LINAC stereotactic radiosurgery for trigeminal neuralgia -retrospective two-institutional examination of treatment outcomes

Frameless image-guided linear accelerator (LINAC) stereotactic radiosurgery for medically refractory trigeminal neuralgia: Clinical outcomes in 116 patients

Background

Frameless image-guided radiosurgery (IGRS) is an effective and non-invasive method of treating patients who are unresponsive to medical management for trigeminal neuralgia (TN). This study evaluated the use of frameless IGRS to treat patients with medically refractory TN.

Methods

We performed a retrospective review of records of 116 patients diagnosed with TN who underwent frameless IGRS using a linear accelerator (LINAC) over 10 years (March 2012-February 2023). All patients had failed medical management for TN. Facial pain was graded using the Barrow Neurological Institute (BNI) scoring system. Each patient received a BNI score before frameless IGRS and following treatment. Failure was defined as a BNI score IV-V at the last follow-up and/or undergoing a salvage procedure following IGRS.

Results

All patients had a BNI score of either IV or V before the frameless IGRS. The mean follow-up duration for all 116 patients following IGRS was 44.1 months. Most patients (81 [69.8%]) had not undergone surgery (microvascular decompression [MVD] or rhizotomy) or stereotactic radiosurgery (SRS) for TN before frameless IGRS. A total of 41 (35.3%) patients underwent a salvage procedure (MVD, rhizotomy, or an additional IGRS) following frameless IGRS. The mean duration between the initial frameless IGRS and salvage procedure was 20.1 months. At the last follow-up, a total of 110 (94.8%) patients had a BNI score of I-III. No complications were reported after the frameless IGRS. The BNI score at the last follow-up was lower compared to the initial BNI for patients regardless of prior intervention (P < 0.001). Patients who failed IGRS had a higher BNI score at the last follow-up compared to those who did not fail IGRS (2.8 vs. 2.5, P = 0.05). Patients with pain relief had a shorter follow-up compared to those with pain refractory to SRS (38.0 vs. 55.1, P = 0.005).

Conclusion

In this large cohort of patients with medically refractory TN, frameless IGRS resulted in durable pain control in the majority of patients without any toxicity.

[Frameless trigeminal neuralgia radiosurgery with a dedicated linear accelerator: From equipment commissioning to initial clinical results]

PURPOSE

Radiosurgery for the treatment of trigeminal neuralgia delivers a very high dose in a single fraction, over a few millimeters, at a single isocenter placed along the nerve. We present here the different steps that have been performed to validate small beams by conical collimators, and report the clinical results of the first patients treated on Novalis Tx®, frameless.

MATERIAL AND METHODS

First, the geometric accuracy of 4 and 6mm conical collimators was evaluated using Winston-Lutz tests; then dosimetric data acquisition was performed using high spatial resolution detectors (PTW 60019 microdiamond and a PTW 60017 E-diode). The corrective factors of the TRS 483 report were applied to calculate the collimator aperture factors. These dosimetric data were then compared with the data implemented in the iPlan® treatment planning system. Then end-to-end tests were performed to control the entire treatment process using an anthropomorphic phantom "STEEV". Between 2020 and 2022, 18 patients were treated for refractory trigeminal neuralgia on Novalis Tx®, frameless, with Exactrac® repositioning. A total of 17 patients were evaluated (one was lost to follow-up) using the BNI score for pain assessment and MRI with a median follow-up of 12 months.

RESULTS

The quality criteria of geometric and dosimetric accuracy were met for the 6-mm cone but not for the 4-mm cone. All patients were treated with a 6-mm cone with a dose of 90Gy prescribed at the isocenter at the root entry zone. Initial pain control was obtained in 70.5% of our patients, and 53% maintained pain control with a median follow-up of 12 months. All recurrences occurred within 3 to 6 months after radiosurgery. No brainstem toxicity was observed. Six patients had non-disabling facial hypoesthesia, half of whom already had pretreatment hypoesthesia.

CONCLUSION

The treatment of trigeminal neuralgia on a dedicated linear accelerator is a highly technical treatment whose accuracy and safety are paramount. The physical measurements allowed the commissioning of the technique with a 6mm cone. Our first clinical results are in accordance with the literature.

