Hypofractionated whole breast irradiation with simultaneous integrated boost in breast cancer using helical tomotherapy with or without regional nodal irradiation: A report of acute toxicities.

Purpose: We prospectively investigated the acute toxicities focusing on skin and hematologic function in breast cancer patients who received hypofractionated whole breast irradiation with simultaneous integrated boost (HF-WBI-SIB) with helical tomotherapy (HT), with or without regional nodal irradiation (RNI). Methods: The dose of WBI and RNI was 42.4 Gy in 16 fractions. Tumor bed was prescribed to 49.6 Gy in 16 fractions simultaneously. The association between the worst grade of acute toxicities during treatment and receiving RNI was analyzed. The integral dose to the whole body between the two groups was also compared. Results: Between May 2021 and May 2022, 85 patients were enrolled; 61 patients received HF-WBI-SIB only (71.8%) and 24 patients (28.2%) received HF-WBI-SIB with RNI. Grade 2 acute skin toxicity was found in 1.2%. The most frequent grade 2 or more hematologic toxicity was leukopenia, which occurred in 4.8% and 11% in the 2nd and 3rd week, respectively. Mean whole body integral dose was significantly higher in patients treated with RNI compared to patients treated without RNI: 162.8 ± 32.8 vs. 120.3 ± 34.7 Gy-L (p-value < 0.001). There was no statistically significant difference in acute grade 2 or more skin and hematologic toxicities between the two groups. Conclusions: HF-WBI-SIB with or without RNI is feasible with acceptable acute skin and hematologic toxicities. RNI and whole body integral dose were not associated with these acute toxicities.

Evaluation and external validation of minor lymphatic pelvic pathway for distant metastases in cervical cancer patients treated with concurrent chemoradiotherapy.

To evaluate and validate the minor lymphatic pathway for distant metastases in cervical cancer. This is a retrospective cohort of cervical cancer patients underwent curative concurrent chemoradiotherapy. We used original dataset from 1 university hospital and validation dataset from 3 university hospitals. Lymphadenopathy status in CT imaging was reviewed by radiologist in either the obturator and external iliac nodes (major pathway) or the internal iliac and presacral nodes (minor pathway). We then used Cox regression to adjust for all potential confounders, including paraaortic nodes, T stage, histology, age, total treatment time, total number of nodes, total short axis of nodes. 397 and 384 patients were in the original and validation datasets (median follow-up period, 59.5 month's). The minor pathway was independent prognostic factor in multivariable analysis [HR=2.64; 95%CI=1.07-6.55; P = 0.036] and [HR=14.84; 95%CI=3.15-70.01; P= 0.001] in original and validation datasets, respectively. Whereas, the major pathway was statistically non-significant. Further validation showed that the minor pathway had the highest HR for distant metastases with both the EMBRACE (HR=6.05; 95% CI=1.30-28.08; P = 0.022) and the FIGO 2018 (HR=7.43; 95% CI=2.94-18.78; P<0.001) in the original dataset. A similar result was found with the validation dataset: EMBRACE, HR=30.91; 95% CI=2.78-343.62; P = 0.005; and FIGO 2018, HR=42.41; 95% CI=8.83-203.60; P<0.001.This is the first clinical study to validate that the minor lymphatic pathway was predominantly associated with distant metastases in cervical cancer. This finding should be validated in larger cohort to further integrate in standard staging for prediction of distant metastases.

Development and validation of a prognostic prediction model including the minor lymphatic pathway for distant metastases in cervical cancer patients.

