Erratum: Single-center developing country analysis of radium-223 therapy in prostate cancer-preliminary results

[This corrects the article on p. 352 in vol. 11, PMID: 34754606.].

Does TRODAT-1 SPECT Uptake Correlate with Cerebrospinal Fluid α-Synuclein Levels in Mid-Stage Parkinson's Disease?

BACKGROUND

Parkinson's disease (PD) is characterized by a progressive loss of nigrostriatal dopaminergic neurons with impaired motor and non-motor symptoms. It has been suggested that motor asymmetry could be caused due to an imbalance in dopamine levels, as visualized by dopamine transporter single emission computed tomography test (DAT-SPECT), which might be related to indirect measures of neurodegeneration, evaluated by the Montreal Cognitive Assessment (MOCA) and α-synuclein levels in the cerebrospinal fluid (CSF). Therefore, this study aimed to understand the correlation between disease laterality, DAT-SPECT, cognition, and α-synuclein levels in PD.

METHODS

A total of 28 patients in the moderate-advanced stage of PD were subjected to neurological evaluation, TRODAT-1-SPECT/CT imaging, MOCA, and quantification of the levels of α-synuclein.

RESULTS

We found that α-synuclein in the CSF was correlated with global cognition (positive correlation, r² = 0.3, p = 0.05) and DAT-SPECT concentration in the putamen (positive correlation, r² = 0.4, p = 0.005), and striatum (positive correlation, r² = 0.2, p = 0.03), thus working as a neurodegenerative biomarker. No other correlations were found between DAT-SPECT, CSF α-synuclein, and cognition, thus suggesting that they may be lost with disease progression.

CONCLUSIONS

Our data highlight the importance of understanding the dysfunction of the dopaminergic system in the basal ganglia and its complex interactions in modulating cognition.

Interictal and postictal 18F-FDG PET/CT in epileptogenic zone localization

Objective

To evaluate the performance of ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography ( ¹⁸F-FDG PET/CT) in localizing epileptogenic zones, comparing ¹⁸F-FDG injection performed in the traditional interictal period with that performed near the time of a seizure.

Materials and Methods

We evaluated patients with refractory epilepsy who underwent ¹⁸F-FDG PET/CT. The reference standards for localization of the epileptogenic zone were histopathology and follow-up examinations (in patients who underwent surgery) or serial electroencephalography (EEG) recordings, long-term video EEG, and magnetic resonance imaging (in patients who did not). The ¹⁸F-FDG injection was performed whether the patient had an epileptic seizure during the EEG monitoring period or not. The ¹⁸F-FDG PET/CT results were categorized as concordant or discordant with the reference standards.

Results

Of the 110 patients evaluated, 10 were in a postictal group (FDG injection after a seizure) and 100 were in the interictal group. The ¹⁸F-FDG PET/CT was concordant with the reference standards in nine (90%) of the postictal group patients and in 60 (60%) of the interictal group patients. Among the nine postictal group patients in whom the results were concordant, the ¹⁸F-FDG PET/CT showed hypermetabolism and hypometabolism in the epileptogenic zone in four (44.4%) and five (55.6%), respectively.

Conclusion

Our data indicate that ¹⁸F-FDG PET/CT is a helpful tool for localization of the epileptogenic zone and that EEG monitoring is an important means of correlating the findings. In addition, postictal ¹⁸F-FDG PET/CT is able to identify the epileptogenic zone by showing either hypometabolism or hypermetabolism.

