Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE in individuals with neck or mediastinal paraganglioma (PGL)

Paragangliomas (PGLs) are neuroendocrine tum-ors that arise embryologically from the neural crest. Sympathetic PGLs can be located in the thoracic-abdominal region while parasympathetic PGLs are mainly situated in the head and neck region. Most PGLs are sporadic, but in 30% of cases they are hereditary (associated with mutations of SDHB, SDHC, SDHD, SDHAF2, SDHA, TMEM, MAX, and VHL); they can be classified into 4 different paraganglioma syndromes: PGL1, PGL2, PGL3, and PGL4. Surgery is the treatment of choice for both sympathetic and parasympathetic PGLs. Other types of treatment include medical agents (such as gemcitabine, cisplatin, or sunitinib) and radiotherapy (external-beam radiotherapy or stereotactic surgery). Surgery and radiotherapy, however, can cause important side effects such as vascular complications and peripheral nerve damage (hypoglossal, recurrent laryngeal, glossopharyngeal, and vagus). Another possible treatment option is the use of peptide receptor radionuclide therapy (PRRT), including PRRT with 177Lu-DOTATATE. We studied 4 patients with hereditary nonmetastatic paraganglioma syndrome type 1 (PGL1), with progressive disease, in whom surgical excision was not possible. They were treated with 177Lu-DOTATATE (3-5 cycles) and all had a partial response (PR) or a stable disease (SD) to the treatment. In conclusion, a good alternative treatment when surgical or radiation therapy are contraindicated could be radiometabolic therapy with 177Lu-DOTATATE.

Financial aspects of sentinel lymph node biopsy in early breast cancer

AIM

At present, early breast cancer is treated with conservative surgery of the primary lesion (BCS) along with axillary staging by sentinel lymph node biopsy (SLNB). Although the scintigraphic method is standardized, its surgical application is different for patient compliance, work organization, costs, and diagnosis related group (DRG) reimbursements.

METHODS

We compared four surgical protocols presently used in our region: (A) traditional BCS with axillary lymph node dissection (ALND); (B) BCS with SLNB and concomitant ALND for positive sentinel nodes (SN); (C) BCS and SLNB under local anaesthesia with subsequent ALND under general anaesthesia according to the SN result; (D) SLNB under local anaesthesia with subsequent BCS under local anaesthesia for negative SN, or ALND under general anaesthesia for positive SN. For each protocol, patient compliance, use of consumables, resources and time spent by various dedicated professionals, were analyzed. Furthermore, a detailed breakdown of 1-/2-day hospitalization costs was calculated using specific DRGs.

RESULTS

We reported a mean costs variation that ranged from 1,634 to 2,221 Euros (protocols C and D). The number of procedures performed and the pathologists' results are the most significant variables affecting the rate of DRG reimbursements, that were the highest for protocol D and the lowest for protocol B.

CONCLUSIONS

In our experience protocol C is the most suitable in terms of patient compliance, impact of surgical procedures, and work organization, and is granted by an appropriate DRG. We observed that a multidisciplinary approach enhances overall patient care and that a revaluation of DRG reimbursements is opportune.

Muscle metastases from gallbladder cancer

Gallbladder cancer is a highly fatal disease with poor prognosis; indeed, a high proportion of tumours are diagnosed at an advanced stage. Metastases are commonly detected in regional lymph nodes, liver and peritoneum, but unusual sites of spread such as thyroid and breast have also been described in the literature.We report a case of unsuspected muscle metastases, associated to pulmonary metastases, detected by FDG-PET/CT in a patient with previously removed gallbladder cancer and persistent episodes of haemoptysis.

Pregnant with metastatic neuroendocrine tumour of the ovary: what now?

Neuroendocrine tumours (NET) are a heterogeneous group of neoplasms commonly occurring in the gastrointestinal tract or lungs but can occur in other regions. Primary ovarian NET account for 5% of all NET and 0.1% of all ovarian malignancies. In metastatic disease, the therapeutic goal is to extend survival and to improve quality of life. As these tumours express somatostatin receptors, somatostatin analogues are frequently used to control symptoms. Here we present a case of a pregnant woman with an ovarian NET with liver metastases and carcinoid syndrome who was treated with the somatostatin analogue, Octreotide LAR. We also summarize reported data of the use of somatostatin analogues during pregnancy.

