Feasibility estimation of injected hydrodissection before definitive radiotherapy of pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma is often not diagnosed until an advanced stage, and so most patients are not eligible for resection. For patients who are inoperable, definitive radiotherapy is crucial for local disease control. However, the pancreas is located close to other vulnerable gastrointestinal organs, making it challenging to deliver an adequate radiation dose. The surgical insertion of spacers or injection of fluids such as hydrogel before radiotherapy has been proposed, however, no study has discussed which patients are suitable for the procedure. METHODS: In this study, we reviewed 50 consecutive patients who received definitive radiotherapy at our institute to determine how many could have benefitted from hydrodissection to separate the pancreatic tumor from the adjacent gastrointestinal tract. By hypothetically injecting a substance using either computed tomography (CT)-guided or endoscopic methods, we aimed to increase the distance between the pancreatic tumor and surrounding hollow organs, as this would reduce the radiation dose delivered to the organs at risk. RESULTS: An interventional radiologist considered that hydrodissection was feasible in 23 (46%) patients with a CT-guided injection, while a gastroenterologist considered that hydrodissection was feasible in 31 (62%) patients with an endoscopic injection. Overall, we found 14 (28%) discrepancies among the 50 patients reviewed. Except for 1 patient who had no available trajectory with a CT-guided approach but in whom hydrodissection was considered feasible with an endoscopic injection, the other 13 patients had different interpretations of whether direct invasion was present in the CT images. CONCLUSION: Our results suggested that about half of the patients could have benefited from hydrodissection before radiotherapy. This finding could allow for a higher radiation dose and potentially better disease control.

Personalized cancer avatars for patients with thymic malignancies: A pilot study with circulating tumor cell-derived organoids.

BACKGROUND: Systemic therapy is the primary treatment for advanced thymic malignancies. However, there is an urgent need to improve clinical outcome. Personalized treatment based on predictive biomarkers is a potential approach to address this requirement. In this study, we aimed to show the correlation between drug sensitivity tests on CTCs-derived organoids and clinical response in patients with thymic malignancies. This approach carries the potential to create personalized cancer avatars and improve treatment outcome for patients. METHODS: We previously reported potential treatment outcome prediction with patient-derived organoids (cancer avatars) in patients with pancreatic ductal adenocarcinoma. To further investigate the feasibility of this approach in advanced thymic malignancies, we conducted a study in which 12 patients were enrolled and 21 liquid biopsies were performed. RESULTS: Cancer avatars were successfully derived in 16 out of 21 samples (success rate 76.2%). We found a sensitivity of 1.0 and specificity of 0.6 for drug sensitivity tests on the cancer avatars, and a two-tailed Fisher's exact test revealed a significant correlation between drug sensitivity tests and clinical responses (p = 0.0275). CONCLUSION: This study supports the potential of circulating tumor cell-derived organoids to inform personalized treatment for advanced thymic malignancies. Further validation of this proof of concept finding is ongoing.

Boron Neutron Capture Therapy Followed by Image-Guided Intensity-Modulated Radiotherapy for Locally Recurrent Head and Neck Cancer: A Prospective Phase I/II Trial.

BACKGROUND: This trial investigated the efficacy and safety of salvage boron neutron capture therapy (BNCT) combined with image-guided intensity-modulated radiotherapy (IG-IMRT) for recurrent head and neck cancer after prior radiotherapy (RT). METHODS: BNCT was administered using an intravenous boronophenylalanine-fructose complex (500 mg/kg) in a single fraction; multifractionated IG-IMRT was administered 28 days after BNCT. For BNCT, the mucosa served as the dose-limiting organ. For IG-IMRT, the clinical target volume (CTV) and the planning target volume (PTV) were generated according to the post-BNCT gross tumor volume (GTV) with chosen margins. RESULTS: This trial enrolled 14 patients, and 12 patients received combined treatment. The median BNCT average dose for the GTV was 21.6 Gy-Eq, and the median IG-IMRT dose for the PTV was 46.8 Gy/26 fractions. After a median (range) follow-up period of 11.8 (3.6 to 53.2) months, five patients had a complete response and four had a partial response. One patient had grade 4 laryngeal edema; another patient had a grade 4 hemorrhage. Most tumor progression occurred within or adjacent to the CTV. The 1-year overall survival and local progression-free survival rates were 56% and 21%, respectively. CONCLUSION: Despite the high response rate (64%) of this trial, there was a high incidence of in-field and marginal failure with this approach. Future studies combining BNCT with modalities other than radiation may be tried.