VALIDATION OF CONVOLUTIONAL NEURAL NETWORK FOR FAST DETERMINATION OF WHOLE-BODY METABOLIC TUMOR BURDEN IN PEDIATRIC LYMPHOMA

INTRODUCTION: ¹⁸F-FDG PET/CT whole-body tumor burden in lymphoma is not routinely performed due to the lack of fast quantification methods. Although the semi-automatic method is fast, it still lacks the necessary speed required to quantify tumor burden in daily clinical practice. PURPOSE: To evaluate the performance of the convolutional neural networks (CNN) software to localize neoplastic lesions in whole-body ¹⁸F-FDG PET/CT images of pediatric lymphoma patients. METHODS: This retrospective image data set, derived from the data pool under the IAEA (CRP# E12017), included 102 baseline staging ¹⁸F-FDG PET/CTs of pediatric lymphoma patients (mean age 11 yrs). Images were quantified to determine the whole-body (wb) tumor burden (wbMTV and wbTLG) using a semi-automatic (SEMI) software and an CNN-based software. Both were displayed as wbMTVSEMI & wbTLGSEMI and wbMTVCNN & TLGCNN. The intraclass correlation coefficient (ICC) was applied to evaluate concordance between the CNN-based software and the SEMI software. RESULTS: Twenty-six patients were excluded from the analyses because the software was unable to perform calculation. In the remaining 76 patients, wbMTVCNN and wbMTVSEMI whole-body tumor burden metrics were highly correlated (ICC=0.993; 95%CI: 0.989 -0.996; p-value<0.0001) as were wbTLGCNN and wbTLGSEMI (ICC=0.999; 95%CI: 0.998-0.999; p-value<0.0001). However, the time spent calculating these metrics was significantly (<0.0001) faster by CNN (mean = 19 seconds; 11 - 50 seconds) compared to the semi-automatic method (mean = 21.6 minutes; 3.2 - 62.1 minutes), especially in patients with advanced disease. CONCLUSION: Determining whole-body tumor burden in pediatric lymphoma patients using CNN is fast and feasible in clinical practice.

Single-center developing country analysis of radium-223 therapy in prostate cancer-preliminary results

We reviewed the records of mCRPC patients treated with off-label use of Ra-223. Ra-223 efficiency in this non-study population was correlated to outcome measures overall survival (OS), progression-free survival (PFS), bone event-free survival, bone marrow failure (BMF), and disease-related biomarkers. There were no limits regarding the number of prior hormonal agents or chemotherapy received before or during Ra-223. Exclusion criteria consisted of baseline platelet counts below 50,000/mm³ and/or absolute neutrophil counts below 1,500/mm³. Twenty-eight patients received 130 cycles of Ra-223 between 2017 and 2018. The overall median OS was 15.6 months. However, in patients submitted to 4 or fewer cycles, the median OS was 9.1 months; in contrast, the median OS was 18.5 months in patients submitted to 5 or 6 cycles. There was a significant inverse correlation between the number of cycles and the occurrence of bone events (76.2% of the patients that completed 6 cycles did not present bone events, while 71.4% of the patients that had skeletal-related events were submitted to less than 6 cycles). 82.1% of the patients were submitted to concomitant therapies with no significant side effects. There was also a decrease in ALP and LDH levels throughout treatment. Radium-223 increased OS and decreased bone events, especially when patients were able to complete 5-6 cycles. The proper selection of patients is crucial to improve outcomes.

The ratio between the whole-body and primary tumor burden, measured on 18F-FDG PET/CT studies, as a prognostic indicator in advanced non-small cell lung cancer

Objective

To determine whether the whole-body tumor burden, as quantified by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT), is a prognostic indicator in advanced (stage III or IV) non-small cell lung cancer (NSCLC).

Materials and Methods

This was a prospective study in which we evaluated ¹⁸F-FDG PET/CT staging parameters to quantify tumor burdens in patients with stage III or IV NSCLC. The following parameters were evaluated for the whole body (including the primary tumor) and for the primary tumor alone, respectively: maximum standardized uptake volume (wbSUV_max and tuSUV_max); metabolic tumor volume (wbMTV and tuMTV); and total lesion glycolysis (wbTLG and tuTLG). To determine whether the ¹⁸F-FDG PET/CT parameters were associated with overall survival (OS) and progression-free survival (PFS), we evaluated the wbSUV_max/tuSUV_max, wbMTV/tuMTV, and wbTLG/tuTLG ratios.