Calculation of electron and isotopes dose point kernels with FLUKA Monte Carlo code for dosimetry in nuclear medicine therapy

PURPOSE

The calculation of patient-specific dose distribution can be achieved by Monte Carlo simulations or by analytical methods. In this study, FLUKA Monte Carlo code has been considered for use in nuclear medicine dosimetry. Up to now, FLUKA has mainly been dedicated to other fields, namely high energy physics, radiation protection, and hadrontherapy. When first employing a Monte Carlo code for nuclear medicine dosimetry, its results concerning electron transport at energies typical of nuclear medicine applications need to be verified. This is commonly achieved by means of calculation of a representative parameter and comparison with reference data. Dose point kernel (DPK), quantifying the energy deposition all around a point isotropic source, is often the one.

METHODS

FLUKA DPKS have been calculated in both water and compact bone for monoenergetic electrons (10-3 MeV) and for beta emitting isotopes commonly used for therapy (89Sr, 90Y, 131I 153Sm, 177Lu, 186Re, and 188Re). Point isotropic sources have been simulated at the center of a water (bone) sphere, and deposed energy has been tallied in concentric shells. FLUKA outcomes have been compared to PENELOPE v.2008 results, calculated in this study as well. Moreover, in case of monoenergetic electrons in water, comparison with the data from the literature (ETRAN, GEANT4, MCNPX) has been done. Maximum percentage differences within 0.8.RCSDA and 0.9.RCSDA for monoenergetic electrons (RCSDA being the continuous slowing down approximation range) and within 0.8.X90 and 0.9.X90 for isotopes (X90 being the radius of the sphere in which 90% of the emitted energy is absorbed) have been computed, together with the average percentage difference within 0.9.RCSDA and 0.9.X90 for electrons and isotopes, respectively.

RESULTS

Concerning monoenergetic electrons, within 0.8.RCSDA (where 90%-97% of the particle energy is deposed), FLUKA and PENELOPE agree mostly within 7%, except for 10 and 20 keV electrons (12% in water, 8.3% in bone). The discrepancies between FLUKA and the other codes are of the same order of magnitude than those observed when comparing the other codes among them, which can be referred to the different simulation algorithms. When considering the beta spectra, discrepancies notably reduce: within 0.9.X90, FLUKA and PENELOPE differ for less than 1% in water and less than 2% in bone with any of the isotopes here considered. Complete data of FLUKA DPKS are given as Supplementary Material as a tool to perform dosimetry by analytical point kernel convolution.

CONCLUSIONS

FLUKA provides reliable results when transporting electrons in the low energy range, proving to be an adequate tool for nuclear medicine dosimetry.

Recent issues on dosimetry and radiobiology for peptide receptor radionuclide therapy

Peptide receptor radionuclide therapy (PRRT) has been constantly evolving over the last decade, providing successful results in the treatment of tumors expressing somatostatin receptors, especially with 90Y -- and 177Lu -- radiolabelled peptides. Recent and/or ongoing studies assure new perspectives to come. Dosimetry represents a precious guide for the selection of radionuclides and peptides, for protocol settings, for toxicity prevention and therapy optimization. Thus, reliable and personalized dosimetry is more and more requested. This paper reviews the important advances recently obtained in the dosimetric methods that have been applied to this therapy. Special emphasis has been given to the impact derived (or derivable in the next future) from more refined dose evaluations focused on the kidneys and the red marrow. The possibility of improving the accuracy of dosimetry represents a further challenge for this therapy. Following the preliminary correlation observed between the biological effective dose and the probability of renal injury, more reliable dose estimates could definitively enhance the predicitivity of the radiobiological effects, for toxicity prevention as well as for tumor control.

Testing of microbial contamination during the preparation of the radiocompound [⁹⁰Y]DOTATOC for clinical trials: a process validation study by Media Fill approach

AIM

Radioisotopes used in nuclear radiopharmacy possess short half-lives, not allowing enough time to wait for completion of sterility tests. Moreover, carrying out sterility tests on highly radioactive solutions inside the hospital microbiology laboratory arises concerns about radioprotection. Therefore, the release of radiopharmaceuticals for injection is allowed in microbial analysis. For this reason, the effectiveness of the aseptic procedures has to be continuously assessed in order to guarantee the safety of the drug. The aim of this study was to validate the sterile preparation of [⁹⁰Y]DOTATOC by means of media fill test.