To develop and validate a prognostic model, including the minor lymphatic pathway (internal iliac and presacral nodes). STUDY DESIGN: Retrospective cohort. PARTICIPANTS: Locally advanced cervical cancer underwent concurrent chemoradiotherapy. SAMPLE SIZE: 397 and 384 patients in the development and validation data set. PREDICTORS: Our new nodal staging system with the minor lymphatic pathway. OUTCOME: Distant metastases. STATISTICAL ANALYSIS: Cox regression; net reclassification improvement (NRI) and decision curve analysis (DCA). Our new nodal system was the strongest predictor. The predictors in the final model were new nodal system, tumor stage, adenocarcinoma, initial hemoglobin, tumor size and age. The nodal system and the pretreatment model had concordance indices of 0.661 and 0.708, respectively, with good calibration curves. Compared to the OUTBACK eligibility criteria, the nodal system showed NRI for both cases (22%) and controls (16%). The pretreatment model showed NRI for cases (31%) and controls (18%). DCA in both models showed threshold probability of 15% and 12%, respectively, when compared with 24% in OUTBACK eligibility criteria. Our new nodal staging system and the pretreatment model could differentiate between high-risk and low-risk patients, thus facilitating decisions to provide more aggressive treatment to prevent distant metastases.

Long-term clinical outcomes of stereotactic radiosurgery and hypofractionated stereotactic radiotherapy using the CyberKnife® robotic radiosurgery system for vestibular schwannoma.

AIM: The study aimed to evaluate the long-term clinical outcomes of patients with vestibular schwannoma (VS) treated with stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (HSRT) with frameless robotic whole-body radiosurgery system (CyberKnife® ). METHODS: This retrospective analysis of prospectively collected data included 123 consecutive patients with VS treated at the Radiosurgery center, Ramathibodi Hospital, Bangkok, Thailand. SRS was recommended for patients with unserviceable hearing and Koos grade I-III tumors, and HSRT for patients with serviceable hearing or Koos grade III-IV tumors. Between March 2009 and December 2015, 23 patients (19%) were treated with SRS, whereas 100 (81%) received HSRT. The commonly used regimen was 12 Gy in one fraction for SRS and 18 Gy in three fractions for HSRT. RESULTS: After a median follow-up of 72 months (range: 12-123 months), the 5-year and 8-year progression-free survival (PFS) rates for the whole cohort were 96% and 92%, respectively. The PFS was not significantly different between the SRS and HSRT groups (p = 0.23). Among 28 patients with serviceable hearing in the HSRT group, the 5-year and 8-year hearing preservation rates were 87% and 65%, respectively. The rate of nonauditory complications was 14%. Koos grade III/IV was a predictor of disease progression and was associated with nonauditory complications. CONCLUSION: SRS and HSRT with the CyberKnife® system provided excellent long-term tumor control with a low rate of nonauditory complications. HSRT may result in acceptable hearing preservation rates.

Secondary cancer risk from modern external-beam radiotherapy of prostate cancer patients: Impact of fractionation and dose distribution.

Modern radiotherapy (RT) uses altered fractionation, long beam-on time and image-guided procedure. This study aimed to compare secondary cancer risk (SCR) associated with primary field, scatter/leakage radiations and image-guided procedure in prostate treatment using intensity-modulated RT (IMRT), CyberKnife stereotactic body RT (CK-SBRT) in relative to 3-dimensional conformal RT (3D-CRT). Prostate plans were generated for 3D-CRT, IMRT (39 fractions of 2 Gy), and CK-SBRT (five fractions of 7.25 Gy). Excess absolute risk (EAR) was calculated for organs in the primary field using Schneider's mechanistic model and concept of organ equivalent dose (OED) to account for dose inhomogeneity. Doses from image-guided procedure and scatter/leakage radiations were determined by phantom measurements. The results showed that hypofractionation relative to conventional fractionation yielded lower SCR for organs in primary field (p ≤ 0.0001). SCR was further modulated by dose-volume distribution. For organs near the field edge, like the rectum and pelvic bone, CK-SBRT plan rendered better risk profiles than IMRT and 3D-CRT because of the absence of volume peak in high dose region (relative risk [RR]: 0.65, 0.22, respectively, p ≤ 0.0004). CK-SBRT and IMRT generated more scatter/leakage and imaging doses than 3D-CRT (p ≤ 0.0002). But primary field was the major contributor to SCR. EAR estimates (risk contributions, primary field: scatter/leakage radiations: imaging procedure) were 7.1 excess cases per 104 person-year (PY; 3.64:2.25:1) for CK-SBRT, 9.93 (7.32:2.33:1) for IMRT and 8.24 (15.99:2.35:1) for 3D-CRT (p ≤ 0.0002). We conclude that modern RT added more but small SCR from scatter/leakage and imaging doses. The primary field is a major contributor of risk which can be mitigated by the use of hypofractionation.

