Clinical Application and Further Development of Augmented Reality Guidance for the Surgical Localization of Pediatric Chest Wall Tumors

BACKGROUND

Surgical treatment of pediatric chest wall tumors requires accurate surgical planning and tumor localization to achieve radical resections while sparing as much healthy tissue as possible. Augmented Reality (AR) could facilitate surgical decision making by improving anatomical understanding and intraoperative tumor localization. We present our clinical experience with the use of an AR system for intraoperative tumor localization during chest wall resections. Furthermore, we present the pre-clinical results of a new registration method to improve our conventional AR system.

METHODS

From January 2021, we used the HoloLens 2 for pre-incisional tumor localization during all chest wall resections inside our center. A patient-specific 3D model was projected onto the patient by use of a five-point registration method based on anatomical landmarks. Furthermore, we developed and pre-clinically tested a surface matching method to allow post-incisional AR guidance by performing registration on the exposed surface of the ribs.

RESULTS

Successful registration and holographic overlay were achieved in eight patients. The projection seemed most accurate when landmarks were positioned in a non-symmetric configuration in proximity to the tumor. Disagreements between the overlay and expected tumor location were mainly due to user-dependent registration errors. The pre-clinical tests of the surface matching method proved the feasibility of registration on the exposed ribs.

CONCLUSIONS

Our results prove the applicability of AR guidance for the pre- and post-incisional localization of pediatric chest wall tumors during surgery. The system has the potential to enable intraoperative 3D visualization, hereby facilitating surgical planning and management of chest wall resections.

LEVEL OF EVIDENCE

IV TYPE OF STUDY: Treatment Study.

Comparison of deep learning networks for fully automated head and neck tumor delineation on multi-centric PET/CT images

OBJECTIVES

Deep learning-based auto-segmentation of head and neck cancer (HNC) tumors is expected to have better reproducibility than manual delineation. Positron emission tomography (PET) and computed tomography (CT) are commonly used in tumor segmentation. However, current methods still face challenges in handling whole-body scans where a manual selection of a bounding box may be required. Moreover, different institutions might still apply different guidelines for tumor delineation. This study aimed at exploring the auto-localization and segmentation of HNC tumors from entire PET/CT scans and investigating the transferability of trained baseline models to external real world cohorts.

METHODS

We employed 2D Retina Unet to find HNC tumors from whole-body PET/CT and utilized a regular Unet to segment the union of the tumor and involved lymph nodes. In comparison, 2D/3D Retina Unets were also implemented to localize and segment the same target in an end-to-end manner. The segmentation performance was evaluated via Dice similarity coefficient (DSC) and Hausdorff distance 95th percentile (HD95). Delineated PET/CT scans from the HECKTOR challenge were used to train the baseline models by 5-fold cross-validation. Another 271 delineated PET/CTs from three different institutions (MAASTRO, CRO, BERLIN) were used for external testing. Finally, facility-specific transfer learning was applied to investigate the improvement of segmentation performance against baseline models.

RESULTS

Encouraging localization results were observed, achieving a maximum omnidirectional tumor center difference lower than 6.8 cm for external testing. The three baseline models yielded similar averaged cross-validation (CV) results with a DSC in a range of 0.71-0.75, while the averaged CV HD95 was 8.6, 10.7 and 9.8 mm for the regular Unet, 2D and 3D Retina Unets, respectively. More than a 10% drop in DSC and a 40% increase in HD95 were observed if the baseline models were tested on the three external cohorts directly. After the facility-specific training, an improvement in external testing was observed for all models. The regular Unet had the best DSC (0.70) for the MAASTRO cohort, and the best HD95 (7.8 and 7.9 mm) in the MAASTRO and CRO cohorts. The 2D Retina Unet had the best DSC (0.76 and 0.67) for the CRO and BERLIN cohorts, and the best HD95 (12.4 mm) for the BERLIN cohort.

CONCLUSION

The regular Unet outperformed the other two baseline models in CV and most external testing cohorts. Facility-specific transfer learning can potentially improve HNC segmentation performance for individual institutions, where the 2D Retina Unets could achieve comparable or even better results than the regular Unet.

A Patient-Specific correspondence model to track tumor location in thorax during radiation therapy

PURPOSE

We present a patient-specific model to estimate tumor location in the thorax during radiation therapy using chest surface displacement as the surrogate signal.

METHODS

Two types of data are used for model construction: Four-dimensional computed tomography (4D-CT) images of the patient and the displacement of two points on the patient's skin on the thoracic area. Principal component analysis is used to fit the correspondence model. This model incorporates the recorded surrogate signals during radiation delivery as input and delivers the 3D trajectory of the tumor as output. We evaluated the accuracy of the proposed model on a respiratory phantom and five lung cancer patients.

RESULTS

For the respiratory phantom, the location of the center of the sphere during treatment was calculated in three directions: Left-Right (LR), Anterior-Posterior (AP) and, Superior-Inferior (SI). The error of localization was less than 1 mm in the LR and AP directions and less than 2 mm in the SI direction. The location of the tumor center for two of the patients, and the location of the apex of the diaphragm for the other three, was calculated in three directions. For all patients, the localization error in the LR and AP directions was less than 1.1 mm for two fractions and the maximum localization error in the SI direction was 6.4 mm.

CONCLUSIONS

This work presents a feasibility study of utilizing surface displacement data to locate the tumor in the thorax during radiation treatment. Future work will validate the model on a larger patient population.

Assessment of Autologous Blood marker localIzation and intraoperative coLonoscopy localIzation in laparoscopic colorecTal cancer surgery (ABILITY): a randomized controlled trial

BACKGROUND

Laparoscopic colorectal surgery has been proved to have similar oncological outcomes with open surgery. Due to the lack of tactile perception, surgeons may have misjudgments in laparoscopic colorectal surgery. Therefore, the accurate localization of a tumor before surgery is important, especially in the early stages of cancer. Autologous blood was thought a feasible and safe tattooing agent for preoperative endoscopic localization but its benefits remain controversial. We therefore proposed this randomized trial to the accuracy and safety of autogenous blood localization in small, serosa-negative lesion which will be resected by laparoscopic colectomy.

