Imaging after radiofrequency ablation of renal tumors

The number of percutaneous radiofrequency ablation procedures performed for renal tumors is progressively increasing worldwide. Periodic imaging follow-up has the double role to guarantee the treatment efficacy over time and to early detect any possible complication. Tumor size reductions, as well as the appearance of the characteristic ‘halo sign’, are normal findings that represent good ablative outcomes. However the most reliable factor of ablation efficacy remains the total absence of contrast enhancing zones within the ablated area. The aim of this article is to illustrate the typical aspect of an effective radiofrequency ablation treatment, which are the imaging findings that may suggest the presence of residual tumoral tissue and which are the main early and late procedural complications.

Hypoxia and tumor angiogenesis in the era of hepatocellular carcinoma transarterial loco-regional treatments

This review focuses upon interactions and potential therapeutic targets in the ‘vicious cycle’ between hypoxia and neoangiogenesis following treatment of hepatocellular carcinoma with transarterial loco-regional therapies. Biomarkers correlated with angiogenesis have been studied by many authors as prognostic determinants following transarterial intrahepatic therapy. According to these results future therapies directed toward specific factors related to angiogenesis could play a significant role in preventing local tumor recurrence and remote metastasis.

Synchronous colorectal cancer using CT colonography vs. other means: a systematic review and meta-analysis

OBJECTIVES

The objective of our study was to systematically review the evidence about synchronous colorectal cancer diagnosed with or without computed tomography colonography (CTC).

MATERIALS AND METHODS

Two systematic searches were performed (PubMed and EMBASE) for studies reporting the prevalence of synchronous colorectal cancer (CRC): one considering patients who underwent CTC and the another one considering patients who did not undergo CTC. A three-level analysis was performed to determine the prevalence of patients with synchronous CRC in both groups of studies. Heterogeneity was explored for multiple variables. Pooled prevalence and 95% confidence interval (CI) were calculated. A quality assessment (STROBE) was done for the studies.

RESULTS

For CTC studies, among 2645 articles initially found, 21 including 1673 patients, published from 1997 to 2018, met the inclusion criteria. For non-CTC studies, among 6192 articles initially found, 27 including 111,873 patients published from 1974 to 2015 met the inclusion criteria. The pooled synchronous CRC prevalence was 5.7% (95% CI 4.7%-7.1%) for CTC studies, and 3.9% (95% CI 3.3%-4.4%) for non-CTC studies, with a significant difference (p = 0.004). A low heterogeneity was found for the CTC group (I² = 10.3%), whereas a high heterogeneity was found in the non-CTC group of studies (I² = 93.5%), and no significant explanatory variables were found. Of the 22 STROBE items, a mean of 18 (82%) was fulfilled by CTC studies, and a mean of 16 (73%) by non-CTC studies.

CONCLUSIONS

The prevalence of synchronous CRC was about 4-6%. The introduction of CTC is associated with a significant increase of the prevalence of synchronous CRCs.

Early cross-sectional imaging following open and laparoscopic cholecystectomy: a primer for radiologists

Abstract

Performed on either an elective or urgent basis, cholecystectomy currently represents the most common abdominal operation due to the widespread use of laparoscopy and the progressively expanded indications. Compared to traditional open surgery, laparoscopic cholecystectomy minimised the duration of hospitalisation and perioperative mortality. Albeit generally considered safe, cholecystectomy may result in adverse outcomes with non-negligible morbidity. Furthermore, the incidence of worrisome haemorrhages and biliary complications has not been influenced by the technique shift. Due to the growing medico-legal concerns and the vast number of cholecystectomies, radiologists are increasingly requested to investigate recently operated patients. Aiming to increase familiarity with post-cholecystectomy cross-sectional imaging, this paper provides a brief overview of indications and surgical techniques and illustrates the expected early postoperative imaging findings. Afterwards, most iatrogenic complications following open, converted, laparoscopic and laparo-endoscopic rendezvous cholecystectomy are reviewed with examples, including infections, haematoma and active bleeding, residual choledocholithiasis, pancreatitis, biliary obstruction and leakage. Multidetector computed tomography (CT) represents the “workhorse” modality to rapidly investigate the postoperative abdomen in order to provide a reliable basis for an appropriate choice between conservative, interventional or surgical treatment. Emphasis is placed on the role of early magnetic resonance cholangiopancreatography (MRCP) and additional gadoxetic acid-enhanced MRCP to provide a non-invasive anatomic and functional assessment of the operated biliary tract.