Old age and EGFR mutation status in inoperable early-stage non-small cell lung cancer patients receiving stereotactic ablative radiotherapy: A single institute experience of 71 patients in Taiwan.

BACKGROUND: Stereotactic ablative radiotherapy (SABR) is now the standard of care for patients with inoperable early-stage lung cancer. Many of these patients are elderly. EGFR (epidermal growth factor receptor) mutation is also common in the Asian population. METHODS: To evaluate the effects of old age and EGFR mutation on treatment outcomes and toxicity, we reviewed the medical records of 71 consecutive patients with inoperable early-stage non-small cell lung cancer (NSCLC) who received SABR at Taipei Veterans General Hospital between 2015 and 2021. RESULTS: The study revealed that median age, follow-up, Charlson comorbidity index, and ECOG score were 80 years, 2.48 years, 3, and 1, respectively. Of these patients, 37 (52.1%) were 80 years or older, and 50 (70.4%) and 21 (29.6%) had T1 and T2 diseases, respectively. EGFR mutation status was available for 33 (46.5%) patients, of whom 16 (51.5%) had a mutation. The overall survival rates at 1, 3, and 5 years were 97.2, 74.9, and 58.3%, respectively. The local control rate at 1, 3, and 5 years was 97.1, 92.5, and 92.5%, respectively. Using Cox proportional hazards regression we found that male sex was a risk factor for overall survival (p = 0.036, 95% CI: 1.118-26.188). Two patients had grade 2 pneumonitis, but no other grade 2 or higher toxicity was observed. We did not find any significant differences in treatment outcomes or toxicity between patients aged 80 or older and those with EGFR mutations in this cohort. CONCLUSION: These findings indicate that age and EGFR mutation status do not significantly affect the effectiveness or toxicity of SABR for patients with inoperable early-stage NSCLC.

Combined modality therapy for patients with esophageal squamous cell carcinoma: Radiation dose and survival analyses.

BACKGROUND: We aimed to analyze the radiation dose and compare survival among combined modality therapy using modern radiation techniques for patients with esophageal squamous cell carcinoma (ESCC). METHODS: This retrospective study included patients with clinically staged T1-4N0-3M0 ESCC from 2014 to 2018. Patients who received combined modality therapies with curative intent were enrolled. The overall survival (OS) rates among combined modality therapy were compared. The clinical variables and impacts of radiation dose on survival were analyzed by the Kaplan-Meier method and Cox regression model. RESULTS: Of the 259 patients, 141 (54.4%) received definitive concurrent chemoradiotherapy (DCCRT); 67 (25.9%) underwent neoadjuvant chemoradiotherapy followed by surgery (NCRT+S); 51 (19.7%) obtained surgery followed by adjuvant chemoradiotherapy (S+ACRT). Two-year OS rates of the DCCRT, NCRT+S and S+ACRT group were 48.9, 61.5 and 51.2%. In the subgroup analysis of DCCRT group, the 2-year OS of patients receiving radiation dose 55-60 Gy was 57.1%. Multivariate analyses showed that clinical stage (p = 0.004), DCCRT with 55-60 Gy (p = 0.043) and NCRT+S with pathological complete response (pCR) (p = 0.014) were significant prognostic factors for better OS. The radiation dose-survival curve demonstrated a highly positive correlation between higher radiation dose and better survival. CONCLUSION: Our results suggest that NCRT+S can provide a favorable survival for patients with ESCC, especially in patients who achieved pCR. The optimal radiation dose might be 55-60 Gy for patients receiving DCCRT via modern radiation techniques. Further randomized clinical studies are required to confirm the survival benefits between NCRT+S and DCCRT with escalated dose.

Skin Surface Dose for Whole Breast Radiotherapy Using Personalized Breast Holder: Comparison with Various Radiotherapy Techniques and Clinical Experiences.