METHODS

The current study is a single-center, open-label, non-inferiority, randomized controlled trial. Eligible participants would be aged 18-80 years and diagnosed with large lateral spreading tumors that could not be treated endoscopically, malignant polyps treated endoscopically that required additional colorectal resection, and serosa-negative malignant colorectal tumors (≤ cT3). A total of 220 patients would be randomly assigned (1:1) to autologous blood group or intraoperative colonoscopy group. The primary outcome is the localization accuracy. The secondary endpoint is adverse events related to endoscopic tattooing.

DISCUSSION

This trial will investigate whether autologous blood marker achieves similar localization accuracy and safety in laparoscopic colorectal surgery compared to intraoperative colonoscopy. If our research hypothesis is statistically proved, the rational introduction of autologous blood tattooing in preoperative colonoscopy can help improve identification of the location of tumors for laparoscopic colorectal cancer surgery, performing an optimal resection, and minimizing unnecessary resections of normal tissues, thereby improving the patient's quality of life. Our research data will also provide high quality clinical evidence and data support for the conduction of multicenter phase III clinical trials.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov, NCT05597384. Registered 28 October 2022.

[Epidemiology and surgical treatment of pancreatic cancer in the State of Brandenburg : Analysis of 5418 cases]

BACKGROUND

Pancreatic cancer is the second most frequent cause of death among all forms of cancer in Germany with more than 19,000 deaths per year. The evaluation of the nationwide clinical cancer register aims to depict the reality of treatment and to improve the quality of treatment in the future by targeted analyses.

METHOD

The data from the clinical cancer register of Brandenburg-Berlin for the diagnosis years 2001-2017 were analyzed with respect to the treatment of pancreatic cancer. Data from patients resident in the State of Brandenburg were evaluated with respect to epidemiological and therapeutic parameters.

RESULTS

A total of 5418 patients with pancreatic cancer were documented in the register from 2001 to 2017 and 49.6% of the patients were diagnosed as having the Union for International Cancer Control (UICC) stage IV. A pancreas resection was carried out in 26.4% of the cases. In cases of cancer of the head of the pancreas the most frequent procedure was a pylorus-preserving resection with 51.8% and a pancreatectomy was carried out in 9.4%. The R0 resection rate of all pancreatic cancers in the period from 2014 to 2017 was 61.9%. After R0 resection the 5‑year survival was 19%. Relevant multivariate survival factors were age, UICC stage and the residual (R) tumor classification. The case numbers per hospital had no influence on the absolute survival of patients operated on in the State of Brandenburg.

CONCLUSION

The treatment reality in the State of Brandenburg for patients with pancreatic cancer corresponds to the results of international publications with respect to the key performance indicators investigated. A qualitative internationally comparable treatment of these patients is also possible in nonmetropolitan regions.

Pre-diagnostic faecal calprotectin levels in patients with colorectal cancer: a retrospective study

BACKGROUND

Faecal calprotectin (FC) is a potential biomarker for colorectal cancer (CRC) screening. There is uncertainty if tumor characteristics are associated with FC levels. We investigated how tumor stage and tumor localization influence the extent of FC levels in patients with CRC in clinical practice.

METHODS

In two cohorts of patients with CRC, we retrospectively analyzed FC tests (CALPRO®) performed within three months prior to diagnosis. One hundred twenty-four patients with CRC were included (mean age 68 years, 44% women).

RESULTS

Ninety-eight patients with CRC (79%) had a FC ≥ 50 µg/g. FC correlated positively with tumor stage (UICC based on WHO TNM classification) (r_s 0.24; p = 0.007) and with CRP levels (r_s 0.31, p = 001), and a negatively with B-haemoglobin (r_s -0.21; p = 0.019). The patients with right-sided CRC had significantly more often a FC ≥ 50 µg/g than patients with left-sided CRC (92% vs 74% p = 0.027). In a binary logistic regression analysis, tumor stage III/IV (adjusted OR 3.47; CI 1.27-9.42) and right-sided tumor localization (adjusted OR 3.80; CI 1.01-14.3) were associated with FC ≥ 50 µg/g. Tumor stage III/IV (adjusted OR 2.30; CI 1.04-5.10) and acetylsalicylic use (adjusted OR 3.54; CI 1.03-12.2) were associated with FC ≥ 100 µg/g. In a cox regression analysis, a FC ≥ 100 µg/g was not associated with survival (Hazard OR 0.61; CI 0.24-1.52).

CONCLUSIONS

Elevated pre-diagnostic FC levels were common in patients with CRC in close proximity to diagnosis. Right-sided localization and tumor stage were significantly associated with a rise in FC levels.

Intraoperative Tumor Localization of Early Gastric Cancers

Recently, endoscopic screening systems have enabled the diagnosis of gastric cancer in the early stages. Early gastric cancer (EGC) is typically characterized by a shallow invasion depth and small size, which can hinder localization of EGC tumors during laparoscopic surgery. Here, we review nine recently reported tumor localization methods for the laparoscopic resection of EGCs. Preoperative dye or blood tattooing has the disadvantage of spreading. Preoperative 3-dimensional computed tomography reconstruction is not performed in real time during laparoscopic gastrectomy. Thus, they are considered to have a low accuracy. Intraoperative portable abdominal radiography and intraoperative laparoscopic ultrasonography methods can provide real-time feedback, but these methods require expertise, and it can be difficult to define the clips in some gastric regions. Despite a few limitations, intraoperative gastrofibroscopy provides real-time feedback with high accuracy. The detection system using an endoscopic magnetic marking clip, fluorescent clip, and radio-frequency identification detection system clip is considered highly accurate and provides real-time feedback; we expect a commercial version of this setup to be available in the near future. However, there is not yet an easy method for accurate real-time detection. We hope that improved devices will soon be developed and used in clinical settings.