Teaching Points

• Having minimised perioperative mortality and hospital stay, laparoscopy has now become the first-line approach to performing cholecystectomy, even in patients with acute cholecystitis.

• Laparoscopic, laparo-endoscopic rendezvous, converted and open cholecystectomy remain associated with non-negligible morbidity, including surgical site infections, haemorrhage, residual lithiasis, pancreatitis, biliary obstruction and leakage.

• Contrast-enhanced multidetector computed tomography (CT) is increasingly requested early after cholecystectomy and represents the “workhorse” modality that rapidly provides a comprehensive assessment of the operated biliary tract and abdomen.

• Magnetic resonance cholangiopancreatography (MRCP) is the best modality to provide anatomic visualisation of the operated biliary tract and is indicated when biliary complications are suspected.

• Additional gadoxetic acid (Gd-EOB-DTPA)-enhanced MRCP non-invasively provides functional biliary assessment, in order to confirm and visualise bile leakage.

Intra-caval Percutaneous Radiofrequency Ablation for a Neuroendocrine Tumor (NET) Metastasis in Transplanted Liver

Less than 1% of patients with liver metastases from neuroendocrine tumors (NETs) are susceptible to liver transplantation. We report a case of a patient transplanted 13 years ago for NET metastases, with a lesion histologically proved for NET metastasis located at the cava vein anastomosis. He was treated with percutaneous radiofrequency ablation (RFA) after a first failed attempt of endovascular approach. The vascular heat sink, which RFA is susceptible to, was considered an advantage in this case, since it restricted the propagation of heat only to the tissue located in the very proximity of the RFA antenna, protecting the inferior vena cava vessel walls. This positive result may suggest an additional use of RFA in selected challenging cases.

DEB-TACE: a standard review

Drug-eluting bead transarterial chemoembolization (DEB-TACE) is a relative new endovascular treatment based on the use of microspheres to release chemotherapeutic agents within a target lesion with controlled pharmacokinetics. This aspect justifies the immediate success of DEB-TACE, that nowadays represents one of the most used treatments for unresectable hepatocellular carcinoma. However, there is no consensus about the choice of the best embolotherapy technique. In this review, we describe the available microspheres and report the results of the main comparative studies, to clarify the role of DEB-TACE in the hepatocellular carcinoma management. We underline that there is no evidence about the superiority of DEB-TACE over conventional TACE in terms of efficacy, but there may be some benefits with respect to safety especially with the improvement of new technologies.

Materials and techniques for percutaneous retrieval of intravascular foreign bodies

The presence of an intravascular foreign body represents a well-known risk of serious complications. While in the past surgical removal of intravascular foreign body was the most common intervention, nowadays a percutaneous approach in the retrieval of an intravascular foreign body is widely accepted as the first-line technique. In the literature, many case reports describe different techniques and materials. This article summarizes and illustrates the main materials and techniques currently applied for percutaneous retrieval of intravascular foreign body, providing a simplified tool with different interventional possibilities, adaptable to different clinical situations.

CT-MRI LI-RADS v2017: A Comprehensive Guide for Beginners

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and the second leading cause of cancer-related deceases worldwide. Early diagnosis is essential for correct management and improvement of prognosis. Proposed for the first time in 2011 and updated for the last time in 2017, the Liver Imaging-Reporting and Data System (LI-RADS) is a comprehensive system for standardized interpretation and reporting of computed tomography (CT) and magnetic resonance imaging (MRI) liver examinations, endorsed by the American College of Radiology to achieve congruence with HCC diagnostic criteria in at-risk populations. Understanding its algorithm is fundamental to correctly apply LI-RADS in clinical practice. In this pictorial review, we provide a guide for beginners, explaining LI-RADS indications, describing major and ancillary features and eventually elucidating the diagnostic algorithm with the use of some clinical examples.

