Small beams, fast predictions: a comparison of machine learning dose prediction models for proton minibeam therapy

BACKGROUND

Dose calculations for novel radiotherapy cancer treatments such as proton minibeam radiation therapy is often done using full Monte Carlo (MC) simulations. As MC simulations can be very time consuming for this kind of application, deep learning models have been considered to accelerate dose estimation in cancer patients.

PURPOSE

This work systematically evaluates the dose prediction accuracy, speed and generalization performance of three selected state-of-the-art deep learning models for dose prediction applied to the proton minibeam therapy. The strengths and weaknesses of those models are thoroughly investigated, helping other researchers to decide on a viable algorithm for their own application.

METHODS

The following recently published models are compared: first, a 3D U-Net model trained as a regression network, second, a 3D U-Net trained as a generator of a generative adversarial network (GAN) and third, a dose transformer model which interprets the dose prediction as a sequence translation task. These models are trained to emulate the result of MC simulations. The dose depositions of a proton minibeam with a diameter of 800μm and an energy of 20-100 MeV inside a simple head phantom calculated by full Geant4 MC simulations are used as a case study for this comparison. The spatial resolution is 0.5 mm. Special attention is put on the evaluation of the generalization performance of the investigated models.

RESULTS

Dose predictions with all models are produced in the order of a second on a GPU, the 3D U-Net models being fastest with an average of 130 ms. An investigated 3D U-Net regression model is found to show the strongest performance with overall 61.0 % ± $\%\pm$ 0.5% of all voxels exhibiting a deviation in energy deposition prediction of less than 3% compared to full MC simulations with no spatial deviation allowed. The 3D U-Net models are observed to show better generalization performance for target geometry variations, while the transformer-based model shows better generalization with regard to the proton energy.

CONCLUSIONS

This paper reveals that (1) all studied deep learning models are significantly faster than non-machine learning approaches predicting the dose in the order of seconds compared to hours for MC, (2) all models provide reasonable accuracy, and (3) the regression-trained 3D U-Net provides the most accurate predictions.

The importance of sentinel lymph node biopsy following neoadjuvant chemotherapy in patients with breast cancer: prospective multicentre trial

INTRODUCTION

The role of sentinel lymph node biopsy (SLNB) in patients with breast cancer after neoadjuvant chemotherapy (NAC) is currently under discussion. The aim of our study was to determine the false negativity rate (FNR) of SLNB, the accuracy of ultrasound examination in the evaluation of the status of lymph nodes and the accuracy of perioperative cryobiopsy of the sentinel lymph node (SLN).

METHODS

Prospective multicentre study, which took place in years 20182020 at three centres in the Czech Republic. A total of 59 patients were evaluated.

RESULTS

The FNR of SLNB in the group of patients with cN1 before NAC and ycN0 after NAC was 12.5%. The FNR of perioperative histological examination of the SLN was 38.5%. The FNR of ultrasound examination of axillary lymph nodes in patients after NAC was 35.5%, and the false positivity rate was 16.7%. The incidence of inflammatory complications in our cohort was 3.3%.

CONCLUSION

The FNR of SLNB in the group of patients with cN1 before NAC and ycN0 after NAC exceeds the tolerable limit of 10%. The FNR of perioperative histological examination of the SLN is high; definitive histological examination of the SLN may change the original diagnostic-therapeutic plan. Ultrasound examination of the axillary lymph nodes in patients after NAC is a method with high false negativity and positivity and may not correspond with the perioperative finding. The incidence of inflammatory complications in our cohort in patients after NAC is comparable to literature data on the frequency of complications in patients without NAC.