Is the Effect of Tumor Localization on Prognosis Compatible with Real-life Data in Metastatic Colon Cancer? Single-Center Experience: A Retrospective Analysis

AIM

In recent years, the prognostic and predictive value of primary tumor localization in colon cancer has become increasingly important. This study aimed to retrospectively analyze the effect of colon cancer tumor localization on progression-free survival, overall survival, and response to treatments and present real-life data.

METHOD

Retrospective evaluation was made of 465 patients who were diagnosed with metastatic colorectal carcinoma between 2010 and 2015 in our clinic. The effect of primary tumor localization on progression-free survival, overall survival, and response to therapy was investigated.

RESULTS

The right colon cancer (RCC) was determined in 66 patients, 14.2% of the whole group, and left colorectal cancer (LCRC) in 399 patients which is 85.8% of patients. Mucinous adenocarcinoma was 16.7% in RCC; however, only 6.4% of LCRC had a mucinous tumor (p < 0.05). Nodal involvement in any stage (N1 and N2) was 46.9% in right colon cancer whereas in LCRC, it was 41.2% (p < 0.05). Primary tumor surgery (74.2% vs. 70.2%) and metastasectomy (33.3% vs. 19.4%) were also more common in RCC(p < 0.05). k-ras mutation status was similar in both groups (28.8% in RCC vs 26.8% in LCRC, p > 0.05). Median progression-free survival was 12.6 months in RCC, and 15.5 in LCRC (p > 0.05). Median overall survival was 28.4 months in RCC and 33.5 months in LCRC (p > 0.05). In k-ras wild-type patients, the median overall survival was 32.3 months (95% CI 25.2-39.5) in the anti-VEGF antibody treatment group and 55.1 months (95% CI 36.5-73.7) in the anti-EGFR antibody treatment group (p < 0.05).

CONCLUSION

Although tumors located in the right colon have been considered to be worse in terms of progression-free and overall survival in clinical trials, the results of this study showed that in daily practice, there was no difference between left and right colon localized tumors in progression-free and overall survival. Further, in k-ras wild-type colon cancers, tumor localization predicts the treatment response. This study is important with the presentation of real-life data and compatibility with the data of the studies to daily life.

[Diagnosis of breast diseases in a certified breast center]

The beginning of the 21st century has seen immense improvements in the quality of diagnosis and treatment of breast cancer due to several, simultaneous developments. In particular, the introduction of a certification program from the German Cancer Society based on level III guidelines has enhanced the transparency and quality of treatment of breast diseases for all actors. As a result, patients have benefited from intensified cooperation especially between core disciplines in breast disease, gynecology, pathology, and radiology. The standardized and synoptic reading of multiple diagnostic modalities has enabled precise sampling of histologic specimen, which has improved prognosis and the successful individualization of therapy. In this article the benefits of breast cancer diagnosis and therapy in a certified breast center are illustrated using four case examples.

A tactile sensor using the acoustic reflection principle for assessing the contact force component in laparoscopic tumor localization

PURPOSE

Localization of an early stage gastric tumor is easily performed in conventional open surgery, whereas it is a difficult procedure in minimally invasive surgery (MIS). A tactile sensor could allow precise resection of the tumor in laparoscopic surgery. The safety of medical tools should be ensured in MIS. Moreover, boundary conditions such as a double-ended beam without a supporting rigid base during tissue palpation were hardly considered. Thus, we suppose that it is informative to assess the normal force and shear force for practical tumor detection considering the boundary condition.

METHODS

In this study, a tactile sensor with normal and shear force measurement functions using the acoustic reflection principle was developed for gastric tumor detection in MIS. The developed tactile sensor was tested using an artificial phantom of the stomach without a supporting rigid base to evaluate the force response of the sensor in intraoperative tumor localization.

RESULTS

The developed sensor is safe for human tissue and can be sterilized. The experimental results show that the developed tactile sensor has the capability to measure normal and shear forces. In the gastric tumor detection test, the shear force of the sensor was more stable and highly responsive to the tumor position than the normal force, which is greatly affected by the bending of the tissue during the operation.

CONCLUSIONS

A two-axis tactile sensor using the acoustic reflection principle was assembled for tissue palpation in MIS. The results showed that the developed sensor is suitable for tumor detection, indicating that the shear force information of the developed sensor is more useful in MIS for early stage gastric tumor localization.

[Three Dimensional Measurement of the Space Distance Between the Hilum and Clinical Stage T 1 Non-small Cell Lung Cancer and Its Relationship with Lymph Node Metastasis]

Objective

The aim of this study was to develop a novel method to quantitatively define the tumor location of clinical stage T ₁ (cT ₁) non-small cell lung cancer (NSCLC) and to evaluate its impact on lymph node metastasis in a large cohort group.

Methods

We developed a novel method to transform the datum of 2D CT scans to 3D datum and to quantitatively measure the distance between the tumor and hilum through the Pythagorean theorem. Multiple logistic regression analysis was applied to identify the risk factors associated with lymph node metastasis.

Results

A total of 399 patients (166 male and 233 female) with cT ₁ NSCLC were enrolled in this study. The mean age was (57.48±10.88) yr., the mean distance between tumor and hilum was (5.44±1.96) cm, and the mean tumor diameter was (1.77±0.65) cm. Patients were divided into lymph node positive group (N ⁺ group) and lymph node negative group (N ^－ group). By multiple logistic regression analysis, we identified 4 risk variables associated with lymph node metastasis. Gender (odds ratio ( OR)=2.118， P=0.022), distance between tumor and hilum ( OR=0.843， P=0.040), differentiation (moderate vs. high， OR=15.547， P=0.008；poor vs. high， OR=70.749， P=0.000), and cancer embolus ( OR=24.769， P=0.004) were independent risk variables associated with lymph node metastasis.

Conclusion

Distance between tumor and hilum was identified as an independent risk factor associated with lymph node metastasis in cT ₁ NSCLC.

A decade of intraoperative ultrasound guided breast conservation for margin negative resection - Radioactive, and magnetic, and Infrared Oh My…

BACKGROUND

The oncologic goal of margin-negative breast conservation requires adequate localization of tumor. Intraoperative ultrasound remains most feasible but under-utilized method to localize the tumor and assess margins.

