CyberKnife Therapy Research Articles

18F]FET PET/MRI: An Accurate Technique for Detection of Small Functional Pituitary Tumors.

Small functional pituitary tumors can cause severely disabling symptoms and early death. The gold standard diagnostic approach includes laboratory tests and MRI, with or without inferior petrosal sinus sampling (IPSS). In up to 40% of patients, however, the source of excess hormone production remains unidentified or uncertain. This excludes patients from surgical, Gamma Knife, and CyberKnife therapy and adversely affects overall cure rates. We here assess the diagnostic yield of O-(2-[18F]fluoroethyl)-l-tyrosine ([18F]FET) PET/MRI for detection of small functional pituitary tumors in these patients. Methods: This retrospective analysis included patients with Cushing disease (CD) but prior negative or inconclusive MRI results who underwent [18F]FET PET/MRI between February 1, 2021, and December 1, 2022. PET/MR images and MR images alone were evaluated by experienced nuclear radiologists, neuroradiologists, or radiologists. Postoperative tissue analysis (when performed) was used as a reference standard to assess diagnostic metrics (i.e., sensitivity and positive predictive value). Results were also compared with previously obtained MR images, preceding IPSS, and clinical or biochemical follow-up. Results: Twenty-two patients (68% female; mean age ± SD, 48 ± 15 y; range, 24-68 y) were scanned. All patients showed a clear metabolic focus on [18F]FET PET, whereas reading of the MRI alone yielded a suspected lesion in only 50%. Fifteen patients underwent surgery directed at the [18F]FET-positive focus. Tissue analysis confirmed a pituitary adenoma/pituitary neuroendocrine tumor of the corticotroph cell type (TPIT lineage) in 10 of 15 and a pituicytoma in 1 of 15, rendering a sensitivity of 100% and a positive predictive value of 73%. Lateralization was more accurate with [18F]FET PET/MRI than with IPSS in 33%. Twelve of 16 (75%) patients who received surgical, Gamma Knife, or CyberKnife therapy after [18F]FET PET/MRI reached short-term remission. Conclusion: [18F]FET PET/MRI shows a high diagnostic yield for localizing small functional pituitary tumors. This multimodal imaging technique provides a welcome improvement for diagnosis, planning of surgery, and clinical outcome in patients with Cushing disease, particularly those with repeated negative or inconclusive MRI results with or without IPSS.

Longitudinal analysis of T2 relaxation time variations following radiotherapy for prostate cancer

Aim of this paper is to evaluate short and long-term changes in T2 relaxation times after radiotherapy in patients with low and intermediate risk localized prostate cancer. A total of 24 patients were selected for this retrospective study. Each participant underwent 1.5T magnetic resonance imaging on seven separate occasions: initially after the implantation of gold fiducials, the required step for Cyberknife therapy guidance, followed by MRI scans two weeks post-therapy and monthly thereafter. As part of each MRI scan, the prostate region was manually delineated, and the T2 relaxation times were calculated for quantitative analysis. The T2 relaxation times between individual follow-ups were analyzed using Repeated Measures Analysis of Variance that revealed a significant difference across all measurements (F (6, 120) = 0.611, p << 0.001). A Bonferroni post hoc test revealed significant differences in median T2 values between the baseline and subsequent measurements, particularly between pre-therapy (M0) and two weeks post-therapy (M1), as well as during the monthly interval checks (M2 - M6). Some cases showed a delayed decrease in relaxation times, indicating the prolonged effects of therapy. The changes in T2 values during the course of radiotherapy can help in monitoring radiotherapy response in unconfirmed patients, quantifying the scarring process, and recognizing the therapy failure.

