Six country vignettes: Strengthening radiotherapy and theranostics

BACKGROUND

For cancer patient populations worldwide, the synchronous scale-up of diagnostics and treatments yields meaningful gains in survival and quality of life. Among advanced cancer therapies, radiotherapy (RT) and theranostics are key to achieving practical, high-quality, and personalized precision medicine - targeting disease manifestations of individual patients and broad populations, alike. Aiming to learn from one another across different world regions, the six country vignettes presented here depict both challenges and victories in de novo establishment or improvement of RT and theranostics infrastructure.

METHODS

The International Atomic Energy Agency (IAEA) convened global RT and theranostics experts from diverse world regions and contexts to identify relevant challenges and report progress in their own six countries: Belgium, Brazil, Costa Rica, Jordan, Mongolia, and South Africa. These accounts are collated, compared, and contrasted herein.

RESULTS

Common challenges persist which could be more strategically assessed and addressed. A quantifiable discrepancy entails personnel. The estimated radiation oncologists (ROs), nuclear medicine physicians (NMPs), and medical physicists (MPs for RT and nuclear medicine) per million inhabitants in the six collective countries respectively range between 2.69-38.00 ROs, 1.00-26.00 NMPs, and 0.30-3.45 MPs (Table 1), reflecting country-to-country inequities which largely match World Bank country-income stratifications.

CONCLUSION

Established goals for RT and nuclear medicine advancement worldwide have proven elusive. The pace of progress could be hastened by enhanced approaches such as more sustainably phased implementation; better multinational networking to share lessons learned; routine quality and safety audits; as well as capacity building employing innovative, resource-sparing, cutting-edge technologic approaches. Bodies such as ministries of health, professional societies, and the IAEA shall serve critical roles in convening and coordinating more innovative RT and theranostics translational research, including expanding nuanced global database metrics to inform, reach, and potentiate milestones most meaningfully.

POLICY SUMMARY

Aligned with WHO 25×25 NCDs target; WHA70.12 and WHA76.5 resolutions.

The Diagnostic and Predictive Value of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Laryngeal Squamous Cell Carcinoma

This retrospective study examines the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and neck magnetic resonance imaging (MRI) in detecting nodal metastasis for patients with laryngeal squamous cell carcinoma (LSCC) and assesses the predictive values of metabolic and structural features derived from 18F-FDG PET/CT. By involving 66 patients from 2014 to 2021, the sensitivity and specificity of both modalities were calculated. 18F-FDG PET/CT outperforms neck MRI for nodal disease detection, with 89% sensitivity, 65% specificity, and 77% accuracy for nodal metastasis (p = 0.03). On the other hand, neck MRI had 66% sensitivity, 62% specificity, and 64% accuracy. Approximately 11% of patients witnessed a change in their therapy intent when relying on 18F-FDG PET/CT nodal staging results. Analyzing the cohort for PET-derived metabolic and morphological parameters, a total of 167 lymph nodes (LN) were visualized. Parameters such as the LN maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and LN size were computed. Logistic regression and receiver operating characteristic (ROC) analyses were performed. Among the 167 identified cervical LNs, 111 were histopathologically confirmed as positive. ROC analysis revealed the highest area under the curve for LN MTV (0.89; p < 0.01), followed by LN size (0.87; p < 0.01). Both MTV and LN size independently predicted LN metastasis through multivariate analysis. In addition, LN MTV can reliably predict false-positive LNs in preoperative staging, offering a promising imaging-based approach for further exploration.

Widespread presentation of brown tumors mimicking multiple myeloma

Brown tumors or osteitis fibrosa cystica has become a rare presentation of primary hyperparathyroidism in up-to-date clinical practice. Here, we describe a case of longstanding untreated hyperparathyroidism presenting itself with brown tumors in a 65-year-old patient. During the diagnostic work-up of this patient, bone SPECT/CT and ¹⁸F-FDG-PET/CT revealed multiple widespread osteolytic lesions. Differentiating from other bone tumors such as multiple myeloma is challenging. In this case, the final diagnosis was made by integrating the medical history, biochemical diagnosis of primary hyperparathyroidism, pathological findings and medical imaging.