METHODS

In order to validate the process, a simulation test was used: the media fill test. To apply this method, operators simulated each step of the process using culture medium (Triptic Soy Broth, TSB) instead of actual radiopharmaceutical product. Media fill test procedure has been subdivided into 5 phases, from the simulation of reagent preparation through the dispensing operations up to ward delivery. After every step, the processed medium was incubated at 35 °C for 14 days. If the compounding procedures are adequately performed, no growth of microorganisms will be detected.

RESULTS

Microbiological analyses, carried out on all vials obtained at the end of each step, showed no microbial growth. For this reason, sterility tests were considered satisfactory.

CONCLUSION

Application of media-fill test allowed both to validate operative modality used for [⁹⁰Y]-DOTATOC handling and to attest the ability of operators who worked on it. Additionally, a correct quality control of the radiopharmaceutical i.v. preparations allows clinic infections control and prevention.

An unusual breast lesion: the ultrasonographic, mammographic, MRI and nuclear medicine findings of mammary hibernoma

We report the case of a 42-year-old woman being treated for an ovarian cancer who was diagnosed at the age of 40. A CT-positron emission tomography (PET) scan performed as follow-up documented abnormal uptake in the right breast. Mammograms were negative for malignancy, while a focal hyperechoic lesion was observed on ultrasonography in the same breast. Thus, she was referred to our institution for breast MRI, which showed a focal area of enhancement with atypical features. Percutaneous biopsy was performed, and a mammary hibernoma was diagnosed. Radiological and pathological correlation was provided. To our knowledge, this is the only report that describes the features of this rare tumour on four different imaging modalities (mammography, ultrasonography, MRI and CT-PET).

Peptide receptor radionuclide therapy (PRRT) of neuroendocrine tumors with somatostatin analogues

BACKGROUND

Clinical experience with the radiolabeled somatostatin analogues 90Y-DOTATOC and, more recently, 177Lu-DOTATATE, is ongoing since more than a decade in few centers. Dosimetric studies demonstrated that 90Y-DOTATOC and 177Lu-DOTATATE are able to deliver high doses to somatostatin receptor sst2-expressing tumors and low doses to normal organs.

RESULTS AND CONCLUSIONS

Clinical studies demonstrated that partial and complete objective responses in up to 30% of patients can be obtained, with a great survival benefit in treated patients. Side effects may involve the kidney and the bone marrow and are usually mild. Renal protection is used to minimize the risk of a late decrease of renal function.

Dosimetry for treatment with radiolabelled somatostatin analogues. A review

Peptide Receptor Radionuclide Therapy (PRRT) has proven its efficacy in the treatment of neuroendocrine and other somatostatin receptor expressing tumours (SR-tumours). Several clinical trials have confirmed that adverse effects are represented by possible renal impairment, which is the major concern, and low but not absent hematological toxicity. High kidney irradiation is a constant, despite the sparing of dose obtained by renal protectors. Hematological toxicity, although low, needs to be monitored. The clinical and dosimetry results collected in more than a decade have recognized weak points to unravel, increased knowledge, offering new views. When planning therapy with radiopeptides, the large patients' variability as for biodistribution and tumour uptake must be taken into account in order to tailor the therapy, or at least to avoid foreseeable gross treatments. Reliable and personalized dosimetry is more and more requested. This paper reviews through the literature the methods to study the biokinetics, the dosimetry outcomes, some clue information and correlations obtained once applying the radiobiological models. Special focus is given on recent improvements and indications for critical organ protection that light up challenging perspectives for PRRT.

A parathyroid carcinoma within a cold thyroid nodule

We report the case of a 71-year-old woman who was referred to our institute with a solid nodule in the right thyroid lobe and hypercalcemia. Ultrasound revealed a well-vascularized right thyroid nodule that was identified as a cold area by ^99mTc-sodium pertechnetate scan. Fine-needle aspiration showed a follicular lesion and blood tests revealed hypercalcemia and hyperparathyroidism. A ^99mTc-methoxyisobutylisonitrile (^99mTc-Sestamibi) scan was subsequently performed revealing a focal area of increased uptake in the right thyroid lobe, within the cold area detected by the thyroid scan. A right emithyroidectomy and right superior and inferior parathyroidectomy was performed and histopathological examination showed a parathyroid carcinoma (immunohistochemistry positive for PTH and chromogranin A, Ki-67 10%) associated with follicular hyperplasia.