Immediate Clinical Success After Percutaneous Ablation of Extra-adrenal Paraganglioma

Paragangliomas (PGLs) are catecholamine-secreting neoplasms of chromaffin cells and represent a rare but curable cause of secondary hypertension. Surgery is the treatment of choice for symptomatic PGLs. A small (7 mm) extra-adrenal PGL was diagnosed in the right retroperitoneal space in a 19-year-old patient affected by symptomatic hypertension unresponsive to medical treatment. Indication to percutaneous radiofrequency ablation (RFA) was given by a multidisciplinary team on the basis of the size of the nodule, the surgical risks, the young age of the patient, and his wish to reduce as much as possible the post-interventional rehabilitation. To our knowledge, the use of percutaneous RFA in the treatment of retroperitoneal extra-adrenal primary paragangliomas has never been described. We describe its feasibility and the patient's clinical outcome.

Type 2 endoleaks in endovascular aortic repair: cone beam CT and automatic vessel detection to guide the embolization

Background Dual-phase cone beam computed tomography (DP-CBCT) and automatic vessel detection (AVD) software are helpful tools for detecting arteries before planned endovascular interventions. Purpose To evaluate the usefulness of DP-CBCT and AVD software in guiding the trans-arterial embolization (TAE) of challenging T2 lumbar endoleaks (T2-L-EL). Material and Methods Ten patients with T2-L-EL were included in this study. The accuracy of DP-CBCT and the AVD software was defined by the ability to detect the endoleak and arterial feeding vessel, respectively. Technical success was defined as the correct positioning of the microcatheter using AVD software and the successful embolization of the endoleak. Clinical success was defined as the absence of recurrent endoleaks during follow-up and the stability of the sac diameter for persistent endoleaks. The total volume of iodinated contrast medium, overall procedure time, mean procedural radiation dose, and mean fluoroscopy time were recorded. Results The EL was detected by DP-CBCT in all patients. The AVD software identified the feeding arterial branch in all cases. In one patient, the nidus of the endoleak was not reached due to the small caliber of the feeding artery, even though the software had clearly identified the vessel route. The mean contrast volume was 109 mL, the mean overall procedural time was 74.3 min. The mean procedural radiation dose was 140.97 Gy cm², and the mean fluoroscopy time was 29.8 min. Conclusion The use of DP-CBCT and the AVD software is feasible and may facilitate successful embolization in challenging occult T2-L-EL with complex vasculature.

Cooled tip radiofrequency ablation of benign thyroid nodules: preliminary experience with two different devices

Background

Thyroid nodules are very common in general population. Even if benign, they may require a treatment in case of symptoms or cosmetic concerns. In the last years, minimally invasive treatments alternative to surgery have been developed, in particular ultrasound (US) guided radiofrequency ablation (RFA).

Methods

Twenty-four patients (9 males; 15 females; mean age 57.9 years) were treated and divided in two groups (A and B) according to the RFA needle used (18 gauge needle, AMICA; 17 gauge needle, COVIDIEN). Nodules and patients characteristics, together with procedural data were registered pre-treatment and at 1-month follow-up. US visibility of the needle, volume of the nodules, symptoms and cosmetic concerns, complications were registered.

Results

Visibility of the needle was not significantly different in the two groups (P=0.0787). At 1 month the mean volume of the nodules dropped from 37.1 to 25 mL in group A and from 23.2 to 15.4 mL in group B; shrinkage rate (36.9% and 39.5%, respectively) was not significantly different (P=0.3137). Symptoms decreased from 3.1 to 1.4 in group A and from 4 to 1.6 in group B: no significant differences in reductions were observed (P=0.3305). Cosmetic score decreased from 3.7 to 3.4 in group A and from 3.9 to 3.6 in group B: no significant differences in reductions were observed (P=0.96). Total complication rate (18.2% in group A vs. 23.1% in group B) did not showed significant differences (P=0.5049).

Conclusions

The two systems used in our study resulted equivalent in terms of US needle visibility, efficacy, symptom/cosmetic relief, safety. More patients and a longer follow-up are necessary to confirm our results.

Onyx liquid embolic system (LES): an underestimated tool in the management of peripheral bleedings

Ethylene vinyl alcohol or Onyx copolymer (Medtronic) is an embolization agent increasingly used in peripheral interventional radiology. The Onyx Liquid Embolic System (LES) offers a liquid, non-adhesive, non-absorbable, injectable and permanent embolic agent with an indication for neuro-interventional procedures. Due to its physical properties, Onyx has more embolic predictability than other currently available liquid agents, and seems to have great potential in endovascular bleeding management, especially for non-coagulated patients. The aim of this brief review is to analyze the advantages of Onyx in the emergency setting on the basis of evidence in the current literature.