Shallow-depth sequencing of cell-free DNA for Hodgkin and diffuse large B-cell lymphoma (differential) diagnosis: a standardized approach with underappreciated potential

Shallow-depth sequencing of cell-free DNA, an inexpensive and standardized approach to obtain molecular information on tumors non-invasively, has been insufficiently explored for the diagnosis of lymphoma and disease follow-up. This study collected 318 samples, including longitudinal liquid and paired solid biopsies, from a prospectively- recruited cohort of 38 Hodgkin lymphoma (HL) and 85 aggressive B-cell non-HL patients, represented by 81 diffuse large B-cell lymphoma (DLBCL) cases. Following sequencing, copy number alterations and viral read fractions were derived and analyzed. At diagnosis, liquid biopsies showed detectable copy number alterations in 84.2% of HL patients (88.6% for classical HL) and 74.1% of DLBCL patients. Of the DLBCL patients, copy number profiles between liquid-solid pairs were highly concordant (r=0.815±0.043); and, compared to tissue, HL liquid biopsies had abnormalities with higher amplitudes (P=0.010). This implies that tumor DNA is more abundant in plasma. Additionally, 39.5% of HL and 13.6% of DLBCL cases had a significantly elevated number of plasma Epstein-Barr virus DNA fragments, achieving a sensitivity of 100% compared to the current standard. A longitudinal analysis determined that, when detectable, copy number patterns were similar across (re)staging moments in refractory or relapsed patients. Further, the overall profile anomaly correlated highly with the total metabolic tumor volume (P<0.001). To conclude, as a proof of principle, we demonstrate that liquid biopsy-derived copy numbers can aid diagnosis: e.g., by differentiating HL from DLBCL, random forest modeling is represented by an area under the receiver operating characteristic curve of 0.967. This application is potentially useful when tissue is difficult to obtain or when biopsies are small and inconclusive.

Differentiated thyroid cancer patients potentially benefitting from postoperative I-131 therapy: a review of the literature of the past decade

BACKGROUND

Since the last major review of literature on the benefit of I-131 therapy, the continued debate on postoperative radioiodine treatment (RIT) in differentiated thyroid carcinoma (DTC) has led to a number of further studies being published on this topic.

AIM

The aim of the present paper is to report the results of an updated structured review of the literature pertaining to the prognostic benefits of postoperative RIT in DTC in terms of recurrence-free and disease-specific survival.

METHODS

A systematic search of the literature was performed using the Medline and Cochrane Library database. The search period started in August 2007 and ended on December 6, 2017. Search terms used included "differentiated thyroid cancer" and "radioiodine therapy" amended by specific terms for recurrence/disease-free survival or overall and/or cancer-specific survival. Included in the search were systematic reviews, randomized clinical trials, or cohort studies consisting of both patients who underwent postoperative RIT and patients treated by surgery alone.

RESULTS

Eleven retrospective cohort studies met the defined inclusion criteria and were included in the present review. Results of the studies were mixed, with some showing a benefit of RIT even in microcarcinoma whereas others showed no benefit at all.

CONCLUSION

Literature published in the last decade offers data that support adjuvant postoperative RIT in DTC patients with a tumor diameter exceeding 1 cm. Therefore, at least until randomized prospective studies prove otherwise, the prescription of adjuvant I-131 treatment to all DTC patients with a primary tumor diameter exceeding 1 cm remains a reasonable option.

Effects of disrupted ghrelin receptor function on fear processing, anxiety and saccharin preference in mice

BACKGROUND

Obesity is a risk factor for stress-related mental disorders such as post-traumatic stress disorder. The underlying mechanism through which obesity affects mental health remains poorly understood but dysregulation of the ghrelin system may be involved. Stress increases plasma ghrelin levels, which stimulates food intake as a potential stress-coping mechanism. However, diet-induced obesity induces ghrelin resistance which in turn may have deleterious effects on stress-coping. In our study, we explored whether disruption of ghrelin receptor function though high-fat diet or genetic ablation affects fear processing, anxiety-like behavior and saccharin preference in mice.

METHODS

Adult male C57BL6/J mice were placed on a standard diet or high-fat diet for a total period of 8 weeks. We first established that high-fat diet exposure for 4 weeks elicits ghrelin resistance, evidenced by a blunted hyperphagic response following administration of a ghrelin receptor agonist. We then carried out an experiment in which we subjected mice to auditory fear conditioning after 4 weeks of diet exposure and evaluated effects on fear extinction, anxiety-like behavior and saccharin preference. To explore whether fear conditioning as such may influence the effect of diet exposure, we also subjected mice to auditory fear conditioning prior to diet onset and 4 weeks later we investigated auditory fear extinction, anxiety-like behavior and saccharin preference. In a final experiment, we further assessed lack of ghrelin receptor function by investigating auditory fear processing, anxiety-like behavior and saccharin preference in ghrelin receptor knockout mice and their wild-type littermates.