Robotic CyberKnife Radiosurgery for the Treatment of Choroidal and Ciliary Body Melanoma

To present the results of robotic assisted radiosurgery in choroidal and ciliary body melanomas treated at the Department of Ophthalmology of Ludwig-Maximilians-University and the European CyberKnife Center in Munich, Germany. Interventional case series METHODS AND MATERIALS: This retrospective study included 594 consecutive patients referred to our clinic for the treatment of choroidal and ciliary body melanomas with robotic radiosurgery (CyberKnife) from 2005 to 2019. Eye retention, local control and disease-specific survival rates were calculated as Kaplan-Meier and actuarial estimates. The impact of prescription dose, tumor size and ciliary body involvement was assessed by likelihood ratio tests and Cox regression. Among all patients that were staged according to the TNM classification system (8th edition), 22.7% were I, 57.9% II, 18.9% III and 0.5% of patients were classified as IV. Median apical tumor height and base diameter were 5.8 and 11.4 mm. The mean follow-up was 41.7 months. Local control after three and five years was 92.0% (95% CI 88.2 - 94.7%)and 84.3% (95% CI 77.9 - 89.0%) respectively for 21-22 Gy and 86.9% (95% CI 79.7 - 91.7%) and 77.7% (95% CI 68.5 - 84.6%) respectively when treated with 20 Gy or less. Eye retention was achieved in 89.9% and 81.0% after three and five years with 21-22 Gy and 85.9% and 80.0% for 20 Gy or less. Disease-specific survival rates were 93.1% (95% CI 90.2 - 95.2%) after three years, 89.8% (95% CI 86.0 - 92.6%) after five years and 87.8% (95% CI 82.8 - 91.4%) after seven years. This is the largest series of patients treated for choroidal and ciliary body melanomas with CyberKnife. Our results reflect an improvement in the outcome of CyberKnife therapy for patients suffering from choroidal and ciliary body melanoma treated with single session radiosurgery in the last decade.

Re-irradiation of multiple brain metastases using CyberKnife stereotactic radiotherapy: Case report.

Introduction:Brain metastasis (BM) is the commonest adult intracranial malignancy and many patients with brain metastases require two course radiotherapy. Re-irradiation is frequently performed in Radiotherapy (RT) departments for multiple brain metastases.Patient concerns:We present a case of a 55-year-old male patient suffering from brain metastases, who had previously received whole-brain radiotherapy (WBRT) and first CyberKnife Stereotactic Radiotherapy (CKSRT) for metastases, presented with a recurrence of metastasis and new lesions in the brain.Diagnoses:An enhanced computed tomography (CT) scan of the brain revealed abnormalities with double-dosing of intravenous contrast that identified >10 lesions scattered in the whole brain.Interventions:Re-irradiation was performed using CKSRT. The patient was treated with 30 Gy in 5 fractions for new lesions and 25 Gy in 5 fractions for lesion that were locally recurrent and close to brainstem lesions.Outcome:The lesions were well-controlled, and the headache of the patient was significantly relieved one month after radiotherapy. The total survival time of the patients was 17 months from the beginning of the Cyberknife treatment.Conclusion:The present case report demonstrates that CyberKnife therapy plays a significant role in the repeated radiotherapy for multiple metastatic brain tumors. CKSRT can be used as a salvage method in recurrent multiple brain metastases.

Comparative dosimetrical analysis of intensity-modulated arc therapy, CyberKnife therapy and image-guided interstitial HDR and LDR brachytherapy of low risk prostate cancer.

