How to manage a ureteral injury after anterior lumbar spine interbody fusion surgery

BACKGROUND

Anterior lumbosacral interbody fusion (ALIF) surgery is a predominant approach used in various indications such as treating discogenic back pain, spondylolisthesis, degenerative lumbar scoliosis, intervertebral foraminal stenosis, or spondylolysis. In comparison with posterior conventional approach, ALIF surgery has several advantages: direct access to the spine without muscle dissection, reduced blood loss, decreased postoperative pain, and improved fusion rates. Rare complications following ALIF surgery need to be reported, therefore the authors present an uncommon case of a ureteral injury diagnosed early after surgery and its management.

MANAGEMENT OF A URINOMA

Herein, we present a case of a 35-year-old man who presented with abnormal abdominal pains 4 days after ALIF surgery. He was diagnosed with a distal left iatrogenic ureteral fistula on a contrast enhanced CT. After the initial endoscopic approach with double J stent and urinary catheter drainage insertion had failed, the injury was finally treated with ureterovesical reimplantation. At the last follow-up, the patient did well without any clinical or biological urinary sequelae after this grade IIIb complication on the Clavien Dindo Scale.

CONCLUSION

Although ureteral lesions during ALIF surgery are extremely uncommon, surgeons must be cautious when dissecting the retroperitoneal area. A methodical identification of the ureter might guarantee the security of each surgery, especially for patients who have undergone previous abdominal interventions.

Combined use of intraoperative MRI and awake tailored microsurgical resection to respect functional neural networks: preliminary experience

INTRODUCTION

The combined use of intraoperative MRI and awake surgery is a tailored microsurgical resection to respect functional neural networks (mainly the language and motor ones). Intraoperative MRI has been classically considered to increase the extent of resection for gliomas, thereby reducing neurological deficits. Herein, we evaluated the combined technique of awake microsurgical resection and intraoperative MRI for primary brain tumours (gliomas, metastasis) and epilepsy (cortical dysplasia, non-lesional, cavernomas).

PATIENTS AND METHODS

Eighteen patients were treated with the commonly used "asleep awake asleep" (AAA) approach at Lille University Hospital, France, from November 2016 until May 2020. The exact anatomical location was insular with various extensions, frontal, temporal or fronto-temporal in 8 (44.4%), parietal in 3 (16.7%), fronto-opercular in 4 (22.2%), Rolandic in two (11.1%), and the supplementary motor area (SMA) in one (5.6%).

RESULTS

The patients had a mean age of 38.4 years (median 37.1, range 20.8-66.9). The mean surgical duration was 4.1 hours (median 4.2, range 2.6-6.4) with a mean duration of intraoperative MRI of 28.8 minutes (median 25, range 13-55). Overall, 61% (11/18) of patients underwent further resection, while 39% had no additional resection after intraoperative MRI. The mean preoperative and postoperative tumour volumes of the primary brain tumours were 34.7 cc (median 10.7, range 0.534-130.25) and 3.5 cc (median 0.5, range 0-17.4), respectively. Moreover, the proportion of the initially resected tumour volume at the time of intraoperative MRI (expressed as 100% from preoperative volume) and the final resected tumour volume were statistically significant (p= 0.01, Mann-Whitney test). The tumour remnants were commonly found posterior (5/9) or anterior (2/9) insular and in proximity with the motor strip (1/9) or language areas (e.g. Broca, 1/9). Further resection was not required in seven patients because there were no remnants (3/7), cortical stimulation approaching eloquent areas (3/7) and non-lesional epilepsy (1/7). The mean overall follow-up period was 15.8 months (median 12, range 3-36).

CONCLUSION

The intraoperative MRI and awake microsurgical resection approach is feasible with extensive planning and multidisciplinary collaboration, as these methods are complementary and synergic rather than competitive to improve patient oncological outcomes and quality of life.

