[111In-DPTA-D-Phe1]-octreotide scintigraphy in the management of patients with advanced renal cell carcinoma

Solitary Contralateral Adrenal Metastasis of Renal Cell Carcinoma: 68Ga-DOTATATE PET/CT Findings

ABSTRACT

68Ga-DOTATATE PET/CT is an imaging technique used in the diagnosis of neuroendocrine tumors. Since renal cell carcinoma (RCC) expresses the somatostatin receptors, 68Ga-DOTATATE PET/CT could be used in the surveillance of RCC. However, limited cases showing 68Ga-DOTATATE uptake in the metastases of RCC have been reported before. Herein, we report a case of a 55-year-old woman with a history of left nephrectomy for clear cell renal cell carcinoma 2 years before, and referred to 68Ga-DOTATATE PET/CT for the evaluation of adrenal mass. 68Ga-DOTATATE PET/CT showed intense 68Ga-DOTATATE uptake on the adrenal mass. Histopathology of the adrenal mass confirmed the diagnosis of clear cell renal cell carcinoma metastasis.

Pancreatic Metastasis of Renal Cell Carcinoma: A Surgical Indication for a Disseminated Disease

Pancreatic metastasis (PM) of renal cancer is a rare condition. It is characterized by a long period after initial nephrectomy and a favorable prognosis compared to other pancreatic malignancies. Its diagnosis may confuse clinicians if the medical history is not known. In the era of targeted therapies for metastatic renal carcinoma, surgery stands as the best treatment option for PM of renal cancer. We report the case of a woman who underwent successfully left splenopancreatectomy for corporeal PM of renal cancer treated seven years ago. This case underlines the necessity of long-term follow-up of patients treated for kidney cancer.

A Plea for Surgery in Pancreatic Metastases from Renal Cell Carcinoma: Indications and Outcome from a Multicenter Surgical Experience

BACKGROUND

Pancreatic metastases from renal-cell carcinoma (RCC-PMs) are rare. Surgery may play a role in improving overall (OS) and disease-free survival (DFS).

METHODS

Clinical-pathological features, surgery and follow-up data of patients with RCC-PMs operated on in three pancreatic surgical centers (2000-2019) were retrospectively evaluated.

RESULTS

Thirty-nine patients (21 male/18 female, averaging 65 years) were enrolled. RCC-PMs were metachronous in 36 patients (mean 94 months, up to 24 years after nephrectomy), multiple in 21 patients, and with a median size of 2.5 (range, 0.7-7.5) cm. All the patients underwent pancreatic surgery (33 standard resections, 6 limited resections). Fifteen patients had post-operative complications (morbidity 38.5%). The median DFS was 63 months, and 19 out of 36 patients showed a disease recurrence. The median OS was 134 months, and 13 out of 36 patients were alive with no evidence of disease. At univariate analysis, lymph node positivity (HR 5.1, 95% CI 1.5-18), multi-visceral resection (HR 3.4, 95% CI 1.1-10) and synchronous RCC-PMs (HR 13, 95% CI 3-55) were significantly associated with a short OS.

CONCLUSION

Surgery may allow a DFS up to 17 years in more than one third of patients, even after limited resections. Splenectomy and lymph node dissection are not mandatory.

Metastatic renal cell carcinoma to the pancreas and subcutaneous tissue 10 years after radical nephrectomy: a case report

Background

Synchronous renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue is very rare. Unusual metastatic sites require attention during follow-up of renal cell carcinoma. It is extremely rare for renal cell carcinoma to metastasize to the pancreas; it is also very rare for it to metastasize to the subcutaneous tissue and extremely rare for it to synchronously metastasize to the pancreas and subcutaneous tissue almost a decade after radical nephrectomy. It is well known that most pancreatic tumors are primary pancreatic adenocarcinoma. However, the pancreas can also be an uncommon site for metastasis. We present a rare case of synchronous metastasis of renal cell carcinoma to the pancreas and subcutaneous tissue; we believe it to be only the second such case reported to date.