The objective of the study was to dosimetrically compare the intensity-modulated-arc-therapy (IMAT), Cyber-Knife therapy (CK), single fraction interstitial high-dose-rate (HDR) and low-dose-rate (LDR) brachytherapy (BT) in low-risk prostate cancer. Treatment plans of ten patients treated with CK were selected and additional plans using IMAT, HDR and LDR BT were created on the same CT images. The prescribed dose was 2.5/70 Gy in IMAT, 8/40 Gy in CK, 21 Gy in HDR and 145 Gy in LDR BT to the prostate gland. EQD2 dose-volume parameters were calculated for each technique and compared. EQD2 total dose of the prostate was significantly lower with IMAT and CK than with HDR and LDR BT, D90 was 79.5 Gy, 116.4 Gy, 169.2 Gy and 157.9 Gy (p < 0.001). However, teletherapy plans were more conformal than BT, COIN was 0.84, 0.82, 0.76 and 0.76 (p < 0.001), respectively. The D2 to the rectum and bladder were lower with HDR BT than with IMAT, CK and LDR BT, it was 66.7 Gy, 68.1 Gy, 36.0 Gy and 68.0 Gy (p = 0.0427), and 68.4 Gy, 78.9 Gy, 51.4 Gy and 70.3 Gy (p = 0.0091) in IMAT, CK, HDR and LDR BT plans, while D0.1 to the urethra was lower with both IMAT and CK than with BTs: 79.9 Gy, 88.0 Gy, 132.7 Gy and 170.6 Gy (p < 0.001). D2 to the hips was higher with IMAT and CK, than with BTs: 13.4 Gy, 20.7 Gy, 0.4 Gy and 1.5 Gy (p < 0.001), while D2 to the sigmoid, bowel bag, testicles and penile bulb was higher with CK than with the other techniques. HDR monotherapy yields the most advantageous dosimetrical plans, except for the dose to the urethra, where IMAT seems to be the optimal modality in the radiotherapy of low-risk prostate cancer.

Radiation therapy for uveal melanoma: a review of treatment methods available in 2021.

Radiation therapy has become the standard of care for the treatment of uveal melanoma. We intend to outline the current radiation therapy methods that are employed to treat uveal melanoma. We will outline their relative benefits over one another. We will also provide some background about radiation therapy in general to accustom the ophthalmologists likely reading this review. Four main options exist for radiation therapy of uveal melanoma. Because the eye is a small space, and because melanomas are relatively radioresistant, oncologists treating uveal melanoma must deliver highly focused doses in high amounts to a small space. Therapies incorporating external beams include proton beam therapy and stereotactic radiosurgery. Stereotactic radiosurgery comes in two forms, gamma knife therapy and cyberknife therapy. Radiation may also be placed directly on the eye surgically via plaque brachytherapy. All methods have been used effectively to treat uveal melanoma. Each particular radiotherapy technique employed to treat uveal melanoma has its own set of benefits and drawbacks. The ocular oncologist can choose amongst these therapies based upon his or her clinical judgment of the relative risks and benefits. Availability of the therapy and cost to the patient remain significant factors in the ocular oncologist's choice.

Usefulness of CyberKnife Therapy in Patients with Differentiated Thyroid Cancer with Distant Metastases

ABSTRACT Aim and objective We reported seven cases in which external beam radiotherapy (EBRT) with CyberKnife therapy was effective against distant metastases from differentiated thyroid carcinoma (DTC). Materials and methods The subjects included seven patients (6 males, 1 female; age 53–77 years, average age 65.85 years) who underwent CyberKnife therapy for metastatic lesions of DTC (pathological diagnosis: differentiated papillary carcinoma). The target lesions included 12 lymph node, 6 bone, and 2 brain metastases. All patients had previously undergone total thyroidectomy, followed by radioactive iodine therapy (RAIT). Since RAIT was not expected to have a therapeutic effect, CyberKnife treatment was selected. CyberKnife irradiation was performed 1–5 times. The radiation doses covering 95% of the planning target volume (D95) ranged from 15 to 26 gray (Gy). To determine the therapeutic effect, lesion size was evaluated by computed tomography (CT) and magnetic resonance imaging (MRI) before and 6–12 months after treatment. Results No increase in size was observed in the brain and bone metastases. Among the lymph node metastatic lesions, a therapeutic effect involving internal necrosis without an increase in size was noted in two lymph node metastases in the cervix. Additionally, two lymph node metastases in the neck had reduced in size. No increases in size were observed in the other lymph node lesions, reflecting the therapeutic effect of CyberKnife. Conclusions CyberKnife may be useful in treating distant metastatic lesions of papillary thyroid cancer. Clinical significance CyberKnife is useful as a multidisciplinary treatment for cases in which radioactive iodine therapy is maladjusted. How to cite this article Higashiyama S, Yoshida A, Katayama Y, et al. Usefulness of CyberKnife Therapy in Patients with Differentiated Thyroid Cancer with Distant Metastases. Int J Otorhinolaryngol Clin 2020;12(2):38–41.