BrachyView: development of an algorithm for real-time automatic LDR brachytherapy seed detection

BrachyView is a novel in-body imaging system developed to provide real-time intraoperative dosimetry for low dose rate prostate brachytherapy treatments. Seed positions can be reconstructed after in-vivo implantation using a high-resolution pinhole gamma camera inserted into the patient rectum. The obtained data is a set of 2D projections of the seeds on the image plane. The 3D reconstruction algorithm requires the identification of the seed's centre of mass. This work presents the development and techniques adopted to build an algorithm that provides the means for fully automatic seed centre of mass identification and 3D position reconstruction for real-time applications. The algorithm presented uses a local feature detector, speeded up robust features, to perform detection of brachytherapy seed 2D projections from images, allowing for robust seed identification. Initial results have been obtained with datasets of 30, 96 and 98 I-125 brachytherapy seeds implanted into a prostate gel phantom. It can detect 97% of seeds and correctly match 97% of seeds. The average overall computation time of 2.75 s per image and improved reconstruction accuracy of 22.87% for the 98 seed dataset was noted. Elimination processes for initial false positive detection removal have shown to be extremely effective, resulting in a 99.9% reduction of false positives, and when paired with automatic frame alignment and subtraction procedures allows for the effective removal of excess counts generated by previously implanted needles. The proposed algorithm will allow the BrachyView system to be used as a real-time intraoperative dosimetry tool for low dose rate prostate brachytherapy treatments.

[Surgical procedures for the correction and stabilization of pes planovalgus]

The medial column of the foot is a relevant factor of the pathogenesis of pes planovalgus. Crucial anatomic structures are the tibiocalcaneonavicular ligament complex, the naviculocuneiform joints, including the ossa cuneiformia, and the first tarsometatarsal joint. A combination of bony and soft tissue reconstructive techniques must, therefore, be taken into account when treating pes planovalgus. The present article presents stabilizing and correcting surgical procedures for the medial column of the foot, including basic anatomy and biomechanics.

Harmonic scalpel versus traditional ligation in axillary dissection for breast cancer: a retrospective multivariate analysis

INTRODUCTION

The aim of this pilot retrospective study is to evaluate the complication rate in patients after axillary dissection comparing preparation with harmonic scalpel vs traditional ligation technique, and to analyse risk factors for complications occurrence.

METHODS

144 patients with 148 axillary dissections operated in a single centre between January 2014 and 2019 were included into the study. Axillary dissection was performed using harmonic scalpel in 73 and absorbable ligations in 70 cases.

RESULTS

Seroma formation was observed in 41 patients (56.2%) in the harmonic scalpel group and in 21 patients (30.0%) in the ligations group (p=0.003). The mean period from the surgery to drain removal was 4.0 days in the harmonic scalpel group and 3.0 days in the ligations group (p<0.001). The mean amount of the drained fluid after mastectomy was 300.9 ml in the harmonic scalpel group and 168.7 ml in the ligations group (p=0.005); after breast conserving surgery, it was 241.9 ml and 107.4 ml, respectively (p =0.023).

CONCLUSION

In comparison with traditional ligations with absorbable material, axillary dissection using harmonic scalpel significantly increases the risk of postoperative seroma formation, prolongs the time from the surgery to drain removal, and increases the amount of drained fluid.

High toxicity of Bi(OH)3 and α-Bi2O3 nanoparticles towards malignant 9L and MCF-7 cells

Here we report the extreme toxicity in vitro of Bi(OH)₃ and α-Bi₂O₃ nanoparticles (NPs), obtained through a facile synthesis with an average single particle size of 6-10 nm, tested on malignant gliosarcoma 9L and MCF-7 human breast cancer cells. For both nanomaterials, clonogenic assays reveal a mortality of over 90% in 9L and MCF-7 cells for a concentration of 50 μg/mL after incubation for 24 h. Moreover, the NPs show a significant mortality of up to 60% in the malignant cells at the very low concentration of 6.25 μg/mL. In contrast, at the same concentration, the nanomaterials exhibit no noticeable mortality towards normal Madin-Darby canine kidney cells. The internalisation of the NPs was demonstrated using flow cytometry and confocal microscopy was used to investigate when the loss of cell viability starts. The NPs show a faster cell death in 9L cells compared with MCF-7 cells, demonstrated via the identification of apoptosis through increased sub G₁ levels after 24 h of NP incubation. Cleavage is identified as the main apoptotic nuclear morphology in 9L, which suggests the presence of reactive oxygen species.