Case presentation

We describe a case of a 74-year-old Chinese man who was diagnosed with metastatic renal cell carcinoma to the pancreas and subcutaneous tissue at the same time, 10 years after left radical nephrectomy. He received distal pancreatectomy with spleen preservation plus resection of the subcutaneous tissue lesions on the left side of the anterior abdominal wall and right waist. Pathology showed that all resected metastatic tumors were of the clear cell type. The patient was seen in regular follow-up afterward.

Conclusion

Synchronous metastatic renal cell carcinoma to the pancreas and subcutaneous tissue is very rare, and it might occur after primary tumor resection. Patients must undergo lifelong monitoring and follow-up with regular examination so that any possible metastasis can be detected early. The optimal resection strategy should involve adequate resection margins and maximal tissue preservation of the pancreas, because renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue has a good prognosis with long-term survival.

68Ga-DOTATATE Uptake in Pancreatic Metastasis of Renal Cell Carcinoma Mimicking Pancreatic Neuroendocrine Tumor

A 61-year-old man, with a history of prior clear cell renal cell carcinoma in remission, was referred to Ga-DOTATATE PET/CT for the further evaluation of pancreatic tail mass. Ga-DOTATATE PET/CT showed pathologically intense uptake on the pancreatic mass; subsequent biopsy of the pancreatic mass confirmed the diagnosis of clear cell renal cell carcinoma metastasis. Ga-DOTATATE uptake is not specific for neuroendocrine tumors. In the presence of prior malignancy, it should be kept in mind that malignancies apart from neuroendocrine tumors express somatostatin receptors, and they can show Ga-DOTATATE uptake.

Metastatic clear cell renal cell carcinoma demonstrating intense uptake on 68Ga-DOTATATE positron emission tomography: Three case reports and a review of the literature

⁶⁸Ga-DOTATATE positron emission tomography (PET) is a molecular imaging technology which has shown superiority over ¹¹¹In-octreotide scanning for the detection and staging of neuroendocrine tumors. We report three patients with pancreatic masses that were ultimately diagnosed as clear cell renal cell carcinoma (ccRCC) metastases on histopathology. During their initial diagnostic assessment, the three patients underwent both ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) and ⁶⁸Ga-DOTATATE PET. While all three patients' lesions showed variable ¹⁸F-FDG avidity, uptake on ⁶⁸Ga-DOTATATE PET was comparatively intense. The small case series illustrates the need to consider ccRCC in the differential diagnosis of ⁶⁸Ga-DOTATATE avid lesions.

68Ga-DOTATATE Uptake in a Soft Tissue Metastasis From Clear Cell Renal Cell Cancer

A 64-year-old man with a history of metastatic clear cell renal cell cancer was referred for progress Ga-DOTATATE PET/CT imaging. Ga-DOTATATE PET/CT imaging demonstrated increased DOTATATE uptake (SUVmax 13.8) in the left thigh localized to a soft tissue lesion. Cytopathology of the resected lesion was in keeping with a clear cell renal cell cancer metastasis. This case illustrates that Ga-DOTATATE accumulation in a soft tissue lesion can be due to a clear cell renal cell cancer metastasis.

The Accessory Spleen Is an Important Pitfall of 68Ga-DOTANOC PET/CT in the Workup for Pancreatic Neuroendocrine Neoplasm

OBJECTIVE

The aim of the study was to assess the value and potential pitfalls of Ga-DOTANOC positron emission tomography/computed tomography (PET/CT) in patients with suspected pancreatic neuroendocrine neoplasms (pNEN).

METHODS

Consecutive patients referred for Ga-DOTANOC PET/CT for suspected pNEN between May 1, 2011, and October 31, 2014, were retrospectively assessed. Scan data were compared with cytological/histological final diagnosis. Pancreatic neuroendocrine neoplasm detection rate was determined on per-patient and per-lesion basis. Maximum standardized uptake values of lesions were determined.