Clinical outcomes of perioptic tumors treated with hypofractionated stereotactic radiotherapy using CyberKnife® stereotactic radiosurgery.

INTRODUCTION: Stereotactic radiation technique is widely reported as an effective treatment for various types of benign intracranial tumors. However, single fraction radiosurgery (SRS) is not recommended for tumors located close to the optic apparatus due to the restricted radiation tolerance dose of the optic pathway. Recent advances in radiotherapy include advanced frameless radiosurgery using hypofractionated stereotactic radiotherapy (HSRT), and this has become an attractive treatment option for perioptic tumors within 2-3 mm of the optic pathway. Accordingly, the aim of this study was to investigate the clinical outcomes of perioptic tumors treated with HSRT using CyberKnife® (CK) robotic radiosurgery system relative to tumor control, vision preservation and toxicity. METHODS: This retrospective analysis of prospectively collected data included consecutive 100 patients that were diagnosed with and treated for perioptic tumor at the Radiosurgery center, Ramathibodi Hospital during the January 2009 to December 2012 study period. RESULTS: The median tumor volume was 6.81 cm3 (range 0.37-51.6), and the median prescribed dose was 25 Gy (range 20-35) in 5 fractions (range 3-5). After the median follow-up time of 37.5 months (range 21-103), two patients developed tumor progression at 6 and 34 months post-HSRT. The 5-year overall survival was 97%, and the 5-year local control was 97.5%. At the last follow-up, no vision deterioration or newly developed hypopituitarism was detected in our study. CONCLUSIONS: Although a longer follow-up is needed, HSRT yields a high level of local control and vision preservation, and should be considered a treatment of choice for perioptic tumor located close to the optic apparatus.

Malignant transformation of phyllodes tumor: a case report and review of literature.

Malignant phyllodes may transform from benign phyllodes; low-aggressive malignant phyllodes tumor is manageable by locally wide excision.

Cervix Cancer Research Network (CCRN): Improving Access to Cervix Cancer Trials on a Global Scale.

Eighty-seven percent of cervix cancer occurs in less-developed regions of the world, and there is up to an 18-fold difference in mortality rate for cervix cancer depending on the region of the world. The Cervix Cancer Research Network (CCRN) was founded through the Gynecologic Cancer InterGroup with the aim of improving access to clinical trials in cervix cancer worldwide, and in so doing improving standards of care. The CCRN recently held its first international educational symposium in Bangkok. Sixty-two participants attended from 16 different countries including Pakistan, India, Bangladesh, Thailand, Malaysia, Singapore, Philippines, Taiwan, China, Vietnam, Korea, Japan, Columbia, Brazil, Canada, and the United States. The focus of this symposium was to evaluate progress, to promote new clinical trials for the CCRN, and to provide education regarding the role of brachytherapy in the treatment of cervical cancer.

Clinical Outcomes of Intracranial Nonvestibular Schwannomas Treated with LinacBased Stereotactic Radiosurgery and Radiotherapy.

BACKGROUND: Intracranial nonvestibular schwannomas arising from various cranial nerves excluding CN VIII are uncommon. Recently, stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) have been widely reported as effective treatment modalities for nonvestibular schwannomas. The purpose of this study was to study the long term clinical outcome for nonvestibular schwannomas treated with both XKnife and CyberKnife (CK) radiosurgery at one institution. MATERIALS AND METHODS: From 2004 to 2013, fiftytwo nonvestibular schwannoma patients were included in this study, 33 patients (63%) were treated with CK, and 19 (37%) were treated with XKnife. The majority of the tumors were jugular foramen schwannomas (38%) and trigeminal schwannomas (27%). HSRT was given for 45 patients (86%), whereas CSRT was for 6 (12%) and SRS for 1 (2%). RESULTS: The median pretreatment volume was 9.4 cm3 (range, 0.5752 cm3). With the median follow up time of 36 months (range, 3135), the 3 and 5 year progression free survival was 94 % and 88%, respectively. Tumor size was decreased in 13 (25%), stable in 29 (56%), and increased in 10 (19%). Among the latter, 3 (30%) required additional treatment because of neurologic deterioration. No patient was found to develop any new cranial nerve deficit after SRS/SRT. CONCLUSIONS: These data confirmed that SRS/ SRT provide high tumor control rates with low complications. Large volume tumors and cystic expansion after radiation should be carefully followed up with neurological examination and MRI, because it may frequently cause neurological deterioration requiring further surgery.