Results

¹⁸F-FDG PET/CT was performed for staging in 52 patients who were followed for a median of 11.0 months (mean, 11.7 months). The estimated median PFS and OS were 9.6 months and 11.6 months, respectively. In the univariate analysis, OS was found to correlate significantly with wbTLG (hazard ratio [HR] = 1.001; 95% confidence interval [95 CI]: 1.000-1.001; p = 0.0361) and with the wbTLG/tuTLG ratio (HR = 1.705; 95% CI: 1.232-2.362; p = 0.0013). In the multivariate analysis, only the wbTLG/tuTLG ratio was independently associated with OS (HR = 1.660; 95% CI: 1.193-2.310; p = 0.0027).

Conclusion

The wbTLG/tuTLG ratio is an independent prognostic indicator of OS in advanced-stage NSCLC.

PSMA whole-body tumor burden in primary staging and biochemical recurrence of prostate cancer

PURPOSE

The objective of this study was to evaluate whether ⁶⁸Ga-PSMA PET/CT whole-body tumor burden (PSMAwbtb) is associated with clinical parameters and laboratory parameters in prostate cancer patients.

METHODS

We retrospectively evaluated prostate cancer patients submitted to PSMA PET/CT for primary staging purposes or due to biochemical recurrence (BR). PSMAwbtb metrics (total volume of PSMA-avid tumor (PSMA-TV)) and total uptake of PSMA-avid lesions (PSMA-TL) were calculated semi-automatically. Spearman's rank correlations between PSMAwbtb metrics and clinical, laboratory parameters (age, time-to-BR, years of diagnosis of prostate cancer, free and total serum PSA levels, and the Gleason score) and with the highest SUVmax of a lesion (hSUVmax) were analyzed.

RESULTS

Among the 257 PSMA PET/CT studies, there were 46 scans (17.9%) performed for primary staging and 211 (82.1%) for BR. PSMA-TV and PSMA-TL were calculated for the 157 positive scans (58.8%), which were 43 patients (93.5%) in the primary staging group and 114 patients (54.0%) in the BR group. In the primary staging group, we observed a significant correlation between PSMA-TL and hSUVmax (p = 0.0021). In the BR group, there was a significant direct correlation between PSMA-TL and the variables age (p = 0.0031), total serum PSA values (p = < 0.0001), free serum PSA values (p = < 0.0001), and the hSUVmax (p = < 0.0001). Similar results were obtained for PSMA-TV.

CONCLUSION

PSMAwbtb has a direct and positive correlation with serum PSA values and age in prostate cancer patients with BR.

18F-FDG PET/CT images defined the true extent of a urothelial bladder carcinoma

A patient was referred, after neoadjuvant chemotherapy, for pre-surgical evaluation of urothelial bladder carcinoma (single lesion). Two thickenings in the left ureter wall identified on the CT scan were equivocal for malignancy. 18F-FDG PET/CT with delayed pelvic images, hyperhydration, and furosemide showed hypermetabolic ureteral metastases and multifocal bladder tumors. There were no lymph nodes or distant metastases. These 18F-FDG PET/CT findings completely altered the surgical treatment. The patient underwent left nephroureterectomy, radical cystoprostatectomy, and lymphadenectomy, followed by a urinary transit reconstruction. Histopathology confirmed multifocal high-grade urothelial carcinoma in the bladder walls and left ureter and benign lymph nodes.

