Unilateral hippocampal sparing during whole brain radiotherapy for multiple brain metastases: narrative and critical review

BackgroundThe landscape of brain metastases radiotherapy is evolving, with a shift away from whole-brain radiotherapy (WBRT) toward targeted stereotactic approaches aimed at preserving neurocognitive functions and maintaining overall quality of life. For patients with multiple metastases, especially in cases where targeted radiotherapy is no longer feasible due to widespread dissemination, the concept of hippocampal sparing radiotherapy (HA_WBRT) gains prominence.MethodsIn this narrative review we explore the role of the hippocampi in memory formation and the implications of their postradiotherapy lateral damage. We also consider the potential advantages of selectively sparing one hippocampus during whole-brain radiotherapy (WBRT). Additionally, by systematic evaluation of relevant papers published on PubMed database over last 20 years, we provide a comprehensive overview of the various changes that can occur in the left or right hippocampus as a consequence of radiotherapy.ResultsWhile it is important to note that various neurocognitive functions are interconnected throughout the brain, we can discern certain specialized roles of the hippocampi. The left hippocampus appears to play a predominant role in verbal memory, whereas the right hippocampus is associated more with visuospatial memory. Additionally, the anterior part of the hippocampus is more involved in episodic memory and emotional processing, while the posterior part is primarily responsible for spatial memory and pattern separation. Notably, a substantial body of evidence demonstrates a significant correlation between post-radiotherapy changes in the left hippocampus and subsequent cognitive decline in patients.ConclusionIn the context of individualized palliative radiotherapy, sparing the unilateral (specifically, the left, which is dominant in most individuals) hippocampus could expand the repertoire of strategies available for adapted WBRT in cases involving multiple brain metastases where stereotactic radiotherapy is not a viable option. Prospective ongoing studies assessing various memory-sparing radiotherapy techniques will define new standard of radiotherapy care of patients with multiple brain metastases

Craniospinal irradiation of medulloblastoma in the supine position

BackgroundMedulloblastoma, a primitive neuroectodermal tumour growing in the cerebellum, is one of the most sensitive childhood brain tumours to radiation therapy. The most common malignant CNS tumour of children is medulloblastoma with an overall incidence among children aged 0–19 years of 16–20% of all paediatric brain tumours. Radiotherapy is an essential method of treatment for these tumours, but surgery is the primary treatment of choice in medulloblastoma. Postoperative radiation therapy has a significant impact on local control and overall survival.AimMedulloblastoma is the most common malignant brain tumour of children. The tumour is sensitive to chemotherapy and radiotherapy. Radiotherapy is an essential method of treatment for these tumours, but surgery is the primary treatment of choice in medulloblastoma.Materials/MethodsBetween January 1997 and March 2005 there were in this study post-operatively irradiated a total number of 33 paediatric patients aged under 15 years (median age 6.6 years) with medulloblastoma. All tumours were histologically proven and were located infratentorially in the posterior fossa. All of the patients were irradiated with a dose of 24–36 Gy to the whole craniospinal axis and boost with conformal therapy restricted to the tumour bed to the total dose of 50–54 Gy (30–36 Gy “high risk”, 24–30 Gy “standard risk” group). 26 patients (78%) received chemotherapy. Patients with craniospinal irradiation were placed in the supine position and fixed by a vacuum-form body immobilizer and head mask. Irradiation was performed using standard fractionation (5 fractions per week) with a single dose of 1.5–1.8 Gy for craniospinal axis by photon beam (6MV) of the linear accelerator.ResultsThe median overall survival for the whole group was 55.3 months. The median disease-free survival was 20.6 months. The overall survival rate at 5 years was 41%; 8 patients (24%) died. No relationship was found between survival and age, sex or tumour size. Endocrine deficits occurred in 30% (8 patients of the group were hypothyroid, growth retardation occurred in 7 patients).ConclusionsResults of overall and disease-free survival and side-effects of the technique of craniospinal axis irradiation in supine position are comparable with results of the technique in prone position

The Diagnostic Ability of Follow-Up Imaging Biomarkers after Treatment of Glioblastoma in the Temozolomide Era: Implications from Proton MR Spectroscopy and Apparent Diffusion Coefficient Mapping