The Clinical Outcome of Hypofractionated Stereotactic Radiotherapy With CyberKnife Robotic Radiosurgery for Perioptic Pituitary Adenoma.

Stereotactic radiation technique including single fraction radiosurgery and conventional fractionated stereotactic radiotherapy is widely reported as an effective treatment of pituitary adenomas. Because of the restricted radiation tolerance dose of the optic pathway, single fraction radiosurgery has been accepted for small tumor located far away from the optic apparatus, while fractionated stereotactic radiotherapy may be suitable for larger tumor located close to the optic pathway. More recently, hypofractionated stereotactic radiotherapy has become an alternative treatment option that provides high rate of tumor control and visual preservation for the perioptic lesions within 2 to 3 mm of the optic pathway. The objective of the study was to analyze the clinical outcomes of perioptic pituitary adenomas treated with hypofractionated stereotactic radiotherapy. From 2009 to 2012, 40 patients with perioptic pituitary adenoma were treated with CyberKnife robotic radiosurgery. The median tumor volume was 3.35 cm3 (range, 0.82-25.86 cm3). The median prescribed dose was 25 Gy (range, 20-28 Gy) in 5 fractions (range, 3-5). After the median follow-up time of 38.5 months (range, 14-71 months), 1 (2.5%) patient with prolactinoma had tumor enlargement, 31 (77.5%) were stable, and the remaining 8 (20%) tumors were smaller in size. No patient's vision deteriorated after hypofractionated stereotactic radiotherapy. Hormone normalization was observed in 7 (54%) of 13 patients. No newly developed hypopituitarism was detected in our study. These data confirmed that hypofractionated stereotactic radiotherapy achieved high rates of tumor control and visual preservation. Because of the shorter duration of treatment, it may be preferable to use hypofractionated stereotactic radiotherapy over fractionated stereotactic radiotherapy for selected pituitary adenomas immediately adjacent to the optic apparatus.

Long Term Outcomes of Preoperative versus Postoperative Concurrent Chemoradiation for Locally Advanced Rectal Cancer: Experience from Ramathibodi Medical School in Thailand.

OBJECTIVES: The study analyzed and compared the long term outcome in locally advanced rectal cancer treated with preoperative and postoperative concurrent chemoradiation (CCRT). MATERIALS AND METHODS: A retrospective review of 105 patients with stage T3-T4 or regional lymph node positive adenocarcinoma of rectum treated with preoperative or postoperative CCRT at Ramathibodi Hospital during 2005 to 2010 was performed. The results of treatment were reported with 5-year overall survival (OS), 5- year locoregional recurrence free survival (LRFS), and toxicity according to preoperative versus postoperative concurrent chemoradiation (CCRT) groups. RESULTS: Among 105 patients, 34 (32%) were treated with preoperative CCRT and 71 (68%) with postoperative CCRT. At the median follow-up time of 50.5 months (range 2-114 months), five-year OS and LRFS of all patients were 87% and 91.6%, respectively. The study found no difference in 5-year OS (81.7% vs 89.2 %) or LRFS (83.4% vs 95.1%) between preoperative versus postoperative CCRT. Seven cases of loco-regional recurrence were diagnosed, 4 (11.8%) after preoperative CCRT and 3 (4.2%) after postoperative CCRT. The recurrent sites were anastomosis in all patients. There was no significant factor associated with outcome after univariate and multivariate testing. Grade 3 or 4 acute and late complications were low in both preoperative and postoperative CCRT groups. CONCLUSIONS: Locally advanced rectum cancer patients experience good results with surgery and adjuvant concurrent chemoradiation.

