[Added value of prone position technique for PET-TAC in breast cancer patients]. / Valor añadido de la técnica en decúbito prono para el estudio con tomografía por emisión de positrones-tomografía computarizada en las pacientes con cáncer de mama.

AIM: This study has aimed to assess if the prone position shows significant differences in regards to the supine position in PET/CT studies in breast cancer patients and to determine which modality offers better evaluation of the images. METHOD: A total of 30 patients were included from October 2009 to February 2010 prior to beginning neoadjuvant chemotherapy. An intravenous (18)F-FDG dose ranging from 180 to 240 MBq was administered. Image acquisition was begun 60 ± 10 min after injection. First of all, a thorax scan was performed with the patient in prone position, followed by a whole body study with the patient in supine position. RESULTS: Uptake in tumor lesions was observed in all of the patients. Twenty-four patients (80%) had the same number of lesions with both techniques. Five patients (17%) had a different amount of axillary lymph nodes. One patient (3.3%) had a different number of lesions. The prone position lesions had a mean SUVmax 8.89 ± 4.18 compared to 7.67 ± 4.34 in supine position. The areas of the primary breast lesions were higher in the prone position (8.59 ± 7.80 compared with 7.81 ± 7.39). Mean SUVmax of axillary nodes was 5.97 ± 4.02 in prone and 4.41 ± 3.10 in supine. CONCLUSION: The hanging breast technique can achieve higher lesion visualization as well as higher semiquantitative values in comparison with standard procedure. This supports its inclusion in acquisition guidelines of PET/CT imaging in breast cancer patients.

Intraoperative radioguidance with a portable gamma camera: a novel technique for laparoscopic sentinel node localisation in urological malignancies.

PURPOSE: Our aim was to assess the feasibility of intraoperative radioguidance with a portable gamma camera during laparoscopic sentinel node (SN) procedures in urological malignancies. METHODS: We evaluated the use of the intraoperative portable gamma camera in 20 patients: 16 patients with prostate carcinoma (PCC), 2 patients with renal cell carcinoma (RC) and 2 patients with testicular cancer (TC). Intra/peritumoural injection of (99m)Tc-nanocolloid ((99m)Tc) was followed by planar lymphoscintigraphy, SPECT/CT and marking of SN levels. Before laparoscopy a (125)I seed was fixed on the laparoscopic gamma probe as a pointer of SN seeking. The portable gamma camera was set to display the (99m)Tc signal for SN localisation and the (125)I signal for SN seeking. Matching of these signals on screen indicated exact SN localisation, and consequently this SN was removed. RESULTS: The mean injected dose was 218 MBq in PCC, 228 MBq in RC and 88 MBq in TC. Pelvic SN were visualised in all PCC patients, with uncommonly located SN in seven patients. SN metastases were found in seven patients (one in a uncommonly located SN). Both RC patients and TC patients had para-aortic SN, which were all tumour free. A total of 59 SN were removed. The portable gamma camera enabled real-time SN display/identification in 18 patients (90%). CONCLUSION: The use of a portable gamma camera in combination with a laparoscopic gamma probe incorporates intraoperative real-time imaging with improved SN identification in urological malignancies. This procedure might also be useful for SN identification of other deep draining malignancies.

[Regional lymph nodes at a distance]. / Regionale lymfekliergebieden op afstand.

In 3 patients, two men aged 22 years and 38 years with melanoma, and one woman aged 46 years with breast cancer, local tumour growth recurred following regional lymph node dissection. All three developed metastasis in new distant regional basins, which were once more dissected. The first melanoma patient died from haematogenous metastasis, 2 years after the excision of his primary melanoma. The other melanoma patient was alive, without evidence of disease, 8 years after the treatment of his primary tumour. The breast cancer patient, who underwent contralateral axillary lymph node dissection, was also alive, without evidence of disease, 27 years after the treatment of her primary tumour. Diversion of lymphatic flow as a result of regional lymph node dissection for cancer may lead to metastasis to a distant lymph node basin if tumour growth recurs in the original area. Knowledge of this usually unknown phenomenon is important since metastasis to these new regional basins can still be treated curatively, in the form of another lymph node dissection. These distant lymph node basins must therefore be carefully checked during follow-up monitoring.