Robotic-assisted radiosurgery for the treatment of vasoproliferative tumours.

Vasoproliferative tumours (VPT) are a rare but benign entity that can lead to severe visual acuity deterioration. There is no standard of care, and depending on the degree of clinical features, including tumour size and dissemination, visual acuity and subretinal fluid, treatment options include observation, cryotherapy and brachytherapy. Particularly in larger tumours, brachytherapy has advantages over other options, although higher radiation doses and the need for surgical application are disadvantages of this otherwise effective treatment option. CyberKnife radiosurgery might represent an alternative therapeutic option as no surgical intervention is needed and radiation doses are lower. All patients diagnosed with vasoproliferative tumors who were treated with CyberKnife radiosurgery with a minimum follow-up time of 12 months were included in this case series. We recorded visual acuity, number of lesions, central retinal thickness with optical coherence tomography (OCT) and reflectivity using A-scan standardizes echography every three months. A total of four patients with a median age of 34 years (range: 24 - 51) who were observed over an average of 26.5 months (range: 17 - 49 months) matched our inclusion criteria. We appreciated stabilization or increase in visual acuity in all four patients and a regression in tumour thickness with subsequent increase in internal reflectivity as a marker of increasing fibrosis. We observed good visual and functional outcome following CyberKnife therapy for VPT. We believe that further studies should be pursued to evaluate CyberKnife therapy for the treatment of VPT not treatable with cryo- or lasertherapy.

Is stereotactic CyberKnife radiotherapy or multicatheter HDR brachytherapy the better option dosimetrically for accelerated partial breast irradiation?

ObjectiveTo compare dosimetrically the stereotactic CyberKnife (CK) therapy and multicatheter high-dose-rate (HDR) brachytherapy (BT) for accelerated partial breast irradiation (APBI). MethodsTreatment plans of 25 patients treated with CK were selected, and additional plans using multicatheter HDR BT were created on the same CT images. The prescribed dose was 6.25/25 Gy in both plans to the target volume (PTV). The dose-volume parameters were calculated for both techniques and compared. ResultsThe D90 total dose of the PTV was significantly lower with CK than with HDR BT, D90 was 25.7 Gy, and 27.0 Gy (p < 0.001). However, CK plans were more conformal than BT, COIN was 0.87, and 0.81 (p = 0.0030). The V50 of the non-target breast was higher with CK than with BT: 10.5% and 3.3% (p = 0.0010), while there was no difference in the dose of the contralateral breast and contralateral lung. Dose to skin, ipsilateral lung, and ribs were higher with CK than with BT: D1 was 20.6 Gy vs. 11.5 Gy (p = 0.0018) to skin, 11.4 Gy vs. 9.6 Gy (p = 0.0272) to ipsilateral lung and 18.5 Gy vs. 12.3 Gy (p = 0.0013) to ribs, while D0.1 to heart was lower, 3.0 Gy vs. 3.2 Gy (p = 0.0476), respectively. ConclusionsMulticatheter HDR BT yields more advantageous plans than stereotactic CyberKnife treatment in accelerated partial breast irradiation, except in terms of dose conformality and the dose to the heart. There was no difference in the dose of the contralateral breast and lung.