Pain Relief-Related Structural Brain Alterations in Trigeminal Neuralgia Induced by Noninvasive Stereotactic Radiosurgery: A Pilot Study

PURPOSE

Trigeminal neuralgia (TN) is a chronic pain disorder defined by unilateral shock-like pain in at least one division of the trigeminal nerve. Although several studies have investigated structural brain plasticity in patients with TN, treatment-induced alterations remain largely uninvestigated.

METHODS AND MATERIALS

Combining T1-weighted magnetic resonance imaging with voxel-based morphometry and multiple-regression analyses, we assessed gray matter maps of patients with TN to investigate changes in gray matter volume (GMV) before and 6 months after stereotactic radiosurgery (SRS).

RESULTS

Comparison of pre- and post-SRS GMV of 25 patients with TN (16 women; mean age 67 years) did not yield any significant clusters, suggesting that the effect of SRS intervention itself on gray matter structure may be negligible. Regarding SRS-induced pain relief, we found a significant GMV increase in the left superior frontal gyrus associated with greater degree of pain relief (P = .024) and a trend toward an increase in GMV in the left dorsolateral prefrontal cortex (P = .097).

CONCLUSIONS

In this pilot study, we observed significant increases in GMV in the left superior frontal gyrus with SRS-induced improvements in pain and a trend toward an increase in GMV in the dorsolateral prefrontal cortex. Future studies are indicated to validate these findings and determine whether SRS-induced decrease in distracting pain events and subsequent increases in GMV result in improved functionality, decreased dependence on "top-down" control, and improved cognitive/executive balance with amelioration of pain events.

Application value of calcium phosphate cement in complete cranial reconstructions of microvascular decompression craniectomies

OBJECTIVE

To investigate the application value of calcium phosphate cement (CPC) in repairing cranial defects during microvascular decompression (MVD) surgery via the retrosigmoid approach.

METHODS

A retrospective study was carried out on patients who underwent MVD. According to the two different cranial reconstruction methods, patients were divided into a titanium mesh (TM) group and a CPC group. We compared in the two groups the length of postoperative hospital stay, the incidence of postoperative cerebrospinal fluid (CSF) leakage, the number of patients with suspected postoperative intracranial infection who underwent lumbar puncture, the number of patients with a definitive etiologic diagnosis of intracranial infection, and the imaging evaluation of plastic shape satisfaction.

RESULTS

Patients in the CPC group had an average hospital stay of 9.15 ± 2.00 days, shorter than that in the TM group (10.69 ± 2.86 days), P < 0.001. In the TM group, the rate of plasticity satisfaction was 70/89 (78.65%), which was significantly lower than that in the CPC group (60/66, 90.91%), P = 0.040. Among the patients with a definitive etiologic diagnosis of intracranial infection, there were eight cases in the TM group and one case in the CPC group, and the difference was statistically significant, P = 0.049.

CONCLUSIONS

CPC is another viable alternative for complete cranial reconstructions of microvascular decompression craniectomies. The use of CPC does not increase the incidence of postoperative complications, such as CSF leakage and intracranial infection, and can reduce the average length of hospital stay and the incidence of etiologic diagnosis of intracranial infection. Furthermore, the evaluation of the plastic shape is satisfactory.

High-Dose Frameless Stereotactic Radiosurgery for Trigeminal Neuralgia: A Single-Institution Experience and Systematic Review

OBJECTIVE

Stereotactic radiosurgery is an effective treatment option for trigeminal neuralgia (TN), with frameless stereotactic radiosurgery (fSRS) allowing for a less invasive experience. A single-institutional series and systematic review of the literature were performed for cases of TN treated with fSRS.

METHODS

Patients at our institution with TN that were treated with fSRS from the years 2012-2021 were included. Similarly, multiple databases were searched for studies regarding TN treated with fSRS where patient-level data was included from 2004-2020. Pain levels, via the Barrow Neurological Institute (BNI) scale, before and after treatment were analyzed. Pooled analysis was performed to compare treatment outcomes between studies using CyberKnife and LINAC modalities.

RESULTS

Twenty-three patients at our institution were treated with LINAC fSRS (median treatment dose: 85 Gy). Most patients had TN refractory to previous procedural treatments. Eight (35%) patients had an excellent posttreatment response (BNI I-II), while 11 (48%) patients had a good result (BNI IIIa/b). Eight patients had recurrence of pain. A total of 30 articles were included in the systematic review, encompassing 1705 patients. At last follow-up, 63.1% (774/1227) of patients endorsed an excellent response, while 16.1% (197/1227) had a good response, and 22.5% (215/957) of patients had recurrence. Pain response, facial numbness rates, and pain recurrence rates were not significantly different between CyberKnife and LINAC modalities.