Measuring the excitations in a new S = 1/2 quantum spin chain material with competing interactions

Recently a new one-dimensional (1D) quantum spin chain system has been reported: catena-dichloro(2-Cl-3Mpy)copper(II), (where 2-Cl-3Mpy=2-chloro-3-methylpyridine). Preliminary calculations and bulk magnetic property measurements indicate that this system does not undergo magnetic ordering down to 1.8 K and is a prime candidate for investigating frustration in a J ₁/J ₂ system (where the nearest neighbour interactions, J ₁, are ferromagnetic and the next nearest neighbour interactions, J ₂, are antiferromagnetic). Calculations predicted three possible magnetic interaction strengths for J ₁ below 6 meV depending on the orientation of the ligand. For one of the predicted J ₁ values, the existence of a quantum critical point is implied. A deuterated sample of catena-dichloro(2-Cl-3Mpy)copper(II) was synthesised and the excitations measured using inelastic neutron scattering. Scattering indicated the most likely scenario involves spin-chains where each chain consists of only one of the three possible magnetic excitations in this material, rather than the completely random array of exchange interactions within each chain as predicted by Herringer et al (2014 Chem. Eur. J. 20 8355-62). This indicates the possibility of tuning the chemical structure to favour a system which may exhibit a quantum critical point.

Do Genetic Markers of Inflammation Modify the Relationship between Periodontitis and Nonalcoholic Fatty Liver Disease? Findings from the SHIP Study

An association between periodontitis and nonalcoholic fatty liver disease (NAFLD) has been reported by experimental animal and epidemiologic studies. This study investigated whether circulating levels of serum C-reactive protein (CRP) and a weighted genetic CRP score representing markers of inflammatory burden modify the association between periodontitis and NAFLD. Data came from 2,481 participants of the Study of Health in Pomerania who attended baseline examination that occurred between 1997 and 2001. Periodontitis was defined as the percentage of sites (0%, <30%, ≥30%) with probing pocket depth (PD) ≥4 mm, and NAFLD status was determined using liver ultrasound assessment. Serum CRP levels were assayed at a central laboratory, and single-nucleotide polymorphisms previously identified through genome-wide association studies as robustly associated with serum CRP were combined into a weighted genetic CRP score (wGS_CRP). Logistic regression models estimated the association between periodontitis and NAFLD within strata of serum CRP and separately within strata of the wGS_CRP. The prevalence of NAFLD was 26.4% (95% confidence interval [CI], 24.6, 28.1) while 17.8% (95% CI, 16.0-19.6) had ≥30% of sites with PD ≥4 mm. Whereas the wGS_CRP was not a modifier ( P_interaction = 0.8) on the multiplicative scale, serum CRP modified the relationship between periodontitis and NAFLD ( P_interaction = 0.01). The covariate-adjusted prevalence odds ratio of NAFLD comparing participants with ≥30% of sites with PD ≥4 mm to those with no site affected was 2.39 (95% CI, 1.32-4.31) among participants with serum CRP <1 mg/L. The corresponding estimate was 0.97 (95% CI, 0.57-1.66) for participants with serum CRP levels of 1 to 3 mg/L and 1.12 (95% CI, 0.65-1.93) for participants with serum CRP >3 mg/L. Periodontitis was positively associated with higher prevalence odds of NAFLD, and this relationship was modified by serum CRP levels.

Comparative measurements of bone mineral density and bone contrast values in canine femora using dual-energy X-ray absorptiometry and conventional digital radiography

BACKGROUND

Aseptic loosening due to bone remodelling processes after total hip replacement is one common cause for revision surgery. In human medicine, dual-energy X-ray absorptiometry (DEXA) is the gold standard for quantitative evaluation of bone mineral density, whereas in veterinary medicine conventional radiography is used for follow-up studies. Recently, a method has been described using digital X-ray images for quantitative assessment of grey scale values of bone contrast. Therefore, the aim of the present study was to evaluate the correlation of bone mineral density (BMD) measured by DEXA with grey scale values (GV) measured in digital X-ray images (RX50, RX66) ex vivo.

RESULTS

The measured GV in the chosen X-ray settings showed on average a good correlation (r = 0.61) to the measured BMD with DEXA. Correlation between the two X-ray settings was very good (r = 0.81). For comparisons among regions of interests (ROIs) a difference of 8.2% was found to be statistically significant, whereas in the case of RX50 and RX66 differences of 5.3% and 4.1% were found to be statistically significant.