Minimally Invasive Approach for Dorsal Arachnoid Web: 2-Dimensional Operative Video

A 67-yr-old patient presented with severe paraparesis and lower limb spasticity. The spinal cord magnetic resonance imaging (MRI) revealed the "scalpel sign" 1,2 at the T7 level, suggesting a diagnosis of a dorsal arachnoid web. This video demonstrates a microsurgical technique for the excision of a dorsal arachnoid web with a minimally invasive approach. A paramedian skin incision, understanding the muscular aponeurosis, was performed from T7 to T8. Then, we inserted the tubular dilators until the lamina, to perform a muscle-sparing approach. An expandable tubular retractor of adequate length was passed over the widest dilator and docked into place along the subperiosteal plane. The T7 lamina was drilled, and the resection of the superior and inferior adjacent spine levels was completed with a rongeur. Additional contralateral bone resection was performed after tubular retractor tilt to the midline.3 After dura mater opening, it was carefully suspended and the dorsal arachnoid leaflet was cut to drain the dorsolateral and lateral spinal cisterns.4 The dorsal arachnoid web was, first, disconnected from its lateral anchorages. It was then gently removed with microsurgical forceps, to help its microdissection from the spinal cord surface. At this step, peculiar attention was paid to limit the traction or displacements of the spinal cord and surrounding vessels. Once the dorsal arachnoid web was removed, the quality of the spinal cord decompression was confirmed by its re-expansion. In conclusion, the minimally invasive approach is a safe and appropriate technique for dorsal arachnoid web excision.2,5,6-7  The patient gave her informed and signed consent for the writing and publication of this article.  Image at 1:00 reused with permission from Castelnovo G et al, Spontaneous transdural spinal cord herniation, Neurology, 2014;82(14):1290.

Management of symptomatic postoperative epidural hematoma in spine surgery: Medicolegal implications

INTRODUCTION

Spine surgery is one of the specialties with the highest medicolegal risk, with a legal action initiated every 17 months per practitioner. One of the most dreaded complications is an epidural hematoma with postoperative deficit. The treatment of this complication is still being debated. We therefore conducted a retrospective study of the database of a medical liability insurer to assess perioperative factors determining the liability of the surgeon or paramedical team during an expert review in the event of a postoperative symptomatic epidural hematoma.

HYPOTHESIS

To identify the factors determining the liability of the medical team in the event of a postoperative symptomatic epidural hematoma.

MATERIALS AND METHODS

We retrospectively analyzed the largest French register of medicolegal expert reviews between 2011 and 2018. We identified 68 cases by entering the following keywords in this database: "spine surgery," "complications," and "epidural hematoma." After a thorough review of each case, only 14 were deemed to be truly relevant to our study. We collected for each patient the perioperative data, complications (including neurologic deficits) and their clinical course.

RESULTS

Only one surgeon was accused and found liable for failing to perform a surgical revision within a reasonable timeframe (time to revision of 11 days). In 2 cases, the liability of a nurse working in the surgical department was called into question for failing to contact the surgeon upon the onset of symptoms. In the other cases (11 patients, 79%), the occurrence of a symptomatic epidural hematoma was considered a no-fault medical accident that was not caused by the surgeon. The presence of a drain did not have any medicolegal impact in the cases reviewed.

CONCLUSION

The key element in medicolegal decisions is the reaction time of the healthcare teams, in particular the time between the onset of symptoms and surgical revision. According to these expert reviews, the placement of a drain was not taken into consideration during the medicolegal assessment of a postoperative symptomatic epidural hematoma.

LEVEL OF EVIDENCE

II; retrospective prognostic study, investigation of patient characteristics and their impact on functional outcome.

Is interstitial photodynamic therapy for brain tumors ready for clinical practice? A systematic review

BACKGROUND

Interstitial photodynamic therapy (iPDT), inserting optical fibers inside brain tumors, has been proposed for more than 30 years. While a promising therapeutic option, it is still an experimental treatment, with different ways of application, depending on the team performing the technique.

OBJECTIVE

In this systematic review, we reported the patient selection process, the treatment parameters, the potential adverse events and the oncological outcomes related to iPDT treatment applied to brain tumors.

METHODS

We performed a search in PubMed, Embase and Medline based on the following Mesh terms: "interstitial" AND "photodynamic therapy" AND "brain tumor" OR "glioma" OR glioblastoma" from January 1990 to April 2020. We screened 350 studies. Twelve matched all selection criteria.