CONCLUSIONS

Frameless SRS for TN appears to be an efficacious noninvasive option for patients with substantial comorbidities, who have failed other treatment methods, although it can be limited by higher recurrence rates.

Non-Oncological Radiotherapy: A Review of Modern Approaches

Despite being usually delivered in oncological patients, radiotherapy can be used as a successful treatment for several non-malignant disorders. Even though this use of radiotherapy has been scarcely investigated since the 1950s, more recent interest has actually shed the light on this approach. Thus, the aim of this narrative review is to analyze the applications of non-oncological radiotherapy in different disorders. Key references were derived from a PubMed query. Hand searching and clinicaltrials.gov were also used. This review contains a narrative report and a critical discussion of non-oncological radiotherapy approaches. In conclusion, non-oncological radiotherapy is a safe and efficacious approach to treat several disorders that needs to be further investigated and used in clinical practice.

Region-of-interest intra-arc MV imaging to facilitate sub-mm positional accuracy with minimal imaging dose during treatment deliveries of small cranial lesions

Purpose

To automate the generation of region‐of‐interest (ROI) apertures for use with megavoltage imaging for online positional corrections during cranial stereotactic radiosurgery.

Materials and methods

Digitally reconstructed radiographs (DRRs) were created for a 3D‐printed skull phantom at 5 degree gantry angle increments for a three‐arc beam arrangement. At each angle, 3000 random rectangular apertures were generated, and 100 shifts on a grid were applied to the anatomy within the frame. For all shifts, the mutual information (MI) between the shifted and unshifted DRR was calculated to derive an average MI gradient. The top 10% of apertures that minimized registration errors were overlaid and discretely thresholded to generate imaging plans. Imaging was acquired with the skull while implementing simulated patient motion on a linac. Control point‐specific couch motions were derived to align the skull to its planned positioning.

Results

Apertures with a range of repositioning errors less than 0.1 mm possessed a 42% larger average MI gradient when compared with apertures with a range greater than 1 mm. Dose calculations with Monte Carlo exhibited an 84% reduction in the dose received by 50% of the skull with the 50% thresholded plan when compared to a constant 22 × 22 cm² imaging plan. For all different imaging plans (with and without motion), the calculated median 3D‐errors with respect to the tracking of a metal‐BB fiducial positioned at isocenter in the skull were sub‐mm except for the 80% thresholded plan.

Conclusions

Sub‐mm positional errors are achievable with couch motions derived from control point–specific ROI imaging. Smaller apertures that conform to an anatomical ROI can be utilized to minimize the imaging dose incurred at the expense of larger errors.

Comparison of survival outcomes after CyberKnife® radiotherapy in Taiwan using preapproved insurance-based reimbursement versus out-of-pocket expenditure

BACKGROUND

With technological advances, radiotherapy has progressed from simple irradiation to robotic arm-based stereotactic radiosurgery systems (SRS, in this case, CyberKnife®). This equipment is high-priced and might be cost-effective or not. The National Health Insurance (NHI) in Taiwan has a premedical claims review process for approving CyberKnife® treatment; however, patients might have to pay for the procedure themselves if the NHI rejects the practice. Under the high treatment cost and such an insurance system, a sketch of patients treated by these high-cost machines and whether the prereview of insurance for reimbursement is reasonable without hindering the patient's right to undergo treatment should be investigated. In this study, the patients of CyberKnife® radiotherapy in our institute were investigated as an example for this purpose.

METHODS

Patients who underwent CyberKnife® radiotherapy in our department were investigated retrospectively. Their demographic characteristics, disease patterns, and treatment sites were analyzed. Survivals were compared according to clinical features, and treatment expenses were reimbursed after prereview or out-of-pocket.

RESULTS

From October 19, 2014, to January 30, 2018, there were 331 patients included in this study, 205 (55.3%) of whom underwent CyberKnife® radiotherapy at their own expense, while 166 (44.7%) had their expenses approved for reimbursement after prereview by NHI. Most patients were treated for metastatic tumors (37.5%), and the brain was the most frequent treatment site (46.1%). The 1-year overall survival was 67.1%, and the 2-year overall survival was 56.3% after CyberKinfe® radiotherapy. The best survival rate (96.8% at 1 year) was for patients with brain tumors. In patient's characteristics, A better Eastern Cooperative Oncology Group (ECOG) performance status, treatment for primary tumors, and outpatient treatment were independent factors for superior survival after CyberKnife® radiotherapy. The survivals for patients whose treatment expenses were approved for reimbursement after prereview by NHI were also better than out-of-pocket.