PURPOSE: Breast immobilization with personalized breast holder (PERSBRA) is a promising approach for normal organ protection during whole breast radiotherapy. The aim of this study is to evaluate the skin surface dose for breast radiotherapy with PERSBRA using different radiotherapy techniques. MATERIALS AND METHODS: We designed PERSBRA with three different mesh sizes (large, fine and solid) and applied them on an anthropomorphic(Rando) phantom. Treatment planning was generated using hybrid, intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques to deliver a prescribed dose of 5000 cGy in 25 fractions accordingly. Dose measurement with EBT3 film and TLD were taken on Rando phantom without PERSBRA, large mesh, fine mesh and solid PERSBRA for (a) tumor doses, (b) surface doses for medial field and lateral field irradiation undergoing hybrid, IMRT, VMAT techniques. RESULTS: The tumor dose deviation was less than five percent between the measured doses of the EBT3 film and the TLD among the different techniques. The application of a PERSBRA was associated with a higher dose of the skin surface. A large mesh size of PERSBRA was associated with a lower surface dose. The findings were consistent among hybrid, IMRT, or VMAT techniques. CONCLUSIONS: Breast immobilization with PERSBRA can reduce heart toxicity but leads to a build-up of skin surface doses, which can be improved with a larger mesh design for common radiotherapy techniques.

Correlation between drug sensitivity profiles of circulating tumour cell-derived organoids and clinical treatment response in patients with pancreatic ductal adenocarcinoma.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive and has poor prognosis. There are few biomarkers to inform treatment decisions, and collecting tumour samples for testing is challenging. METHODS: Circulating tumour cells (CTCs) from patients with PDAC liquid biopsies were expanded ex vivo to form CTC-derived organoid cultures, using a laboratory-developed biomimetic cell culture system. CTC-derived organoids were tested for sensitivity to a PDAC panel of nine drugs, with tests conducted in triplicate, and a weighted cytotoxicity score (CTS) was calculated from the results. Clinical response to treatment in patients was evaluated using Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1 criteria at the time of blood sampling and 3 months later. The correlation between CTS and clinical response was then assessed. RESULTS: A total of 41 liquid biopsies (87.8% from patients with Stage 4 disease) were collected from 31 patients. The CTC-derived organoid expansion was achieved in 3 weeks, with 87.8% culture efficiency. CTC-derived organoid cultures were positive for EpCAM staining and negative for CD45 staining in the surface marker analysis. All patients had received a median of two lines of treatment prior to enrolment and prospective utility analysis indicated significant correlation of CTS with clinical treatment response. Two representative case studies are also presented to illustrate the relevant clinical contexts. CONCLUSIONS: CTCs were expanded from patients with PDAC liquid biopsies with a high success rate. Drug sensitivity profiles from CTC-derived organoid cultures correlated meaningfully with treatment response. Further studies are warranted to validate the predictive potential for this approach.

The overview and prospects of BNCT facility at Tsing Hua Open-pool reactor.

The whole picture of the BNCT facility at Tsing Hua Open-pool Reactor will be presented which consists of the following aspects: the construction project, the beam quality, routine operations including the QA program for the beam delivery, determination of boron-10 concentration in blood, T/N ratio, and the clinical affairs including the patient recruit procedure and the patient irradiation procedure. The facility is positioned to serve for conducting clinical trials, emergent (compassionate) treatments, and R&D works.

Nuclear Theranostics in Taiwan.

Boron neutron capture therapy and Y-90 radioembolization are emerging therapeutic methods for uncontrolled brain cancers and hepatic cancers, respectively. These advanced radiation therapies are heavily relied on theranostic nuclear medicine imaging before the therapy for the eligibility of patients and the prescribed-dose simulation, as well as the post-therapy scanning for assessing the treatment efficacy. In Taiwan, the Taipei Veterans General Hospital is the only institute performing the BNCT and also the leading institute performing Y-90 radioembolization. In this article, we present our single institute experiences and associated theranostic nuclear medicine approaches for these therapies.

The Dosimetric Impact of Shifts in Patient Positioning during Boron Neutron Capture Therapy for Brain Tumors.