RESULTS

251 patients underwent iPDT. Tumors were mainly de novo or recurrent high-grade gliomas (171 (68%) of glioblastomas), located supratentorial, with a median volume of 12 cm³. Hematoporphyrin derive agent (HpD) or protoporphyrin IX (PpIX) induced by 5-aminolevulinic acid (5-ALA) was used as a photosensitizer. Up to 6 optical fibers were introduced inside the tumor, delivering 200 mW/cm at a wavelength of 630 nm. Overall mortality was 1%. Transient and persistent morbidity were both 5%. No permanent deficit occurred using 5-ALA PDT. Tumor response rate after iPDT was 92% (IQR, 67; 99). Regarding glioblastomas, progression-free-survival was respectively 14.5 months (IQR, 13.8; 15.3) for de novo lesions and 14 months (IQR, 7; 30) for recurrent lesions, while overall survival was respectively 19 months (IQR, 14; 20) and 8 months (IQR, 6.3; 8.5). In patients harboring high-grade gliomas, 33 (13%) were considered long-term survivors (> 2 years) after iPDT.

CONCLUSION

Regardless of heterogeneity in its application, iPDT appears safe and efficient to treat brain tumors, especially high-grade gliomas. Stand-alone iPDT (i.e., without combined craniotomy and intracavitary PDT) using 5-ALA appears to be the best option in terms of controlling side effects: it avoids the occurrence of permanent neurological deficits while reducing the risks of hemorrhage and sepsis.

Standardized intraoperative 5-ALA photodynamic therapy for newly diagnosed glioblastoma patients: a preliminary analysis of the INDYGO clinical trial

PURPOSE

Glioblastoma (GBM) is the most aggressive malignant primary brain tumor. The unfavorable prognosis despite maximal therapy relates to high propensity for recurrence. Thus, overall survival (OS) is quite limited and local failure remains the fundamental problem. Here, we present a safety and feasibility trial after treating GBM intraoperatively by photodynamic therapy (PDT) after 5-aminolevulinic acid (5-ALA) administration and maximal resection.

METHODS

Ten patients with newly diagnosed GBM were enrolled and treated between May 2017 and June 2018. The standardized therapeutic approach included maximal resection (near total or gross total tumor resection (GTR)) guided by 5-ALA fluorescence-guided surgery (FGS), followed by intraoperative PDT. Postoperatively, patients underwent adjuvant therapy (Stupp protocol). Follow-up included clinical examinations and brain MR imaging was performed every 3 months until tumor progression and/or death.

RESULTS

There were no unacceptable or unexpected toxicities or serious adverse effects. At the time of the interim analysis, the actuarial 12-months progression-free survival (PFS) rate was 60% (median 17.1 months), and the actuarial 12-months OS rate was 80% (median 23.1 months).

CONCLUSIONS

This trial assessed the feasibility and the safety of intraoperative 5-ALA PDT as a novel approach for treating GBM after maximal tumor resection. The current standard of care remains microsurgical resection whenever feasible, followed by adjuvant therapy (Stupp protocol). We postulate that PDT delivered immediately after resection as an add-on therapy of this primary brain cancer is safe and may help to decrease the recurrence risk by targeting residual tumor cells in the resection cavity. Trial registration NCT number: NCT03048240. EudraCT number: 2016-002706-39.

Effectiveness of Bilateral Ultrasound-Guided Erector Spinae Plane Block in Percutaneous Lumbar Osteosynthesis for Spine Trauma: A Retrospective Study

BACKGROUND

Postoperative pain in spine surgery is an issue. Erector spinae plane block (ESPB) may reduce such postoperative pain, but its usefulness has never been evaluated in the specific context of trauma surgery. We thus studied the effect of bilateral ultrasound-guided ESPB on postoperative pain and opioid requirement after percutaneous lumbar arthrodesis for trauma.

METHODS

All patients who underwent percutaneous lumbar arthrodesis for spine trauma between December 2019 and March 2020 were retrospectively studied. Some patients received preoperative bilateral ESPB (30 mL of 0.375% ropivacaine on each side; ESPB group), others received the standard of care (i.e., postoperative muscular infiltration with 30 mL of 0.75% of ropivacaine; control group), according to the preference of the anesthesiologist in charge of the patient. The rest of the management was identical in all patients. The primary outcome was the cumulative morphine consumption at 24 hours postoperatively. Secondary outcomes included pain score at various time points until 24 hours.

RESULTS

Fifty-five patients were included, of whom 24 received an EPSB and 31 received the standard of care. The cumulative morphine consumption (mean [standard deviation]) at 24 hours was 13 (12) mg in the ESPB group, and 35 (17) mg in the control group (P < 0.001). Pain scores were significantly lower in the ESPB group compared with the control group up to 9 hours after surgery (P < 0.01).