Radium-223 as an Approved Modality for Treatment of Bone Metastases

Radium-223 dichloride (²²³Ra) is an α-emitter radionuclide approved for treatment of osteoblastic metastases in castrate-resistant prostate cancer (mCRPC) patients. ²²³Ra increases overall survival, improves bone pain, increases the median time to the first skeletal-related event, reduces the use of external beam radiation therapy for bone pain palliation, reduces the rates of spinal cord compression, and hospitalization. ²²³Ra therapy has minimal side effects; the most common hematological side effects are anemia, thrombocytopenia and neutropenia while the nonhematological side effects that may occur are bone pain flare, nausea, fatigue, and diarrhea. Alongside ²²³Ra therapy there are currently a variety of first-line therapeutic options available to treat mCRPC patients and much debate regarding the appropriate treatment algorithm for these patients and the possible combination of therapies among the ones available. In this article, we review the rationale behind ²²³Ra therapy as well as ²²³Ra mechanisms of action, biodistribution and dosimetry, optimal timing possibilities to initiate ²²³Ra in contrast to other treatments available, the association of ²²³Ra with other therapies and the means of evaluating patients in order to properly deliver to ²²³Ra therapy. Furthermore, we will discuss ²²³Ra dose administration possibilities, patient and dose preparation and the challenges of treatment response evaluation during and after ²²³Ra.

Proposal for a Quantitative 18F-FDG PET/CT Metabolic Parameter to Assess the Intensity of Bone Involvement in Multiple Myeloma

Many efforts have been made to standardize the interpretation of ¹⁸F-FDG PET/CT in multiple myeloma (MM) with qualitative visual analysis or with quantitative metabolic parameters using various methods for lesion segmentation of PET images. The aim of this study was to propose a quantitative method for bone and bone marrow evaluation of ¹⁸F-FDG PET/CT considering the extent and intensity of bone ¹⁸F-FDG uptake: Intensity of Bone Involvement (IBI). Whole body ¹⁸F-FDG PET/CT of 59 consecutive MM patients were evaluated. Compact bone tissue was segmented in PET images using a global threshold for HU of the registered CT image. A whole skeleton mask was created and the percentage of its volume with ¹⁸F-FDG uptake above hepatic uptake was calculated (Percentage of Bone Involvement - PBI). IBI was defined by multiplying PBI by mean SUV above hepatic uptake. IBI was compared with visual analysis performed by two experienced nuclear medicine physicians. IBI calculation was feasible in all images (range:0.00–1.35). Visual analysis categorized PET exams into three groups (negative/mild, moderate and marked bone involvement), that had different ranges of IBI (multi comparison analysis, p < 0.0001). There was an inverse correlation between the patients’ hemoglobin values and IBI (r = −0.248;p = 0.02). IBI score is an objective measure of bone and bone marrow involvement in MM, allowing the categorization of patients in different degrees of aggressiveness of the bone disease. The next step is to validate IBI in a larger group of patients, before and after treatment and in a multicentre setting.

SPECT/CT with 99mTc-sestamibi for the evaluation of skeletal muscle perfusion after electrical muscle stimulation in athletes

Objective

The purpose of this study was to evaluate the effects of electrical muscle stimulation (EMS) on muscles, using ^99mTc-sestamibi SPECT/CT.

Materials and Methods

We prospectively enrolled 20 consecutive male professional water polo players. The mean age was 25 years (range, 18-36 years). All athletes underwent ^99mTc-sestamibi SPECT/CT of the thigh (rectus femoris and vastus medialis muscle groups) before and after EMS. Images were quantified to identify increases in perfusion after EMS.

Results

Before EMS, there were no significant differences between the right and left thigh (rectus femoris and vastus medialis muscles) in terms of perfusion (p = 0.4). However, the comparison between the pre- and post-EMS analyses of the same muscle groups showed significant differences in radiotracer uptake (p < 0.001), with a mean increase in perfusion of 128% for the rectus femoris muscle group (95% CI: 0.86-1.61) and 118% for the vastus medialis muscle group (95% CI: 0.96-1.79).

Conclusion

^99mTc-sestamibi SPECT/CT is an objective means of evaluating blood flow in muscles submitted to EMS, which appears to promote significant increases in such blood flow.

