MRI and FDG-PET for Assessment of Response to Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer

Background

The purpose of this study was to assess the value of magnetic resonance imaging (MRI) and additional ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC).

Methods

Data on 40 patients with LARC, who were treated with NAC and underwent MRI and FDG-PET/CT before and after NAC, were analyzed retrospectively. Surgery was performed at a median of 6 weeks after NAC and the images were compared with the histological findings. The tumor regression grade 3/4 was classified as a responder.

Results

Sixteen patients were pathological responders. Receiver operating characteristic (ROC) analysis revealed that MRI total volume after NAC (MRI-TV2) and ΔMRI-TV had the highest performance to assess responders (area under the ROC curve [AUC] 0.849 and AUC 0.853, respectively). The reduction rate of the maximum standardized uptake value (ΔSUVmax) was also an informative factor (AUC 0.719). There seems no added value of adding FDG-PET/CT to MRI-TV2 and ΔMRI-TV in assessment of NAC responders judging from changes in AUC (AUC of ΔSUVmax and MRI-TV2 was 0.844, and AUC of ΔSUVmax and ΔMRI-TV was 0.846).

Conclusions

MRI-TV2 and ΔMRI-TV were the most accurate factors to assess pathological response to NAC. Although ΔSUVmax by itself was also informative, the addition of FDG-PET/CT to MRI did not improve performance. Patients with LARC who were treated by induction chemotherapy should receive an MRI examination before and after NAC to assess treatment response. A more than 70 % volume reduction shown by MRI volumetry may justify the omission of subsequent radiotherapy.     

Intraoperative Liver Ultrasound Still Affects Surgical Strategy for Patients with Colorectal Metastases in the Modern Era

Background

The present study was designed to evaluate the role of intraoperative ultrasound (IOUS) in intrahepatic staging and the impact on surgical strategy for patients with colorectal liver metastases (CRLM).

Methods

The study included 515 patients who had undergone liver resection for CRLM at two tertiary care referral centers. Data from a prospectively collected database were retrospectively analysed. Early intrahepatic recurrence was assessed at 3 and 6 months after resection and was considered as residual disease undetected by IOUS. Performance of imaging modalities was compared by analysis of studies on individual patients.

Results

A total of 1,370 liver metastases were detected preoperatively with a median of 3 imaging modalities. MRI and PET were performed in 51 and 42 % of the patients, respectively. Median number of days between last imaging and surgery was 18. Contrast-enhanced IOUS was performed in 136 patients (26.4 %). Intraoperatively, 293 new nodules were found in 132 patients: on histology 280 were CRLM (17.6 %). Surgical strategy was changed in 140 patients (27.2 %). On multivariate analysis synchronous and bilobar metastases ≥3 in number, BMI ≥30, and time between last imaging and surgery longer than 18 days resulted in predictive factors indicating new nodules detected by IOUS. Early intrahepatic recurrences were 3.7 and 7.9 % at 3 and 6 months. Performance of CT, MRI, FDG-PET, and intraoperative staging was compared: sensitivity was 63.6, 68.8, 53.6, and 92 % and specificity was 91, 92.3, 95.8, and 97.8 %, respectively

Conclusions

The use of IOUS continues to be mandatory for correct staging of patients with CRLM undergoing liver resection.     

Inzidenz nichtmetastatischer Leberläsionen bei Tumorpatienten

Introduction

Even in patients with a history of solid malignant tumors, especially of gastrointestinal origin, newly diagnosed solid liver lesions do not necessarily correspond to metastases of the respective primary tumor. A reliable diagnosis can only be made by definitive histological examination.

Material and methods

Data of all patients who underwent liver resection under the preoperative diagnosis of liver metastases between 1997 and 2011 and for whom liver specimens were examined histologically, were extracted from the prospectively maintained cancer registry.