METHODS

A prospectively maintained breast cancer database over a decade was queried for margin status in breast cancer patients undergoing breast conservation. Techniques of tumor localization, margin re-excision and closest margins were analyzed. Rate of conversion to mastectomy was determined.

RESULTS

Of the 945 breast cancer patients treated at a university-based Breast Center of Excellence between January 1, 2009 and December 31, 2018, 149(15.8%) had ductal carcinoma in situ; 712(75.3%) had invasive ductal carcinoma, and 63(6.7%) had invasive lobular carcinoma. Clinical stage distribution was: T1 = 372(39.4%); T2 = 257(27.2%); T3 = 87(9.2%). Five hundred and eighty three (61.7%) patients underwent breast conservation. The median (25th -75th centile) closest margin was 6(2.5, 10.0) mm. Thirty five (6.0%) patients underwent margin re-excision, of which 9(25%) were converted to mastectomy. Tumor localization was achieved with ultrasound in 521(89.4%) patients and with wire localization in 62(10.6%) patients. The median (25th-75th centile) closest margin with wire localization was 5.0(2.0, 8.5) mm versus 5.0 (2.0, 8.0) mm with ultrasound guidance [p = 0.6635]. The re-excision rate with wire localization was 14.5% versus 4.9% with ultrasound guidance [p = 0.0073]. The unadjusted Odds Ratio (95% CI) for margin revision in wire localized group compared with ultrasound was 3.2 (7.14, 1.42) [p = 0.0045]; multivariate adjusted OR (95%) was 4(9.09, 1.7) [p = 0.0013].

CONCLUSIONS

Ultrasound guidance for localization of breast cancer remains the most effective option for margin negative breast conservation.

Diagnostic accuracy of the gastric cancer T-category with respect to tumor localization

Purpose

Diagnosing early gastric cancer (EGC) or advanced gastric cancer (AGC) according to T-category is important for optimal GC treatment; however, the clinical and pathological diagnosis of tumor depths can sometimes vary. This study investigated the accuracy of clinical diagnosis of the tumor depth from the viewpoint of tumor localization and prognosis of patients with GC with discordance between clinical and pathological findings.

Methods

This study enrolled 741 patients with primary GC who underwent curative gastrectomy. Based on the clinical and pathological diagnosis of T-category, the patients were classified into four groups: Early-look EGC, Early-look AGC, Advanced-look EGC, and Advanced-look AGC. Tumor localization was classified longitudinally (the upper [U], middle [M], and lower [L] parts and cross-sectionally (the anterior [Ant] and posterior [Post] walls, and the lesser [Less] and greater [Gre] curvatures).

Results

Of the 462 clinical EGC cases, 52 were Early-look AGC cases that exhibited a significant association of tumor localization with the Post and Less in the U and M locations (UM-PL; p = 0.037). An Advanced-look EGC (p = 0.031) and Advanced-look AGC (p = 0.025) were independent prognostic factors for relapse-free survival each in pathological EGC and AGC, respectively.

Conclusions

Patients with clinically diagnosed EGC but with pathologically diagnosed AGC more frequently presented tumor in the UM-PL than in any other location. Selection of therapeutic strategy according to the clinical diagnosis might be critical; however, it should be also considered that the accuracy of preoperative assessments varies with tumor localization.

Electronic supplementary material

The online version of this article (10.1007/s00423-020-01971-3) contains supplementary material, which is available to authorized users.

Evaluating the distribution of the locations of colorectal cancer after appendectomy and cholecystectomy

Backgrounds

The number of appendectomies and cholecystectomies performed is gradually increasing worldwide. An increasing incidence of colorectal cancer (CRC) after appendectomy and cholecystectomy has been reported, but the location of tumors in certain segments of the colon and rectum after appendectomy and cholecystectomy is still uncertain. We aimed to evaluate the distribution of the locations of colorectal cancer after appendectomy and/or cholecystectomy in patients who underwent CRC surgery.

Methods

We reviewed the medical records of patients who had undergone CRC surgery between 2015 and 2017 for the presence of previous appendectomy/cholecystectomy. Data were collected from the Colorectal Data Base of the University of Szeged, Department of Surgery.

Results

Surgery for CRC was performed in 640 patients during the study period. Data of 604 patients were analyzed. Appendectomy was performed in 100 patients (16.6%), cholecystectomy in 65 (10.8%), and both interventions in 18 (3%) before the CRC surgery. Out of those patients who underwent appendectomy alone, 92 (92%) had undergone appendectomy more than 10 years before the CRC surgery. Also in these 100 patients, the prevalence of right-sided colon cancer (CC) was 35% (n = 35), in comparison with the prevalence among the 504 other patients (20.4%, n = 103). The prevalence of right-sided CC among patients who underwent cholecystectomy alone was 36.9% (n = 24), in comparison with 21.2% (n = 114) of the 539 other patients.

Conclusions

A significant left to right side shift in CRC was noted among patients who had previously undergone appendectomy/cholecystectomy. Because right-sided CC has a worse prognosis, the role of incidental appendectomy and routine cholecystectomy seems that need re-evaluation.

An advanced RFID-based system to localize gastric and colon cancers during laparoscopic surgery

BACKGROUND

We aimed to improve the tumor localization system using radiofrequency identification (RFID) technology used during laparoscopic surgery for gastric and colorectal cancer. To this end, we developed a detection algorithm and designed improvement for the RFID clip.

METHODS

To evaluate the proposed system, a swine-based animal study was conducted, followed by experiments on porcine stomachs and colons using the EASIE-R simulator. The success rates of endoscopic clipping, detection time, and detection accuracy, which is the distance between the detection point and RFID tag, were measured.

RESULTS

Results of the in vivo swine animal study showed success in all three clippings and detections of the RFID clips. Results of the 60 RFID endoclip attempts using the EASIE-R simulator showed a total clipping success rate of 85.0% (n = 51/60; stomach, 83.3%, n = 25/30; colon, 86.7%, n = 26/30). The median detection times were 29.2 s for the stomach and 25.5 s for the colon. The median detection accuracy was 4.0 mm for the stomach and 4.5 mm for the colon.