Outcomes for Pituitary Adenoma Patients Treated with Linac- Based Stereotactic Radiosurgery and Radiotherapy: a Long Term Experience in Thailand.

BACKGROUND: The study analyzed the long term clinical outcomes of pituitary adenoma cases treated with the first Thailand installation of a dedicated Linac-based stereotactic radiation machine (X-Knife). MATERIALS AND METHODS: A retrospective review of 115 consecutive pituitary adenoma patients treated with X-Knife at the Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand from 1997 to 2003 was performed. Stereotactic radiosurgery (SRS) was selected for 21 patients (18%) including those with small tumors (≤3 cm) located ≥5 mm. from the optic apparatus, whereas the remaining 94 patients (82%) were treated with fractionated stereotactic radiotherapy (FSRT). RESULTS: With a median follow-up time of 62 months (range, 21-179), the six-year progression free survival was 95% (93% for SRS and 95% for FSRT). The overall hormone normalization at 3 and 5 years was 20% and 30%, respectively, with average time required for normalization of approximately 16 months for SRS and 20 months for FSRT. The incidence of new hypopituitarism was 10% in the SRS group and 9% in the FSRT group. Four patients (5%) developed optic neuropathy (1 in the SRS group and 3 in the FSRT group). CONCLUSIONS: Linac-based SRS and FSRT achieved similar high local control rates with few complications in pituitary adenoma cases. However, further well designed, randomized comparative studies between SRS versus FSRT particularly focusing on hormone normalization rates are required.

Esthesioneuroblastoma metastasis to the breast: A case report and review of the literature.

Metastasis to the breast from an extramammary malignant neoplasm, including esthesioneuroblastoma, is uncommon. The present study describes a rare case of sinonasal esthesioneuroblastoma, Hyams' histologic grade 2, Kadish's stage C, T4N0M0, in a 30-year-old female. The patient underwent a radical ethmoidectomy with external beam radiotherapy, followed by chemotherapy including five cycles of cisplatin and etoposide. One year after the initial diagnosis, the patient presented to the hospital with the chief complaint of a rapidly enlarging lump in the right breast. A fine needle aspiration was performed and immunocytochemistry revealed a metastatic esthesioneuroblastoma. The patient received palliative chemotherapy and radiotherapy; however, the patient developed a local recurrence with systemic metastasis and succumbed to the disease seven months later.

Clinical outcome of postoperative radiotherapy with or without chemotherapy in adult glioblastoma multiforme in Ramathibodi Hospital: a retrospective study.

OBJECTIVE: To identify the treatment outcome of glioblastoma multiforme (GBM) in Ramathibodi Hospital from overall survival rate and related prognostic factors. MATERIAL AND METHOD: Medical records of patients with histological diagnosis of GBM treated at Radiation Oncology Division, Radiology Department, Ramathibodi Hospital between 2000 and 2010 were reviewed and available data extracted for evaluation of treatment outcome. RESULTS: There were 47 patients with mean age at diagnosis of 51.9 years (range from 18 to 82 years). Surgery (partial 76.6%, total 12.8%, and biopsy 10.6%) followed by postoperative radiotherapy (mean dose 52 gray) was the treatment of choice with or without concurrent and adjuvant Temozolomide (TMZ). With median follow-up time of 0.9 years, the median survival of the patients was 2.1 years (95% CI 1.08-7.36), whereas one and two-year overall survival rates were 78.0% and 57.8%, respectively. In univariate analysis, persistent neurological deficit after surgery and presenting symptom of visual disturbance were identified to lower overall survival while multivariate analysis, younger age, and higher radiation dose were identified as favorable prognostic factors to improve overall survival. Re-surgery or re-irradiation in some selected cases of recurrent or progressive disease was considered as a choice for palliative treatment. CONCLUSION: Proper management of GBM patient was surgical removal and postoperative radiotherapy with or without chemotherapy. Proper palliative treatment modality was considered in selected cases of recurrent or progressive disease.

The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy.