Results

An unexpected histological result occurred in 47 out of 770 patients (6.1?%). Primary tumors in these patients included renal cell (n=12), colorectal (n=11), breast (n=8), gastric (n=4), pancreatic (n=3), skin (n=3) and other cancers (n=6). Liver lesions were diagnosed synchronously in 15 cases or metachronously after a median of 17 months following primary therapy in 32 patients. Histology revealed a benign tumor in 38 cases (81?%) as well as 6 cases of HCC, 2 cases of CCC and in 1 case metastasis of a previously unknown colorectal cancer in a patient with known esophageal carcinoma. Suspicion of metastatic disease was based on four different imaging modalities in two cases and on three different imaging modalities in nine cases. Either computed tomography (CT) or magnetic resonance imaging (MRI) was combined with ultrasound in another 23 patients and with positron emission tomography (PET) CT in 6 more cases. In two patients CT plus MRI and CT only, respectively, was performed. In the remaining three patients, suspicion of metastases occurred intraoperatively after macroscopic examination of the liver. Preoperative percutaneous biopsy was attempted in four patients with indeterminate results.

Conclusion

Even with modern diagnostics the risk of treating a benign or other form of malignant tumor with neoadjuvant or palliative chemotherapy persists. The same holds true for local ablative procedures. Prior to local ablation or definitive palliative chemotherapy histological confirmation of metastases should be attempted.     

Bedeutung der FDG-PET/CT für die Chirurgie des Rektumkarzinoms

Background

Examinations using 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) are becoming increasingly more important in clinical practice for the diagnosis and therapy of cancer patients.

Question

What role does FDG-PET/CT examination play in the diagnosis and therapy of rectal cancer?

Results

The FDG-PET/CT method is especially valuable during postoperative care when a recurrence is suspected. Especially when tumor marker levels rise with no other symptoms, FDG-PET/CT can be used to evaluate unclear lesions in the liver and unclear tissue formations at the surgery site and distinguish between scar tissue and recurring tumors. Currently, there is increasing evidence that a survival prognosis may be possible based on the tracer uptake of FDG-PET/CT. There is also a great interest in the possibility of evaluating the success of neoadjuvant therapy with FDG-PET/CT.

Discussion

Despite some limitations FDG-PET/CT plays a significant role in the diagnosis and treatment of patients with rectal cancer.     

The Role and Limitations of 18-Fluoro-2-deoxy-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography (FDG-PET) Scan and Computerized Tomography (CT) in Restaging Patients with Hepatic Colorectal Metastases Following Neoadjuvant Chemotherapy: Comparison with Operative and Pathological Findings

Background Recent data confirmed the importance of 18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in the selection of patients with colorectal hepatic metastases for surgery. Neoadjuvant chemotherapy before hepatic resection in selected cases may improve outcome. The influence of chemotherapy on the sensitivity of FDG-PET and CT in detecting liver metastases is not known. Methods Patients were assigned to either neoadjuvant treatment or immediate hepatic resection according to resectability, risk of recurrence, extrahepatic disease, and patient preference. Two-thirds of them underwent FDG-PET/CT before chemotherapy; all underwent preoperative contrast-enhanced CT and FDG-PET/CT. Those without extensive extrahepatic disease underwent open exploration and resection of all the metastases according to original imaging findings. Operative and pathological findings were compared to imaging results. Results Twenty-seven patients (33 lesions) underwent immediate hepatic resection (group 1), and 48 patients (122 lesions) received preoperative neoadjuvant chemotherapy (group 2). Sensitivity of FDG-PET and CT in detecting colorectal (CR) metastases was significantly higher in group 1 than in group 2 (FDG-PET: 93.3 vs 49%, P < 0.0001; CT: 87.5 vs 65.3, P = 0.038). CT had a higher sensitivity than FDG-PET in detecting CR metastases following neoadjuvant therapy (65.3 vs 49%, P < 0.0001). Sensitivity of FDG-PET, but not of CT, was lower in group 2 patients whose chemotherapy included bevacizumab compared to patients who did not receive bevacizumab (39 vs 59%, P = 0.068). Conclusions FDG-PET/CT sensitivity is lowered by neoadjuvant chemotherapy. CT is more sensitive than FDG-PET in detecting CR metastases following neoadjuvant therapy. Surgical decision-making requires information from multiple imaging modalities and pretreatment findings. Baseline FDG-PET and CT before neoadjuvant therapy are mandatory. The abstract was presented before the 58th Cancer Symposium of the Society of Surgical Oncology, Atlanta, GA, USA, 2005, and before the 2005 Congress of the American Hepato-Pancreato-Biliary Association, Fort-Lauderdale, FL, USA.     

