[18F]DCFPyL PET/CT versus [18F]fluoromethylcholine PET/CT in Biochemical Recurrence of Prostate Cancer (PYTHON): a prospective, open label, cross-over, comparative study

PURPOSE

Primary objective was to compare the per-patient detection rates (DR) of [18F]DCFPyL versus [18F]fluoromethylcholine positron emission tomography/computed tomography (PET/CT), in patients with first prostate cancer (PCa) biochemical recurrence (BCR). Secondary endpoints included safety and impact on patient management (PM).

METHODS

This was a prospective, open label, cross-over, comparative study with randomized treatment administration of [18F]DCFPyL (investigational medicinal product) or [18F]fluoromethylcholine (comparator). Men with rising prostate-specific antigen (PSA) after initial curative therapy were enrolled. [18F]DCFPyL and [18F]fluoromethylcholine PET/CTs were performed within a maximum time interval of 12 days. DR was defined as the percentage of positive PET/CT scans identified by 3 central imaging readers. PM was assessed by comparing the proposed pre-PET/CT treatment with the local treatment", defined after considering both PET/CTs.

RESULTS

A total of 205 patients with first BCR after radical prostatectomy (73%; median PSA = 0.46 ng/ml [CI 0.16;27.0]) or radiation therapy (27%; median PSA = 4.23 ng/ml [CI 1.4;98.6]) underwent [18F]DCFPyL- and/or [18F]fluoromethylcholine -PET/CTs, between July and December 2020, at 22 European sites. 201 patients completed the study. The per-patient DR was significantly higher for [18F]DCFPyL- compared to [18F]fluoromethylcholine -PET/CTs (58% (117/201 patients) vs. 40% (81/201 patients), p < 0.0001). DR increased with higher PSA values for both tracers (PSA ≤ 0.5 ng/ml: 26/74 (35%) vs. 22/74 (30%); PSA 0.5 to ≤ 1.0 ng/ml: 17/31 (55%) vs. 10/31 (32%); PSA 1.01 to < 2.0 ng/ml: 13/19 (68%) vs. 6/19 (32%);PSA > 2.0: 50/57 (88%) vs. 39/57 (68%) for [18F]DCFPyL- and [18F]fluoromethylcholine -PET/CT, respectively). [18F]DCFPyL PET/CT had an impact on PM in 44% (90/204) of patients versus 29% (58/202) for [18F]fluoromethylcholine. Overall, no drug-related nor serious adverse events were observed.

CONCLUSIONS

The primary endpoint of this study was achieved, confirming a significantly higher detection rate for [18F]DCFPyL compared to [18F]fluoromethylcholine, in men with first BCR of PCa, across a wide PSA range. [18F]DCFPyL was safe and well tolerated.

169Erbium-citrate synoviorthesis after failure of local corticosteroid injections to treat rheumatoid arthritis-affected finger joints

OBJECTIVES

Intra-articular injection of 169Erbium-citrate (169Er-citrate; radiosynoviorthesis or radiosynovectomy) is an effective local treatment of rheumatic joint diseases. However, its efficacy in corticosteroid-resistant rheumatoid arthritis-affected joints has not been clearly demonstrated.

METHODS

A double-blind, randomised, placebo-controlled, international multicentre study was conducted in patients with rheumatoid arthritis with recent (< or = 24 months) ineffective corticosteroid injection(s) into their finger joint(s). Eighty-five finger joints of 44 patients were randomised to receive a single injection of placebo (NaCl 0.9%) or 169Er-citrate. Results of evaluation 6 months later were available for 82 joints (46 metacarpophalangeal and 36 proximal interphalangeal joints) of 42 patients: 39 169Er-citrate-injected joints and 43 placebo-injected joints. Efficacy was assessed using a rating scale for joint pain, swelling and mobility.

RESULTS

Intent-to-treat analysis of the results of the 82 joints showed a significant effect of 169Er-citrate compared to placebo for the principal criteria decreased pain or swelling (95 vs 79%; p = 0.038) and decreased pain and swelling (79 vs 47%; p = 0.0024) and for the secondary criteria decreased pain (92 vs 72%; p = 0.017), decreased swelling (82 vs 53%; p = 0.0065) and increased mobility (64 vs 42%; p = 0.036). Per-protocol analysis, excluding 18 joints of patients who markedly changed their usual systemic treatment for arthritis, gave similar percentages of improvement but statistical significance was lower owing the reduced power of the statistical tests.

CONCLUSION

These results confirm the clinical efficacy of 169Er-citrate synoviorthesis of rheumatoid arthritis-diseased finger joints after recent failure of intra-articular corticotherapy.