Recent publications have reported stereotactic radiosurgery as an effective and safe treatment for intracranial hemangioblastomas. However, because of the low incidence of these particular tumors, reports on large patient number studies have not yet been available. The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same institute. The median age of patients was 41 years (range, 28-73 years). Nine of the patients (64%) had von Hippel-Lindau disease. A total of 39 lesions (70%) were treated with CyberKnife (CK), and 17 lesions (30%) were treated with X-Knife. The median pretreatment volume was 0.26 cm(3) (range, 0.026-20.4 cm(3)). The median marginal dose was 20 Gy (range, 10-32 Gy) in 1 fraction (range, 1-10 fractions). The median follow-up time was 24 months (range, 11-89 months). At the last follow-up, 47 tumors (84%) were stable, 7 (13%) decreased and 2 (4%) increased. The 1-, 2- and 6-year local control rates were 98%, 88% and 73%, respectively. No radiation complications were observed in this study. There was a trend toward local failure only in cystic tumors, but this trend was not found to be statistically significant. SRS/SRT achieved a high local control rate in intracranial hemangioblastomas without radiation-induced complications.

Linac-based stereotactic radiosurgery and fractionated stereotactic radiotherapy for vestibular schwannomas: comparative observations of 139 patients treated at a single institution.

Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) have been recognized as an alternative to surgery for small to medium sized vestibular schwannoma (VS). This study analysed and compared the outcomes of VS treated with the first Thailand installation of a dedicated Linac-based stereotactic radiation machine using single-fraction radiosurgery (SRS), hypofraction stereotactic radiotherapy (HSRT) and conventional fraction stereotactic radiotherapy (CSRT). From 1997 to 2010, a total of 139 consecutive patients with 146 lesions of VS were treated with X-Knife at Ramathibodi hospital, Bangkok, Thailand. SRS was selected for 39 lesions (in patients with small tumors ≤3 cm and non-serviceable hearing function), whereas HSRT (79 lesions) and CSRT (28 lesions) were given for the remaining lesions that were not suitable for SRS. With a median follow-up time of 61 months (range, 12-143), the 5-year local control rate was 95, 100 and 95% in the SRS, HSRT and CSRT groups, respectively. Hearing preservation was observed after SRS in 75%, after HSRT in 87% and after CSRT in 63% of the patients. Cranial nerve complications were low in all groups. There were no statistically significant differences in local control, hearing preservation or complication between the treatment schedules. In view of our results, it may be preferable to use HSRT over CSRT for patients with serviceable hearing because of the shorter duration of treatment.

Preliminary experience of CyberKnife treatment of lung metastasis: the question about real clinical benefit.

OBJECTIVE: Evaluate the effectiveness of radiotherapy plan and physical parameters including local tumor response and clinical outcome of lung metastasis in patients who received CyberKnife treatment at Ramathibodi Hospital. MATERIAL AND METHOD: Six cases with twenty lesions of lung metastasis patients were evaluated for tumor response after having received CyberKnife treatment. The prescribed radiation dose was calculated approximately to biological equivalent dose (BED) around 60 to 100 gray (Gyz). The response of each lesion to treatment was evaluated from roentgenographic study during follow-up period along with adverse event, status of patients, and disease. RESULTS: At the third month after treatment, roentgenographic partial response (PR, 50% decrease in size) was demonstrated in eight lesions and stable disease (SD, unchanged size) in eight lesions with no complete response (CR, disappearance of tumor) detected. Progressive disease (PD, 25% increase in size) of six treated lesions was detected during the follow-up period. At the time of report, two patients were alive and still received palliative chemotherapy, two patients died from uncontrolled progressive metastases and failed palliative chemotherapy, and two patients lost follow-up after progressive metastases with unknown surviving status. No severe adverse event was observed. The treatment planning parameters demonstrated borderline of radiation dose homogeneity, and conformality coverage of the target volume. CONCLUSION: This preliminary report aimed to provide the idea of choosing the appropriate lung metastasis patient to receive CyberKnife treatment that must strictly clarify the real clinical benefit of each selected case to achieve the best outcome from this special treatment procedure.