Clinical applicability of magnetic resonance imaging in acute spinal cord trauma

Purpose

To assess the clinical application of magnetic resonance imaging (MRI) in patients with acute spinal cord trauma (SCT) according to the type, extension, and severity of injury and the clinical–radiological correlation.

Methods

Diagnostic imaging [computed tomography (CT) and MRI] tests of 98 patients with acute SCT were analyzed to assess their clinical diagnostic value. The following radiological findings of SCT were investigated: vertebral compression fractures, bursts and dislocations, posterior element fractures, C1 and C2 lesions, vertebral listhesis, bone swelling, spinal canal compression, disk herniation, extradural hematoma, spinal cord contusions, spinal cord swelling, and posterior ligamentous complex (PLC) injuries.

Results

The radiological findings were better visualized using MRI, except for the posterior elements (p = 0.001), which were better identified with CT. A total of 271 lesions were diagnosed as follows: 217 using MRI, 154 using CT, and 100 (36.9 %) using both MRI and CT. MRI detected 117 more lesions than CT.

Conclusion

MRI was significantly superior to CT in the diagnosis of bone swelling, PLC injury, disk herniation, spinal canal compression, spinal cord contusion and swelling present in SCT. MRI detected a larger number of lesions than CT and is highly useful for the diagnosis of soft tissue and intrathecal injuries.     

Staging fluorodeoxyglucose positron emission tomography/computed tomography for muscle-invasive bladder cancer: a nationwide population-based study

Objective

To provide insight into the use and staging information on lymph-node involvement added by fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with muscle-invasive bladder cancer (MIBC), based on a nationwide population-based cohort study.

Patients and methods

We analysed a nationwide cohort of patients with MIBC without signs of distant metastases, newly diagnosed in the Netherlands between November 2017 and October 2019. From this cohort, we selected patients who underwent pre-treatment staging with CT only or CT and FDG-PET/CT. The distribution of patients, disease characteristics, imaging findings, nodal status (clinical nodal stage cN0 vs cN+) and treatment were described for each imaging modality group (CT only vs CT and FDG-PET/CT).

Results

We identified 2731 patients with MIBC: 1888 (69.1%) underwent CT only; 606 (22.2%) underwent CT and FDG-PET/CT, 237 (8.6%) underwent no CT. Of the patients who underwent CT only, 200/1888 (10.6%) were staged as cN+, vs 217/606 (35.8%) who underwent CT and FDG-PET/CT. Stratified analysis showed that this difference was found in patients with clinical tumour stage (cT)2 as well as cT3/4 MIBC. Of patients who underwent both imaging modalities and were staged with CT as cN0, 109/498 (21.9%) were upstaged to cN+ based on FDG-PET/CT. Radical cystectomy (RC) was the most common treatment within both imaging groups. Preoperative chemotherapy was more frequently applied in cN+ disease and in FDG-PET/CT-staged patients. Concordance of pathological N stage after upfront RC was higher among patients staged as cN+ with CT and FDG-PET/CT (50.0% pN+) than those staged as cN+ with only CT (39.3%).

Conclusion

Patients with MIBC who underwent pre-treatment staging with FDG-PET/CT were more often staged as lymph node positive, regardless of cT stage. In patients with MIBC who underwent CT and FDG-PET/CT, FDG-PET/CT led to clinical nodal upstaging in approximately one-fifth. Additional imaging findings may influence subsequent treatment strategies.     