RESULTS

Fifty-eight patients with 65 lesions were enrolled. Twelve patients had nonconfirmed diagnosis; of these, 7 were positive and 5 negative at PET/CT. Of 46 patients with confirmed diagnosis, 36 had pNEN; of these, 33 were positive, 1 negative, and 2 nonevaluable at PET/CT. Ten patients had non-NE lesions, of which 8 were positive, 1 negative, and 1 nonevaluable at PET/CT. Of 48 patients with positive PET/CT, 8 proved to have non-NE lesions, of which 6 were intrapancreatic accessory spleen. No significant maximum standardized uptake values difference was found between pNEN and non-NE lesions.

CONCLUSIONS

Intrapancreatic accessory spleen is an important pitfall in Ga-DOTANOC PET/CT for suspected pNEN. Cytological/histological confirmation is mandatory before any surgical procedure is undertaken.

Metastases to the Pancreas Encountered on Endoscopic Ultrasound-Guided, Fine-Needle Aspiration

Metastatic lesions in the pancreas are very uncommon and may be difficult to differentiate from the more commonly encountered primary neoplasms derived from the exocrine and endocrine pancreas because of the significant overlap in clinical presentation, imaging, and cytologic features. Metastasis to the pancreas may occur years after treatment of the primary neoplasm and is often not considered on initial evaluation because of the rarity of such events. The possibility of a metastasis to the pancreas should be entertained in patients with any prior history of malignancy because a proper diagnosis is essential in identifying surgical candidates, or avoiding potentially unnecessary surgery and facilitating triage to more appropriate nonoperative therapy. Herein, we describe intrapancreatic metastases secondary to renal cell carcinoma, melanoma, and lung carcinoma, as documented by cytologic examination of endoscopic ultrasound-guided fine-needle aspiration of the pancreatic masses.

Imaging of pancreatic metastases from renal cell carcinoma

Background

To describe the main imaging characteristics of pancreatic metastases from renal cell carcinoma (RCC) with particular attention to CT features, underlining possible criteria for a differential diagnosis.

Methods

15 patients have been included in this study. 14 patients underwent multislice CT with triphasic acquisition (unenhanced, pancreatic parenchymal and portal venous phases). In 9 cases a delayed phase (120 sec) was also acquired. 5 patients underwent MRI, before and after administration of gadolinium.

Results

The mean time interval between nephrectomy and recurrence was 7.5 years (range 1-17 years). On CT metastases avidly enhanced in the parenchymal phase and then demonstrated a significant wash-out, approaching isodensity to the normal pancreatic parenchyma in the portal phase. In the portal phase 20 of the 25 lesions found in the arterial phase were recognizable. On non-enhanced scans, only 13 of the 25 lesions were detected.

On MRI, with the limitations due to the paucity of cases, the metastatic foci appeared hypointense to normal pancreatic tissue on T1-weighted images, and hyperintense on T2- and diffusion-weighted images. After gadolinium, the behaviour was similar to that reported for CT, except for one patient in whom two metastatic foci presented a signal intensity almost isointense to the surrounding parenchyma, accompanied also by an unusual lowering of the signal on DWI (diffusion-weighted imaging) with high b-values. Compared to CT, with MRI the lesions appeared all detectable even on non-enhanced acquisitions.

Conclusion

Renal Cell Carcinomas require a prolonged CT or MRI follow-up.

In patients with RCC history, an early arterial or a pancreatic parenchymal phase is always mandatory, as pancreatic metastases typically present themselves as hypervascular lesions. This behavior is similar to that of neuroendocrine tumors, while the other primary pancreatic tumors tend to be hypovascular.