CyberKnife Boost in Pediatric Ependymoma of the Fourth Ventricle

Background: Ependymoma of the fourth ventricle is a challenging disease. Brain stem tolerance dose usually hinders the delivery of adequate radiation dose to target volumes. Aim: To present the treatment outcome of pediatric ependymoma of the fourth ventricle using combined CyberKnife and volumetric modulated arc therapy (VMAT) and compare it to VMAT plans. Methods: The medical charts of 15 patients were retrospectively reviewed. All patients underwent surgery and received radiotherapy in 2 phases using combined plans of VMAT and CyberKnife boost aiming for a total prescription dose of 59.4 Gy in 33 fractions. These plans were compared to a cone-down two-phase VMAT plans. At least 95% of the target volume was required to be encompassed by the 95% isodose level of prescription dose. Results: It was not feasible to achieve adequate target coverage using VMAT without exceeding the brain stem tolerance doses in all but one case. Brain stem maximum point dose, V59 Gy, V55.8 Gy and mean doses were 60.46 ± 0.3 Gy, 1.62 ± 0.42 cc, 37.49 ± 5.78% and 54.79 ± 0.64 Gy in VMAT plans compared to 59.67 ± 0.21 Gy, 0.55 ± 0.22 cc, 25.49 ± 3.84% and 52.86 ± 0.88 Gy in combined technique plans (p = 0.002, 0.001, 0.001 and 0.001; respectively). The estimated 5-year progression-free and overall survival rates were 53.3% and 63.6%. Performance status and extent of surgery significantly influenced overall survival. None of the patients had serious toxicities. Conclusion: On the contrary to VMAT cone-down plans, it was possible to achieve adequate target coverage without violating brain stem constraints using the combination of VMAT and CyberKnife techniques in pediatric ependymoma of the fourth ventricle. The treatment protocol was well tolerated with no reported serious radiation toxicities.

Evaluation of volumetric and morphological changes of vestibular schwannomas following CyberKnife therapy

Evaluation of volumetric and morphological changes of vestibular schwannomas following CyberKnife therapy

Computed tomography or contrast-enhanced ultrasonography for follow-up of liver metastases after Cyberknife therapy?: A prospective pilot study.

Contrast-enhanced ultrasonography (CEUS) allows the study of vascularization of secondary liver lesions. The Cyberknife (Accuray, Inc, Sunnyvale, CA) is a therapeutic method that allows a tumor target to be subjected to a high radiant dose gradient. This prospective pilot study aimed to demonstrate the concordance of CEUS versus contrast-enhanced computed tomography (CECT) in determining the stability or disease progression of secondary liver lesions after treatment with the Cyberknife. Twenty-four patients were consecutively enrolled, and 3 different operators evaluated the CEUS images and the intermodality concordance with CECT. All patients received CEUS at 1 and 2 months after the Cyberknife therapy. The intermodality agreement was evaluated by the Cohen κ coefficient and a multivariate analysis according to the method of Janson and Olsson (Educ Psychol Meas 2001; 61:277-289). Forty secondary liver lesions were detected and treated. Forty-one CECT and 51 CEUS examinations were performed without any adverse events in the 24 patients. The intermodality agreement rates, calculated for the operators as Cohen κ values, were κ = 1.00, 0.881, and 0.767, respectively. The multivariate analysis of intermodality agreement showed an almost perfect value (ι = 0.841). This pilot study found excellent diagnostic correspondence between CEUS and CECT in the evaluation of local disease stability or progression after Cyberknife therapy in liver metastases. These findings suggest that CEUS could play an important role in the surveillance of these patients because of its high accuracy and reproducibility, thus reducing the need for CECT.

Effects of CyberKnife therapy for vestibular schwannoma on hearing: a retrospective study.

To evaluate the effects of CyberKnife stereotactic radiotherapy for the treatment of vestibular schwannoma on hearing, as evaluated by audiological tests. Patients with vestibular schwannoma were evaluated before and after CyberKnife radiosurgery. Evaluation included pure tone thresholds, speech discrimination scores, auditory brainstem responses and radiological signs. The study comprised 26 patients diagnosed with vestibular schwannoma and subsequently treated with CyberKnife radiosurgery. The mean follow-up time was 16.4 months. The mean post-treatment hearing preservation rate was 69.23 per cent. There was no significant relationship between hearing loss after treatment and patient age, radiation dosage during treatment, or size of tumour. With regard to auditory brainstem responses, patients with hearing loss following treatment had a significantly higher inter-peak latency between waves I-III than patients with preserved hearing. Stereotactic CyberKnife radiosurgery is an excellent alternative treatment modality for patients with vestibular schwannoma, and results in acceptable preservation of hearing. Residual hearing following CyberKnife therapy is not significantly affected by factors such as age, size of tumour or dosage of treatment.