Palliative effect of metaiodobenzylguanidine in metastatic carcinoid tumors.

PURPOSE: To evaluate the therapeutic effect of iodine-131-labeled metaiodobenzylguanidine (131I-MIBG) and unlabeled MIBG in patients with carcinoid tumor. MATERIALS AND METHODS: A therapeutic dose of 7.4 GBq (200 mCi) 131I-MIBG infused over 4 hours was administered to 30 patients with either carcinoid syndrome (n = 20) or tumor symptoms such as pain and fever due to carcinoid tumor (n = 10). In general, two courses were given, 6 weeks apart. Due to radioactivity, patients had to be isolated for 5 to 7 days. Subsequently, we studied the effect of unlabeled MIBG based on the possible pharmaceutic activity of MIBG and to avoid the isolation procedure. A doseescalation study of 8.5, 17, and 34 mg/m2 MIBG infused over 4 hours at 4-week intervals was performed in 20 patients with carcinoid syndrome who were not suitable for treatment with the radioactive compound. RESULTS: Following 131I-MIBG treatment, symptomatic responses were observed in 60% of patients (median duration, 8 months; maximum, 2 years). Side effects were mild and rapidly reversible in 16 patients, and were related to the isolation procedure in seven of these patients. Unlabeled MIBG resulted in symptomatic improvement in 60% of patients (median duration, 4.5 months). Side effects, which included changes in blood pressure, were mild and transient. Symptomatic responses were not accompanied by biochemical responses. CONCLUSION: Both MIBG treatment regimens were equally effective in the palliation of symptoms, but duration of response tended to be much longer with the radioactive compound. However, the unlabeled compound provided a simpler treatment, eg, in elderly patients and those in poor condition, without the need for isolation.

Radioimmunotherapy in medullary thyroid cancer using bispecific antibody and iodine 131-labeled bivalent hapten: preliminary results of a phase I/II clinical trial.

The toxicity and therapeutic efficacy of escalating doses of anti-carcinoembryonic antigen x anti-N alpha-(diethylenetriamine-N,N,N',N''-tetraacetic acid)-In bispecific monoclonal antibody (F6-734) and iodine 131-labeled bivalent hapten were determined in a Phase I/II trial. A total of 26 patients with recurrences of medullary thyroid cancer documented by imaging and a rise in serum thyrocalcitonin were enrolled. Twenty to 50 mg of F6-734 and 40-100 mCi of 131I-hapten were injected 4 days apart. Quantitative scintigraphy was performed after the second injection for dosimetry estimations in eight cases. Clinical, biological, and morphological follow-up was carried out for 1 year after treatment. The mean percentage of injected activity per gram of tumor at the time of maximum uptake was 0.08% (range, 0.003-0.26%). The tumor biological half-life ranged from 3 to 95 days, and tumor doses ranged from 2.91 to 184 cGy/mCi. The estimated tumor-to-nontumor dose ratios were 43.8 x 53.4, 29.6 x 35.3, 10.9 x 13.6, and 8.4 x 10.0 for total body, red marrow, liver, and kidney, respectively. Grade III/IV hematological toxicity was observed in seven patients, most of them with bone metastases. Among the 17 evaluable patients, 4 pain reliefs, 5 minor tumor responses, and 4 biological responses with decrease of thyrocalcitonin were observed. Nine patients developed human anti-mouse antibody. Dose-limiting toxicity was hematological, and maximum tolerated activity was 48 mCi/m2 in this group of patients, most of whom had suspected bone marrow involvement. The therapeutic responses observed in patients mainly with a small tumor burden are encouraging for the performance of a Phase II trial with minimal residual disease.

Interferon and meta-iodobenzylguanidin combinations in the treatment of metastatic carcinoid tumours.