Objective. To prospectively determine institutional cut-off values of apparent diffusion coefficients (ADCs) and concentration of tissue metabolites measured by MR spectroscopy (MRS) for early differentiation between glioblastoma (GBM) relapse and treatment-related changes after standard treatment. Materials and Methods. Twenty-four GBM patients who received gross total resection and standard adjuvant therapy underwent MRI examination focusing on the enhancing region suspected of tumor recurrence. ADC maps, concentrations of N-acetylaspartate, choline, creatine, lipids, and lactate, and metabolite ratios were determined. Final diagnosis as determined by biopsy or follow-up imaging was correlated to the results of advanced MRI findings. Results. Eighteen (75%) and 6 (25%) patients developed tumor recurrence and pseudoprogression, respectively. Mean time to radiographic progression from the end of chemoradiotherapy was 5.8 ± 5.6 months. Significant differences in ADC and MRS data were observed between those with progression and pseudoprogression. Recurrence was characterized by N-acetylaspartate ≤ 1.5 mM, choline/N-acetylaspartate ≥ 1.4 (sensitivity 100%, specificity 91.7%), N-acetylaspartate/creatine ≤ 0.7, and ADC ≤ 1300 × 10−6 mm2/s (sensitivity 100%, specificity 100%). Conclusion. Institutional validation of cut-off values obtained from advanced MRI methods is warranted not only for diagnosis of GBM recurrence, but also as enrollment criteria in salvage clinical trials and for reporting of outcomes of initial treatment

MicroRNAs Involvement in Radioresistance of Head and Neck Cancer

Resistance to the ionizing radiation is a current problem in the treatment and clinical management of various cancers including head and neck cancer. There are several biological and molecular mechanisms described to be responsible for resistance of the tumors to radiotherapy. Among them, the main mechanisms include alterations in intracellular pathways involved in DNA damage and repair, apoptosis, proliferation, and angiogenesis. It has been found that regulation of these complex processes is often controlled by microRNAs. MicroRNAs are short endogenous RNA molecules that posttranscriptionally modulate gene expression and their deregulated expression has been observed in many tumors including head and neck cancer. Specific expression patterns of microRNAs have also been shown to predict prognosis and therapeutic response in head and neck cancer. Therefore, microRNAs present promising biomarkers and therapeutic targets that might overcome resistance to radiation and improve prognosis of head and neck cancer patients. In this review, we summarize the current knowledge of the functional role of microRNAs in radioresistance of cancer with special focus on head and neck cancer

Recurrent Nasopharyngeal Cancer: Critical Review of Local Treatment Options Including Recommendations during the COVID-19 Pandemic

Recurrent nasopharyngeal carcinoma represents an extremely challenging therapeutic situation. Given the vulnerability of the already pretreated neurological structures surrounding the nasopharynx, any potential salvage retreatment option bears a significant risk of severe complications that result in high treatment-related morbidity, quality of life deterioration, and even mortality. Yet, with careful patient selection, long-term survival may be achieved after local retreatment in a subgroup of patients with local or regional relapse of nasopharyngeal cancer. Early detection of the recurrence represents the key to therapeutic success, and in the case of early stage disease, several curative treatment options can be offered to the patient, albeit with minimal support in prospective clinical data. In this article, an up-to-date review of published evidence on modern surgical and radiation therapy treatment options is summarized, including currently recommended treatment modifications of both therapeutic approaches during the coronavirus disease 2019 pandemic

Advanced MRI increases the diagnostic accuracy of recurrent glioblastoma: Single institution thresholds and validation of MR spectroscopy and diffusion weighted MR imaging

The accurate identification of glioblastoma progression remains an unmet clinical need. The aim of this prospective single-institutional study is to determine and validate thresholds for the main metabolite concentrations obtained by MR spectroscopy (MRS) and the values of the apparent diffusion coefficient (ADC) to enable distinguishing tumor recurrence from pseudoprogression. Thirty-nine patients after the standard treatment of a glioblastoma underwent advanced imaging by MRS and ADC at the time of suspected recurrence — median time to progression was 6.7 months. The highest significant sensitivity and specificity to call the glioblastoma recurrence was observed for the total choline (tCho) to total N-acetylaspartate (tNAA) concentration ratio with the threshold ≥1.3 (sensitivity 100.0% and specificity 94.7%). The ADCmean value higher than 1313 × 10−6 mm2/s was associated with the pseudoprogression (sensitivity 98.3%, specificity 100.0%). The combination of MRS focused on the tCho/tNAA concentration ratio and the ADCmean value represents imaging methods applicable to early non-invasive differentiation between a glioblastoma recurrence and a pseudoprogression. However, the institutional definition and validation of thresholds for differential diagnostics is needed for the elimination of setup errors before implementation of these multimodal imaging techniques into clinical practice, as well as into clinical trials