Application of cyberknife in treatment of retroperitoneal lymph node metastatic tumors in 81 cases

Objective To evaluate the clinical efficacy and side effects of cyberknife therapy in the treatment of retroperitoneal lymph node metastatic tumor. Methods Among the 81 patients presenting with postoperative retroperitoneal lymph node metastases, 33 cases suffered from abdominal pain or low back pain, 7 had unilateral hydronephrosis and ureteral dilatation, and 8 developed unilateral or bilateral lower limb swelling. Using stereotactic radiotherapy with a cyberknife, DT was delivered at 33-45 Gy/3-6 F. The improvement of symptoms, objective tumor response rate, and irradiation-induced side effects were observed. Results At 4 weeks after treatment, pain and swelling of the lower extremities were completely mitigated, and hydronephrosis was fully healed in all patients. Enhanced CT or MRI was performed every 2 to 3 months. After 6-month follow-up, the complete response (CR) rate was calculated as 77%(62/81), 21%(17/81) for the partial response (PR) rate, 3%(2/81) for the stable disease (SD) rate and the effective rate (CR+ PR) was 98%.No case progressed. The main side effect was intestinal injury, including grade 1 in 16%(13/81), grade 2 in 9%(7/81). Multivariate analysis demonstrated the CR rate was not correlated with the type of the primary tumor or the size of the tumor (P>0.05), but was significantly associated with the distance of>0.5 cm between the tumor and intestine and the BED (α/β=10)>70 Gy of the tumor irradiation (P 5 cm and the distance of<0.5 cm between the tumor and intestine (P<0.01). Conclusion Cyberknife is an efficacious and safe approach in the treatment of retroperitoneal lymph node metastatic tumors. Key words: Retroperitoneal lymph node metastatic neoplasms/stereotactic radiotherapy; Radiotherapy, cyber knife

Stereotactic body radiotherapy using the CyberKnife® system in the treatment of patients with liver metastases: state of the art.

BackgroundThe management of patients with liver metastases presents a challenging problem in clinical oncology. Patients with limited involvement of the liver may be suitable for surgical resection or local ablative techniques. Stereotactic body radiotherapy (SBRT) presents an emerging new technology that has shown high efficacy in ablating tumors at various disease sites.MethodsA comprehensive literature search was performed to identify articles in regard to the SBRT in the treatment of patients with liver metastases.ResultsSBRT allows for the delivery of high-dose radiation in few fractions to the tumor with extreme accuracy, while minimizing the damage to normal surrounding tissue. The CyberKnife® system is an image-guided robotic system that delivers SBRT, tracks tumors during respiration, and automatically adjusts treatment for any patient movement. The most frequently used indications for CyberKnife® therapy are ≤5 liver metastases with maximum tumor sizes of 6 cm, no extrahepatic disease, good performance status, and adequate hepatic functions. Local control rates range from 70%–100% at 1 year and from 60%–90% at 2 years. Severe toxicity related to SBRT is uncommon – grade three side effects occur in less than 5% of cases. Despite excellent local control rates, out-of-field metastatic progression (out-of-field hepatic metastases and extrahepatic metastases) develops in a substantial proportion of patients after SBRT. Therefore, it seems essential to improve the selection of patients with liver metastases for SBRT.ConclusionThe CyberKnife® system presents an effective minimally invasive treatment modality for patients with hepatic oligometastases who are not suitable candidates for radical liver resection. The available data suggest that liver metastases can be treated by CyberKnife therapy with very low toxicity and excellent local control rates.