RESULTS

High-fat diet exposure had no significant effect on auditory fear conditioning and its subsequent extinction or on anxiety-like behavior but significantly lowered saccharin preference. Similarly, ghrelin receptor knockout mice did not differ significantly from their wild-type littermates for auditory fear processing or anxiety-like behavior but showed significantly lower saccharin preference compared to wild-type littermates.

CONCLUSION

Taken together, our data suggest that disruption of ghrelin receptor function per se does not affect fear or anxiety-like behavior but may decrease saccharin preference in mice.

Controversies, Consensus, and Collaboration in the Use of 131I Therapy in Differentiated Thyroid Cancer: A Joint Statement from the American Thyroid Association, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association

BACKGROUND

Publication of the 2015 American Thyroid Association (ATA) management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer was met with disagreement by the extended nuclear medicine community with regard to some of the recommendations related to the diagnostic and therapeutic use of radioiodine (¹³¹I). Because of these concerns, the European Association of Nuclear Medicine and the Society of Nuclear Medicine and Molecular Imaging declined to endorse the ATA guidelines. As a result of these differences in opinion, patients and clinicians risk receiving conflicting advice with regard to several key thyroid cancer management issues.

SUMMARY

To address some of the differences in opinion and controversies associated with the therapeutic uses of ¹³¹I in differentiated thyroid cancer constructively, the ATA, the European Association of Nuclear Medicine, the Society of Nuclear Medicine and Molecular Imaging, and the European Thyroid Association each sent senior leadership and subject-matter experts to a two-day interactive meeting. The goals of this first meeting were to (i) formalize the dialogue and activities between the four societies; (ii) discuss indications for ¹³¹I adjuvant treatment; (iii) define the optimal prescribed activity of ¹³¹I for adjuvant treatment; and (iv) clarify the definition and classification of ¹³¹I-refractory thyroid cancer.

CONCLUSION

By fostering an open, productive, and evidence-based discussion, the Martinique meeting restored trust, confidence, and a sense of collegiality between individuals and organizations that are committed to optimal thyroid disease management. The result of this first meeting is a set of nine principles (The Martinique Principles) that (i) describe a commitment to proactive, purposeful, and inclusive interdisciplinary cooperation; (ii) define the goals of ¹³¹I therapy as remnant ablation, adjuvant treatment, or treatment of known disease; (iii) describe the importance of evaluating postoperative disease status and multiple other factors beyond clinicopathologic staging in ¹³¹I therapy decision making; (iv) recognize that the optimal administered activity of ¹³¹I adjuvant treatment cannot be definitely determined from the published literature; and (v) acknowledge that current definitions of ¹³¹I-refractory disease are suboptimal and do not represent definitive criteria to mandate whether ¹³¹I therapy should be recommended.

Correction to: Dosimetry in clinical radionuclide therapy: the devil is in the detail

The above article which was published in Volume 44/ Issue 12 has incorrect page numbers. Instead of 1-3, it should have been 2137-2139.

Primary hyperparathyroidism associated to thrombocytopenia: an issue to consider?

Primary hyperparathyroidism (PHPT) is probably the most common endocrine disorder of the parathyroid glands, causing hypercalcemia. It is diagnosed often in persons with elevated serum calcium levels. However, hematological manifestations, such as thrombocytopenia are less known. In this case we describe the possible association of PHPT with reversible thrombocytopenia after parathyroidectomy. This hematological abnormality can be included in the spectrum of possible causes, including seemingly non-specific symptoms, in the decision tree towards surgical assessment.

[Non Hodgkin's lymphomas: a major breakthrough with immunotherapy]

Non hodgkin's lymphomas are a group of haematological malignancies in which spectacular progress has been made over the last ten years thanks to immunotherapy. Furthermore, the new WHO classification, based upon tumour immunology, the degree of tumour differentiation and cytogenetic abnormalities, has finally improved identification of each lymphoma and has enabled comparison of homogeneous populations between different clinical studies. The increase in the incidence of non hodgkin's lymphoma is related to the aging of the population and to other factors that are yet to be elucidated--a real challenge for the future. We have tried to offer an overview of the latest therapeutic advances, with a focus on (radio-) immunotherapy and haemopoietic stem cell transplantation.