Better results with rhenium-186 radiosynoviorthesis than with cortivazol in rheumatoid arthritis (RA): a two-year follow-up randomized controlled multicentre study

OBJECTIVE

The aim of this international multicentric randomized phase 3 clinical trial was to compare prospectively radiosynoviorthesis (RSO) with rhenium-186-sulfide (186Re) to intra-articular corticotherapy in patients with clinically controlled rheumatoid arthritis (RA), but in whom one or a few medium-sized joints remained painful or swollen.

METHODS

One hundred and twenty-nine joints in 81 RA patients [stratified into 2 groups: wrists (group 1, n = 78) and all the other joints (group 2, n = 51, including 18 elbows, 21 shoulders and 12 ankles)] were randomized to receive intra-articular injections of either 186Re-sulfide (64 +/- 4 MBq), or cortivazol (Altim) 3.75 mg. Clinical assessment was performed before and then at 3, 6, 12, 18 and 24 months after local therapy, using a 4-step verbal rating scale (VRS) and a 100 mm visual analog scale for pain, a 4-step VRS for joint swelling and mobility and a 2-step VRS for the radiological stage. The Mantel-Haenszel test was used for qualitative variables, analysis of variance (ANOVA) for quantitative pain analysis and Kaplan-Meyer survival test for relapse analysis.

RESULTS

186Re was observed to be statistically superior to cortivazol at 18 and 24 months while no statistical difference was seen for any criterion at 3, 6 and 12 months post injection. At 24 months, the difference in favor of 186Re was significant for pain (p = 0.024), joint swelling (p = 0.01), mobility (p = 0.05, non-wrists only), pain and swelling (p = 0.03) and pain or swelling (p = 0.02). "Survival" studies (Kaplan-Meyer) demonstrated a greater relative risk of relapse in corticoid treated joints, but only from the second year of follow-up. No serious side effect was observed in any patient, with only light and transient local pain and/or swelling occurring in 24% of cases, regardless of the treatment used.

CONCLUSION

186Re-sulfide and cortivazol had similar efficacy up to 12 months post-injection, but 186Re became clearly more effective at 18 and 24 months, for all criteria monitored and for RA outcome. Therefore, 186Re RSO can be recommended for routine clinical use.

Étude clinique en phase 2 de la BZA2 (123IN-(2-diéthylaminoéthyl)-2-iodobenzamide) dans le diagnostic du mélanome malin oculaire et de ses métastases

PURPOSE

Iodobenzamides are reported to possess an affinity for melanoma. A first selected compound, BZA, was studied in a phase 2 clinical trial on 159 patients as an imaging agent for the detection of primary melanoma and metastases with good results. We report the results of a second phase 2 clinical trial on 40 patients with a new radiopharmaceutical BZA2 (an orthoiodinated BZA analog), which was expected to provide quality images sooner after injection and with better imaging contrast.

PATIENTS AND METHODS

Performance was evaluated in 40 patients classified with primary ocular lesions (12), suspicion of metastases of ocular or cutaneous origin (15), or with no known secondary lesion (13), and results were compared with conventional investigation techniques (ophthalmoscopy, ultrasonography, and angiography for ocular melanoma, whole-body CT scan and ultrasonography for metastases).

RESULTS

No adverse events were recorded. The overall results on a per patient basis showed a sensitivity of 78% and a specificity of 95%. The four false negatives observed were ocular lesions (three with a thickness<3mm and one achromic), but all the proven secondary lesions were imaged. Moreover, negative BZA2 scintigraphy in cases of suspicious lesions led to the correction of two diagnoses: the prostatic origin of bone metastases and the endocrine tumor origin (APUD system) of an ocular lesion.

DISCUSSION

BZA2 scintigraphy is an easy test with good tolerance. In the diagnosis of ocular primary melanoma, the sensitivity of the test is 64%, although limited by the thickness (3mm) and the pigmentation of the lesion. However, the BZA2 scintigraphy is a very useful test for the detection of melanoma metastases, with a sensitivity of 100% and a specificity of 95%.

CONCLUSION

BZA2 scintigraphy showed good tolerance in patients and it appears promising for differential diagnosis, staging, and restaging of melanoma.

123I-N-(2-diethylaminoethyl)-2-iodobenzamide: a potential imaging agent for cutaneous melanoma staging