CONCLUSIONS

Besides the patients' characteristics, the treatment expense could be approved or rejected for reimbursement by the NHI prereview was an independent factor for survival in CyberKnife® radiotherapy. Prereview to reimburse expensive treatment is not an unreasonable requirement.

Outcomes using linear accelerator stereotactic radiosurgery for the treatment of trigeminal neuralgia: A single-center, retrospective study

Background:

Linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) treatment of trigeminal neuralgia (TN) may have similar efficacy to Gamma Knife SRS (GK-SRS), but the preponderance of data comes from patients treated with GK-SRS. Our objective was to analyze the outcomes for LINAC-based treatment of TN in patients at our institution.

Methods:

We retrospectively analyzed data for patients who underwent LINAC-based SRS for TN from 2006 to 2018. Data were collected from the patients’ medical records. Nonparametric statistics were used for the analysis.

Results:

Of the 41 patients treated with LINAC-based SRS (typically 90 Gy dosed using a 4 mm collimator for one fraction) during that time, follow-up data of >3 weeks post-SRS were available for 32 patients. The median pretreatment Barrow Neurological Institute (BNI) pain score was 5 (range 4–5). The follow-up period ranged from 0.9 to 113.2 months (median 5 months). There was significant improvement in postradiation BNI pain score (P < 0.001), with 23 (72%) patients who improved to a BNI pain score of 1–3. One patient had bothersome hypoesthesia postradiation. Approximately 38% of patients who had initial pain control had recurrence of symptoms (BNI > 3). Survival analysis showed a median time to pain recurrence of 30 months. There was no relationship between prior microvascular decompression (MVD) surgery and change in BNI pain score pre- to posttreatment.

Conclusion:

The results demonstrate that LINAC-based SRS is an effective means to treat TN. Prior MVD surgery did not affect efficacy of SRS in lowering the BNI score from pre- to posttreatment in this patient cohort.

Investigating the impacts of intrafraction motion on dosimetric outcomes when treating small targets with virtual cones

Purpose

Intrafraction patient motion is a well‐documented phenomenon in radiation therapy. In stereotactic radiosurgery applications in which target sizes can be very small and dose gradients very steep, patient motion can significantly impact the magnitude and positional accuracy of the delivered dose. This work investigates the impact of intrafraction motion on dose metrics for small targets when treated with a virtual cone.

Materials and Methods

Monte Carlo simulations were performed to calculate dose kernels for treatment apertures ranging from 1 × 2.5 mm² to 10 × 10 mm². The phantom was an 8.2‐cm diameter sphere and isotropic voxels had lengths of 0.25 mm. Simulated treatments consisted of 3 arcs: 1 axial arc (360° gantry rotation, couch angle 0°) and 2 oblique arcs (180° gantry rotation, couch angle ±45°). Dose distributions were calculated via superposition of the rotated kernels. Two different collimator orientations were considered to create a virtual cone: (a) each treatment arc was delivered twice, once each with a static collimator angle of ±45°, and (b) each treatment arc was delivered once, with dynamic collimator rotation throughout the arc. Two different intrafraction motion patterns were considered: (a) constant linear motion and (b) sudden, persistent motion. The impact of motion on dose distributions for target sizes ranging from 1 to 10 mm diameter spheres was quantified as a function of the aperture size used to treat the lesions.

Results

The impact of motion on both the target and the surrounding tissue was a function of both aperture shape and target size. When a 0.5‐mm linear drift along each dimension occurred during treatment, targets ≥5 mm saw less than a 10% decrease in coverage by the prescription dose. Smaller apertures accrued larger penalties with respect to dosimetric hotspots seen in the tissues surrounding the target volume during intrafraction motion. For example, treating a 4‐mm‐sized target that undergoes 2.60 mm (3D vector) of continuous linear motion, the D₅ in the concentric shells that extend 1, 2, and 3 mm from the surface of the target was 39%, 24%, and 14% smaller, respectively when comparing the delivery of a larger aperture (6 × 10 mm²) to a smaller aperture (2 × 5 mm²). Using a static collimator for shaping a virtual cone during treatment minimized the dosimetric impact of motion in the majority of cases. For example, the volume that is covered by 70% or more of the prescription dose is smaller in 60.4% of cases when using the static collimator. The volume covered by 50, and 30% or more of the prescription dose is also smaller when treating with a static collimator, but the clinical significance of this finding is unknown.