18F-FDG PET/CT performed immediately after percutaneous ablation to evaluate outcomes of the procedure: preliminary results

Objective

To determine whether ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography performed immediately after percutaneous ablation (_iPA¹⁸F-FDG PET/CT) is useful in evaluating the outcomes of the procedure.

Materials and Methods

This was a retrospective study of 20 patients (13 males, 7 females; mean age, 65.8 ± 12.1 years) submitted to percutaneous ablation of metastases. All of the lesions treated had shown focal uptake on a ¹⁸F-FDG PET/CT scan obtained at baseline. The primary tumors were mainly colorectal cancer (in 45%) or lung cancer (in 40%). _iPA¹⁸F-FDG PET/CT was performed to identify any residual viable tumor cells. The treatment was considered a success (no viable tumor cells present) if no uptake of ¹⁸F-FDG was noted on the _iPA¹⁸F-FDG PET/CT scan.

Results

Twenty-six lesions were submitted to percutaneous ablation with either cryoablation (n = 7) or radiofrequency ablation (n = 19). The mean lesion diameter was 2.52 ± 1.49 cm. For the detection of viable tumor cells, _iPA¹⁸F-FDG PET/CT had a sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 66.7%, 95%, 88.5%, 80%, and 90.5%, respectively. There was a significant correlation between the _iPA¹⁸F-FDG PET/CT findings and the results of the follow-up studies (kappa = 0.66; p < 0.01).

Conclusion

_iPA¹⁸F-FDG PET/CT studies appear to constitute a useful means of evaluating the outcomes of percutaneous ablation. By detecting residual viable tumor cells, this strategy might allow early re-intervention, thus reducing morbidity. Studies involving larger numbers of patients are needed in order to confirm our findings.

Is interim 18F-fluoride PET/CT a predictor of outcomes after radium-223 therapy?

Objective

To determine whether an interim ¹⁸F-fluoride positron-emission tomography/computed tomography (PET/CT) study performed after the third cycle of radium-223 dichloride (²²³RaCl₂) therapy is able to identify patients that will not respond to treatment.

Materials and Methods

We retrospectively reviewed 34 histologically confirmed cases of hormone-refractory prostate cancer with bone metastasis in patients submitted to ²²³RaCl₂ therapy. All of the patients underwent baseline and interim ¹⁸F-fluoride PET/CT studies. The interim study was performed immediately prior to the fourth cycle of ²²³RaCl₂. The skeletal tumor burden-expressed as the total lesion fluoride uptake above a maximum standardized uptake value of 10 (TLF₁₀)-was calculated for the baseline and the interim studies. The percent change in TLF₁₀ between the baseline and interim studies (%TFL₁₀) was calculated as follows: %TFL₁₀ = interim TLF₁₀ - baseline TLF₁₀ / baseline TLF₁₀. End points were overall survival, progression-free survival, and skeletal-related events.

Results

The mean age of the patients was 72.4 ± 10.2 years (range, 43.3-88.8 years). The %TLF₁₀ was not able to predict overall survival (p = 0.6320; hazard ratio [HR] = 0.753; 95% confidence interval [CI]: 0.236-2.401), progression-free survival (p = 0.5908; HR = 1.248; 95% CI: 0.557-2.797) nor time to a bone event (p = 0.5114; HR = 1.588; 95% CI: 0.399-6.312).

Conclusion

The skeletal tumor burden on an interim ¹⁸F-fluoride PET/CT, performed after three cycles of ²²³RaCl₂, is not able to predict overall survival, progression-free survival, or time to bone event, and should not be performed to monitor response at this time.

Impact of 68GA-PSMA PET / CT on treatment of patients with recurrent / metastatic high risk prostate cancer - a multicenter study

Purpose:

The purpose of our study was to evaluate the clinical impact of ⁶⁸Ga-PSMA PET / CT in the setting of biochemical recurrence of prostate cancer.