MRI with Gadoxetate Disodium for Colorectal Liver Metastasis: Is It the New “Imaging Modality of Choice”?

Background

Accurate detection of colorectal liver metastasis is paramount in the role of management. This study aims to compare magnetic resonance imaging (MRI) with gadoxetate disodium (a hepatocyte-specific agent—Eovist®) to triple-phase enhanced computed tomography in detecting colorectal liver metastases.

Methods

A retrospective chart analysis of 30 patients from 2011 to 2013 with colorectal liver metastases was performed. Patients with more than 6 weeks or two cycles of chemotherapy between the two imaging modalities were excluded. The number of lesions identified on triple-phase enhanced computed tomography vs. MRI with Eovist® was compared.

Results

Of the 30 patients that met the inclusion criteria, 12 (40 %) patients had more lesions identified on MRI with Eovist® compared to triple-phase enhanced computed tomography. Eighteen (60 %) had no change in the number of lesions identified. When MRI with Eovist® detected more lesions, the mean number of additional lesions detected was 1.5. Eovist® MRI changed the surgical management in 36.7 % of patients.

Conclusion

MRI with Eovist® is superior to enhanced computed tomography in identifying colorectal liver metastases. The increased number of lesion identified on MRI with Eovist® can profoundly change the surgeon’s management. It should be considered the “imaging modality of choice” in preoperative imaging for liver metastases in these patients.     

Evaluation of Tumor Stiffness by Elastography Is Predictive for Pathologic Complete Response to Neoadjuvant Chemotherapy in Patients with Breast Cancer

Background

Breast elastography (EG), which can objectively evaluate tumor stiffness, has been useful for differentiation of benign and malignant breast lesions. However, the value of EG for prediction of response to systemic therapy is poorly understood.

Methods

The baseline evaluations of EG in 55 patients who received neoadjuvant chemotherapy were reviewed. We investigated the correlation between tumor stiffness and response to neoadjuvant chemotherapy. Tumor stiffness was evaluated by the Tsukuba elasticity scoring system.

Results

The mean EG scores were significant lower for the clinical and pathologic complete response (pCR) groups than for the others. When we categorized patients into two groups according to tumor stiffness, 26 patients were assigned to the low EG group (soft, scores from 1 to 3) and 29 patients were assigned to the high EG group (hard, score 4 and 5). The low EG group had significantly higher clinical complete response and pCR rates than the high EG group (clinical complete response, low EG group 38?% vs. high EG group 10?%, P?=?0.024; pCR, low EG group 50?% vs. high EG group 14?%, P?=?0.003, respectively). Furthermore, multivariate analysis indicated that estrogen receptor, human epidermal growth factor receptor 2, and low EG (odds ratio 13.04, 95?% confidence interval 1.19?C458.28, P?=?0.035) were independent predictive factors of pCR.

Conclusions

Tumor stiffness evaluated by EG bears predictive potential for response to neoadjuvant chemotherapy. Stiffness evaluated by EG may be recognized as a clinically significant tumor characteristic, comparable to other data obtained by functional imaging techniques.     

The effects of neoadjuvant chemotherapy and chemo-radiation therapy on MRI staging in invasive bladder cancer: comparative study based on the pathological examination of whole layer bladder wall

Objective

We evaluated the correlation of radiological findings obtained by MRI study with pathological diagnosis in invasive bladder cancer treated with neoadjuvant chemotherapy, with or without radiation.

Design, Setting, and Participants

Twenty-seven patients, who underwent total or partial cystectomy for invasive bladder tumors, were enrolled into the present study. Eight cases had received neoadjuvant chemotherapy following the staging biopsy (group A), ten cases had received chemo-radiation therapy following the staging biopsy (group B), and nine cases had received preoperative staging biopsy alone (group C). As a final treatment, 12 of the 27 patients underwent total cystectomy and the other 15 patients underwent partial cystectomy. MRI was conducted prior to total or partial cystectomy in each case. The pathological stage was assessed by histological examination of the entire layer of the bladder wall.