Melanoma is a neoplasia of dramatically increasing incidence that has a propensity to spread rapidly. Early detection is fundamental and patient management requires reliable, sensitive and reproducible staging methods, such as a single examination by planar scintigraphy or single-photon emission tomography (SPET) using a radiopharmaceutical with selectivity for melanoma tissue. Among iodobenzamides reported to possess an affinity for melanoma, a new compound, N-(2-diethylaminoethyl)-2-iodobenzamide (BZA(2)), was selected for a clinical trial in view of its pharmacokinetic experimental profile in melanoma-bearing mice. Planar whole-body scintigraphy using (123)I-BZA(2) was performed in 25 patients with histologically proven cutaneous melanoma. Performance was evaluated in two groups of patients with one or more documented secondary lesions ( n=13) or with no known secondary lesions ( n=12), and results were compared with those of conventional investigation techniques. No adverse clinical or biological events were recorded. Lesions were imaged by increased tracer uptake, and good quality images were obtained 4 h after administration. After a follow-up of more than 1 year, the overall results of (123)I-BZA(2) scintigraphy on a per patient basis showed a sensitivity of 100%, a specificity of 95%, a positive predictive value of 86% and a negative predictive value of 100%. The proven secondary lesions were imaged with a sensitivity of 100% and a specificity of 91%. In seven patients with suspected metastases, the absence of (123)I-BZA(2) uptake was confirmed as true negative, and in one patient without suspected metastases, (123)I-BZA(2) scintigraphy revealed a gastric lesion. Hence eight diagnoses would have been modified by (123)I-BZA(2) scintigraphy data. (123)I-BZA(2) allowed discrimination between benign and malignant lesions and, in the case of malignancies, between those of melanomatous origin and others. This compound, which is selective for melanoma tissue, appears promising for the staging and restaging of melanoma.

Quantitative analysis of striatal dopamine D2 receptors with 123 I-iodolisuride SPECT in degenerative extrapyramidal diseases

123I-Iodolisuride has high specific affinity for binding on dopamine D2 receptors in the striatum and has been used in a few single photon emission computed tomography (SPECT) studies of extrapyramidal disorders. The diagnosis of Parkinson's disease (PD) is very difficult in the first 5 years of evolution, with 15-25% false positive diagnoses. The aim of this study was therefore to determine the value of iodolisuride SPECT in discriminating Parkinson's from the most frequent Parkinson-plus syndromes (PPS). Seventeen patients with an extrapyramidal syndrome had a SPECT examination 1 h after injection of 180-185 MBq of 123I-iodolisuride. They were followed under dopaminergic treatment for at least 2 years. After 2 years, they were separated in two groups according to specific clinical criteria and sensitivity to dopaminergic treatment: nine patients had PD (age = 59.8+/-8.8 years; Hoehn and Yahr = 1.8+/-0.7; evolution = 4.3+/-3 years) and eight had PPS (age = 71.6+/-7.3 years; Hoehn and Yahr = 2.9+/-2.0; evolution = 4.1+/-1.5 years). The binding potential of iodolisuride in the striatum was assessed by considering the striatum (S)/occipital lobe (O) ratio at the pseudo-equilibrium 1 h after injection. The S/O ratio was statistically different between PD and PPS (1.97+/-0.3 vs. 1.65+/-0.2 (P<0.02)). Iodolisuride SPECT could differentiate both groups with a sensitivity of 88.8% and a specificity of 75%. Iodolisuride is a good specific D2 receptor ligand for SPECT and complements specific clinical criteria for the diagnosis of Parkinson's disease and differentiation between different extrapyramidal disorders.

Physical and biological dosimetry in patients undergoing radiosynoviorthesis with erbium-169 and rhenium-186

Physical and biological dosimetry were investigated in 45 rheumatoid arthritis patients treated by radiosynoviorthesis (RSO) with 186Re-sulphide (medium-sized joints) and 169Er-citrate (digital joints). Biological dosimetry involved scoring dicentrics in lymphocytes, cultured from blood samples withdrawn just before and 6 h, 24 h and 7 days after treatment. Physical methods included repeated blood sample counts and scintigraphy data. For erbium-169 (pure beta emitter), only bremsstrahlung could be measured and solely in the injection area. For rhenium-186 (both beta and gamma emitter), whole body scans and static images of joints and locoregional lymph nodes were performed. Dosimetry calculations were in accordance with the MIRDOSE 3 software and tables. For erbium-169 (21 patients), either metacarpophalangeal (30 MBq) or proximal interphalangeal (20 MBq) joints of the hands were treated (one joint per patient); 18 patients (out of 21) were interpretable for biological dosimetry, 10 (out of 11) for physical dosimetry and six (out of 10) for both. For rhenium-186, 23 wrists, nine elbows, three shoulders and two ankles were injected in 24 patients, with a maximum of three joints per patient (70 MBq per joint); 20 patients (out of 24) and 10 (out of 10) were interpretable for biological and physical dosimetry, respectively, and eight (out of 10) for both methods. Erbium-169 biological dosimetry was negative in all interpretable patients, and physical dosimetry gave a blood dose of 15 +/- 29 microGy and an effective dose lower than 1 mSv/30 MBq. For rhenium-186, biological results were negative in 16 patients (out of 20), but showed a blood irradiation around 200 mGy in the last four. A significant cumulative increase of dicentrics 7 days after injection (16/10,000 instead of 5/10,000 prior to treatment; p < 0.04) was also noted. Gamma counts gave a blood dose of 23.9 +/- 19.8 mGy/70 MBq and the effective dose was found to be 26.7 +/- 5.1 mGy/70 MBq, i.e. about 380 microGy.MBq-1. Erbium-169 RSO is very safe from both physical and biological dosimetry standpoints. Rhenium-186 leak is greater, as demonstrated by the higher blood activity and the measurable, although limited, dicentrics induction in blood lymphocytes. However, the effective dose remains moderate, i.e. 30 times lower than in 131I therapy in benign thyroid diseases.