Unlike conventional photon radiotherapy, sophisticated patient positioning tools are not available for boron neutron capture therapy (BNCT). Thus, BNCT remains vulnerable to setup errors and intra-fractional patient motion. The aim of this study was to estimate the impact of deviations in positioning on the dose administered by BNCT for brain tumors at the Tsing Hua open-pool reactor (THOR). For these studies, a simulated head model was generated based on computed tomography (CT) images of a patient with a brain tumor. A cylindrical brain tumor 3 cm in diameter and 5 cm in length was modeled at distances of 6.5 cm and 2.5 cm from the posterior scalp of this head model (T6.5 cm and T2.5 cm, respectively). Radiation doses associated with positioning errors were evaluated for each distance, including left and right shifts, superior and inferior shifts, shifts from the central axis of the beam aperture, and outward shifts from the surface of the beam aperture. Rotational and tilting effects were also evaluated. The dose prescription was 20 Gray-equivalent (Gy-Eq) to 80 % of the tumor. The treatment planning system, NCTPlan, was used to perform dose calculations. The average decreases in mean tumor dose for T6.5 cm for the 1 cm, 2 cm, and 3 cm lateral shifts composed by left, right, superior, and inferior sides, were approximately 1 %, 6 %, and 11 %, respectively, compared to the dose administered to the initial tumor position. The decreases in mean tumor dose for T6.5 cm were approximately 5 %, 11 %, and 15 % for the 1 cm, 2 cm, and 3 cm outward shifts, respectively. For a superficial tumor at T2.5cm, no significant decrease in average mean tumor dose was observed following lateral shifts of 1 cm. Rotational and tilting up to 15° did not result in significant difference to the tumor dose. Dose differences to the normal tissues as a result of the shifts in positioning were also minimal. Taken together, these data demonstrate that the mean dose administered to tumors at greater depths is potentially more vulnerable to deviations in positioning, and greater shift distances resulted in reduced mean tumor doses at the THOR. Moreover, these data provide an estimation of dose differences that are caused by setup error or intra-fractional motion during BNCT, and these may facilitate more accurate predictions of actual patient dose in future treatments.

Irradiation-Induced Secondary Tumors following Pediatric Central Nervous System Tumors: Experiences of a Single Institute in Taiwan (1975-2013).

PURPOSE: Complications can occur following a prolonged latency period after radiation therapy for cancer, and this is a growing concern because secondary tumors are potentially fatal. Few studies have examined secondary tumors in patients who received radiation therapy as children. METHODS AND MATERIALS: This retrospective study examined 1697 pediatric patients with central nervous system tumors who received treatment at Taipei Veterans General Hospital from January 1, 1975, to December 31, 2013. Secondary tumors developed in 27 of 681 patients who received cranial irradiation. Overall survival was estimated using the Kaplan-Meier method, and the significance of differences was determined by the log-rank test. RESULTS: The overall cumulative incidence of secondary tumors at 25 years was 3.96%, and there were similar numbers of male patients (n = 16) and female patients (n = 11). The mean age at diagnosis was 8.8 years (range, 3-16.5 years), the median dose of cranial irradiation was 52.5 Gy (mean, 53.4 Gy), the mean latency period was 14.6 years (range, 2-33 years), and the mean age at diagnosis of a secondary tumor was 23.1 years. The secondary tumors were mainly meningiomas (n = 13), sarcomas (n = 7), and high-grade gliomas (n = 6), and the mean latency periods were 19.66, 8.00, and 10.83 years, respectively. The overall survival rate from these secondary tumors was significantly different (P < .05). Age at irradiation of <7 years and craniospinal irradiation significantly increased the risk of a secondary tumor (P < .05). Secondary tumors developed in 11 of 128 patients (8.6%) with primary medulloblastomas, which was higher than the overall cumulative incidence. CONCLUSIONS: Clinicians should consider the increased risk of secondary tumors in long-term cancer survivors who received craniospinal irradiation as children. Using a selective dose de-escalation strategy or deferring radiation therapy for young patients at highest risk of secondary cancers should be studied.

EGFR mutation, smoking, and gender in advanced lung adenocarcinoma.

PURPOSE: In the current targeted therapy era, information on the effect of smoking in epidermal growth factor receptor (EGFR)-mutant lung cancer patients is scarce. RESULTS: In total, 11,678 adenocarcinoma patients were enrolled. Of these, 33.3% and 91.8% of male and female patients were non-smokers, respectively. An increased amount of smoking (P < 0.001 for trend), fewer smoke-free years (P < 0.001 for trend), and younger age of smoking initiation (P = 0.034 for trend) were all associated with significantly lower EGFR mutation rates. Smokers had a shorter median overall survival (OS) among both EGFR-mutant and EGFR-wild type patients (17.8 vs. 21.1 months, and 7.9 vs. 11.4 months respectively; both P < 0.001). Among patients with EGFR-mutant adenocarcinoma, younger smokers were associated with shorter OS (P = 0.047). In multivariate analysis, female gender was an independent prognostic factor for OS (hazard ratio: 0.86 [95% confidence interval {CI}: 0.80-0.93]; P < 0.001 in the EGFR-mutant group and 0.88 [95% CI: 0.81-0.96]; P = 0.004 in the EGFR-wild type group). MATERIALS AND METHODS: We reviewed the National Lung Cancer database (Taiwan) to assess the impact of smoking on the EGFR mutation rate and survival in advanced lung adenocarcinoma patients during 2011 and 2014 retrospectively. CONCLUSIONS: Smoking was associated with lower incidence of EGFR mutation rate and reduced OS of advanced lung adenocarcinoma patients in a dose-dependent manner. In addition to EGFR mutation and smoking, gender also plays an important role in survival among these patients.