Conclusions

In this work, the dosimetric trade‐offs between aperture size and target size when irradiating with virtual cones has been demonstrated. These findings provide information about the tradeoffs between target coverage and normal tissue sparing that may help inform clinical decision making when treating smaller targets with virtual cones.

Radiotherapy of non-tumoral refractory neurological pathologies

Intracranial radiotherapy has been improved, primarily because of the development of stereotactic approaches. While intracranial stereotactic body radiotherapy is mainly indicated for treatment of benign or malignant tumors, this procedure is also effective in the management of other neurological pathologies; it is delivered using GammaKnife® and linear accelerators. Thus, brain arteriovenous malformations in patients who are likely to experience permanent neurological sequelae can be managed by single session intracranial stereotactic body radiotherapy, or radiosurgery, in specific situations, with an advantageous benefit/risk ratio. Radiosurgery can be recommended for patients with disabling symptoms, which are poorly controlled by medication, such as trigeminal neuralgia, and tremors, whether they are essential or secondary to Parkinson's disease. This literature review aims at defining the place of intracranial stereotactic body radiotherapy in the management of patients suffering from non-tumoral refractory neurological pathologies. It is clear that the multidisciplinary collaboration of experienced teams from Neurosurgery, Neurology, Neuroradiology, Radiation Oncology and Medical Physics is needed for the procedures using high precision radiotherapy techniques, which deliver high doses to locations near functional brain areas.

Optimizing Radiosurgery for Trigeminal Neuralgia: Impact of Radiation Dose and Anatomic Target on Patient Outcomes

OBJECTIVE

Radiosurgery is an increasingly popular treatment for trigeminal neuralgia (TN); however, several treatment variables require further study. This meta-analysis was conducted to clarify ambiguity in the literature and optimize treatment parameters.

METHODS

A random-effects proportions meta-analysis using subgroup analysis and meta-regression investigated the association of prescription dose and anatomic target on outcomes in patients with typical TN. The PRISMA guidelines were used. Radiation doses used ranged from 70 to 90 Gy and the anatomic targets were either the root entry zone or a more distal nerve location. Outcome measures were pain at last follow-up and the development of bothersome numbness.

RESULTS

Increasing radiation prescription dose was associated with improved outcomes across all analyzed doses (P < 0.001). Patients treated at a distal trigeminal nerve target had better pain control compared with a root entry zone target (P < 0.001). Despite a higher median dose, a distal target was independently associated with improved pain control. There were similar rates of bothersome numbness across radiation doses and both treatment targets.

CONCLUSIONS

Higher radiation dose was associated with superior pain control without increasing bothersome numbness. Independent of dose, the distal target was also associated with improved pain control. Bothersome numbness was not related to dose or target.

Microvascular Decompression versus Stereotactic Radiosurgery for Trigeminal Neuralgia: A Single-Institution Experience

OBJECTIVE

Microvascular decompression (MVD) is the standard surgical procedure for patients with medically refractory trigeminal neuralgia (TN). Stereotactic radiosurgery (SRS) has gained increasing popularity as a less invasive technique. We report our institution's outcome in the surgical treatment of TN (MVD vs. SRS), taking patient's age and gender into consideration.

METHODS

We retrospectively reviewed a prospectively collected database of patients undergoing MVD or SRS for type 1 idiopathic TN between 2004 and 2019 at the University of Iowa. Standardized data collection focused on preoperative clinical characteristics and postoperative outcomes including the Barrow Neurological Institute (BNI) Pain Intensity Score.

RESULTS

A total of 111 patients underwent MVD and 103 patients underwent SRS for TN. Patients were younger in the MVD (median, 60 years) than SRS (median, 72 years) group. More females (58%) than males (42%) had TN. Multivariate ordinal regression analysis showed that an outcome of BNI score I-II (P = 0.365) and III (P = 0.736) can be achieved with either MVD or SRS; however, BNI score IV (P = 0.031) and V (P = 0.022) were more associated with SRS. Six percent of patients in the MVD group and 26% in the SRS group developed pain recurrence and required a second operation. Nine of 10 patients who underwent MVD after failed SRS had complete pain relief.