Multidetector CT of iatrogenic and self-inflicted vascular lesions and infections at the groin

Abstract

The number and complexity of endovascular procedures performed via either arterial or venous access are steadily increasing. Albeit associated with higher morbidity compared to the radial approach, the traditional common femoral artery remains the preferred access site in a variety of cardiac, aortic, oncologic and peripheral vascular procedures. Both transarterial and venous cannulation (for electrophysiology, intravenous laser ablation and central catheterisation) at the groin may result in potentially severe vascular access site complications (VASC). Furthermore, vascular and soft-tissue groin infections may develop after untreated VASC or secondarily to non-sterile injections for recreational drug use. VASC and groin infections require rapid diagnosis and appropriate treatment to avoid further, potentially devastating harm. Whereas in the past colour Doppler ultrasound was generally used, in recent years cardiologists, vascular surgeons and interventional radiologists increasingly rely on pelvic and femoral CT angiography. Despite drawbacks of ionising radiation and the need for intravenous contrast, multidetector CT rapidly and consistently provides a panoramic, comprehensive visualisation, which is crucial for correct choice between conservative, endovascular and surgical management. This paper aims to provide radiologists with an increased familiarity with iatrogenic and self-inflicted VASC and infections at the groin by presenting examples of haematomas, active bleeding, pseudoaneurysms, arterial occlusion, arterio-venous fistula, endovenous heat-induced thrombosis, septic thrombophlebitis, soft-tissue infections at the groin, and late sequelae of venous injuries.

Teaching Points

• Complications may develop after femoral arterial or venous access for interventional procedures.

• Arterial injuries include bleeding, pseudoaneurysm, occlusion, arteriovenous fistula, dissection.

• Endovenous heat-induced thrombosis is a specific form of iatrogenic venous complication.

• Iatrogenic infections include groin cellulitis, abscesses and septic thrombophlebitis.

• CT angiography reliably triages vascular access site complications and groin infections.

Elucidating early CT after pancreatico-duodenectomy: a primer for radiologists

Abstract

Pancreatico-duodenectomy (PD) represents the standard surgical treatment for resectable malignancies of the pancreatic head, distal common bile duct, periampullary region and duodenum, and is also performed to manage selected benign tumours and refractory chronic pancreatitis. Despite improved surgical techniques and acceptable mortality, PD remains a technically demanding, high-risk operation burdened with high morbidity (complication rates 40–50% of patients). Multidetector computed tomography (CT) represents the mainstay modality to rapidly investigate the postoperative abdomen, and to provide a consistent basis for an appropriate choice between conservative, interventional or surgical treatment. However, radiologists require familiarity with the surgically altered anatomy, awareness of expected imaging appearances and possible complications to correctly interpret early post-PD CT studies. This paper provides an overview of surgical indications and techniques, discusses risk factors and clinical manifestations of the usual postsurgical complications, and suggests appropriate techniques and indications for early postoperative CT imaging. Afterwards, the usual, normal early post-PD CT findings are presented, including transient fluid, pneumobilia, delayed gastric emptying, identification of pancreatic gland remnant and of surgical anastomoses. Finally, several imaging examples review the most common and some unusual complications such as pancreatic fistula, bile leaks, abscesses, intraluminal and extraluminal haemorrhage, and acute pancreatitis.

Teaching Points

• Pancreatico-duodenectomy (PD) is a technically demanding surgery burdened with high morbidity (40–50%).

• Multidetector CT is the mainstay technique to investigate suspected complications following PD.

• Interpreting post-PD CT requires knowledge of surgically altered anatomy and expected findings.

• CT showing collection at surgical site supports clinico-biological diagnosis of pancreatic fistula.

• Other complications include biliary leaks, haemorrhage, abscesses and venous thrombosis.

State of the art of prostatic arterial embolization for benign prostatic hyperplasia

Prostatectomy via open surgery or transurethral resection of the prostate (TURP) is the standard treatment for benign prostatic hyperplasia (BPH). Several patients present contraindication for standard approach, individuals older than 60 years with urinary tract infection, strictures, post-operative pain, incontinence or urinary retention, sexual dysfunction, and blood loss are not good candidates for surgery. Prostatic artery embolization (PAE) is emerging as a viable method for patients unsuitable for surgery. In this article, we report results about technical and clinical success and safety of the procedure to define the current status.