Preliminary dosimetric study on feasibility of multi-beam boron neutron capture therapy in patients with diffuse intrinsic pontine glioma without craniotomy.

Diffuse intrinsic pontine glioma is a very frustrating disease. Since the tumor infiltrates the brain stem, surgical removal is often impossible. For conventional radiotherapy, the dose constraint of the brain stem impedes attempts at further dose escalation. Boron neutron capture therapy (BNCT), a targeted radiotherapy, carries the potential to selectively irradiate tumors with an adequate dose while sparing adjacent normal tissue. In this study, 12 consecutive patients treated with conventional radiotherapy in our institute were reviewed to evaluate the feasibility of BNCT. NCTPlan Ver. 1.1.44 was used for dose calculations. Compared with two and three fields, the average maximal dose to the normal brain may be lowered to 7.35 ± 0.72 Gy-Eq by four-field irradiation. The mean ratio of minimal dose to clinical target volume and maximal dose to normal tissue was 2.41 ± 0.26 by four-field irradiation. A therapeutic benefit may be expected with multi-field boron neutron capture therapy to treat diffuse intrinsic pontine glioma without craniotomy, while the maximal dose to the normal brain would be minimized by using the four-field setting.

Change of Serum IgG4 in Patients with Ocular Adnexal Marginal Zone B Cell Lymphoma Associated with IgG4-Related Ophthalmic Disease After Treatment.

PURPOSE: To investigate the change of serum IgG4 concentrations correlated with clinical evolution in patients with ocular adnexal marginal zone B cell lymphoma associated with IgG4-related ophthalmic disease (IgG4-ROD). METHODS: Three consecutive patients with histopathologically confirmed ocular adnexal marginal zone B cell lymphoma associated with IgG4-ROD were evaluated. Two patients received radiotherapy and 1 patient received steroid therapy. Treatment outcome was evaluated by clinical symptoms, radiologic examination, and change of serum IgG4 level in these patients. RESULTS: All patients had elevated serum IgG4 before treatment (462, 338, and 780 mg/dL respectively.) The 2 patients who received radiotherapy achieved complete remission and the serum IgG4 decreased to 345 and 92 mg/dL, respectively. The patient who underwent systemic steroid achieved partial remission and the serum IgG4 decrease to 161 mg/dL. CONCLUSION: Our study showed elevated serum IgG4 in all patients with ocular adnexal marginal zone B cell lymphoma associated with IgG4-ROD. In addition, the elevated serum IgG4 may decrease or keep stable after treatment, accompanied by improvement in clinical symptoms and reduction of lesions.

Large cell/anaplastic medulloblastoma is associated with poor prognosis-a retrospective analysis at a single institute.

PURPOSE: Medulloblastoma (MB) is the most commonly occurring malignant pediatric brain tumor worldwide. However, a recent study found that the treatment outcomes in those with high-risk disease receiving conventional treatment were suboptimal. This study aimed to assess outcomes and treatment strategies for specific histologic subtypes of pediatric MB. METHODS: A total of 114 pediatric patients (age < 20 years) diagnosed with MB between March 1998 and August 2011 were retrospectively reviewed; 52 that were treated with surgery followed by adjuvant radiotherapy (RT) and chemotherapy (CHT) were included. RESULTS: The 5-year overall survival (OS) and relapse-free survival (RFS) rates were 73 and 69%, respectively. Median time to relapse was 17 months with a median survival time of 6 months after relapse. Patients of average risk had a better 5-year OS rate compared with high-risk patients (p = 0.027). The 5-year RFS of high-risk patients was lower compared with average risk (p = 0.038). A greater proportion of patients with large cell/anaplastic (LC/A) MB had recurrence than classic MB with 5-year RFS rate of 34 and 76%, respectively (p = 0.001), and OS rate of 56 and 76%, respectively (p = 0.04). CONCLUSION: High-risk group and histology of LC/A were the most significant factors associated with worse OS and RFS. Patients with LC/A-MB had higher relapse rates and worse survival than those with classic MB. LC/A-MB carries a high risk for recurrence and should be treated with the more aggressive strategies.