Results and Limitations

Tumor stage assessed by MRI was consistent with pathological findings in 16 of the 27 cases (59.3%), while MRI produced over-staging in 7 cases and under-staging in 4 cases. The accuracy of staging was 75.0, 30.0, and 77.8% in groups A, B, and C, respectively. The accuracy of MRI staging in group B was lower than that in group C (P < 0.05). There was no difference in the accuracy of MRI staging between groups A and C.

Conclusion

MRI is useful for the staging of bladder cancer. However, care needs to be taken when staging invasive bladder tumors treated with neoadjuvant chemo-radiation therapy, because inflammatory infiltrations and/or fibrous changes caused by the chemotherapy or chemo-radiation therapy make precise staging with MRI difficult.     

Safety and Outcomes Following Resection of Colorectal Liver Metastases in the Era of Current Perioperative Chemotherapy

Background

Preoperative chemotherapy is increasingly utilized in the treatment of colorectal liver metastases (CRLM). Although this strategy may improve resectability, long-term advantages of preoperative chemotherapy for resectable CRLM are less clear. The objective of this study is to report safety and outcomes when perioperative chemotherapy is routinely added to surgery for CRLM.

Methods

A retrospective review of patients undergoing liver resections for CRLM during 2003–2011 in single academic oncology center. Demographic data, tumor characteristics, chemotherapy, surgical details, complications and survival were analyzed.

Results

The study included 157 patients that underwent 168 liver operations. One hundred eighteen patients (70 %) underwent preoperative chemotherapy (75 % oxaliplatin-based). Preoperative portal vein embolization was utilized in 16 (10.1 %) patients. Overall survival (OS) was 89, 57, and 27 % at 1, 3, and 5 years, respectively (median survival—42.8 months). Eleven (7 %) patients had repeat resections for liver recurrence. Thirty-day mortality was 1.26 %, morbidity—24 % (6 %—liver related). Complications were not significantly different in patients that had preoperative chemotherapy. On a multivariate analysis advanced age and >3 lesions predicted poor OS, while advanced age, lesions >5 cm, synchronous lesions, margin-positivity and resection less than hepatectomy were associated with decreased DFS.

Conclusions

Our results suggest that even with chemotherapy and resection only a subset of patients remain disease-free after 5 years. However, even in a high-risk patient with multiple lesions, preoperative chemotherapy can be administered safely without apparent increase in postoperative complications. Perioperative chemotherapy should be considered particularly in patients with multifocal or large lesions, synchronous disease and short disease-free interval.     

Tumor Relapse after Pancreatic Cancer Resection is Detected Earlier by 18-FDG PET than by CT

Introduction

Pancreatic cancer recurrence is often difficult to detect by conventional imaging. Our aim was to evaluate the impact of fluorodeoxyglucose-positron emission tomography (FDG-PET) in the diagnosis of recurrent pancreatic cancer.

Methods

One-hundred thirty-eight patients were followed after resection for pancreatic cancer. Sixty-six underwent only CT and were excluded. Seventy-two patients also had FDG-PET. Recurrent patients were divided in two groups: group-1, CT positive and group 2, CT non diagnostic, FDG-PET positive. Characteristics and survival curves of the two groups were compared. Significance was set at p?<?0.05.

Results

Overall, tumors recurred in 63 of 72 (87.5%) patients; two patients had a second cancer resected, thanks to FDG-PET. Tumor relapse was detected by CT in 35 patients and by FDG-PET in 61. Prognostic factors were similar in groups 1 and 2. Five out of 35 group 1 patients underwent surgery (two R0, two bypass, and one exploratory). Ten out of 28 group 2 patients underwent surgery (four R0, two R2, two bypass, and two exploratory). FDG-PET influenced treatment strategies in 32 of 72 patients (44.4%). Group 2 patients survived longer (P?=?0.09), but the difference was not significant. Disease-free survival was similar in groups 1 and 2.