Materials and Methods:

We retrospectively evaluated 125 prostate cancer patients submitted to the ⁶⁸Ga-PSMA PET / CT due to biochemical recurrence. The parameters age, Gleason score, PSA levels, and the highest SUVmax were correlated to potential treatment changes. The highest SUVmax values were correlated with age and Gleason score. The median follow-up time was 24 months.

Results:

⁶⁸Ga-PSMA PET / CT led to a treatment change in 66 / 104 (63.4%) patients (twenty-one patients were lost to follow-up). There was a significant change of treatment plan in patients with a higher Gleason score (P = 0.0233), higher SUVmax (p = 0.0306) and higher PSA levels (P < 0.0001; median PSA = 2.55 ng / mL).

Conclusion:

⁶⁸Ga-PSMA PET / CT in prostate cancer patients with biochemical recurrence has a high impact in patient management.

Final Outcome of 223Ra-therapy and the Role of 18F-fluoride-PET in Response Evaluation in Metastatic Castration-resistant Prostate Cancer-A Single Institution Experience

BACKGROUND

223Ra was the first therapeutic alpha-emitting radionuclide registered for clinical practice. This radionuclide is targeting actively bone-forming cells, and it is approved for treating metastatic skeletal disease in prostate cancer. 18F-PET is used to detect skeletal metastatic disease based on osteoblastic activity. The aim of this study was to analyze, if 18F-PET can be used assessing the results of 223Ra therapy, and to report final median overall survival in a total of 773 therapy cycles.

METHODS

A 161 men with castration-resistant prostate cancer were included in a single institution study (Protocol#: PA14-0848) and they received a total of 773 223Ra therapy cycles.

RESULTS

The median overall survival (95% CI) was 12.4 (9.1, 16.1) months in patient population. Interim Na18F-PET imaging was applied in 14 patients at baseline, after 3 cycles and after 6 cycles. TLF10 (skeletal disease burden at SUV-values >10 on Na18F -PET) were calculated in all these PET studies, and there was no significant association between change in TLF10 after 3 cycles and TLF10 after 6 cycles (p=0.20).

CONCLUSION

From these results, we conclude that interim imaging does not help in assessing the final outcome of 223Ra therapy. The survival benefit of 223Ra therapy alone is more than a year in a high-risk group of advanced prostate cancer.

Validation of the Semiautomatic Quantification of 18F-Fluoride PET/CT Whole-Body Skeletal Tumor Burden

Our purpose was to validate a semiautomatic quantification of the skeletal tumor burden on ¹⁸F-fluoride PET/CT using manual quantification as a reference. Methods: We quantified 51 ¹⁸F-fluoride PET/CT examinations performed on female breast cancer patients. Clinical information (age; time of disease presentation; presence of visceral metastases; and time to death, progression, or a bone event) was recorded. The total volume of ¹⁸F-fluoride-avid skeletal metastases and the total activity of ¹⁸F-fluoride-avid metastases were calculated manually and semiautomatically. Results: Manual and semiautomatic metrics correlated strongly (P < 0.0001; 95% confidence interval, 0.9300-0.9769). On multivariable analysis, the semiautomatic measures of total activity for ¹⁸F-fluoride-avid metastasis correlated significantly with overall survival (P = 0.0001) and progression-free survival (P = 0.0006). Approximate times for calculating skeletal tumor burden (semiautomatic vs. manual) were, respectively, 30 s versus 321 s in patients with fewer than 5 metastases, 120 s versus 640 s in patients with 5-10 metastases, and 240 s versus 1207s in patients with more than 10 metastases. Conclusion: Semiautomatic quantification of whole-body ¹⁸F-fluoride PET/CT skeletal tumor burden can replace manual quantification in breast cancer patients and is a strong independent biomarker of prognosis.