IART (Intra-Operative Avidination for Radionuclide Therapy) for accelerated radiotherapy in breast cancer patients. Technical aspects and preliminary results of a phase II study with 90Y-labelled biotin

BACKGROUND

Breast conserving surgery (BCS) plus external beam radiotherapy (EBRT) is considered the standard treatment for early breast cancer. We have investigated the possibility of irradiating the residual gland, using an innovative nuclear medicine approach named IART(®) (Intra-operative Avidination for Radionuclide Therapy).

AIM

The objective of this study was to determine the optimal dose of avidin with a fixed activity (3.7 GBq) of (90)Y-biotin, in order to provide a boost of 20 Gy, followed by EBRT to the whole breast (WB) at the reduced dose of 40 Gy. Local and systemic toxicity, patient's quality of life, including the cosmetic results after the combined treatment with IART(®) and EBRT, were assessed.

METHODS

After tumour excision, the surgeon injected native avidin diluted in 30 ml of saline solution into and around the tumour bed (see video). Patients received one of three avidin dose levels: 50 mg (10 pts), 100 mg (15 pts) and 150 mg (10 pts). Between 12 to 24 h after surgery, 3.7 GBq (90)Y-biotin spiked with 185 MBq (111)In-biotin was administered intravenously (i.v.). Whole body scans and SPECT images were performed up to 30 h post-injection for dosimetric purposes. WB-EBRT was administered four weeks after the IART(®) boost. Local toxicity and quality of life were evaluated.

RESULTS

Thirty-five patients were evaluated. No side effects were observed after avidin administration and (90)Y-biotin infusion. An avidin dose level of 100 mg resulted the most appropriate in order to deliver the required radiation dose (19.5 ± 4.0 Gy) to the surgical bed. At the end of IART(®), no local toxicity occurred and the overall cosmetic result was good. The tolerance to the reduced EBRT was also good. The highest grade of transient local toxicity was G3, which occurred in 3/32 pts following the completion of WB-EBRT. The combination of IART(®)+EBRT was well accepted by the patients, without any changes to their quality of life.

CONCLUSIONS

These preliminary results support the hypothesis that IART(®) may represent a valid approach to accelerated WB irradiation after BCS. We hope that this nuclear medicine technique will contribute to a better management of breast cancer patients.

Detection of a cardiac mass by [18F]FDG-PET/CT: a rare case

Intra-cardiac masses present an important problem in cardiology. The differential diagnoses includes tumours, which may be primary (benign or malignant) or metastatic, and infected mural thrombi.Myxomas, sarcomas, breast, lung and renal cancer represent the commonest causes of primary benign, malignant and metastatic intra-cardiac masses, respectively.Recent studies have shown that cardiac involvement in malignant lymphoma is common but under-investigated.Diagnostic imaging techniques for detection of cardiac masses include echocardiography, CT and MRI, with echocardiography having the highest sensitivity. We propose that 18-F-PET/CT may play an important role in the detection and evaluation of intra-cardiac masses.

Peptide receptor therapies in neuroendocrine tumors

Neuroendocrine tumors (NETs) are relatively rare tumors, mainly originating from the digestive system, able to produce bioactive amines and hormones. NETs tend to be slow growing and are often diagnosed when metastatic. The localization of a NETs and the assessment of the extent of disease are crucial for management. Commonly used diagnostic techniques include morphological imaging (ultrasound, computerized tomography, magnetic resonance), and functional imaging (somatostatin receptor scintigraphy, positron emission tomography techniques). Treatment is multidisciplinary and should be individualized according to the tumor type, burden, and symptoms. Therapeutic tools include surgery, interventional radiology, and medical treatments such as somatostatin analogues, interferon, chemotherapy, new targeted drugs and peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogues. NETs usually over-express somatostatin receptors, thus enabling the therapeutic use of somatostatin analogues, one of the basic tools, able to reduce signs and symptoms of hormone hypersecretion, improve quality of life, and slow tumor growth. PRRT with somatostatin analogues 90Y-DOTATOC and 177Lu-DOTATATE has been explored in NETs for more than a decade. Present knowledge and clinical studies indicate that it is possible to deliver high-absorbed doses to tumors expressing sst2 receptors, with partial and complete objective responses in up to 30% of patients. Side effects, involving the kidney and the bone marrow, are mild if adequate renal protection is used. Moreover, a consistent survival benefit is reported. As NETs may also express cholecystokinin 2, bombesin, neuropeptide Y or vasoactive intestinal peptide receptors even simultaneously, the potential availability and biological stability of radio-analogues will improve the multireceptor targeting of NETs.