Interferon (IFN) and meta-iodobenzylguanidin (MIBG) are active in metastatic carcinoids. In a phase II study, we evaluated the effect upon diagnostic 131I-MIBG uptake and the clinical response of the combination. 131I-MIBG scintigraphy was performed prior to treatment, after 8 weeks of IFN and after unlabelled MIBG. The tumour over non-tumour (T/NT) ratios were quantitatively determined by comparing counts in the centre of the tumour (liver metastases) with those in an adjacent area of normal liver uptake (T/NT1) and with abdominal background area (T/NT2). The T/NT1 ratio showed an increase of >10% in only four out of 21 patients (19%) after IFN (P = 0.178) and significantly more often in nine out of 18 patients (50%) after unlabelled MIBG (P = 0.016). The absolute uptake in tumour deposits was also increased if compared with the abdominal background (T/NT2: 23% increase after IFN and 83% increase after unlabelled MIBG). The combination produced 91% of patients with stable disease (using World Health Organisation criteria) at computed tomography scan and a biochemical response (a reduction of at least 50% in urinary 5-hydroxyindolacetic acid excretion) in 39%. IFN-alpha did not significantly improve tumour retention of 131I-MIBG. In contrast, unlabelled MIBG significantly improved biodistribution and tumour uptake in 83%. A synergistic effect was not seen.

131I-rose bengal therapy in hepatoblastoma patients.

If conventional treatment modalities have failed in hepatoblastoma patients and no distant metastases can be demonstrated therapy with radionuclide agents can be considered. In 6 patients diagnostic technetium-99m (99mTc)-disofenin and two iodine-131 (131I)-rose bengal scans were made. 2 patients demonstrated specific uptake of disofenin. One of these had a positive scintigram with radiolabelled rose bengal. This patient was subsequently treated with 1.1 GBq 131I-rose bengal. No toxicity was observed. A clear decrease in the level of alpha-fetoprotein indicated a response and demonstrated that this radiopharmaceutical can be used for tumour targeted radiation therapy in selected patients with therapy resistant tumours.

Radioimmunoscintigraphy using [111In]antimyosin Fab fragments for the diagnosis and follow-up of rhabdomyosarcoma.

Between 1987 and 1992, 39 radioimmunoscintigraphic studies using 111In-labelled antimyosin Fab fragments were performed in 27 patients with rhabdomyosarcoma (RMS), 2 patients with leiomyosarcoma (LMS) and 1 with alveolar soft tissue sarcoma. 21 patients were children aged 3-14 years. These patients, who had histologically proven myosarcoma, were examined scintigraphically to search for local recurrences or metastases and to determine the response to treatment. The results of immunoscintigraphy were compared with histopathological parameters and other imaging modalities. The sensitivity of antimyosin scintigraphy in this series was 82% and the specificity was 73%. Although the technique appears to be not highly specific for RMS, it was found to be useful for the early detection of local recurrence and metastases, as well as for the evaluation of the response to therapy.

Combined diagnostic imaging with 131I-metaiodobenzylguanidine and 111In-pentetreotide in carcinoid tumours.

Carcinoid tumours derived from the neural crest are usually associated with the symptoms of flushing and diarrhoea in the presence of liver metastases. Scintigraphs with 131I-metaiodobenzylguanidine (131I-MIBG) which is accumulated in the argentaffin granules of the cell, as well as with 111In-pentetreotide for the imaging of somatostatin receptors on the cell surface, are positive in a large proportion of carcinoid patients. To evaluate the complementary role of both radionuclide tests, we studied 20 consecutive carcinoid patients: 14 with the characteristic carcinoid syndrome and 6 with tumour symptoms, such as pain or obstruction. A positive test was found in 84% with either 131I-MIBG or 111In-pentetreotide; the combination yielded a sensitivity of 95%. A positive correlation was found with the presence of the carcinoid syndrome, but not with 5-HIAA excretion. A positive test may help in adjusting treatment: either to predict the response to octreotide or to select patients for 131I-labelled MIBG treatment. Application of a therapeutic dose of 111In-pentetreotide may be limited by the high normal uptake in the kidneys.