CONCLUSIONS

Results indicate that measuring absolute changes in bone mineral density might be possible using digital radiography. Not all significant differences between ROIs detectable with DEXA can be displayed in the X-ray images because of the lower sensitivity of the radiographs. However, direct comparison of grey scale values of the periprosthetic femur in one individual patient during the follow-up period, in order to predict bone remodelling processes, should be possible, but with a lesser sensitivity than with DEXA. It is important that the same X-ray settings are chosen for each patient for follow-up studies.

[Distal osteotomy for the treatment of hallux valgus (Chevron osteotomy)]

Distal osteotomies, like the Chevron osteotomy, is indicated for mild to moderate hallux valgus deformities. Splayfoot, painful pseudoexostosis, and transfer metatasalgia are observed in the clinical examination. Radiographic examination should be done with weight bearing in two planes. Preoperatively the intermetatarsal (IM), hallux valgus, and distal metatarsal articular (DMAA) angles should be measured. The operative technique is based on soft tissue and bony correction. Modifications of the osteotomy allow a shortening, lengthening, or neutral correction of the first metatarsal. With a modified Chevron osteotomy, an increased DMAA can be also corrected.

[Left hepatic vein injury during laparoscopic fundoplication for giant paraoesophageal hiatal hernia]

INTRODUCTION

After laparoscopic cholecystectomy, laparoscopic fundoplication has become another gold standard of minimal invasive surgery. The level of satisfaction of patients undergoing endoscopic surgery is almost 90%. Laparoscopic fundoplication, like other surgery methods, can also be burdened with grave complications, which could result in a fatal outcome even if the surgery is performed by a skilled surgeon. Even the authors themselves encounter complications despite their rich experience (more than 3,500 laparoscopic operations in the diaphragmatic hiatus area in more than 20 years).

CASE REPORT

The authors report on a rare left hepatic vein injury during laparoscopic hiatoplasty and fundoplication according to Toupet for giant paraoesophageal hiatal hernia.

CONCLUSION

For its low percentage of complications, laparoscopic fundoplication is considered as a safe operative method for gastroesophageal reflux disease and hiatal hernias. However, severe complications may still arise during the surgery and the surgeon should be familiar with them, be prepared for them and be able to manage such complications.Key words: gastroesophageal reflux disease hiatal hernia laparoscopic fundoplication left hepatic vein.

[Secondary angiosarcoma of the abdominal wall after adjuvant radiotherapy in a patient with uterine carcinoma - a case report]

INTRODUCTION

Adjuvant radiotherapy is an integral part of the current treatment of many malignant tumours. However, this mode of treatment does not provide only benefits in the sense of lowering the risks of recurrence, but it is also associated with many undesirable side effects, from which one of the most serious is the development of secondary malignancies.

CASE REPORT

The author describes a case report of 77 years old woman who underwent hysterectomy with bilateral adnexectomy and pelvic lymphadenectomy for uterine carcinoma pT1bN0M0, G1 in 2005. Adjuvant external radiotherapy with the dose 45Gy and brachytherapy 3x4Gy followed. Subsequently the patient was followed at the department of gynecology, which referred her in January 2015 with a quickly growing tumour of the skin and subdermal tissue in the hypogastric area, where previous radiation had been applied. Its excision was indicated with the diagnosis of suspected uterine carcinoma metastasis, but subsequent histological evaluation confirmed angiosarcoma. Despite negative resection margins the tumour quickly recurred and disseminated.

CONCLUSION

Angiosarcoma as a side effect of irradiation is described increasingly more often nowadays. The vast majority of cases are related to the treatment of breast carcinoma. Its prognosis is very poor and therapeutic possibilities are limited. Surgical excision with negative margins remains the mainstay of the treatment. It is necessary to keep this diagnosis in mind and patients undergoing radiation treatment should be followed over a long period.

KEY WORDS

angiosarcoma.

[Laparoscopic resection rectopexy in the treatment of obstructive defecation syndrome]

INTRODUCTION

Obstructive defecation syndrome (ODS) presents a common medical problem, which can be caused by various pelvic disorders; multiple disorders are frequently diagnosed. At the present, a high number of corrective techniques are available via various surgical approaches. Laparoscopic resection rectopexy is a minimally invasive technique, which comprises redundant sigmoidal resection with rectal mobilisation and fixation.