Radiolabeled antibodies in renal cell carcinoma

Renal cell carcinoma (RCC) is a radio- and chemotherapy resistant tumor, which has a very high morbidity and mortality when metastasized. The current treatment options demonstrate limited efficacy and severe side-effects. Therefore, there is a need for new therapeutic strategies for RCC. As for other malignancies, monoclonal antibodies (mAbs) targeting tumor-associated antigens have been developed for RCC. One of these, mAb G250, targets the MN/CAIX/G250 antigen, which is ubiquitously expressed in clear cell RCC (ccRCC). ccRCC is the most common form of RCC with a prevalence of 80%. Expression of G250 in normal tissue is restricted to the gastrointestinal mucosa and related structures, thereby making it a suitable candidate for targeting ccRCC. In several clinical studies the efficient accumulation of mAb G250 in ccRCC has been demonstrated, resulting in high contrast images. G250-imaging could prove to be a valuable tool in diagnosing metastases in patients with a G250-antigen positive primary tumor and/or in the differential diagnosis of suspect kidney lesions. Furthermore, the therapeutic efficacy of radiolabeled G250 has been investigated in a series of studies. Thus far, most efforts have been devoted to G250 labeled with high doses of ¹³¹I. Other radionuclides which may enhance the therapeutic index of this radiolabeled mAb are currently under investigation. In our institution, an activity dose escalation study is currently ongoing to investigate the therapeutic potential of ¹⁷⁷Lu-labeled G250 in metastatic ccRCC patients. In this review, the current status of the diagnostic and therapeutic properties of radiolabeled antibodies in RCC is described.

Intracranial collision tumor mimicking an octreotide-SPECT positive and FDG-PET negative meningioma

OBJECTIVE/IMPORTANCE: Cancer metastasis to a pre-existing intracranial tumor is rare, but several cases have been reported. We report an unusual case of a "collision tumor" consisting of a renal cell carcinoma metastasis to an intracranial meningioma.

CLINICAL PRESENTATION

A 67-year old male with renal cell carcinoma had an asymptomatic right posterior frontal dural-based lesion identified on a screening CT scan. MRI characteristics of the tumor were consistent with meningioma. On octreotide-SPECT and F-18 fluorodeoxyglucose (FDG)-PET scans, the lesion showed octreotide uptake but did not accumulate FDG, both of which are consistent with a diagnosis of benign meningioma. One week later, he presented with a 1-day history of progressive left-sided weakness. The intracranial tumor was resected, and subacute subdural blood was found overlying a soft, reddish tumor. Microscopic examination was consistent with renal cell carcinoma with a minor portion consisting of meningioma. The meningothelial component was strongly immunoreactive to vimentin and weakly reactive to epithelial membrane antigens. Neither area reacted with glucose transporter-1 (GLUT-1), correlating with low FDG-PET uptake.

CONCLUSION

Collision tumor involving metastatic renal cell carcinoma to an intracranial meningioma is a rare occurrence. Diagnosis by non-invasive means, with use of a combination of octreotide-SPECT and FDG-PET may not accurately reflect the malignant component of such a collision tumor. In this case, the collision tumor also demonstrated a propensity to undergo spontaneous hemorrhage. A high degree of suspicion of intracranial metastasis should be maintained for patients who have known systemic cancer and are found incidentally to have a dural-based mass lesion.

Neuropeptide Y receptors in renal cell carcinomas and nephroblastomas

Numerous peptide receptors are overexpressed in human cancer, permitting in vivo tumor targeting. Among such receptors, those for the neurotransmitter neuropeptide Y (NPY) are overexpressed in various tumors. Since NPY can play a role in the kidney, NPY receptor expression and/or endogenous production of peptides of the NPY family (NPY, PYY, PP) were evaluated in 40 renal cell carcinomas (RCCs) and 18 nephroblastomas. NPY receptor protein expression was investigated by in vitro autoradiography using (125)I-labeled PYY in competition with NPY receptor subtype-selective analogs. NPY, PYY and PP production was assessed immunohistochemically. Fifty-six percent of RCCs expressed the Y1 receptor subtype in moderate density, and 80% of nephroblastomas expressed Y1 and Y2 subtypes in moderate to high density. Y1 was also highly expressed in intratumoral blood vessels. In selected cases, NPY was observed in nerve fibers in close association with intratumoral blood vessels and in the vicinity of tumor cells, while no PYY or PP was detected immunohistochemically in these sites. NPY receptors on renal tumor cells and tumor blood vessels may therefore be the molecular targets of endogenous NPY released by intratumoral nerve fibers. With regard to clinical applications, NPY receptors may act as in vivo targets for receptor-directed therapy of RCCs and nephroblastomas for which alternative therapeutic approaches are still required.