Risk of Second Primary Malignancies in Lung Cancer Survivors - The Influence of Different Treatments.

BACKGROUND: Currently, no large study addressing the relationship between lung cancer patients with different therapies and second primary malignancies (SPMs) is available. METHODS: Using the Taiwan National Health Insurance Research Database, we conducted a population-based cohort study. Patients with newly diagnosed lung cancer between 1997 and 2005 were enrolled and followed up until Dec. 31, 2011. The endpoint of the study was SPM occurrence. Standardized incidence ratios (SIRs) of cancers were calculated to compare the cancer incidence of the study cohort to that of the general population. RESULTS: We identified 52,639 patients with lung cancer and excluded 34,267 patients who had expired within one year after diagnosis. The study included 18,372 subjects with a median follow-up period of 2.24 years. 590 patients developed an SPM. The overall cancer risk was significantly increased (SIR 1.33, 95% confidence interval [CI]: 1.22-1.44, p < 0.001), and there was a significant increase in the incidences of head and neck (SIR 1.60, 95% CI 1.21-2.07, p = 0.001), bone and soft tissue (SIR 2.65, 95% CI 1.27-4.87, p = 0.011), genitourinary (SIR 1.50, 95% CI 1.27-1.76, p < 0.001), and thyroid (SIR 3.85, 95% CI 2.28-6.08, p < 0.001) cancers. Importantly, after multivariate adjustment, the use of tyrosine kinase inhibitors (TKIs) statistically significantly reduced SPM incidence (HR, 0.41; 95% CI, 0.21-0.79; p = 0.008). CONCLUSIONS: Our study indicates that lung cancer may be a risk factor for SPM. TKI use was associated with a significantly lower risk of SPM development. However, because patients with epidermal growth factor receptor mutant lung adenocarcinoma (associated with non-smokers) tend to receive TKI treatment, they might have fewer smoking-related SPMs.

Clinical considerations and surgical approaches for low-grade gliomas in deep hemispheric locations: thalamic lesions.

BACKGROUND: Tumors with epicenter in the thalamus occur in about 4 % of pediatric brain tumors. The histological diagnosis is mainly gliomas. Among them, low-grade glioma (LGG) constituted of a significant entity of the tumors (Cuccia et al., Childs Nerv Syst 13:514-521, 1997; Puget et al., J Neurosurg 106:354-362, 2007; Bernstein et al., J Neurosurg 61:649-656, 1984; Bilginer et al., Childs Nerv Syst 30:1493-1498, 2014). Since Kelly's report in 1989, >90 % resection of thalamic tumors were achieved in reported series (Ozek and Ture, Childs Nerv Syst 18:450-6, 2002; Villarejo et al., Childs Nerv Syst 10:111-114, 1994; Moshel et al., Neurosurgery 61:66-75, 2007; Albright, J Neurosurg 100(5 Suppl Pediatrics): 468-472, 2004; Kelly, Neurosurgery 25:185-195, 1989; Drake et al., Neurosurgery 29: 27-33, 1991). MATERIALS AND METHODS: Sixty-nine cases of thalamic tumors in children were retrospectively reviewed. There were 25 cases of LGGs. We analyzed our experience and correlated it with reported series. RESULTS: Summing up of 4 reported series and the present series, there were 267 cases of thalamic tumors in children. Among these tumors, 107 (40.1 %) were LGGs and 91 (34.1 %) were low-grade astrocytomas (LGAs). In the present series, all of the 25 LGGs were LGAs that consisted of 11 pilocytic astrocytomas (PAs) and 14 diffuse astrocytomas (DAs). Six cases received biopsy sampling only. The remaining 19 cases received different degrees of surgical resection via several approaches. Radical (>90 %) resection was achieved better in PAs comparing with DAs. There was no operative mortality. Two patients had increased neurological deficits. In a mean follow-up period of 11.9 years, three patients died of tumor progression and one patient died of anaplastic change. The 5- and 10-year overall survival (OS) was 87.1 and 87.1 %, respectively. CONCLUSION: Thalamic LGGs are mainly LGAs and are indolent. The rate of >90 % resection was relatively low in the present series. By applying contemporary diagnostic MRI studies, surgical facilities, and appropriate approaches in selective cases, we may try maximum neuroprotective radical (>90 %) resection.