The ESTRO Breur Lecture 2009. From population to voxel-based radiotherapy: exploiting intra-tumour and intra-organ heterogeneity for advanced treatment of non-small cell lung cancer

Evidence is accumulating that radiotherapy of non-small cell lung cancer patients can be optimized by escalating the tumour dose until the normal tissue tolerances are met. To further improve the therapeutic ratio between tumour control probability and the risk of normal tissue complications, we firstly need to exploit inter patient variation. This variation arises, e.g. from differences in tumour shape and size, lung function and genetic factors. Secondly improvement is achieved by taking into account intra-tumour and intra-organ heterogeneity derived from molecular and functional imaging. Additional radiation dose must be delivered to those parts of the tumour that need it the most, e.g. because of increased radio-resistance or reduced therapeutic drug uptake, and away from regions inside the lung that are most prone to complication. As the delivery of these treatments plans is very sensitive for geometrical uncertainties, probabilistic treatment planning is needed to generate robust treatment plans. The administration of these complicated dose distributions requires a quality assurance procedure that can evaluate the treatment delivery and, if necessary, adapt the treatment plan during radiotherapy.

[Thyroid cancers]

During the last two decades, the incidence of thyroid cancer has doubled, mainly do to the early detection of small papillary tumors. However, mortality stayed stable (0.05/100.000). Well differentiated cancers (papillary and follicular) demonstrated a excellent survival prognosis (95 % at 30 years for the majority of the patients), factors of prognosis: age, size of the initial tumor, presence (or not) of distant metastases, lymph node involvement (only in patients 45 year or older). Surgery is the main treatment and should be with curative intent, hence the importance of a thorough preoperative work-up: sonography, needle aspiration cytology and MRI of cervicomediastinum for large tumors and/or suspected lymph nodes. Total thyroidectomy is mandatory, excepted for well selected patients with small (pT1) unilateral tumors under the age of 45. Central compartment lymph node clearance is advocated (but not evidence based) with presentation of the recurrent laryngeal nerves and of the parathyroids. Ablation of residual thyroid tissue (Iode 131) should be advocated for patients at high (or intermediary) risk of recurrence, only after multidisciplinary concertation. Unlimited follow-up checking the thyroglobulin serum local after the total thyroidectomy and radioactive ablation, the availability of recombinant rhTSH avoids the withdrawal of thyroid hormones (hypothyroid period). Anaplastic carcinomas are very aggressive, no therapeutic solution, excepted in some selected case for when radical surgery is possible (flap reconstruction) followed by chemoradiation. Calcitoninenia to detect and to follow medullary thyroid cancer after total thyroidectomy and lymph node clearance.

FDG PET predicts prognosis of patients with resectable metastatic colorectal cancer (CRC) treated with preoperative chemotherapy

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Background: Standard evaluation of response to chemotherapy in metastatic CRC is unsatisfactory. Metabolism based imaging using positron emission tomography and fluorodeoxyglucose (FDG-PET) is increasingly used to assess treatment efficacy. Aim: To evaluate the prognostic value of FDG-PET metabolic response to chemotherapy in resectable metastatic CRC. Methods: We reviewed retrospectively 382 patients with metastatic CRC between 7/2002 and 8/2006. Patients curatively operated from CRC metastases treated with preoperative chemotherapy and evaluated by FDG PET at baseline and before surgery were considered eligible for the study. Time to progression (TTP) was defined as the time between surgery and the first proof of recurrence of disease. Total Lesion Glycolysis (TLG) was used as the metabolic parameter. It represents the product of the mean standardised FDG uptake (SUV) of each lesion and its volume. The change of the sum of the TLG of all lesions was calculated. A cut-off of 30% was used to differentiate responders and non- responders. Results: 18 patients (median age 65 yrs) were included. 16 patients were operated from liver mets, and 2 from lung mets. Chemotherapy regimen was FOLFOX 4 in 10 patients, FOLFIRI in 7, and FOLFIRI-bevacizumab in 1 patient. Median number of lesions was 3 (1 to 10) before and 1 after chemotherapy. Median baseline TLG was 115.8 (6.8–841.8). Median post chemo TLG was 12.8 (0–1608.9). The distribution of the metabolic responses was CR 5, PR 9, SD 1, PD 3, with a response rate of 14/18 (78%, 95% CI : 52%-94%). Baseline TLG was not different between responders and non responders (p=0.88). Median follow-up was 422 days: 6 patients died, 15 had recurrent disease. Median TTP was 31 days for non responders, and 197 days for responders (p value not calculated because of the small number of non responding patients). After dichotomization of TLG values using their median as threshold, the post chemo TLG influenced significantly TTP (p=0.001, median TTP 86 days vs 263 days) along with the change of TLG (p=0.002, 107 days vs 263 days). Conclusions: Metabolic response assessment using PET allows a prognostic stratification after preoperative chemotherapy in resectable metastatic CRC.