METHODS

The aim of this paper was to evaluate the safety and effectiveness of laparoscopic resection rectopexy in the treatment of patients with ODS. The evaluation was performed via our own patients data analysis and via literature search focused on laparoscopic resection rectopexy.

RESULTS

In total, 12 patients with ODS undergoing laparoscopic resection rectopexy in University Hospital Ostrava during the study period (2012-2015) were included in the study. In our study group, mean age was 64.5 years and mean BMI was 21.9; the group included 11 women (91.6%). ODS was caused by multiple pelvic disorders in all patients. Dolichosigmoideum and rectal prolapse (internal or external) were diagnosed in all included patients. On top of that, rectocoele and enterocoele were diagnosed in several patients. Laparoscopic resection rectopexy was performed without intraoperative complications; mean operative time was 144 minutes. Mean postoperative length of hospital stay was 7 days. Postoperative 30-day morbidity was 16.6%. All postoperative complications were classified as grade II according to Clavien-Dindo classification. Mean preoperative Wexner score was 23.6 points; mean score 6 months after the surgery was 11.3 points. Significant improvement in ODS symptoms was noted in 58.3% of patients, and a slight improvement in 16.6% of patients; resection rectopexy provided no clinical effect in 25% of patients.

CONCLUSION

It is fundamental to carefully select those patients with ODS who could possibly profit from the surgery. Our results, in accordance with published data, suggest that laparoscopic resection rectopexy is a valuable surgical technique in the treatment of patients with ODS caused by multiple pelvic disorders.

KEY WORDS

obstructive defecation syndrome - constipation - resection rectopexy - operative techniques - pelvic floor disorders.

[Rare injury of perineum and anorectum - case report]

Anorectal injuries, with the exception of iatrogenic damage, are rare. Considering the extensive range of causes and potential extent of damage, the diagnosis and treatment of these injuries requires an individual approach to every patient. Based on the extent of damage, the best way of treatment strategy has to be selected for successful treatment of the primary injury and elimination of frequent complications, especially fecal incontinence. The authors present a rare injury of the perineum and anorectum with anorectal sphincter damage in an elderly man after falling down from a stepladder.

KEY WORDS

anorectum - anorectal trauma - anal sphincter.

[Fracture of the Anatomical Neck of the Humerus Associated with Posterior Shoulder Dislocation. Case Report]

A rare case of a fracture of the anatomical neck of the humerus associated with a posterior dislocation of the shoulder in a 43-year-old man is presented. It was managed by immediate surgery using locking plate osteosynthesis. The shoulder was immobilised for 5 weeks in a Gilchrist brace. The outcome was very good with a full range of motion and a stable shoulder at 1 year after injury, with no signs of avascular necrosis of the humeral head. The aetiology of this injury and possibilities of its treatment are discussed. Key words: shoulder dislocation, humeral fractures.

[Perforation of the right ventricle of the heart as a complication of CT guided percutaneous drainage of a subphrenic abscess - a case report]

INTRODUCTION

CT guided percutaneous drainage is currently the gold standard in the treatment of abdominal fluid collections, having substituted open surgical drainage in many cases. It burdens the patient less than surgical drainage. Its efficiency is comparable to standard surgical drainage when properly indicated. It is readily available even in smaller hospitals. However, this method can also have many complications, which originate most often from an improperly targeted drainage catheter.

CASE REPORT

The authors describe a case report of a 55 years old man with a right-sided subphrenic abscess. The right ventricle of the heart was perforated during a CT guided percutaneous drainage. The bleeding was minimal, but the patient suffered a profound septic shock as a result of massive bacteremia during direct communication of the contents of the abscess cavity with blood circulation. He was operated immediately. The right ventricle was sutured, and the subphrenic abscess was drained. There were no complications after the operation, and the patient was discharged on day 17 after the surgery.

CONCLUSION

The CT guided drainage of an abdominal abscess or a fluid collection in a risk area should be preferably done in hospitals whose therapeutic portfolio also includes the handling of serious complications.

KEY WORDS

heart injury drainage.