Conclusion

Tumor relapse is detected earlier by FDG-PET than by CT. FDG-PET can help select the best candidates for surgical exploration, although the real benefit is still to be defined. It influences treatment strategies in a significant percentage of patients. An earlier diagnosis did not influence survival due to the lack of effective therapies.     

Evaluation von Art und Ausmaß der präoperativen Bildgebung vor radikaler Prostatektomie

Background

According to current guidelines, in cases of newly diagnosed prostate cancer the type and extent of imaging to be performed should be based on the patient’s risk profile. We investigated the rate of computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy carried out before radical prostatectomy (RP) depending on the individual risk profile.

Patients and mehod

Between 1 January 2006 and 31 December 2007, a total of 1,018 consecutive patients who had not received neoadjuvant hormone therapy were treated with RP in our department. We determined the preoperative rates of CT, MRI, and bone scintigraphy by reviewing the medical charts. The patients were stratified according to the D’Amico criteria into low-risk, intermediate-risk, and high-risk groups.

Results

Of the 1,018 subjects, 493 (48%) were classified as low-risk, 403 (40%) as intermediate-risk, and 122 (12%) as high-risk patients, respectively. The rate of preoperative abdominal CT/MRI and bone scintigraphy was 17 and 23% in the low-risk group, 25 and 39% in the intermediate-risk patients, and 39 and 57% in the high-risk group.

Conclusion

The rate of preoperative CT and bone scintigraphy is extremely high in the low-risk group. In contrast the rate in the high-risk patients more likely appears to be too low. The discrepancy between the rates of preoperative imaging subject to the patient’s risk profile shows that precisely formulated guidelines addressing this issue are needed.     

Clinical risk scores in the current era of neoadjuvant chemotherapy for colorectal liver metastases

Background

Clinical risk scores (CRS) within the context of neoadjuvant chemotherapy for colorectal liver metastases (CRLM) has not been validated. The predictive value of clinical risk scoring in patients administered neoadjuvant chemotherapy prior to liver surgery for CRLM is evaluated.

Methods

A prospective database over a 15‐year period (April 1999 to March 2014) was analysed. We identified two groups: A, neoadjuvant chemotherapy prior to CRLM surgery; and B, no neoadjuvant chemotherapy.

Results

Overall median survival in groups A and B were 36 (2–137) months and 33 (2–137) months. In group A, nodal status, size, number of metastases and carcinoembryonic antigen levels were not found to be independent predictors of overall survival (OS). However, patients with a shorter disease‐free interval of less than 12 months had an increased OS (P = 0.0001). Multivariate analysis of high‐ and low‐risk scores compared against survival in group B (P < 0.05) confirms the applicability of the scoring system in traditional settings.

Conclusion

Traditional CRS are not a prognostic predictive tool when applied to patients receiving neoadjuvant chemotherapy for CRLM. Disease‐free interval may be one independent variable for use in future risk score systems specifically developed for the neoadjuvant chemotherapy era.     

Radiofrequency Ablation to Improve Survival After Conversion Chemotherapy for Colorectal Liver Metastases

Introduction

Systemic chemotherapy is able to convert colorectal liver metastases (CRLM) that are initially unsuitable for local treatment into locally treatable disease. Surgical resection further improves survival in these patients. Our aim was to evaluate disease-free survival (DFS), overall survival, and morbidity for patients with CRLM treated with RFA following effective downstaging by chemotherapy, and to identify factors associated with recurrence and survival.

Materials and methods

Included patients had liver-dominant CRLM initially unsuitable for local treatment but eligible for RFA or RFA with resection after downstaging by systemic chemotherapy. Chemotherapeutic regimens consisted predominantly of CapOx, with or without bevacizumab. Follow-up was conducted with PET-CT or thoraco-pelvic CT.