Gallium-68 in Medical Imaging

Over the past several years, Positron Emission Tomography (PET) imaging agents labeled with ;68Gallium (68Ga) have undergone a significant increase in clinical utilization. 68Ga is conveniently produced from a germanium-68/gallium-68 (68Ge/68Ga) generator. Because of the compact size and ease of use of the generator, 68Ga labeled compounds may be more cost-effective than PET radioisotopes that are cyclotron-produced. The convenient half-life of 68Ga (T1/2=68 min) provides sufficient radioactivity for various PET imaging applications, while delivering acceptable radiation doses to patients. This chapter summarizes the emerging clinical utilization of 68Ga-based radiotracers in medical imaging.

18-fluorodeoxy-glucose positron emission computed tomography as predictive of response after chemoradiation in oesophageal cancer patients

INTRODUCTION

The purpose of this study was to evaluate if a baseline, an interim or a post-chemoradiation (CTRT) 18-fluorodeoxy-glucose positron emission computed tomography (18F-FDG PET/CT) studies could provide information on pathologic response to CTRT and overall survival (OS).

MATERIALS AND METHODS

Thirty-one patients with histologically proven adenocarcinoma or squamous cell carcinoma of the oesophagus, fit for trimodality therapy were prospectively enrolled. Most were men (93.5%), and had a stage III cancer (74.2%). Chemotherapy consisted of oxaliplatin/5-fluorouracil (45.2%) and taxane/5-fluorouracil (54.8%). All patients underwent a baseline, an interim (performed 12 ± 2 days after the onset of CTRT) and a post-CTRT 18F-FDG PET/CT study. The 18F-FDG PET/CT variables evaluated were at baseline, interim and post-CTRT studies maximum standardised uptake value (SUV max) and total lesion glycolysis (TLG). Clinical and 18F-FDG PET/CT parameters were correlated with pathologic complete response (pathCR) and OS.

RESULTS

Among the 31 patients studied, 61.3% achieved a clinical complete response (cCR) and 87.1% had surgery. The median OS was 35.1 months (95% confidence interval (CI): 19.9-NA). PathCR rate was 22.2%. There was only a marginal association between cCR and pathCR (p = 0.06). None of the other variables was predictive of pathCR. There was association between OS and baseline TLG (p = 0.03) at the optimal cutoff TLG value of 75.15. Additionally, TLG and ΔTLG post-CTRT were also associated with OS (p = 0.01 and 0.03, respectively).

CONCLUSION

None of the PET parameters is predictive of pathCR but TLG at baseline and post-CTRT are prognostic of OS.

Scintigraphic follow-up of the effects of therapy with hydroxyurea on splenic function in patients with sickle cell disease

Patients with sickle cell disease (SCD) may develop functional asplenia as a chronic complication, secondary to repeated episodes of polymerisation of haemoglobin S. It is known that increased plasma concentrations of fetal haemoglobin (HbF) reduce the polymerisation of haemoglobin S. Hydroxyurea is a chemotherapeutic agent capable of increasing HbF levels in the red blood cells and its use has recently been proposed in the treatment of SCD. The objective of this study was to evaluate the effects of long-term therapy with hydroxyurea on recovery of splenic function. Twenty-one patients (aged 3-22 years; 14 with SS haemoglobinopathy, 7 with Sbeta(0) haemoglobinopathy) were studied with liver/spleen scintigraphy before and after 6 and 12 months of treatment. All studies were submitted to visual inspection and semi-quantitative analyses using spleen/liver ratios. Imaging prior to treatment demonstrated functional asplenia in nine SS patients and one Sbeta(0) patient and impaired splenic function in five SS patients and six Sbeta(0) patients. After treatment, splenic function improved in ten patients, remained unchanged in eight and worsened in three. Using liver/spleen imaging, it was possible to demonstrate that hydroxyurea is capable of improving splenic function in some SCD patients. Improvement is not always possible and frequently does not lead to a normal splenic function even after 1 year of treatment.