The quarterly journal of nuclear medicine : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR)最新文献

Aim: This study was aimed at assessing the clinical performances of a NaI(Tl) crystal 3D PET scanner, C-PET (ADAC-UGM), using a multi-ring 2D BGO PET scanner (multi-ring PET), as a reference.

Methods: Thirty-seven oncological patients were studied in sequence with multi-ring PET and C-PET, within 30 days of a CT study. In order to assess the behaviour of C-PET in relation to acquisition count rate, patients were divided into 3 groups according to the count rate at the time of the C-PET scan acquisition. Group A (n=21): 3000-5000 kcounts/sec (recommended count rate range); Group B (n=8): <3000 Kcounts/sec and Group C (n=8): >5000 Kcounts/sec.

Results: The number of lesions detected by multi-ring PET and C-PET, classified according to size, was compared. For Group A and Group B there was a good agreement between C-PET and multi-ring PET in terms of lesion detectability (relative sensitivity: 99.9% and 96.0%, respectively), while for Group C the relative sensitivity of C-PET was 61.9%.

Conclusion: Optimal performances of the C-PET scanner can thus be obtained at a count rate within or below the recommended range. Despite a lower lesion/background contrast resulting from a high scatter and random noise, the sensitivity of C-PET in detecting hypermetabolic lesions is comparable to that of multi-ring PET. These findings are discussed in relation to the physical performance of the two scanners and particularly in relation to the 3D vs 2D acquisition modality.

Aim: The aim of this study is to assess the clinical impact of gallium-67 scintigraphy, before and after treatment, in patients with Hodgkin's disease, and to compare the overall survival between the patients whose gallium studies after treatment were negative and those whose studies remained positive.

Methods: We have studied 75 patients (40 women, 35 men) with Hodgkin's disease. All the patients underwent (67)Ga scintigraphy at the moment of the diagnosis (basal study) and in the case that basal study was positive (abnormal hyper-uptake focus) we performed follow-up studies after the treatment. We have calculated the overall survival among patients whose studies after treatment were negative (1(st) group) and those whose studies remained positive (2(nd) group) and between patients whose studies were negative at diagnosis (3(rd) group).

Results: Gallium scintigraphy was positive at diagnosis in 47 patients (62.6%). In 39 of them we were able to perform the follow-up study after treatment. The follow-up study was negative in 31 patients while in 8 patients the gallium scintigraphy remained positive. The overall survival was significantly higher (p<0.001) in the 1(st) group compared with the 2(nd) group. The overall survival was higher in the 1(st) group compared with the 3(rd) but statistic significance level was not reached.

Conclusion: Our data suggest that: 1) in Hodgkin's disease (67)Ga scintigraphy is useful to establish the diagnosis of complete remission; 2) if the gallium scan remains positive after treatment, the prognosis of patients is worse than the prognosis of patients with a negative scan.

Aim: We evaluated the usefulness of (99m)Tc-tetrofosmin axillary pinhole (P)-SPECT in breast cancer (BC) non palpable axillary lymph node metastasis detection compared with conventional planar and SPECT scintimammography.

Methods: We studied prospectively 188 consecutive patients with suspected primary BC, negative at axillary clinical examination. Ten minutes after 740 MBq (99m)Tc-tetrofosmin injection, planar and SPECT scintimammography were acquired, followed by axillary P-SPECT imaging.

Results: At histology, 12 patients had benign mammary lesions and 176 had BC. Axillary lymph node dissection (ALND) was performed in all BC patients, bilaterally in 3 cases: 74/179 axillae had metastases. P-SPECT showed a significantly higher overall sensitivity than SPECT and planar (93.2% vs 85.1% and 36.5%, respectively; p<0.05 and p<0.0005, respectively) and was false negative in 5 patients with 1 metastatic node each, micrometastatic in 4/5 cases; SPECT and planar were also false negative in these 5 cases and in 6 and in 42 further cases, respectively. P-SPECT added important prognostic information by distinguishing single from multiple and pound 3 from >3 nodes; only P-SPECT defined the exact number of nodes in 15/25 patients with 2-4 nodes. P-SPECT showed the highest accuracy and NPV: 92.7% and 95%, respectively (SPECT 90.5% and 90%, respectively; planar 73.2% and 68.9%, respectively).