Receptor-Mediated Tumor Targeting with Radiopeptides. Part 1. General Concepts and Methods: Applications to Somatostatin Receptor-Expressing Tumors

Radiolabeled peptides have become important tools in nuclear oncology, both as diagnostics and more recently also as therapeutics. They represent a distinct sector of the molecular targeting approach, which in many areas of therapy will implement the old "magic bullet" concept by specifically directing the therapeutic agent to the site of action. In this three-part review, we present a comprehensive overview of the literature on receptor-mediated tumor targeting with the different radiopeptides currently studied. Part I summarizes the general concepts and methods of targeting, the selection of radioisotopes, chelators, and the criteria of peptide ligand development. Then, the >400 studies on the application to somatostatin/somatostatin-release inhibiting factor receptor-mediated tumor localization and treatment will be reviewed, demonstrating that peptide radiopharmaceuticals have gained an important position in clinical medicine.

Peptide receptors as molecular targets for cancer diagnosis and therapy

During the past decade, proof of the principle that peptide receptors can be used successfully for in vivo targeting of human cancers has been provided. The molecular basis for targeting rests on the in vitro observation that peptide receptors can be expressed in large quantities in certain tumors. The clinical impact is at the diagnostic level: in vivo receptor scintigraphy uses radiolabeled peptides for the localization of tumors and their metastases. It is also at the therapeutic level: peptide receptor radiotherapy of tumors emerges as a serious treatment option. Peptides linked to cytotoxic agents are also considered for therapeutic applications. The use of nonradiolabeled, noncytotoxic peptide analogs for long-term antiproliferative treatment of tumors appears promising for only a few tumor types, whereas the symptomatic treatment of neuroendocrine tumors by somatostatin analogs is clearly successful. The present review summarizes and critically evaluates the in vitro data on peptide and peptide receptor expression in human cancers. These data are considered to be the molecular basis for peptide receptor targeting of tumors. The paradigmatic peptide somatostatin and its receptors are extensively reviewed in the light of in vivo targeting of neuroendocrine tumors. The role of the more recently described targeting peptides vasoactive intestinal peptide, gastrin-releasing peptide, and cholecystokinin/gastrin is discussed. Other emerging and promising peptides and their respective receptors, including neurotensin, substance P, and neuropeptide Y, are introduced. This information relates to established and potential clinical applications in oncology.

Pancreatic resection for metastatic tumors to the pancreas

BACKGROUND AND OBJECTIVES

The incidence of metastases to the pancreas is very low. The benefit of resection of pancreatic metastasis is poorly defined. In this review we evaluated the outcome of patients undergoing pancreatic resection for metastatic tumors to the pancreas.

METHODS

Eight patients underwent pancreatic resection for metastatic tumor from December 1980 to June 2001. The primary cancer was colon carcinoma (n = 4), renal cell cancer (n = 2), duodenal leiomyosarcoma (n = 1), and malignant fibrous histiocytoma (n = 1). The median interval between primary treatment and detection of pancreatic metastases was 36 months. In two cases pancreatic metastases were synchronous with the primary tumor.

RESULTS

Four patients underwent pancreatoduodenectomy, two distal pancreatectomy, one total pancreatectomy, and one median pancreatectomy. Associated resection of extrapancreatic lesions was performed in four patients, including two left hepatectomy and two left colectomy. There was no postoperative mortality, but two patients had a pancreatic and a biliary fistula, respectively. Survival averaged 23 months (range 14-42 months): four patients died for metastatic disease from 14 to 42 months after operation, while four patients are alive and well 14 to 31 months after surgery.

CONCLUSIONS

Pancreatic resection for metastatic disease to the pancreas should be considered even in selected patients with limited extrapancreatic disease. Long-term survival or good palliation may be achieved.