Results

Fifty-one patients had a total of 325 CRLM (median = 7). Following chemotherapy, 183 lesions were still visible on CT (median = 3). Twenty-six patients were treated with RFA combined with resection. During surgery, 309 CRLM were retrieved on intraoperative ultrasound (median = 5). Median survival was 49 months and was associated with extrahepatic disease at time of presentation and recurrences after treatment. Estimated cumulative survival at 1, 3 and 4 years was 90, 63 and 45 %, respectively. Median DFS was 6 months. Twelve patients remained free of recurrence after a mean follow-up of 32.6 months.

Conclusion

RFA of CRLM after conversion chemotherapy provides potential local control and a good overall survival. To prevent undertreatment, the involvement of a multidisciplinary team in follow-up imaging and assessment of local treatment possibilities after palliative chemotherapy for liver-dominant CRLM should always be considered.

     

Positron Emission Tomography (PET) has Limited Utility in the Staging of Pancreatic Adenocarcinoma

Background

Positron emission tomography (PET) as an adjunct to conventional imaging in the staging of pancreatic adenocarcinoma is controversial. Herein, we assess the utility of PET in identifying metastatic disease and evaluate the prognostic potential of standard uptake value (SUV).

Methods

Imaging and follow-up data for patients diagnosed with pancreatic adenocarcinoma were reviewed retrospectively. Resectability was assessed based on established criteria, and sensitivity, specificity, and accuracy of PET were compared to those of conventional imaging modalities.

Results

For 123 patients evaluated 2005–2011, PET and CT/MRI were concordant in 108 (88 %) cases; however, PET identified occult metastatic lesions in seven (5.6 %). False-positive PETs delayed surgery for three (8.3 %) patients. In a cohort free of metastatic disease in 78.9 % of cases, the sensitivity and specificity of PET for metastases were 89.3 and 85.1 %, respectively, compared with 62.5 and 93.5 % for CT and 61.5 and 100.0 % for MRI. Positive predictive value and negative predictive value of PET were 64.1 and 96.4 %, respectively, compared with 75.0 and 88.9 % for CT and 100.0 and 91.9 % for MRI. Average difference in maximum SUV of resectable and unresectable lesions was not statistically significant (5.65 vs. 6.5, p?=?0.224) nor was maximum SUV a statistically significant predictor of survival (p?=?0.18).

Conclusion

PET is more sensitive in identifying metastatic lesions than CT or MRI; however, it has a lower specificity, lower positive predictive value, and in some cases, can delay definitive surgical management. Therefore, PET has limited utility as an adjunctive modality in staging of pancreatic adenocarcinoma.     

Immunotherapy response evaluation with 18F-FDG-PET in patients with advanced stage renal cell carcinoma

Background

CT imaging is widely used for response evaluation of immunotherapy in patients with advanced stage renal cell carcinoma (RCC). However, this kind of treatment may not immediately be cytoreductive, although the treatment is successful. This poses new demands on imaging modalities. Positron emission tomography (PET) using ¹⁸F-fluorodeoxyglucose (FDG) proved to be useful in monitoring the effect of several antitumour treatments. We investigated the potential of FDG-PET for the evaluation of response to immunotherapy.

Methods

In seven patients with metastasized RCC, who were treated with either interferon-alpha (IFN-α) monotherapy or a combination of IFN-α, interleukin-2 and 5-fluorouracil, FDG-PET was performed prior and after 5 and 9 weeks of treatment. Quantitative changes of glucose metabolic rate (MR_Glu) were compared with changes in tumour size on CT imaging using Response Evaluation Criteria in Solid Tumors (RECIST) and to survival and progression-free survival.

Results

No consistent changes in MR_Glu were observed within different response groups. And no correlation with CT imaging, neither with survival or progression-free survival, was found.

Conclusion

In contrast to the positive results reported on (chemo) therapy response evaluation with FDG-PET in different malignancies, this imaging modality appears not useful in response monitoring of immunotherapeutic modalities in RCC.     