Assessment of anthracycline-related myocardial adrenergic derangement by [123I]metaiodobenzylguanidine scintigraphy.

Myocardial adrenergic neuron integrity and function were evaluated in 21 patients who had received doxorubicin or epirubicin for various malignancies. Myocardial uptake of iodine-123 metaiodobenzylguanidine ([123I]MIBG), a marker suitable for the study of myocardial neuron injury, was calculated from planar scintigraphic images after 4 h and the washout between 15 min and 4 h. In 13 patients with normal left ventricle ejection fraction (LVEF) analysed at three cumulative dose levels (no, low and middle dose), [123I]MIBG uptake tended to be significantly impaired (z = -2.772, P = 0.0056), at higher cumulative dose levels, before significant LVEF changes were observed. [123I]MIBG values were considerably decreased in 2/7 patients investigated at low cumulative dose and in 3/8 cases at the middle dose level. On follow-up, 1 of these patients, who had normal LVEF after completion of chemotherapy but whose [123I]MIBG values had progressively deteriorated during anthracycline therapy, subsequently developed congestive heart failure; another patient, whose [123I]MIBG values were impaired at the middle dose level, developed persistent reduced LVEF 5 months after completing therapy. In 8 patients, who had developed persistently, reduced LVEF at high doxorubicin cumulative dose levels, [123I]MIBG, performed in the period after chemotherapy discontinuation, was invariably abnormal. These data suggest that myocardial adrenergic derangement plays a role in anthracycline-associated cardiotoxicity: its appearance, even at low cumulative anthracycline dose levels, may reflect impairment of the intravesicular norepinephrine storage by incipient anthracycline-associated cardiac neuron injury. [123I]MIBG scintigraphy may be useful to assess myocardial adrenergic derangement during and in the follow-up of anthracycline therapy and potentially detect patients who are at risk.

Clinical experience with radiation enhancement by hyperbaric oxygen in children with recurrent neuroblastoma stage IV.

The high risk group of patients with neuroblastoma are children over 1 year with stage IV disease. Most series report a maximum of 20% survival at 5 years. For recurrent neuroblastoma stage IV, cure rates are not reported in the literature, but they are nil. Any treatment for recurrent neuroblastoma stage IV remains a therapeutic dilemma. The outcome of radiation therapy is variable. A very important factor in tumour treatment remains tumour hypoxia, and others, such as metabolic factors, also play a role. Combined application of radiation modifiers may influence the final survival rate. In an attempt to improve the survival of recurrent neuroblastoma stage IV, hyperbaric oxygen and radioionated meta-Iodobenzylguanidine (MIBG) was used in a clinical setting. Although survival may not be used as a determinant of the usefulness of a treatment for stage IV neuroblastoma disease, a better one is not available. In this study, at 28 months, a cumulative probability of survival of 32% was recorded for patients treated with [131I]MIBG and hyperbaric oxygen compared to 12% for [131I]MIBG treatment alone. These preliminary results are promising but further studies are needed to reveal substantial therapeutic gain.

First line targeted radiotherapy, a new concept in the treatment of advanced stage neuroblastoma.

33 previously untreated advanced stage neuroblastoma patients were treated with [131I]meta-iodobenzylguanidine (MIBG). The number of treatments varied between 2 and 7 per patient (mean 3). Toxicity was seldom severe. Only thrombocytopenia WHO-grade 4 was noticed. Response was documented before surgery for the primary tumour was performed. There was one complete response (CR), 18 partial responses (PR), 11 had stable disease (SD) and 3 had progressive disease (PD). After MIBG therapy and surgery, 12 of 33 patients achieved a CR. This approach is feasible, comparable to multidrug chemotherapy in efficacy and less toxic. Long term results are not known yet.

Radiation injury in the human kidney: a prospective analysis using specific scintigraphic and biochemical endpoints.