Conclusion: (99m)Tc-tetrofosmin axillary P-SPECT appears highly accurate in BC non palpable axillary lymph node metastasis detection and significantly more sensitive than both planar and SPECT, its few false negative results predominantly concerning micrometastases; moreover, only P-SPECT gave additional important prognostic information. Given its very high NPV, P-SPECT could also be used to better select patients who might avoid ALND.

Aim: (99m)Tc-MIBI radio-guided surgery results, obtained in a group of 141 patients with primary hyperparathyroidism (HPT), are reported.

Methods: All patients were preoperatively evaluated by a single day protocol based on double-tracer parathyroid scintigraphy and neck ultrasound, and then operated by the same surgical team. In 102 patients (72.3%) with a high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, a minimally invasive radio-guided surgery was planned. In the other 39 patients (27.7%) with scan/ultrasound evidence of multi-glandular disease (n=8) or concomitant nodular goiter (n=31), the intraoperative gamma probe was used during a standard bilateral neck exploration. Intraoperative quick parathyroid hormone (PTH) levels were routinely measured. The minimally invasive radio-guided surgery technique we developed, consisted of: a) injection of a low 37 MBq (99m)Tc-MIBI dose in the operative theatre during anaesthesia induction, b) patient's neck scan with a hand-held gamma probe just before the surgical cut to localize the cutaneous projection of the parathyroid adenoma, c) intraoperative probe detection of the parathyroid adenoma and its removal through a small 2-2.5 cm skin incision.

Results: Minimally invasive radio-guided surgery was successfully performed in 99/102 patients (97.0%). The gamma probe was particularly useful in patients with an ectopic parathyroid adenoma in the upper mediastinum (n=11) or to the carotid bifurcation (n=1) or located deep in the neck (n=8). Minimally invasive radio-guided surgery was also obtained in 18/23 patients who had previously undergone thyroid/parathyroid surgery. The mean operative time for minimally invasive radio-guided surgery was 38 min. No major surgical complication was recorded. Conversion to bilateral neck exploration was required in only 3 cases because of intra-operative diagnosis of parathyroid carcinoma (n=2), and persistence of elevated quick PTH levels after removal of the preoperatively visualized parathyroid adenoma (n=1). Among patients treated by standard bilateral neck exploration, the gamma probe was useful in localizing a thymical enlarged parathyroid gland in 1 patient with multi-glandular disease, a parathyroid adenoma located deep in the neck in 4 patients with concomitant nodular goiter and an ectopic parathyroid adenoma to the carotid bifurcation in another. However, in some other patients with a parathyroid adenoma located near to the thyroid, it was difficult to intraoperatively distinguish the parathyroid adenoma from a MIBI avid thyroid nodule.

Conclusion: It can be concluded that: (a) in primary HPT patients with high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, the gamma probe appears to be an effective, rapid and safe technique to perform minimally invasive radio-guided surgery; b) a (99m)Tc-MIBI