Interventional radiology of the adrenal glands: current status

As more and more adrenal neoplasms are found incidentally or symptomatically, the need for interventional procedures has being increasing. In recent years these procedures registered continued steady expansion. Interventional radiology of the adrenal glands comprises angiographic and percutaneous procedures. They may be applied both in benign and in malignant pathologies. The present review reports the current status of indications, techniques results and complications of the image-guided procedures.

The prostate cancer focal therapy

Despite prostate cancer (PCa) is the leading form of non-cutaneous cancer in men, most patients with PCa die with disease rather than of the disease. Therefore, the risk of overtreatment should be considered by clinicians who have to distinguish between patients with high risk PCa (who would benefit from radical treatment) and patients who may be managed more conservatively, such as through active surveillance or emerging focal therapy (FT). The aim of FT is to eradicate clinically significant disease while protecting key genito-urinary structures and function from injury. While effectiveness studies comparing FT with conventional care options are still lacking, the rationale supporting FT relies on evidence-based advances such as the understanding of the index lesion's central role in the natural history of the PCa and the improvement of multiparametric magnetic resonance imaging (mpMRI) in the detection and risk stratification of PCa. In this literature review, we want to highlight the rationale for FT in PCa management and the current evidence on patient eligibility. Furthermore, we summarize the best imaging modalities to localize the target lesion, describe the current FT techniques in PCa, provide an update on their oncological outcomes and highlight trends for future research.

The role of interventional radiology in the treatment of epiphora

Epiphora is a relatively common ophthalmologic affection representing almost 5% of clinical consultations in ophthalmology and it consists in the complete or partial obstruction of nasolacrimal duct, leading to insufficient drainage of tears. The traditional treatment is represented by surgery namely, external dacryocystorhinostomy (DCR). Despite the high success rate DCR has many disadvantages and limitations since it requires general anesthesia, it may arise in a permanent facial scar and it is often affected by the reobstruction of the anastomotic tract by fibrotic scars and osteogenic activity. Fluoroscopically guided interventional procedures are a therapeutic alternative to surgery for lacrimal duct system obstructions that can consist either in balloon dacryocystoplasty or in nasolacrimal stent placement. In both cases, a pre-operative imaging characterization of the occlusion is needed for a correct treatment planning. In this review, we propose to highlight the role of interventional radiology in the treatment of epiphora and the role of computed tomography dacryocystography (CTD) in depiction and the pre-interventional planning.

Percutaneous microwave thermosphere ablation of pancreatic tumours

Background

In oncologic field, thermo-ablative procedures have spread more and more. Percutaneous microwave ablation (MWA) showed same benefits and some advantages over radiofrequency ablation (RFA). To date, a disadvantage of both was the not totally predictable size and shape of ablation volume. The aim of this study was to assess feasibility and safety of MWA in nonresectable pancreatic head cancer using a new technology of MW with high power (100 W) and frequency of 2,450 MH.

Methods

Five patients with pancreatic head cancer treated with percutaneous MWA under ultrasound guidance were retrospectively reviewed. Mean lesion diameter was 27.8 mm (range, 25-32 mm). Follow-up was performed by CT after 1, 3, 6 and, when possible, 12 months. The shape of the ablation volume was evaluated with multiplanar reformatting (MPR) using roundness index (RI): a value near 1 represents a more spherical ablation zone shape, and a value distant from 1 implies an oval configuration. Ablation and procedure times were registered, together with hospital stay. The feasibility, safety and quality of life (QoL) were reported.

Results

The procedure was feasible in all patients (100%). A spherical shape of ablation zone was achieved in all cases (mean RI =0.97). Mean ablation and procedure time were respectively of 2.48 and 28 minutes. Mean hospital stay was 4 days. No major complications were observed. Minor complications resolved during the hospital stay. An improvement in QoL was observed in all patients despite a tendency to return to preoperative levels in the months following the procedure.

Conclusions

Percutaneous MWA is a feasible and safe approach for the palliative treatment of advanced stage tumors of the head of the pancreas, despite its complex anatomic relations. The spherical shape of the ablation volume could be related with an improving of the effectiveness and safety.

