6 weeks, respectively. CONCLUSION: In triple-negative tumours a PET/CT scan after 6 weeks (three cycles) appears to be optimally predictive of pCR. In HER2-positive tumours neither a PET/CT scan after 3 weeks nor after 8 weeks seems to be useful. The changes in SUVmax of both the tumour and axillary nodes combined correlates best with pCR.