Effect of Acupuncture in Pain Management of Head and Neck Cancer Radiotherapy: Prospective Randomized Unicentric Study

This prospective randomized open-label trial aimed to evaluate the role of acupuncture in the treatment of pain related to curative and adjuvant (chemo)radiotherapy of head and neck cancer. Patients in two arms (30 patients in each arm) underwent standard oncology therapy and standard supportive care with or without acupuncture. The stratification factors were the type of treatment and chemotherapy indication. The toxicity assessed was represented by pain rated on a 10-point pain scale and analgesic use. Average pain (AP) and the worst pain during the day (WP) were significantly lower in the acupuncture arm during radiotherapy (AP median 0.16 vs. 1.36, p < 0.001; WP median 0.90 vs. 1.96, p < 0.001) and three months after radiotherapy (AP median 0.07 vs. 0.50, p < 0.001; WP median 0.30 vs. 0.83, p = 0.002). The analgesic consumption between arms was statistically significantly different. A median of the proportion of days when the patients used analgesics was 8% and 32.5% during radiotherapy (p = 0.047) and 0% and 20.8% during three months after radiotherapy (p = 0.006) for the acupuncture and control arm, respectively. Results point out lower analgesic consumption and milder pain in acupuncture arm. Acupuncture consequently offers another alternative to standard treatment leading to a reduction in the toxicity of oncological treatment

Radiotherapy of glioblastoma 15 years after the landmark Stupp’s trial: more controversies than standards?

The current standard of care of glioblastoma, the most common primary brain tumor in adults, has remained unchanged for over a decade. Nevertheless, some improvements in patient outcomes have occurred as a consequence of modern surgery, improved radiotherapy and up-to-date management of toxicity. Patients from control arms (receiving standard concurrent chemoradiotherapy and adjuvant chemotherapy with temozolomide) of recent clinical trials achieve better outcomes compared to the median survival of 14.6 months reported in Stupp’s landmark clinical trial in 2005. The approach to radiotherapy that emerged from Stupp’s trial, which continues to be a basis for the current standard of care, is no longer applicable and there is a need to develop updated guidelines for radiotherapy within the daily clinical practice that address or at least acknowledge existing controversies in the planning of radiotherapy

11C-methionine in the diagnostics and management of glioblastoma patients with rapid early progression: nonrandomized, open label, prospective clinical trial (GlioMET)

Abstract Background Glioblastoma (GBM) is the most common and aggressive primary brain cancer. The treatment of GBM consists of a combination of surgery and subsequent oncological therapy, i.e., radiotherapy, chemotherapy, or their combination. If postoperative oncological therapy involves irradiation, magnetic resonance imaging (MRI) is used for radiotherapy treatment planning. Unfortunately, in some cases, a very early worsening (progression) or return (recurrence) of the disease is observed several weeks after the surgery and is called rapid early progression (REP). Radiotherapy planning is currently based on MRI for target volumes definitions in many radiotherapy facilities. However, patients with REP may benefit from targeting radiotherapy with other imaging modalities. The purpose of the presented clinical trial is to evaluate the utility of 11C-methionine in optimizing radiotherapy for glioblastoma patients with REP. Methods This study is a nonrandomized, open-label, parallel-setting, prospective, monocentric clinical trial. The main aim of this study was to refine the diagnosis in patients with GBM with REP and to optimize subsequent radiotherapy planning. Glioblastoma patients who develop REP within approximately 6 weeks after surgery will undergo 11C-methionine positron emission tomography (PET/CT) examinations. Target volumes for radiotherapy are defined using both standard planning T1-weighted contrast-enhanced MRI and PET/CT. The primary outcome is progression-free survival defined using RANO criteria and compared to a historical cohort with REP treated without PET/CT optimization of radiotherapy. Discussion PET is one of the most modern methods of molecular imaging. 11C-Methionine is an example of a radiolabelled (carbon 11) amino acid commonly used in the diagnosis of brain tumors and in the evaluation of response to treatment. Optimized radiotherapy may also have the potential to cover those regions with a high risk of subsequent progression, which would not be identified using standard-of-care MRI for radiotherapy planning. This is one of the first study focused on radiotherapy optimization for subgroup of patinets with REP. Trial Registration NCT05608395, registered on 8.11.2022 in clinicaltrials.gov; EudraCT Number: 2020–000640-64, registered on 26.5.2020 in clinicaltrialsregister.eu. Protocol ID: MOU-2020–01, version 3.2, date 18.09.2020