CONCLUSIONS

We confirmed that the proposed RFID-based system showed improvements over the system of a previous study. This RFID-based system is effective at localizing gastric and colorectal tumors.

[Neuroendocrine tumors of the stomach, duodenum and pancreas : Value of (hybrid) radiological diagnostics]

CLINICAL/METHODICAL ISSUE

Neuroendocrine tumors (NET) of the stomach, duodenum and pancreas are rare tumors with a low incidence but the exact tumor localization and staging diagnostics are of critical importance for further planning of treatment.

STANDARD RADIOLOGICAL METHODS

Standard primary diagnostic methods include multimodal imaging with computed tomography (CT) and magnetic resonance imaging (MRI) but in 20-50% of the cases the localization of the primary tumor cannot be identified.

METHODICAL INNOVATIONS

Modern hybrid imaging procedures combine radiological procedures and functional imaging, e.g. using somatostatin receptor (SSR) positron emission tomography CT (PET)/CT imaging. For the exact diagnostics of the primary tumor and distant metastases morphological and functional aspects can be combined for targeted diagnostics. For primary tumor staging a sensitivity of 80.0% and a specificity of 88.4% are given in the literature.

PERFORMANCE

The application of SSR PET/CT led to a change in patient management in 44% of all cases according to a recently published meta-analysis and therefore had a significant influence on the further procedure.

ASSESSMENT

The use of SSR PET/CT can provide critical information for further treatment and can lead to a significant change in treatment management in a relevant proportion of patients.

PRACTICAL RECOMMENDATIONS

Radiological imaging diagnostics and in particular hybrid functional imaging procedures using PET/CT will become increasingly more relevant for the diagnostics, treatment and follow-up of NET patients.

Consensus Meeting of Breast Imaging: BI-RADS® and Beyond

Organizers of medical educational courses are often confronted with questions that are clinically relevant yet trespassing the frontiers of scientifically proven, evidence-based medicine at the point of care. Therefore, since 2007 organizers of breast teaching courses in German language met biannually to find a consensus in clinically relevant questions that have not been definitely answered by science. The questions were prepared during the 3 months before the meeting according to a structured process and finally agreed upon the day before the consensus meeting. At the consensus meeting, the open questions concerning 2D/3D mammography, breast ultrasound, MR mammography, interventions as well as risk-based imaging of the breast were presented first for electronic anonymized voting, and then the results of the audience were separately displayed from the expert votes. Thereafter, an introductory statement of the moderator was followed by pros/cons of two experts, and subsequently the final voting was performed. With ≥75% of votes of the expert panel, an answer qualified as a consensus statement. Seventeen consensus statements were gained, addressing for instance the use of 2D/3D mammography, breast ultrasound in screening, MR mammography in women with intermediate breast cancer risk, markers for localization of pathologic axillary lymph nodes, and standards in risk-based imaging of the breast. After the evaluation, comments from the experts on each field were gathered supplementarily. Methodology, transparency, and soundness of statements achieve a unique yield for all course organizers and provide solid pathways for decision making in breast imaging.

[Preliminary application of endoscopic titanium clip localization combined with three-dimensional CT reconstruction in the determination of resection margin of gastric central cancer under laparoscopy]

Objective: To evaluate the accuracy of endoscopic titanium clip localization combined with CT three-dimensional reconstruction for the control of incision margin in early gastric cancer under laparoscopy. Methods: A prospective analysis was made for gastric cancer whose lesions were located in the middle of the stomach and T stage was 1 to 2 from October 2017 to January 2019 at Department of Gastrointestinal and Pancreatic Surgery, Zhejiang Provincial People's Hospital. Totally 25 patients were eventually enrolled in the study. There were 17 males and 8 females aging of (63.6± 7.2) years (range: 48 to 77 years). All cases were treated with titanium clip localization under endoscope combined with CT three-dimensional (3D) reconstruction to construct a virtual panorama of gastric cavity and lesions, and to design surgical margins. Laparoscopic surgical resection was performed according to the surgical margins designed before operation. The distance from the gastric angle to the origin of the minor curvature of the incisional margin, the distance from the gastric angle to the the center of lesion and the distance of the upper incision margin were measured under three-dimensional CT reconstruction and under actual specimen. Paired t test was used to compare the three distances measured by two methods. Results: The measured distances from the gastric angle to the center of the lesion and the proximal incisional margin under 3D reconstruction CT were according to the measured values of actual specimens ((2.67±1.38) cm vs. (2.83±1.56) cm, t=1.51, P=0.14; (5.23±0.60) cm vs. 5 cm, t=1.93, P=0.07); the measured distances from the gastric angle to the origin of the minor curvature of the incisional margin under CT 3D reconstruction were different with the measured values of solid specimens ((5.94±0.94) cm vs. (6.37±0.90) cm, t=3.52, P=0.00). Conclusion: The method of titanium clip localization combined with CT 3D reconstruction can provide a feasible laparoscopic localization method and incision edge solution for T1 to 2 gastric central cancer.

The Feasibility and Safety of Preoperative Fluorescence Marking with Indocyanine Green (ICG) in Laparoscopic Gastrectomy for Gastric Cancer

BACKGROUND

Securing the surgical margin is the most essential and important task in curative surgery. However, it is difficult to accurately identify the tumor location during laparoscopic surgery for gastric cancer, and existing methods, such as preoperative endoscopic marking with tattooing and clipping, have multiple disadvantages.

AIMS

We investigated the feasibility and safety of indocyanine green (ICG) fluorescence marking for determining the tumor location during laparoscopic gastrectomy.

METHODS

We retrospectively analyzed preoperative and perioperative data from consecutive patients with gastric cancer undergoing planned laparoscopic distal gastrectomy. Data was maintained in a prospectively compiled surgical database, and patients were categorized into ICG (n = 84) or non-ICG (n = 174) groups based on whether they underwent preoperative endoscopic mucosal ICG injection. One-to-one propensity score matching (PSM) was performed to compare outcomes between the two groups.