SPECT/CT 90Y-Bremsstrahlung images for dosimetry during therapy

Background:

the characteristics of ⁹⁰Y, suitable for therapy, are denoted by the lack of γ-emission. Alternative methods, using analogues labelled with ¹¹¹In or ⁸⁶Y, are generally applied to image ⁹⁰Y-conjugates, with some inevitable drawbacks. New generation SPECT/CT image systems offer improved Bremsstrahlung images. The intent of this brief communication is to show that high quality ⁹⁰Y-Bremsstrahlung SPECT-CT images can be obtained, allowing the biodistribution of pure β-emitter therapeutical agents to be evaluated, also during the course of therapy.

Methods:

the hybrid system Siemens Symbia-T2 was used for the acquisition of images of a patient given 1.7 GBq of ⁹⁰Y-DOTATATE. The following parameters were set for SPECT: 80 (50%) and 120 (30%) keV energy windows; medium energy collimators; 128 × 128 matrix, 64 projections (40s/step). Low-dose CT was acquired (80 mAs) for attenuation correction. Images were reconstructed with the OSEM 3D-Fast algorithm.

Results:

post-therapy SPECT-CT ⁹⁰Y-Bremsstrahlung images of a patient undergoing receptor peptide radionuclide therapy are presented. ⁹⁰Y-Bremsstrahlung images obtained are suitable for tumour and normal organ dosimetry, providing detailed information on biodistribution, comparable to ¹¹¹In-diagnostic images.

Conclusions:

the improved Bremsstrahlung images means that the diagnostic examinations can be used for patient recruitment and that dosimetry evaluation can be restricted only to treated patients. This could avoid the need for a different radionuclide or isotope to mimic therapy. The clinical impact might be notable, as dosimetry and toxicity information are essential in radionuclide therapy, especially in patients with risk factors.

Hormone replacement therapy as a risk factor for non-small cell lung cancer: results of a case-control study

PURPOSE

It was the aim of this study to assess the risk of lung cancer in postmenopausal women who received hormone replacement therapy (HRT).

EXPERIMENTAL DESIGN

This case-control study involves women who received medical services at Roswell Park Cancer Institute (RPCI) in Buffalo, New York, between 1982 and 1998, and who agreed to complete an epidemiological questionnaire. Participants with missing smoking data were excluded. The case group consisted of 595 women with primary lung cancer. Controls included 1,195 women, randomly selected from a pool of 5,845 eligible individuals, who received medical services at RPCI for non-neoplastic conditions; they had come to RPCI with a suspicion of neoplastic disease, but were diagnosed with neither benign nor malignant conditions. Controls were frequency matched 2:1 to cases on 5-year age intervals and exposure to smoking (ever/never). Cases and controls were comparable for age (means 61.3 and 61.0 years) and ever smoking (90%).

RESULTS

There were more former smokers among the cases (67 vs. 59% in controls); cases were less likely to be high school educated, were thinner, and were less likely to report HRT use compared with controls. Overall, hormone use was associated with a significant reduction in risk of lung cancer (adjusted odds ratio = 0.67; 95% confidence interval 0.53-0.85). Stratified analyses showed significant reductions in lung cancer risk in former smokers and women with normal to low body mass index.

CONCLUSION

This study supports the hypotheses that there is a protective effect of HRT use on lung cancer risk in women.

The value of radiotherapy on metastatic internal mammary nodes in breast cancer. Results on a large series

The 'regional nodal mapping', is a fundamental step to stage breast carcinoma. In addition to the axillary nodes status, the involvement of internal mammary nodes is an important prognostic factor. Six hundred and sixty-three patients with breast carcinoma, mainly in the inner quadrants, underwent a biopsy of internal mammary nodes. Positive internal mammary nodes were found in 68 out of 663 cases (10.3%) representing 27.2% of all cases with regional node metastases (250). When histologically proven metastases were detected, radiotherapy was administered to the internal mammary nodes chain. In 254 cases, the surgeon's exploration was guided by a gamma probe. Out of these cases, 28 (11.0%) showed metastatic involvement. Out of the other 409 cases, not radioguided, 40 showed positive nodes (9.8%). Patients with internal mammary metastases treated with radiotherapy and appropriate systemic treatment showed an excellent survival (95% at 5 years), a result which is in opposition to the previous experience, which stated that invasion of internal mammary nodes is an ominous prognostic sign. We assume that this excellent result is due to radiotherapy to internal mammary nodes and we propose that exploration of internal mammary nodes should be part of the staging process of carcinomas of the medial part of the breast.