Renal function was prospectively analyzed in 26 evaluable patients, irradiated to various doses on their kidneys for neoplastic disease. Glomerular function was assessed by 99mTc-DTPA renography, creatinine clearance, and serum beta 2-microglobulin, whereas tubular function was monitored by 99mTc-DMSA scintigraphy, urine beta 2-microglobulin, urine N-acetyl glucosaminidase, and alanine aminopeptidase and a urine concentration test. In the patients given the highest irradiation dose to the entire left kidney, that is, 40 Gy in 5 1/2 weeks, glomerular and tubular functional impairment, as assessed scintigraphically, progressed at a rate of 2.0 +/- 1.0% (+/- 1 SD) and 2.0 +/- 0.5% per month, respectively, down to 30-40% after 3 to 5 years. The overall glomerular function, as assessed by creatinine clearance, decreased by only 20%. In the patients irradiated unilaterally on the upper pole to 40 Gy in 4 weeks, glomerular and tubular function in the left kidney deteriorated at 0.75 +/- 0.33% and 0.75 +/- 0.20% per month in the first 2 years, down to 75-80% at 5 years. This smaller reduction was due to shielding of a part of the left kidney. No changes were observed, thus far, after bilateral whole kidney irradiation to 17-18 Gy in 3 1/2 weeks. The concentration capacity of the kidney after total volume irradiation was not impaired. There was a trend for an increase in diastolic blood pressure in 3 out of 5 patients given the high dose irradiation to the entire left kidney and in 2 out of 7 patients irradiated on the upper pole of the left kidney. The progressive nature of the radiation nephropathy stresses the need for long term follow-up to determine more accurately the "tolerance dose" of the human kidney for irradiation.

Role of thallium-201 total-body scintigraphy in follow-up of thyroid carcinoma.

To evaluate the reliability of total-body scintigraphy using [201Tl]chloride in postoperative follow-up of thyroid carcinoma, this procedure was performed in 326 patients after total thyroidectomy for thyroid carcinoma. The results were compared with those of 131I scintigraphy and thyroglobulin assays. 201Tl total-body scintigraphy was found to have the greatest sensitivity (94%), whereas 131I scintigraphy had the highest specificity (99%). It is shown that 201Tl total-body scintigraphy is a useful procedure in follow-up of thyroid cancer, however, the combination of parameters provides the greatest reliability. In medullary thyroid carcinoma, which is usually 131I negative, 201Tl total-body scintigraphy can be of great value for the localization of metastases which are indicated by elevated serum levels of calcitonin and carcinoembryonic antigen.

Radionuclide diagnosis and therapy of neural crest tumors using iodine-131 metaiodobenzylguanidine.

The successful application of [131I]metaiodobenzylguanidine (MIBG) in diagnosis and therapy of pheochromocytoma has led to its use in other tumors which derive from the neural crest and potentially concentrate this radiopharmaceutical as well. In the present series, [131]MIBG total-body scintigraphy was used for detection of neuroblastoma in 47 patients and 47 cases of other neural crest tumors. The method was found to be as reliable in neuroblastoma (sensitivity 95%, specificity 100%), as it is in pheochromocytoma. Although other neural crest tumors may concentrate [131I]MIBG, this is not a consistent finding; however, it is useful to investigate which tumors do, as this may provide an alternative treatment modality for some patients. Although followup is still very short, preliminary results of therapeutic use of [131I] MIBG in 21 patients indicate that this treatment modality may be effective in neuroblastoma and malignant pheochromocytoma.

Radioimmunoscintigraphy using iodine-131-anti-CEA monoclonal antibodies and thallium-201 scintigraphy in medullary thyroid carcinoma: a case report.

This case report demonstrates the use of thallium-201 (201Tl) scans versus iodine-131- (131l) anti-CEA F(ab')2 scans in a patient with high serum CEA levels due to metastases of medullary thyroid carcinoma in the suprarenal region and sacroiliacal region. Scintigraphy using monoclonal antibodies directed against CEA showed a higher tumor uptake (0.26% dose and 0.64% dose, respectively) than a thallium scan and is believed to be promising for future radiotherapeutic applications.