RESULTS

We included 84 patient pairs after PSM, and there were no significant differences in preoperative patient characteristics. The ICG group had shorter procedure time (p < 0.001), lower estimated blood loss (p = 0.005), and significantly shorter postoperative hospital stay (p < 0.001). Positive resection margins were confirmed in five cases (6.0%) in the non-ICG group, whereas there were none in the ICG group (p = 0.008). Real-time confirmation was possible during laparoscopy, and the injected ICG did not affect the surgical procedure or result in adverse events.

CONCLUSION

ICG fluorescence imaging is feasible and safe and can potentially be used as a tumor-marking agent for determining the surgical resection line.

Prognostic significance of primary tumor localization in stage II and III colon cancer

AIM

To investigate the effects of tumor localization on disease free survival (DFS) and overall survival (OS) in patients with stage II-III colon cancer.

METHODS

This retrospective study included 942 patients with stage II and III colon cancer, which were followed up in our clinics between 1995 and 2017. The tumors from the caecum to splenic flexure were defined as right colon cancer (RCC) and those from splenic flexure to the sigmoid colon as left colon cancer (LCC).

RESULTS

The median age of the patients was 58 years (range: 19-94 years). Male patients constituted 54.2%. The rates of RCC and LCC were 48.4% (n = 456) and 51.6% (n = 486), respectively. During the median follow-up of 90 mo (range: 6-252 mo), 14.6% of patients developed recurrence and 9.1% of patients died. In patients with stage II and III disease with or without adjuvant therapy, DFS was similar in terms of primary tumor localization (stage II; P = 0.547 and P = 0.481, respectively; stage III; P = 0.976 and P = 0.978, respectively). In patients with stage II and III disease with or without adjuvant therapy, OS was not statistically significant with respect to primary tumor localization (stage II; P = 0.381 and P = 0.947, respectively; stage III; P = 0.378 and P = 0.904, respectively). The difference between median OS of recurrent RCC (26 ± 6.2 mo) and LCC (34 ± 4.9 mo) cases was eight months (P = 0.092).

CONCLUSION

Our study showed no association of tumor localization with either DFS or OS in patients with stage II or III colon cancer managed with or without adjuvant therapy. However, post-recurrence OS appeared to be worse in RCC patients.

Intraoperative ultrasound in breast cancer surgery-from localization of non-palpable tumors to objectively measurable excision

Background

The utilization of intraoperative ultrasound (IOUS) in breast cancer surgery is a relatively new concept in surgical oncology. Over the last few decades, the field of breast cancer surgery has been striving for a more rational approach, directing its efforts towards removing the tumor entirely yet sparing tissue and structures not infiltrated by tumor cells. Further progress in objectivity and optimization of breast cancer excision is possible if we make the tumor and surrounding tissue visible and measurable in real time, during the course of the operation; IOUS seems to be the optimal solution to this complex requirement. IOUS was introduced into clinical practice as a device for visualization of non-palpable tumors, and compared to wire-guided localization (WGL), IOUS was always at least a viable, or much better alternative, in terms of both precision in identification and resection and for patients’ and surgeons’ comfort. In recent years, intraoperative ultrasound has been used in the surgery of palpable tumors to optimize resection procedures and overcome the disadvantages of classic palpation guided surgery.

Objective

The aim of this review is to show the role of IOUS in contemporary breast cancer surgery and its changes over time.

Methods

A PubMed database comprehensive search was conducted to identify all relevant articles according to assigned key words.

Conclusion

Over time, the use of IOUS has been transformed from being the means of localizing non-palpable lesions to an instrument yielding a reduced number of positive resection margins, with a smaller volume of healthy breast tissue excided around tumor, by making the excision of the tumor optimal and objectively measurable.

Vulvar cancer: Two pathways with different localization and prognosis

BACKGROUND

Two etiologic pathways for vulvar squamous cell carcinoma (SCC) are described: in a background of lichen sclerosus and/or differentiated vulvar intraepithelial neoplasia and related to high-risk human papillomavirus (HPV) infection with high grade squamous intraepithelial lesion (HSIL) as precursor. The aim was to compare the predilection site and survival of HPV-related to non HPV-related vulvar SCCs.

METHODS

Data of patients treated for primary vulvar SCC at the Radboudumc between March 1988 and January 2015 were analyzed. All histological specimens were tested for HPV with the SPF₁₀/DEIA/LiPA₂₅ system assay and p16^INK4a staining was performed using CINtec® histology kit. Vulvar SCCs were considered HPV-related in case of either >25% p16^INK4a expression and HPV positivity or >25% p16^INK4a expression and HSIL next to the tumor without HPV positivity. Tumor localization, disease specific survival (DSS), disease free survival (DFS) and overall survival (OS) of patients with HPV-related and non HPV-related vulvar SCC were compared.

RESULTS

In total 318 patients were included: 55 (17%) had HPV-related (Group 1) and 263 (83%) had non HPV-related vulvar SCC (Group 2). Tumors in Group 1 were significantly more often located at the perineum compared to Group 2, 30% and 14%, respectively (p=0.001). The DSS, DFS and OS were significantly better in HPV-related than in non HPV-related vulvar SCC patients.

CONCLUSION

HPV-related vulvar SCCs are more frequently located at the perineum and have a favorable prognosis compared to non HPV-related vulvar SCCs. Both localization and HPV-relation could explain this favorable prognosis. HPV-related vulvar SCC seems to be a separate entity.

Diagnostic utility of staging abdominal computerized tomography and repeat endoscopy in detecting localization errors at initial endoscopy in colorectal cancer

BACKGROUND

Colonoscopy has a reported localization error rate as high as 21% in detecting colorectal neoplasms. Preoperative repeat endoscopy has been shown to be protective against localization errors. There is a paucity of literature assessing the utility of staging computerized tomography (CT) and repeat endoscopy as diagnostic tools for detecting localization errors following initial endoscopy. The objective of this study is to determine the diagnostic characteristics of staging CT and repeat endoscopy in correcting localization errors at initial endoscopy.