The clinical results of pediatric brain tumors treated with Linac-based stereotactic radiosurgery and radiotherapy.

OBJECTIVE: Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) for brain tumor is increasingly acceptable worldwide. In Thailand, the first Linac-based stereotactic radiation machine was implemented at the Radiosurgery Center, Ramathibodi Hospital since 1997. This is the first study in Thailand to report the results of pediatric brain tumor patients treated with SRS and FSRT MATERIAL AND METHOD: The clinical outcome of 39 pediatric patients treated with SRS/FSRT between 1998 and 2010 was retrospectively reviewed. RESULTS: The median follow-up time was 26 months (range, 1 to 154 months). The local progression free survival (LPFS) at one and five years after SRS/FSRT for all patients was 87.5% and 54.2%, respectively. The 5-year LPFS by tumor histology was as follow, pituitary adenoma 100%, meningioma 100%, ependymoma, and low-grade astrocytoma 75%, and craniopharyngioma 68.6%. High-grade tumor had the worst LPFS and the median LPFS of this group was only 12 months. On univariate analysis, low-grade tumor (pituitary adenoma and menigioma) and small tumor volume (< 10 ml) were the factors that correlated significantly with good local control. After multivariate analysis, small tumor volume was the only factor associated with good LPFS (HR = 2.35, p = 0.042). No other radiation complication except panhypopituitarism was reported. CONCLUSION: SRS/FSRT in pediatric brain tumor is technically feasible, with minimal acute side effects. SRS/FSRT plays an important role for the small low-grade tumor

Preliminary experience of CyberKnife treatment of primary non-small cell lung cancer.

OBJECTIVE: Provide the effectiveness of treatment protocol, radiotherapy plan, technique, and early clinical results of inoperable primary non-small cell lung cancer (NSCLC) in patients who received CyberKnife treatment at Ramathibodi Hospital. MATERIAL AND METHOD: Six cases of inoperable primary NSCLC patients were evaluated for tumor response after having received CyberKnife treatment. The prescribed radiation dose was 45 gray (Gy) in three consecutive fractions for peripherally located tumor and 50 Gy in five fractions within two weeks for centrally located tumor (biological equivalent dose, BED, 112.5 Gy 10, and 100 Gy 10, respectively). The response to treatment was evaluated from roentgenographic study during follow-up period along with clinical outcome and adverse event. RESULTS: Overall response after the treatment was demonstrated in five cases with roentgenographic complete response (CR, disappearance of tumor) and partial response (PR, 50% decrease in size) in two and three cases, respectively without any severe adverse event. The treatment planning parameters demonstrated the effectiveness of radiation dose homogeneity and conformity coverage of the target volume. CONCLUSION: This preliminary report has provided the effectiveness of treatment plan and local tumor controlled without severe adverse event for primary inoperable NSCLC patients receiving CyberKnife treatment.

Stereotactic radiation therapy for optic nerve sheath meningioma; an experience at Ramathibodi Hospital.

OBJECTIVE: To evaluate results of stereotactic radiotherapy for the treatment of optic nerve sheath meningioma (OM) at Ramathibodi Hospital. MATERIAL AND METHOD: Twelve patients with primary OM were treated with stereotactic radiation between 1998 and 2005. Five patients underwent surgery and had no light perception before radiation. All patients except one were treated with fractionated stereotactic radiotherapy (FSRT). Mean average dose of FSRT was 55. 7 Gy; 180 cGy/fraction. One patient was treated with 15-Gy stereotactic radiosurgery. RESULTS: With a median follow-up of 34 months, there was no visual improvement in the five patients who were completely blind before radiation. Visual acuity improved in four patients and remained stable in two patients. Four of six patients had improved visual field, and five of six decreased in proptosis. Follow-up images were available in six patients, showing minimal tumor regression in five and stable in one. No serious acute side effect was observed. Vision became worse in one patient, who developed vitreous hemorrhage two years after FSRT. CONCLUSION: Stereotactic radiotherapy is an effective treatment for primary OM. It provides tumor control and visual preservation with low risk of complications. However more patients and further follow-up are needed for long-term outcomes.