[Pruritus ani]

INTRODUCTION

Pruritus ani is defined as a dermatologic disease characterized by itching and/or burning in the perianal area. It occurs in 15% of the population. Men are affected more frequently than women, in the ratio 4:1. It is accompanied by an irresistible desire to scratch in the perianal area. Pruritus ani is divided into two subtypes: primary (idiopathic) and secondary. In idiopathic (primary) pruritus it is not possible to detect any other cause of itching. Secondary pruritus has an obvious causal origin.The aim of this paper is to offer a complex overview of possible causes, diagnostic procedures and treatment possibilities of this unpleasant and annoying disease.

METHODS

We have researched available publications using PubMed and MEDLINE databases, focusing on articles on anal pruritus. At first the key word "Pruritus ani" was put in without any restrictions. Subsequently, we limited the selection by the time period of 5 years and 10 years; then we looked up articles in English, German and Czech languages, and finally review articles, clinical trials and others.

RESULTS

574 articles were found without entering any restrictions; 45 of them were review articles and 25 clinical trials. 437 articles were in the English language and 40 of them were review articles. 44 were in the German language and 1 of them was a review article. A total of 33 articles were found with a 5-year time limit. 6 of them were review articles and 4 were clinical trials. 66 articles from the last 10 years were found. 14 of them were review articles and 10 were clinical trials. In most of the other articles among the total number of articles found, pruritus ani was mentioned only marginally in articles focused on different topics. We have not found any summary articles on this topic in Czech publications.

CONCLUSION

Pruritus ani is a common disease with a number of causes; therefore, effective treatment may be insufficient in the initial stages. The therapy is focused on the primary cause, if found. Broad differential diagnosis options need to be taken into consideration, and reevaluation of the therapy is a priority. When no obvious secondary cause is found, the empiric treatment is focused on an improvement of hygiene and change in the life style, removal of common irritators, and protection of perianal skin.

Li ion dynamics along the inner surfaces of layer-structured 2H-LixNbS2

Layer-structured materials, such as graphite (LiCy) or Lix(Co,Ni,Mn)O2, are important electrode materials in current battery research that still relies on insertion materials. This is due to their excellent ability to reversibly accommodate small alkali ions such as Li(+) and Na(+). Despite of these applications, microscopic information on Li ion self-diffusion in transition metal sulfides are relatively rare. Here, we used (7)Li nuclear magnetic resonance (NMR) spectroscopy to study translational Li ion diffusion in hexagonal (2H) LixNbS2 (x = 0.3, 0.7, and 1) by means of variable-temperature NMR relaxometry. (7)Li spin-lattice relaxation rates and (7)Li NMR spectra were used to determine Li jump rates and activation barriers as a function of Li content. Hereby, NMR spin-lattice relaxation rates recorded with the spin-lock technique offered the possibility to study Li ion dynamics on both the short-range and long-range length scale. Information was extracted from complete diffusion-induced rate peaks that are obtained when the relaxation rate is plotted vs inverse temperature. The peak maximum of the three samples studied shifts toward higher temperatures with increasing Li content x in 2H-LixNbS2. Information on the dimensionality of the diffusion process was experimentally obtained by frequency dependent Rρ measurements carried out at T = 444 K, that is in the high-temperature regime of the rate peaks. A slight, but measurable frequency-dependence within this limit is found for all samples; it is in good agreement with predictions from relaxation models developed to approximate low-dimensional (2D) jump diffusion.

Ternary transition-metal fluoride precursors for the fluorolytic sol–gel route: new insights into speciation and decomposition

After successive, incomplete fluorination, complexes containing the motifs [MF_n]⁽³⁻ⁿ⁾⁺ (M = V, Mn, Ni; n = 0–4) have been trapped with pyridine and identified using X-ray diffraction.

Fluorite-Type Solid Solutions in the System Y-Ta-O-N: A Nitrogen-Rich Analogue to Yttria-Stabilized Zirconia (YSZ)

Fluorite-type phases in the system Y-Ta-O-N have been prepared by ammonolysis of Y-Ta-O precursors. X-ray powder patterns show unusual asymmetrical reflection profiles explained by DFT and MD methods. The anion vacancy concentration of some of these oxynitrides is similar to that of yttria-doped zirconia, commercially used as solid electrolyte in fuel cells. Hence, these compounds are interesting candidates for mixed oxygen-nitrogen superion conductors

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.