A multiparametric analysis combining DCE-MRI- and IVIM -derived parameters to improve differentiation of parotid tumors: a pilot study

AIM

To evaluate dynamic contrast-enhanced (DCE)-MRI and diffusion weighted (DW)-MRI diagnostic value to differentiate Warthin tumors (WT) by pleomorphic adenomas (PA).

MATERIALS & METHODS

Seven WT and seven PA were examined. DCE- and  DW-MRI parameters were extracted from volumes of interest; volume of interest-based averages and standard deviations were calculated. Statistical analysis included: linear discriminant analysis, receiver operating characteristic curves, sensitivity and specificity.

RESULTS

No single feature was able to differentiate WT by PA (p > 0.05); linear discriminant analysis analysis showed that a combination of all features or combinations of feature pairs (namely: K^trans(std) & f(std), K^trans(std) & D(std), k_ep(std) & D(std), MRE(av) & TTP(av)) might achieve sensitivity (SENS), specificity (SPEC) = 100%, with a slight reduction after cross-validation analysis (SENS = 0.875; SPEC = 1).

CONCLUSION

Although preliminary and not conclusive, our results suggest that differentiation between WT and PA is possible through a multiparametric approach based on combination of DCE- and DW-MRI parameters.

Use of the ultrasound-based total malignancy score in the management of thyroid nodules

Purpose

The purpose of this study was to validate the role of the total malignancy score (TMS) in identifying thyroid nodules suspicious for malignancy through the sum of their ultrasound features.

Methods

The local ethical committee approved this prospective observational study. We examined 231 nodules in 231 consecutive patients (164 females and 67 males; age range, 20 to 87 years; median age, 59 years; interquartile range, 48 to 70 years) who underwent ultrasound followed by fine-needle aspiration cytology (FNAC). The nodules were further classified using the TMS, which considers ultrasound features (number, echogenicity, structure, halo, margins, Doppler signal, calcifications, and growth), and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), which considers cytological features. Patients with non-negative nodules (TBSRTC categories III to VI) underwent histological analysis, repeated FNAC, or 2 years of regular ultrasound follow-up. The associations between the final diagnosis, each of the ultrasound features, and the TMS were estimated using the chi-square test, the Mann-Whitney U test, and multivariate logistic regression. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of the TMS.

Results

On ultrasound, 47% of the nodules (108 of 231) had a TMS <3, 18% (42 of 231) had a TMS of 3, and 35% (81 of 231) had a TMS >3. The FNAC results of 85% of the nodules (196 of 231) were benign, while 15% (35 of 231) had non-negative results. Hypoechogenicity, solid structure, the presence of microcalcifications, and the number of nodules were independent predictors of the final diagnosis, and the diagnostic accuracy of the TMS was good (area under the ROC curve, 0.82).

Conclusion

The TMS system is simple to use, reliable, easily reproducible, and closely reflects malignancy risk. Based on our results, FNAC could be limited to nodules with a TMS ≥3 without missing any cases of carcinoma.

Immunotherapy treatment: an issue for metabolic response

Since the beginning of second decade of last century, when it was introduced in many oncologic scenarios, immunotherapy has become an important tool in the management of a growing number of cancers. Immunotherapy for cancer appears to be useful, improving not only progression free survival but also overall survival, thus achieving the goal that many advanced cancers, previously considered without effective treatment options, have now become successfully treatable. However, considering the relatively recent introduction of these drugs in clinical scenarios and the continuous release of new drugs, there is a lack of large validated clinical experiences and many issues are today debated amongst which the evaluation of the response to immune-therapy. Engaging the host immune system in fighting against cancer is an energy-consuming process, requiring T-cell recruiting; this process, named "pseudo-progression," sometimes produces an increase of both dimensional and metabolic ratio of the lesions, as well as the appearance of "new lesions." This behavior, always considered as undisputed progressive disease when traditional chemotherapy is employed, should be carefully considered in the field of immunotherapy, where the phenomenon of "flare" followed by regression of the disease can occur. In this paper, Authors analyzed the best available evidence in this field, reviewed the most important issues concerning the development of immunotherapy, and addressed evidence and concerns about the evaluation of response when using immunotherapy drugs, in terms of both radiological and nuclear medicine criteria.