Neuroblastoma is a frequent tumor of childhood and remains a leading cause of death despite treatment intensification. Many clinical, biological and genetic factors have been identified and are associated with prognosis and outcome after treatment. Initial staging plays a major role for determining the therapeutic strategy. Radioiodinated metaiodobenzylguanidine (MIBG) scintigraphy is a highly sensitive and specific method for diagnosing, staging and also monitoring response to therapy. In children with high-risk neuroblastoma, relapse may occur any time after remission has been obtained. (123)I-MIBG scintigraphy is a reliable method to follow-up those children and allows early detection of recurrence. As far as outcome is concerned, MIBG scintigraphy has not proven to have any prognostic value. Other radiolabeled tracers, such as pentetreotide, monoclonal antibodies, and sestamibi have been compared with MIBG. Up to now, no method has demonstrated a reliable prognostic value, even though neuroblastoma that express somatostatin receptor seem to have a better clinical outcome and survival rate. Positron emission tomography (PET) with (18)F-fluorodeoxyglucose has been used successfully in staging and monitoring response to treatment of MIBG negative tumors. (11)C-hydroxyephedrine has shown promising results in staging neuroblastoma, but is not as widely available as MIBG. With respect to biological and genetic factors, nuclear medicine procedures play a major role in initial diagnosis and staging of neuroblastoma. At the moment, MIBG scintigraphy is certainly the most sensitive and specific method for initial staging of the disease, as well as monitoring the response to treatment and detecting early relapse.

Little is known about the clinical value of FDG PET for assessing treatment response in pediatric oncology. After systematic review of literature, the very few publications concerning response control in pediatric oncology using FDG PET are summarized. There were only 4 studies concerning FDG PET in the assessment of therapy response in pediatric patients. None of the publications fulfilled the requirements for high quality studies because of the small number of patients studied. The clinical value of FDG PET in the assessment of therapy response in pediatric oncology is likely in osseous sarcomas and possibly in high-grade brain tumors. In other pediatric tumor entities such as lymphomas, soft-tissue sarcomas, germ cell tumors, or neuroblastomas, the clinical usefulness of FDG PET can either be assumed analogous to adults, or can be assumed from staging studies, or is still unknown. There is a need for large, systematic studies evaluating FDG PET in therapy monitoring, but also in grading, staging, and in the diagnosis of recurrences in pediatric malignancies.

Non-invasive imaging methods in the evaluation of chemotherapy response in malignant tumours are currently being explored. Standard Nuclear Medicine procedures seem to offer the clinician a promising tool in the management of those oncologic patients, who might benefit from chemotherapy. Early studies focused on the relationship between radionuclides used in tumour diagnosis and factors associated with multidrug resistance (MDR). The tumour expression of P-glycoprotein (Pgp) and multidrug resistance-related protein-1 expression (MRP) have been suggested as important factors in the failure of chemotherapy. Most studies found an association between Pgp levels and (99m)Tc-sestamibi ((99m)Tc-MIBI) or (99m)Tc-Tetrofosmin uptake ((99m)Tc-TF). Currently investigations in nuclear medicine oncology are focusing on the potential role of radionuclide imaging in the assessment of chemotherapy. Recent papers discuss the usefulness of radionuclides as (99m)Tc-MIBI and (99m)Tc-TF as non-invasive procedures to predict and to monitor therapy response in patients affected by malignant tumours treatable using chemotherapy. This chapter will review the latest development in (99m)Tc-TF, giving an overview of recent investigations carried out using this radiotracer in therapy oncology, with emphasis on its potential role as predictor of tumour response.

Aim: The aim of the present paper is to describe the accuracy of gallium ((67)Ga) scintigraphy in adolescents and children with Hodgkin's disease (HD). We have studied the diagnostic value of this nuclear imaging technique at disease presentation (staging) and its prognostic value based on changes in (67)Ga uptake observed after treatment (response assessment).

Methods: From April 1985 to July 1999 74 consecutive untreated patients with a median age of 13 y underwent (67)Ga scans 48-72 h after injection of 37-111 MBq of (67)Ga-citrate. Planar whole-body scintigraphy was performed, supplemented with single photon emission tomography (SPET) of the mediastinum from 1996 onwards. Three patients did not undergo further scintigraphic examination because they were treated with radical surgery. After the 1st examination 71 of the 74 patients were monitored by 1-3 (67)Ga scans during the course of their disease. All of them had at least one (67)Ga scintigraphy at the end of the induction phase of chemotherapy, before any other therapeutic regimens were planned.