CONCLUSIONS

In this pilot study, compared with standard analgesia, ESPB reduced opioid requirement and postoperative pain after percutaneous lumbar arthrodesis for trauma. A randomized controlled trial is required to prove this effectiveness.

Impact of the skull contour definition on Leksell Gamma Knife® Icon™ radiosurgery treatment planning

INTRODUCTION

The Gamma Knife^® planning software (TMR 10, Elekta Instruments, AB, Sweden) affords two ways of defining the skull volume, the "historical" one using manual measurements (still perform in some centers) and the new one using image-based skull contours. Our objective was to assess the potential variation of the dose delivery calculation using consecutively in the same patients the two above-mentioned techniques.

MATERIALS AND METHODS

We included in this self-case-control study, 50 patients, treated with GKRS between July 2016 and January 2017 in Lausanne University Hospital, Switzerland, distributed among four groups: convexity targets (n = 18), deep-seated targets (n = 13), vestibular schwannomas (n = 11), and trigeminal neuralgias (n = 8). Each planning was performed consecutively with the 2 skull definition techniques. For each treatment, we recorded the beam-on time (min), target volume coverage (%), prescription isodose volume (cm³), and maximal dose (Gy) to the nearest organ at risk if relevant, according to each of the 2 skull definition techniques. The image-based contours were performed using CT scan segmentation, based upon a standardized windowing for all patients.

RESULTS

The median difference in beam-on time between manual measures and image-based contouring was + 0.45 min (IQR; 0.2-0.6) and was statistically significant (p < 0.0001), corresponding to an increase of 1.28% beam-on time per treatment, when using image-based contouring. The target location was not associated with beam-on time variation (p = 0.15). Regarding target volume coverage (p = 0.13), prescription isodose volume (p = 0.2), and maximal dose to organs at risk (p = 0.85), no statistical difference was reported between the two skull contour definition techniques.

CONCLUSION

The beam-on time significantly increased using image-based contouring, resulting in an increase of the total dose delivery per treatment with the new TMR 10 algorithm. Other dosimetric parameters did not differ significantly. This raises the question of other potential impacts. One is potential dose modulation that should be performed as an adjustment to new techniques developments. The second is how this changes the biologically equivalent dose per case, as related to an increased beam on time, delivered dose, etc., and how this potentially changes the radiobiological effects of GKRS in an individual patient.

Biologically effective dose and prediction of obliteration of unruptured arteriovenous malformations treated by upfront Gamma Knife radiosurgery: a series of 149 consecutive cases

OBJECTIVE

Arteriovenous malformations (AVMs) present no pathologic tissue, and radiation dose is confined in a clear targeted volume. The authors retrospectively evaluated the role of the biologically effective dose (BED) after Gamma Knife radiosurgery (GKRS) for brain AVMs.

METHODS

A total of 149 consecutive cases of unruptured AVMs treated by upfront GKRS in Lille University Hospital, France, were included. The mean length of follow-up was 52.9 months (median 48, range 12-154 months). The primary outcome was obliteration, and the secondary outcome was complication appearance. The marginal dose was 24 Gy in a vast majority of cases (n = 115, 77.2%; range 18-25 Gy). The mean BED was 220.1 Gy2.47 (median 229.9, range 106.7-246.8 Gy2.47). The mean beam-on time was 32.3 minutes (median 30.8, range 9-138.7 minutes). In the present series, the mean radiation dose rate was 2.259 Gy/min (median 2.176, range 1.313-3.665 Gy/min). The Virginia score was 0 in 29 (19.5%), 1 in 61 (40.9%), 2 in 41 (27.5%), 3 in 18 (12.1%), and 4 in 0 (0%) patients, respectively. The mean Pollock-Flickinger score was 1.11 (median 1.52, range 0.4-2.9). Univariate (for obliteration and complication appearance) and multivariate (for obliteration only) analyses were performed.

RESULTS

A total of 104 AVMs (69.8%) were obliterated at the last follow-up. The strongest predictor for obliteration was BED (p = 0.03). A radiosurgical obliteration score is proposed, derived from a fitted multivariable model: (0.018 × BED) + (1.58 × V12) + (-0.013689 × beam-on time) + (0.021 × age) - 4.38. The area under the receiver operating characteristic curve was 0.7438; after internal validation using bootstrap methods, it was 0.7088. No statistically significant relationship between radiation dose rate and obliteration was found (p = 0.29). Twenty-eight (18.8%) patients developed complications after GKRS; 20 (13.4%) of these patients had transient adverse radiological effects (perilesional edema developed). Predictors for complication appearance were higher prescription isodose volume (p = 0.005) and 12-Gy isodose line volume (V12; p = 0.001), higher Pollock-Flickinger (p = 0.02) and Virginia scores (p = 0.003), and lower beam-on time (p = 0.03).