Biodistribution, dosimetry, and safety of myocardial perfusion imaging agent 99mTcN-NOET in healthy volunteers

99mTcN-NOET (bis[N-ethoxy,N-ethyl]dithiocarbamato nitrido technetium (V)) has been proposed for myocardial perfusion imaging. Biodistribution, safety, and dosimetry were studied in 10 healthy volunteers (5 at rest and 5 during exercise).

METHODS

Biodistribution was studied by acquiring dynamic images up to 60 min after injection and whole-body images up to 24 h after injection. The MIRDOSE3 analysis program was used for radiation dosimetry calculations.

RESULTS

Safety parameters measured to 48 h after injection revealed no clinically significant changes. Cardiac uptake of 99mTcN-NOET was high (2.9%-3%), with biologic half-life of 210-257 min on average. Lung uptake of 99mTcN-NOET was higher (10%-20%) but, on average, biologic half-life was shorter (1-77 min). Clearance from the blood was rapid (5% by 5 min). Radiation dosimetry calculations indicated an effective absorbed dose of 5.11 x 10(-3) mSv/MBq at rest and 5.38 x 10(-3) mSv/MBq after exercise.

CONCLUSION

99mTcN-NOET exhibits high cardiac uptake and an estimated effective absorbed dose comparable with that of the other 99mTc-labeled compounds used in myocardial perfusion imaging.

Clinical study of [123I] N-(2-diethylaminoethyl)-4-iodobenzamide in the diagnosis of primary and metastatic ocular melanoma

PURPOSE

To assess the value of scintigraphy with [123I]N-(2-diethylaminoethyl)-4-iodobenzamide (BZA), a phase II clinical trial was performed on 48 patients with a suspicion of ocular melanoma.

METHODS

56 examinations were performed to image lesions with a clinical diagnosis of primary ocular melanoma before and/or after treatment, to observe the results in simulating lesions or to image metastases.

RESULTS

Ocular BZA-scintigraphy demonstrated a sensitivity of 86%, and a specificity of 83%. Whole-body scintigraphy was used in the follow-up of treated patients and could be repeated. We imaged orbital recurrence, known and occult metastases, specially in the liver. After 9 conservative treatments ocular BZA-scintigraphy was negative in 9 eyes.

CONCLUSION

The BZA-scintigraphy in combination with other diagnostic procedures appeared to be a suitable method in the diagnosis of ocular melanoma and a potentially useful imaging modality to screen for ocular malignant melanoma metastases.

Myocardial perfusion imaging with technetium-99m-Tc NOET: comparison with thallium-201 and coronary angiography

We compared TcN-NOET [bis(N-ethoxy, N-ethyl dithiocarbamato)nitrido 99mTc] and 201Tl images to estimate the utility of this compound in the detection of coronary artery disease (CAD).

METHODS

Twenty-five patients undergoing cardiac catheterization had stress-redistribution-reinjection 201Tl SPECT imaging, stress-delayed (2, 4 and 6 hr postinjection) and rest-delayed (4 hr postinjection) TcN-NOET SPECT imaging.

RESULTS

Nineteen patients had coronary stenosis > or = 50% and six were normal. Stress TcN-NOET and 201Tl imaging were concordant for the presence of CAD in 22/25 patients (88%, kappa = 0.76 +/- 0.20). The overall sensitivity of TcN-NOET SPECT imaging was 74% (14/19 patients) and 68% (13/19 patients) for 201Tl SPECT imaging. The specificity was 100% (6/6 patients) for both techniques. The overall agreement of TcN-NOET and 201Tl for the presence of disease in individual coronary arteries was 96% (72/75 arteries, kappa = 0.92 +/- 0.16). Segmental analysis of stress images showed a concordance in 211/225 segments (94%, kappa = 0.82 +/- 0.09). Comparison of the 4-hr images showed a concordance between 201Tl and TcN-NOET in 21/23 patients. Following TcN-NOET injection at rest, seven patients had a defect on the initial images, which had normalized 4 hr postinjection in four patients (57%).

CONCLUSION

Perfusion imaging with TcN-NOET and 201Tl gives comparable diagnostic information in patients undergoing exercise testing for assessment of CAD. Because of the normalization of myocardial activity 4 hr after injection in some patients, we conclude that TcN-NOET is a potential technetium compound equivalent to 201Tl.