Results: At disease presentation (67)Ga scintigraphy was positive in all patients, detecting 285 of 335 (85.0%) lymph nodal sites of disease. The best sensitivity was observed in the mediastinum (100%; 63/63) and the laterocervical supraclavicular region (85.6%; 125/146); it was lower for axillary (72.7%; 16/22) and retroperitoneal (68.7%; 11/16) lymph node masses. In detecting visceral involvement the sensitivity of (67)Ga scintigraphy was 66.6% (8/12) for lung and 80% (4/5) for bone involvement. Among 71 patients in follow-up, 2 showed rapid progression of disease during induction therapy while 69 patients were monitored for a long period. The response to therapy has been classified according to the changes observed on nuclear medicine or radiological images as complete response (CR) or partial response (PR). On the basis of (67)Ga scans 55 patients (72.4%) were considered as having a CR, while with radiological modalities (chest X-ray, CT, MRI) CR was observed in only 29 patients (40.8%). PR or progression was found with (67)Ga scintigraphy in 16 patients (22.5%) and with radiological modalities in 42 patients (59.1%). (67)Ga scan was concordant with clinical outcome in 97% (28/29). The diagnostic effectiveness of this imaging technique has been analysed by comparing the scintigraphic or radiological changes at the 1st scintigraphic/radiological follow-up examination after induction therapy with the clinical outcome. In this population the relapse rate was 50% (8/16) in the group that did not achieve a CR according to post-treatment (67)Ga scintigraphy, while it was only 10.9% (6/55) in the group that achieved a CR on the basis of scintigraphy findings. The overall survival (OS) and disease-free survival (DFS) were calculated by means of Kaplan-Meier cumulative survival plotting. When the 2 groups of patients with complete (CR) or

Aim: This prospective study is focused on the assessment of tumour response in a group of 28 bone sarcoma patients using (99m)Tc-MIBI scintigraphy.

Methods: The quantitative changes in MIBI uptake before and after chemotherapy were measured and associated with the pathological evaluation of the degree of tumour necrosis. Besides this, another group of 40 patients with bone and soft tissue tumours was studied in order to evaluate the diagnostic efficacy of (99m)Tc-MIBI scintigraphy versus computed tomography (CT) and/or magnetic resonance imaging (MRI) in detecting the status of the disease and its recurrences. After injection of 555-740 MBq of (99m)Tc-MIBI, regional and whole body images were acquired at 20 and 60 min. The lesion/normal (L/N) uptake ratio was calculated in both early and delayed images and the washout rate (WR%) of (99m)Tc-MIBI was obtained. Following 3-4 courses of chemotherapy, bone tumours were assessed by comparing the uptake ratio in the viable tumours with the amount of necrotic processes described in the surgically removed specimens.

Results: In the first group of patients the rate of tumour response to chemotherapy, calculated according to the percentage of necrosis and the (99m)Tc-MIBI uptake ratios, was as follows: complete response in 12 patients, partial response in 8 and no response in 8 patients. Linear regression analysis of quantitative changes in (99m)Tc-MIBI uptake (expressed as changes percent) and of (99m)Tc-MIBI uptake ratio showed a positive correlation (r=0.77), whereas it showed a negative correlation with the changes in the washout ratio (r=-0.32). In the second group of patients (40 patients) (99m)Tc-MIBI scintigraphy proved to be able to detect recurrences of bone and soft tissue tumours. The sensitivity, specificity and accuracy of (99m)Tc-MIBI scan versus CT and/or MRI were calculated and they resulted 93%, 95% and 92% versus 86%, 75% and 84%, respectively.

Conclusion: The application of (99m)Tc-MIBI scan in the management of patients treated with chemotherapy may allow an early identification of the non-responder patients and lead to a choice of different strategies (alternative chemotherapy or salvage surgery).

The advantages and limitations of (201)Tl imaging in assessing the tumor response to anti-cancer therapy are discussed in this review. (201)Tl has distinctive advantages but more recent agents such as (99m)Tc MIBI and positron emitters have some clinical superiorities over (201)Tl in this usage.