CONCLUSIONS

The BED was the strongest predictor of obliteration of unruptured AVMs after upfront GKRS. A radiosurgical score comprising the BED is proposed. The V12 appears as a predictor for both efficacy and toxicity. Beam-on time was illustrated as statistically significant for both obliteration and complication appearance. The radiation dose rate did not influence obliteration in the current analysis. The exact BED threshold remains to be established by further studies.

Anatomo-radiological correlation between diffusion tensor imaging and histologic analyses of glial tumors: a preliminary study

BACKGROUND AND PURPOSE

The challenge of the neurosurgical management of gliomas lies in achieving a maximal resection without persistent functional deficit. Diffusion tensor imaging (DTI) allows non-invasive identification of white matter tracts and their interactions with the tumor. Previous DTI validation studies were compared with intraoperative cortical stimulation, but none was performed based on the tumor anatomopathological analysis. This preliminary study evaluates the correlation between the preoperative subcortical DTI tractography and histology in terms of fiber direction as well as potential tumor-related fiber disruption.

METHODS

Eleven patients harboring glial tumors underwent preoperative DTI images. Correlations were performed between the visual color-coded anisotropy (FA) map analysis and the tumor histology after "en bloc" resection. Thirty-one tumor areas were classified according to the degree of tumor infiltration, the destruction of myelin fibers and neurofilaments, the presence of organized white matter fibers, and their orientation in space.

RESULTS

After histologic comparison, the DTI sensitivity and specificity to predict disrupted fiber tracts were respectively of 89% and 90%. The positive and negative predicted values of DTI were 80% and 95%. The DTI data were in line with the histologic myelin fiber orientation in 90% of patients. In our series, the prevalence of destructed fiber was 31%. Glioblastoma WHO grade IV harbored a higher proportion of destructed white matter tracts. Lower WHO grades were associated with higher preservation of subcortical fiber tracts.

CONCLUSION

This DTI/histology study of "en bloc"-resected gliomas reported a high and reproducible concordance of the visual color-coded FA map with the histologic examination to predict subcortical fiber tract disruption. Our series brought consistency to the DTI data that could be performed routinely for glioma surgery to predict the tumor grade and the postoperative clinical outcomes.

Patients with Coronavirus 2019 (COVID-19) and Surgery: Guidelines and Checklist Proposal

The management of patients with novel coronavirus 2019 (COVID-19) represents a new challenge for medical and surgical teams. Each operating room in the world should be prepared thoughtfully, and the development of a protocol and patient route seems mandatory. An adequate degree of protection must be used. We propose recommendations to help different professionals in the establishment of protocols for the management of patients with COVID-19. We also offer a checklist that could be used in the operating room.

INtraoperative photoDYnamic Therapy for GliOblastomas (INDYGO): Study Protocol for a Phase I Clinical Trial

BACKGROUND

Glioblastoma (GBM) is characterized by marked proliferation, major infiltration, and poor prognosis. Despite current treatments, including surgery, radiation oncology, and chemotherapy, the overall median survival is 15 mo and the progression-free survival is 7 to 8 mo. Because of systematic relapse of the tumor, the improvement of local control remains an issue. In this context, photodynamic therapy (PDT) may offer a new treatment modality for GBM.

OBJECTIVE

To assess the feasibility of intraoperative PDT early after surgical resection of GBM without unacceptable and unexpected toxicities.

METHODS

The INDYGO clinical trial (INtraoperative photoDYnamic Therapy for GliOblastomas) treatment will be carried out in addition to the current standard of care (SOC) of glioblastoma: maximum resection surgery followed by concomitant radio-chemotherapy and adjuvant chemotherapy. PDT treatment will be delivered during surgery early, after the fluorescence-guided resection. Immunological responses and biomarkers will also be investigated during the follow-up. A total of 10 patients will be recruited during this study.

EXPECTED OUTCOMES

Clinical follow-up after the SOC with PDT is expected to be similar (no significant difference) to the SOC alone.