Die Positronenemissionstomographie zur präoperativen Lymphknotendiagnostik bei Ösophaguskarzinom

Background

Exact preoperative staging is a prerequisite for the indication and the choice of appropriate operative technique for patients with esophageal carcinoma. The objective of this prospective study was to assess whether positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) increases the accuracy of preoperative lymph node staging with standard computed tomography (CT) and thus leads to a different surgical approach.

Patients and methods

Fifty-eight patients with carcinoma of the esophagus (46 men and 12 women) with a median age of 61 years underwent FDG-PET imaging of the neck, chest, and abdomen as well as CT of the chest and abdomen. Sensitivity, specificity, and accuracy were calculated for both imaging techniques to evaluate the detection of histologically verified lymph node metastases.

Results

The FDG-PET showed higher specificity, whereas CT proved to be more accurate for detecting lymph node metastases not only of the abdomen (73% vs 59%) but also of the thorax (73% vs 63%). Resections were transhiatal in 23 patients and transthoracal in 16. As a supplement to conventional CT diagnostic procedure, FDG-PET was not decisive for the surgical approach.

Conclusions

Altogether, pretherapeutical PET imaging did not increase the accuracy of lymph node staging for our patients with esophageal carcinoma, which had already been defined through CT. Therefore, no new consequences resulted for the surgical procedure. Due to the high costs involved with PET investigation, lymph node staging with it is momentarily indicated mainly for clinical studies and when CT does not offer unequivocal results. Increased sensitivity of the already advantageous whole-body FDG-PET imaging by means of tumor-affinitive radiopharmaceuticals and optimized apparatus resolution could lead to new indications for this staging procedure.     

Evolution of Long-Term Outcome of Liver Resection for Colorectal Metastases: Analysis of Actual 5-Year Survival Rates over Two Decades

Background

Liver resection (LR) is the only potentially curative treatment of colorectal liver metastases (CRLM). Its outcome over the past 2 decades was studied using actual 5-year survival rates.

Methods

Data of 393 consecutive patients who underwent LR for CRLM at Mauriziano Umberto I (Turin) until June 2005 were analyzed. Excluding R2 resections (n?=?4) or incomplete 5-year follow-up (n?=?13), 376 patients were divided according to LR date into groups A (before 1995: 90 patients), B (1995?C2000: 94 patients), C (2001?C2005: 192).

Results

Group C presented increased multiple and bilobar metastases compared with combined group A and B (C vs AB: 54.7% vs 40.2%, P?=?0.005; 28.1% vs 19.0%, P?=?0.038, respectively), decreased metastases diameter (C vs AB: 32 vs 40?mm, P?=?0.0001). The 5-year overall survival, calculated excluding 4 operative mortalities (group AB), increased over the years (A, 20.5%; B, 32.6%; C, 46.4%; P?P?=?0.015). Recurrence-free 5-year survival improved (C vs AB: 23.4% vs 13.9%, P?=?0.019) linked to decreased liver recurrences (C vs AB: 26.8% vs 37.4%, P?=?0.023). Resection rate (59% overall for liver recurrence) increased along with 5-year survival after recurrence (A, 4.0%; B, 14.2%; C, 21.4%; P?P?=?0.003) and synchronous metastases (P?=?0.008), N+ tumors (P?=?0.005), and in patients without chemotherapy (P?=?0.001).

Conclusions

Long-term outcome of LR for CRLM improved over 20?years, even in patients with negative prognostic factors, linked to hepatic recurrences reduction and increased survival after recurrence.     

Outcome of Microscopic Incomplete Resection (R1) of Colorectal Liver Metastases in the Era of Neoadjuvant Chemotherapy

Background  

Data from patients with colorectal liver metastases (CRLM) who received neoadjuvant chemotherapy before resection were reviewed and evaluated to see whether neoadjuvant chemotherapy influences the predictive outcome of R1 resections (margin is 0 mm) in patients with CRLM.