METHODS

A retrospective cohort study was conducted at a large tertiary academic center between January 2006 and August 2014. All patients undergoing surgical resection for CRC were identified. Group comparisons were conducted between (1) patients that underwent only staging CT (staging CT group), and (2) patients that underwent staging CT and repeat endoscopy (repeat endoscopy group). The primary outcome was localization error correction rate for errors at initial endoscopy.

RESULTS

594 patients were identified, 196 (33.0%) in the repeat endoscopy group, and 398 (77.0%) patients in the staging CT group. Error rates for each modality were as follows: initial endoscopy 8.8% (95% CI 6.5-11.0), staging CT 9.3% (95% CI 6.5-11.0), and repeat endoscopy 2.6% (95% CI 0.3-4.7); p < 0.01. Repeat endoscopy was superior to staging CT in correcting localization errors for left-sided / rectal lesions (81.2% vs. 33.3%; p < 0.01), right-sided lesions (80.0% vs. 54.5%; p = 0.21), and overall lesions (80.8% vs. 42.3%; p < 0.01). Repeat endoscopy compared to staging CT demonstrated relative risk reduction of 66.7% (95% CI 22-86%), absolute risk reduction of 38.5% (95% CI 14.2-62.8%), and odds ratio of 0.18 (95% CI 0.05-0.61) for correcting errors at initial endoscopy.

CONCLUSIONS

Repeat endoscopy in colorectal cancer is superior to staging CT as a diagnostic tool for correcting localization-based errors at initial endoscopy.

A Promising Method for Tumor Localization during Total Laparoscopic Distal Gastrectomy: Preoperative Endoscopic Clipping based on Negative Biopsy and Selective Intraoperative Radiography Findings

PURPOSE

Precise localization of tumors and creation of sufficient proximal resection margins are complicated processes during total laparoscopic distal gastrectomy (TLDG) for clinical T1/T2 gastric cancers. Various solutions to this problem have also yielded many disadvantages. In this study, we reviewed a preoperative endoscopic clipping method based on the results of negative biopsy and selective intraoperative radiography.

MATERIALS AND METHODS

A retrospective review of 345 consecutive patients who underwent TLDG and preoperative endoscopic clipping for tumor localization was conducted. During preoperative endoscopy, the endoscopists performed negative biopsies just 1-2 cm selectively above the tumor's upper limit. After confirming the biopsy results, endoscopic metal clips were applied just proximal to the negative biopsy site the day before surgery. Selective intraoperative tumor localization using portable abdominal radiography was performed only when we could not ensure a precise resection line.

RESULTS

Negative biopsy was performed in 244 patients. Larger tumor size (P=0.008) and more distally located tumors (P=0.052) were observed more frequently in the negative biopsy group than in the non-negative biopsy group. The non-negative biopsy group had significantly higher frequencies of differentiated tumor types than the negative biopsy group (P=0.003). Of the 244 patients who underwent negative biopsies, 6 had cancer cells in their biopsy specimens. We performed intraoperative radiography in 12 patients whose tumors had difficult-to-determine proximal margins. No tumors were found in the proximal resection margins of any patients.

CONCLUSIONS

Our tumor localization method is a promising and accurate method for securing a sufficient resection margin during TLDG.

Reflector-guided breast tumor localization versus wire localization for lumpectomies: A comparison of surgical outcomes

PURPOSE

To compare surgical outcomes of SAVI SCOUT reflector localization (SSL) versus wire localization (WL) for breast tumors.

METHODS

Retrospective review of 42 SSL cases and 42 WL cases. WL patients were consecutively matched for clinical-pathologic features. Final surgical outcome measures were tumor specimen volume, margin status, and re-excision rates.

RESULTS

No significant differences were present in median specimen volumes (SSL-15.2cm³ vs. WL-16.3cm³), positive margin rate (SSL-9.5% vs. WL-7.1%), close margin rate (SSL-7.1% vs. WL-11.9%) or re-excision rate (SSL-7.1% vs. WL-9.5%).

CONCLUSION

SSL is an acceptable alternative to WL with no significant differences in surgical outcomes.

Simple and reliable method for tumor localization during totally laparoscopic gastrectomy: intraoperative laparoscopic ultrasonography combined with tattooing

We have developed a new method to localize a tumor during totally laparoscopic gastrectomy that uses intraoperative laparoscopic ultrasonography combined with preoperative clipping and tattooing. One or 2 days before the surgery, endoscopic clipping was performed just proximal to the tumor, followed by tattooing with India ink at the clipping site. Examination by intraoperative laparoscopic ultrasonography was performed at the tattooed site to detect the clips. The resection line of the stomach was determined with use of the detected clips as a marker of the proximal margin of the tumor. This method was attempted in 14 patients who underwent totally laparoscopic gastrectomy, and the clips were successfully identified in all patients. The clips were visualized as several layers of a hyperechoic bar, which was termed a "ladder sign." The mean time from insertion of the laparoscopic probe to identification of the clips was 2 min. The ladder sign is an important finding in this method.

The Value and Evaluability of the PCA3 Urine Assay in Prostate Carcinoma is Independent of the Tumor Localization

INTRODUCTION

The prostate cancer gene 3 (PCA3) test is based on the analysis of tumor cell mRNA in urine. As an exprimated urinary marker, its retrieval is subject to certain physical aspects like palpation pressure and detachment force during the squeezing of cells. Other potential factor of influence may be the distance the cells have to cover until they reach the urethra. Thus, it was investigated whether the localization of the tumors within the prostate with regard to the urethra and the seminal colliculus influences the PCA3 score.

METHODS

Prostatectomy specimens of 55 organ-confined prostate cancer patients were processed according to the Stanford protocol. For each prostatectomy specimen, a three-dimensional reconstruction including the surface of the prostate, the tumor areas and the urethra was created. By model simulating, virtual concentric tubes were placed around the urethra and spherical volumes were virtually positioned around the seminal colliculus at diameters of 8, 16 and 32 mm. Depending on localization, tumor volumes may or may not protrude into the tubes or spherical volumes. For each respective diameter, PCA3 levels were compared between the subgroup with and without protrusion of tumor tissue into the tube or spherical ball.