CONCLUSIONS

Factoring in patients' age and gender, both MVD and SRS can achieve a favorable outcome for medically refractory TN, although BNI scores of IV and V were more common with SRS.

Treatment Outcomes in Trigeminal Neuralgia-A Systematic Review of Domains, Dimensions and Measures

BACKGROUND

Trigeminal neuralgia (TN) is a painful disorder characterized by sudden electric shock-like pain. It is a rare condition for which multiple treatments are available, including medical and surgical. The best treatment option is yet to be defined, and this is related to the lack of definition in the treatment outcomes and outcome measures. The aim of this systematic review was to summarize all the outcomes and outcomes measures that have been published to date and highlight variability in their use.

METHODS

We have conducted a literature search using a wide range of databases (1946-2019 for medical and 2008-2019 for surgical treatment), for all intervention studies in TN. Four hundred and sixty-seven studies were selected for data extraction on TN classification, data collection method, intervention, and treatment outcomes mapped to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT guidelines).

RESULTS

Most studies collected data on pain (n = 459) and side effects (n = 386) domains; however, very few collected data on the impact of treatment on physical (n = 46) and emotional functioning (n = 17) and on patient satisfaction (n = 35). There was high variability on outcome measures used for pain relief (n = 10), pain intensity (n = 9), and frequency of pain episodes (n = 3).

CONCLUSIONS

A clear definition of what are the important outcomes for patients with TN is essential. The choice of standardized outcome measures allowing for consistent reporting in TN treatment will allow for comparison of studies and facilitate treatment choice for patients and clinicians thus, improving health outcomes and reducing health care cost.

Minimally invasive trigeminal ablation in patients with refractory trigeminal neuralgia who are ineligible for intracranial intervention

We describe the use of minimally invasive trigeminal ablation, an endoscopic ablative technique to treat trigeminal neuralgia in patients who are traditionally poor surgical candidates. We present 4 patients who presented with refractory unilateral trigeminal neuralgia. Three of the patients had previously failed stereotactic radiosurgery and three of them have multiple sclerosis. Due either to lack of neurovascular compression, minimally invasive trigeminal ablation was offered. Intraoperatively, an incision is made along the buccal mucosa or mid-brow and the tissue is endoscopically dissected in a plane towards the symptomatic nerve. Once isolated, the epineurium is partially ablated with thermocautery and the tissue surrounding the nerve is decompressed. All patients reported resolution of their pain post-operatively and were pain free at last follow up. Two patients had mild hypesthesia over the ablated nerve territory. Minimally invasive trigeminal ablation is a safe and effective technique for symptomatic control of trigeminal neuralgia. The efficacy, low risk, and relative ease of the procedure makes it ideal for use in patients who are refractory to medical management and have no neurovascular compression, are unable to tolerate traditional surgery or have failed other therapies.

Gamma Knife Radiosurgery for Trigeminal Neuralgia: A Comparison of Dose Protocols

Purpose: A variety of treatment plans including an array of prescription doses have been used in radiosurgery treatment of trigeminal neuralgia (TN). However, despite a considerable experience in the radiosurgical treatment of TN, an ideal prescription dose that balances facial dysesthesia risk with pain relief durability has not been determined. Methods and Materials: This retrospective study of patients treated with radiosurgery for typical TN evaluates two treatment doses in relation to outcomes of pain freedom, bothersome facial numbness, and patient satisfaction with treatment. All patients were treated with radiosurgery for intractable and disabling TN. A treatment dose protocol change from 80 to 85 Gy provided an opportunity to compare two prescription doses. The variables evaluated were pain relief, treatment side-effect profile, and patient satisfaction. Results: Typical TN was treated with 80 Gy in 26 patients, and 85 Gy in 37 patients. A new face sensory disturbance was reported after 80 Gy in 16% and after 85 Gy in 27% (p = 0.4). Thirteen failed an 80 Gy dose whereas seven failed an 85 Gy dose. Kaplan–Meier analysis found that at 29 months 50% failed an 80 Gy treatment compared with 79% who had durable pain relief after 85 Gy treatment (p = 0.04). Conclusion: The 85 Gy dose for TN provided a more durable pain relief compared to the 80 Gy one without a significantly elevated occurrence of facial sensory disturbance.