Evaluation of mammary lymphoscintigraphy by a single intratumoral injection for sentinel node identification.

UNLABELLED: The aim of this study was to evaluate the findings of mammary lymphoscintigraphy by a single intratumoral injection in 150 patients with breast carcinoma: 100 patients (group A) investigated in the validation phase of the study and 50 (group B) studied after the tracer dose was optimized. METHODS: Immediately after injection of 99mTc-nanocolloid using a 25-gauge needle and a 0.2-mL volume, simultaneous anterior and lateral images were acquired with a dual-head gamma camera during 20 min followed by sequential static anterior and prone lateral breast images after 30 min and after 2 and 4 h. 57Co-assisted skin marking defined the sentinel node location for subsequent gamma probe, blue dye-guided sentinel node biopsy. RESULTS: In group A (mean dose, 61.6 MBq; range, 42-88 MBq) scintigraphy revealed lymph nodes in 83 patients (83%), with an increase in the rate of visualization from 72% for the first 40 patients to 90% for the last 60; patient age (P = 0.01) and administered tracer dose (P = 0.04) were found to be significant factors for visualization, with optimal results obtained from doses higher than 65 MBq. Lymph nodes were visible in 34 patients (41%) during the first 30 min after injection, whereas in 49 patients appearance occurred at 2-4 h. A total of 97 lymphatic basins were visualized (80 axillary, 3 clavicular, 14 internal mammary). In group B (mean dose, 90.8 MBq; range, 68-124 MBq), the visualization rate was 94%, with early lymph node appearance in 27 patients (57%) and a total of 53 basins (45 axillary, 8 internal mammary). In combination with intraoperative blue dye mapping and y probing, the identification rate increased to 90% in group A and 98% in group B. Prone lateral images contributed to identification of intramammary lymph nodes in a total of 14 patients and axillary nodes close to the injection site in 8 other patients. CONCLUSION: Mammary lymphoscintigraphy by single intratumoral injection is a valid method for lymphatic mapping and identification of both axillary and nonaxillary sentinel nodes. Lymph node visualization appears to be improved with higher tracer doses. The compactness of the injection site enables high-quality additional lateral images that can depict intramammary or axillary lymph nodes adjacent to the injection site.

Reproducibility of lymphoscintigraphy for lymphatic mapping in cutaneous melanoma.

UNLABELLED: One of the indications for lymphoscintigraphy in patients with melanoma is to determine the lymphatic drainage pattern and position of the first draining lymph node--the sentinel node. Metastasis in the sentinel node indicates the need for therapeutic lymph node dissection. The purpose of the present study was to examine the reproducibility of lymphoscintigraphy in assessing the location and number of sentinel nodes. METHODS: Twenty-five patients with clinically localized melanoma were investigated. The same investigator performed two scintigraphic studies with a 2-4 wk interval in each patient, in an identical manner. A 60-MBq dose of 99mTc-nanocolloid was injected intradermally at the primary tumor site. The lymph flow was studied dynamically, complemented by lateral/oblique views. The images were evaluated by a panel of three observers. RESULTS: The sentinel node was visualized within 20 min in all patients. A difference in number of sentinel nodes depicted on the first and second study was noted in three patients (12%). The melanoma was situated on the head (two patients) and arm (one patient) in these patients. Otherwise, the images were identical for number and location of nodes. CONCLUSIONS: Reproducibility of lymphoscintigraphy with 99mTc-nanocolloid was high in this study. However, some sentinel nodes may be missed in lymphoscintigraphy for melanoma.

Correlative 201Tl SPECT, MRI and ex vivo 201Tl uptake in detecting and characterizing cervical lymphadenopathy in head and neck squamous cell carcinoma.