RESULTS

For none of the diameters, whether in tubes or spherical balls, were patients without intersection volumes-hence showing peripherally located tumors-found to have lower PCA3 levels. No clinical or histopathological parameter correlated with the PCA3 score.

CONCLUSION

The location of the tumor mass in the prostate with respect to the urethra or the seminal colliculus did not to affect the PCA3 score. Hence, the location of the tumor does not limit the validity of the PCA3 score, and even for exclusively peripherall y located tumors, this possible influencing factor did not lead to an artificial modulation of the PCA3 score.

Utilization of iron (III)-doped nanoshells for in vivo marking of nonpalpable tumors using a VX2 rabbit model

BACKGROUND

We aimed to evaluate the potential for ultrasound (US) visible biodegradable nanoshells (NS) as an alternative to wire-guided localization for nonpalpable tumors in vivo.

METHODS

VX2 tumor was injected in bilateral thighs of 22 New Zealand rabbits and after 5 to 10 days, 1 tumor was marked with a wire as a control and the contralateral tumor was injected with 1 mL of 500 nm gas-filled silica NS under Doppler US. Tumors were excised after 24 hours. Chi-square was used for significance, P = .05.

RESULTS

One rabbit was excluded on postoperative day 1 due to equipment failure, no ill effects were observed from the NS. The NS were used to localize and resect 100% of marked tissue, 4/21 wires were displaced (P < .05).

CONCLUSIONS

We have shown that preoperatively injected US visible silica NS can be successfully used to mark nonpalpable tumors in vivo more consistently than WL.

Application of an unsupervised multi-characteristic framework for intermediate-high risk prostate cancer localization using diffusion-weighted MRI

PURPOSE

The aim of this proof-of-concept work is to propose an unsupervised framework that combines multiple parameters, in "positive-if-all-positive" manner, from different models to localize tumors.

METHODS

A voxel-by-voxel analysis of the DW-MRI images of whole prostate was performed to obtain parametric maps for D*, D, f, and K using the IVIM and kurtosis models. Ten patients with moderate or high-risk prostate cancer were included in study. The mean age and serum PSA for these 10 patients were 65years (range 54-78) and 21.9ng/mL (range 4.84-44.81), respectively. These patients were scanned using a DW spin-echo sequence with echo-planar readout with 16 equidistantly spaced b-values in the range of 0-2000s/mm² (TE=58ms; TR=3990ms; spatial resolution 2.19×2.19×2.73mm³, slices =26, FOV=140×140mm, slice gap =0.27mm, NSA=2).

RESULTS

The proposed framework detected 24 lesions of which 14 were true positive with 58% tumor detection rate on lesion-based analysis with sensitivity of 100%. The mpMRI evaluation (PIRADSv2) identified 12 of 14 true positive lesions with sensitivity of 86%; positive predictive value of mpMRI was 92%. The index lesions were visible on all framework maps and were coded as the most suspicious in 9 of 10 patients.

CONCLUSION

Preliminary results of the proposed framework indicate high patient-based sensitivity with 100% detection rate for identifying moderate-high risk aggressive index lesions.

Nanoparticle tumor localization, disruption of autophagosomal trafficking, and prolonged drug delivery improve survival in peritoneal mesothelioma

The treatment outcomes for malignant peritoneal mesothelioma are poor and associated with high co-morbidities due to suboptimal drug delivery. Thus, there is an unmet need for new approaches that concentrate drug at the tumor for a prolonged period of time yielding enhanced antitumor efficacy and improved metrics of treatment success. A paclitaxel-loaded pH-responsive expansile nanoparticle (PTX-eNP) system is described that addresses two unique challenges to improve the outcomes for peritoneal mesothelioma. First, following intraperitoneal administration, eNPs rapidly and specifically localize to tumors. The rate of eNP uptake by tumors is an order of magnitude faster than the rate of uptake in non-malignant cells; and, subsequent accumulation in autophagosomes and disruption of autophagosomal trafficking leads to prolonged intracellular retention of eNPs. The net effect of these combined mechanisms manifests as rapid localization to intraperitoneal tumors within 4 h of injection and persistent intratumoral retention for >14 days. Second, the high tumor-specificity of PTX-eNPs leads to delivery of greater than 100 times higher concentrations of drug in tumors compared to PTX alone and this is maintained for at least seven days following administration. As a result, overall survival of animals with established mesothelioma more than doubled when animals were treated with multiple doses of PTX-eNPs compared to equivalent dosing with PTX or non-responsive PTX-loaded nanoparticles.

A novel endoscopic fluorescent band ligation method for tumor localization. Surg Endosc. 2016;30:4659-4663. [PMID: 26895900 DOI: 10.1007/s00464-016-4785-1]

BACKGROUND

Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery.

METHODS AND MATERIALS

The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system.

RESULTS

The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery.

CONCLUSION

These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.

Anti-cancer, pharmacokinetics and tumor localization studies of pH-, RF- and thermo-responsive nanoparticles

The curcumin-encapsulated chitosan-graft-poly(N-vinyl caprolactam) nanoparticles containing gold nanoparticles (Au-CRC-TRC-NPs) were developed by ionic cross-linking method. After "optimum RF exposure" at 40 W for 5 min, Au-CRC-TRC-NPs dissipated heat energy in the range of ∼42°C, the lower critical solution temperature (LCST) of chitosan-graft-poly(N-vinyl caprolactam), causing controlled curcumin release and apoptosis to cancer cells. Further, in vivo PK/PD studies on swiss albino mice revealed that Au-CRC-TRC-NPs could be sustained in circulation for a week with no harm to internal organs. The colon tumor localization studies revealed that Au-CRC-TRC-NPs were retained in tumor for a week. These results throw light on their feasibility as multi-responsive nanomedicine for RF-assisted cancer treatment modalities.