No significant financial relationships to disclose.

18F-fluoro-2-deoxy-D-glucose positron emission tomographic imaging: recent developments in head and neck cancer

PURPOSE OF REVIEW

Positron emission tomography using 18F-fluoro-2-deoxy-D-glucose (18FDG-PET) is well established in clinical routine as a metabolism-based whole-body imaging tool for cancer diagnosis and follow-up. Several reports have appeared indicating the potential and limitations of this technique in head and neck cancer (HNC). This review limits its scope to the recent advances using 18FDG-PET in the clinical management of HNC.

RECENT FINDINGS

The combination of 18FDG-PET and sentinel node biopsy has been explored for the surgical treatment planning of oral and oropharyngeal cancer. Recent reports indicate that multimodality imaging combining PET with high-end CT scanning increases the diagnostic accuracy. 18FDG-PET has a potential for use in radiation treatment planning and for the prediction of response and early evaluation of treatment efficacy.

SUMMARY

Increasingly 18FDG-PET is used as a clinical imaging modality in the different stages of the management of HNC. In particular, its clinical value in initial staging of neck lymph nodes and in the evaluation of recurrent or residual disease is well established. In these settings 18FDG-PET has been shown to be more accurate than conventional imaging. Recent studies indicate that 18FDG-PET could be of additional value in staging the N0 neck, in radiation treatment planning, and in prediction of treatment efficacy.

Optimal dose of 18F-FDG required for whole-body PET using an LSO PET camera

Reducing the acquisition time of whole-body fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) (corrected for attenuation) is of major importance in clinical practice. With the introduction of lutetium oxyorthosilicate (LSO), the acquisition time can be dramatically reduced, provided that patients are injected with larger amounts of tracer and/or the system is operated in 3D mode. The aim of this study was to determine the optimal dose of 18F-FDG required in order to achieve good-to-excellent image quality when a "3-min emission, 2-min transmission/bed position" protocol is used for an LSO PET camera. A total of 218 consecutive whole-body 18F-FDG PET studies were evaluated retrospectively. After excluding patients with liver metastases, hyperglycaemia and paravenous injections, the final study population consisted of 186 subjects (112 men, 74 women, age 59 +/- 15 years). Patients were injected with an activity of 18F-FDG ranging from 2.23 to 15.21 MBq/kg. Whole-body images corrected for attenuation (3 min emission, 2 min transmission/bed position) were acquired with an LSO PET camera (Ecat Accel, Siemens) 60 min after tracer administration. Patients were positioned with their arms along the body. Image reconstruction was done iteratively and a post-reconstruction filter was applied. Image quality was scored visually by two independent observers using a five-point scoring scale (poor, reasonable, good, very good, excellent). In addition, the coefficient of variability (COV) was measured in a region of interest over the liver in order to quantify noise. Of the images obtained in 118 patients injected with > or =8 MBq/kg 18F-FDG, 92% and 90% were classified as good, very good or excellent by observer 1 and observer 2, respectively. The COV averaged 10.63% +/- 3.19% for doses > or =8 MBq/kg and 16.46% +/- 5.14% for doses <8 MBq/kg. Administration of an 18F-FDG dose of > or =8 MBq/kg results in images of good to excellent quality in the vast majority of patients when using an LSO PET camera and applying a 3-min emission, 2-min transmission/bed position acquisition protocol. At lower doses, a rapid decline in image quality and increasing noise are observed. Alternative protocols should be adopted in order to compensate for the loss in image quality when doses <8 MBq/kg are used.