UNLABELLED: The value of SPECT with 201Tl chloride, in combination with MRI (particularly short inversion-time inversion recovery [STIR] sequences that suppress fat signals) to detect and characterize cervical lymphadenopathies (nodes > or = 1 cm), and ex vivo lymph node 201Tl uptake were studied in patients with squamous cell carcinoma of the head and neck. METHODS: Preoperative SPECT and MRI, displayed in similar planes, were compared with the histologic findings in 15 neck dissection specimens from 12 patients with squamous cell carcinoma of the head and neck (9 with unilateral and 3 with bilateral neck dissection). Results were evaluated topographically with regard to the lymph node compartments (levels) of the neck. In addition, in 8 of these patients, the 201Tl activity of dissected lymph nodes of 10 neck sides was measured immediately after surgery in a gamma counter and expressed as percentage of the injected dose per gram tissue (%ID/g). RESULTS: Sixty-two lymph node levels were evaluated histologically. The high sensitivity of MRI (92% versus 71% for 201Tl SPECT), which correctly detected lymph node involvement in 22 of 24 levels, and the high specificity of 201Tl SPECT (92% versus 71% for MRI), which correctly characterized as negative 35 of 38 lymph node levels without metastasis on histology, led to a combined 201Tl SPECT/MRI accuracy of 92%. 201Tl SPECT was particularly effective in excluding involvement in 9 tumor-free neck levels with pathologically enlarged lymph nodes on MRI but failed to confirm involvement in 5 other tumor-positive levels. Mean 201Tl uptake in 53 lymph nodes with confirmed histologic involvement was significantly higher than uptake in 145 tumor-free lymph nodes (0.0043+/-0.0022 %ID/g versus 0.0023+/-0.0014 %ID/g, P = 0.0001), muscle and fat tissue but clearly lower than salivary gland uptake. CONCLUSION: Although 201Tl SPECT is not sensitive enough to be used as an independent imaging modality for staging of the neck, its correlative application with MRI appears to be an accurate method for the assessment of regional spread in head and neck squamous cell carcinoma. The ability of 201Tl SPECT to characterize neck lymphadenopathies detected by MRI appears to be based on the difference in 201Tl concentration found in lymph nodes with and without tumor involvement.

Radiation pneumonitis imaged with indium-111-pentetreotide.

UNLABELLED: Early recognition of radiation pneumonitis enables adequate treatment with a reasonable chance to prevent late sequelae. The feasibility of 111In-pentetreotide in detecting this condition was explored in this study. METHODS: The degree of lung uptake of 111In-pentetreotide, evaluated both visually and quantitatively by irradiated-to-nonirradiated area ratios (INIA ratio) from planar images after 24 hr, was analyzed in relation to the radiation field and compared with ventilation/perfusion (V/Q) images and chest radiographs or CT in 11 patients who had received radiotherapy to the mediastinum or to the internal mammary nodes, 10 of whom were suspected of having clinical radiation pneumonitis. Additional SPECT studies were used to map lung uptake distribution. RESULTS: Indium-111-pentetreotide scans were positive in nine symptomatic patients examined 2-5 mo after radiotherapy; strongly or moderately positive in eight patients, one of whom was receiving steroid therapy without clinical response; and weakly positive in one patient with good steroid response. Indium-111-pentetreotide studies were negative in one asymptomatic patient examined 1 mo after radiotherapy and in one symptomatic patient, with subsequent diagnosis of aspecific viral pneumonitis, examined 4 mo after irradiation. Positive 111In-pentetreotide scans delineated areas of radiation pneumonitis that adequately correlated with areas of decreased ventilation/perfusion and x-ray abnormalities. INIA ratios varied from 1.01 to 2.16 and, in irradiated areas with visible uptake, the lowest value was 1.29. SPECT showed lung uptake in both superficial and deep lying areas in patients with mantle irradiation fields whereas distribution was limited to anterior areas in internal mammary lymph node chain irradiation. CONCLUSION: Indium-111-pentetreotide can detect radiation pneumonitis and may have a role in both the differential diagnosis of patients who have complaints after radiotherapy, and when supported by quantification in the monitoring of response to steroid therapy.