Cyberknife therapy for locally recurrent gynecologic cancers after external-beam radiation therapy

Cyberknife therapy for locally recurrent gynecologic cancers after external-beam radiation therapy

Cyberknife therapy for locally recurrent gynecologic cancers after external-beam radiation therapy

Cyberknife therapy for locally recurrent gynecologic cancers after external-beam radiation therapy

Symptom experience and needs of spinal tumor patients with esophagus mucositis treated by Cyberknife: a qualitative study

Objective To explore the symptom experience and nursing needs of spinal tumor patients with esophagus mucositis treated by Cyberknife. Methods From May to November 2017, we selected 9 spinal tumor patients treated by Cyberknife of Peking University Third Hospital as subjects by convenience sampling. All of the patients were interviewed by telephone. These data were analyzed with the phenomenological approach of the qualitative study. Results A total of four themes were refined including the esophagus mucositis-correlated symptoms were obvious during Cyberknife therapy, the esophagus mucositis during Cyberknife therapy affected the patients' psychology and treatment progress, the esophagus mucositis during Cyberknife therapy affected taking food, weight and nutrition of patients, patients thought that it was necessary for health care providers to provide patients the esophagus mucositis-correlated professional guidance and late follow-up during and after Cyberknife therapy. Conclusions The radioactive esophagus mucositis has a great influence on patients' physiology and psychology. Health care providersshould strengthen the related guidance and follow-up for patients during and after Cyberknife therapy. Key words: Spine; Cyberknife; Esophagus mucositis; Qualitative study

Effects of two medicines for prevention of acute radiation skin injury in radiation field among liver cancer patients with Cyberknife therapy

Objective To explore the protective effect of DWK skin protectant and Sanyrene for prevention of acute radiation skin injury in radiation field among liver cancer patients with Cyberknife therapy. Methods A total of 100 liver cancer patients with Cyberknife therapy were selected by convenience sampling from March to November 2016. They were randomly divided into the group of DWK and the group of Sanyrene with 50 cases in each group. Skins in radiation field on hepatic region of patients in two groups used DWK skin protectant and Sanyrene respectively since one day before radiotherapy. The acute radiation skin injury of radiation field on hepatic region was observed from one day before treatment to two weeks the end of treatment during Cyberknife therapy. Results The scores of The Radiation Induced Skin Reaction Assessment Scale (RISRAS) , an instrument for assessing the degree of acute radiation skin injury of radiation field on hepatic region, of patients in two groups increased with the increasing cumulated dose of irradiation with significant differences (F=3.780, 12.325; P<0.05) . There were statistically significant differences in evaluations at the fifth and beyond between two groups (t=5.213, 12.437, 16.846; P<0.05) . Conclusions Intervention for local prevention can alleviate the acute radiation skin injury in radiation field on hepatic region among liver cancer patients with Cyberknife therapy. The protective effect of DWK skin protectant on skin in radiation field on hepatic region among liver cancer patients with Cyberknife therapy is better than that of Sanyrene. Key words: Liver neoplasms; Cyberknife; Radiation damage; Skin protection

Surgical Management of Extracranial Meningiomas Arising in the Head and Neck

To determine outcomes in the management of extracranial meningiomas of the head and neck. This is a retrospective single-surgeon series performed at a tertiary-care referral center. In all, 23 patients met the inclusion criteria, consisting of 12 men and 11 women. The mean age of patients treated was 60.5years (range, 32 to 71years). Subsite involvement included the infratemporal fossa (n= 8), greater wing of the sphenoid and orbit (n= 7), clivus (n= 2), and parapharyngeal space (n= 6). In all, recurrence occurred in 21% of patients (n= 5) who underwent gross tumor resection. Two patients underwent subtotal resection because of the tumor's location within the clivus with adjuvant CyberKnife therapy (Accuray, Sunnyvale, CA). Both patients had persistent disease with no new neurologic symptoms. Examination showed that 100% of patients (N= 23) had dural involvement. Post-ablative complications occurred in 43% of patients (n= 10). We presently report the largest series of surgical treatment for extracranial meningiomas. Gross tumor resection should be the mainstay of therapy, except in anatomically restricted regions such as the petrous apex and clivus. Adjuvant therapy including CyberKnife therapy may be used in such lesions. All lesions showed dural involvement. A more unified nomenclature is required for the characterization of these lesions.