DISCUSSION

This INDYGO trial assesses the feasibility of intraoperative 5-aminolevulinic acid PDT, a novel seamless approach to treat GBM. The technology is easily embeddable within the reference treatment at a low-incremental cost. The safety of this new treatment modality is a preliminary requirement before a multicenter randomized clinical trial can be further conducted to assess local control improvement by treating infiltrating and nonresected GBM cells.

Does the hip positioning matter for oblique lumbar interbody fusion approach? A morphometric study

PURPOSE

To evaluate whether left hip positioning widened the access corridor using oblique lateral interbody fusion (OLIF) approach during right lateral decubitus (RLD).

METHODS

Ten healthy adult volunteers underwent a T2 lumbosacral MRI (1.5 T) in the supine position, RLD position with left hip in extension and then in flexion. L2-L3 to L5-S1 disc spaces were identified. At each level, left psoas surface (in cm²), access corridor (in mm) and vessel movement were calculated in the three positions. Paired t test was used for comparison.

RESULTS

The mean surface of the left psoas ranged from 7.83 to 17.19 cm² in the three positions (p > 0.05). From L2-3 to L4-5, in RLD, when the left hip shifted from extension to flexion, nor the access corridor nor vessel movements were significantly different. When the volunteers shifted from supine to RLD position with hip in extension, arteries moved 3.66-5.61 mm to the right (p < 0.05 at L2-3, L3-4 and L5-S1), while the venous structures moved 0.92-4.96 mm (p < 0.05 at L2-3) to the right. When the position shifted from supine to RLD with hip in flexion, the arterial structures moved 0.47-4.88 mm (p < 0.05 at L2-3 and L3-4) to the right, while the venous structures moved - 0.94 to 4.13 mm (p < 0.05 at L2-3 and L3-4) to the right.

CONCLUSION

Hip positioning was not associated with a significant widening of the surgical corridor. To perform OLIF, we advocate for RLD position with left hip in extension to move away the vascular structures and reduce the psoas volume. These slides can be retrieved under Electronic Supplementary Material.

Comparison of different treatment schemes in 5-ALA interstitial photodynamic therapy for high-grade glioma in a preclinical model: An MRI study

BACKGROUND

There is currently no therapy that prevents high-grade glioma recurrence. Thus, these primary brain tumors have unfavorable outcomes. Recently, 5-ALA photodynamic therapy (PDT) has been proposed to delay relapse and is highly expected to have potential synergistic effects with the current standard of care. However, PDT treatment delivery needs to be optimized by evaluating the impact of both the number of fractions and the light power used.

OBJECTIVES

Previous studies have reported MRI examination-based outcomes for PDT in glioblastoma. Our study aimed to compare MRI markers across different treatment schemes that use interstitial PDT in high-grade glioma in a preclinical model.

MATERIALS AND METHODS

Forty-eight "nude" rats were grafted with human U87 cells into the right putamen and subsequently submitted to interstitial PDT. The rats were randomized into six groups, including two different sham groups and four different treated groups (5 fractions at 5 mW or 30 mW and 2 fractions at 5 mW or 30 mW). After photosensitizer (PS) precursor (5-ALA) intake, an optical fiber was introduced into the tumor. Treatment effects were assessed with early high-field MRI to acquire T1 and T2 diffusion and perfusion images.

RESULTS

There was no difference in the variation of the diffusion coefficient among the six groups (p = 0.0549, Kruskal-Wallis test). However, a significant difference was identified among the six groups in terms of variation in perfusion (p = 0.048, Kruskal-Wallis test), supporting a lesional effect in the treated groups. Additionally, the sham groups had significantly smaller edema volumes than were observed in the treated groups. Moreover, the 5-fraction group treated with 30 mW was associated with edema volumes that were significantly greater than those in the 5-fraction group treated with 5 mW (p = 0.019).

CONCLUSION

Based on observations of MRI data and considering treatment effects, the 5-fraction group treated at 5 mW was not significantly different from the other treated groups in terms of cell deaths, characterized by diffusion imaging, or necrosis level. However, the significantly lower level of edema observed in this group indicated that this treatment scheme had limited toxicity.

Radiosurgery and fractionated radiotherapy for cavernous sinus meningioma: a systematic review and meta-analysis

INTRODUCTION

Radiosurgery (RS) and fractionated radiotherapy (FRT) are part of the therapeutic armamentarium for the management of cavernous sinus meningiomas. We propose a systematic review of the local tumor control and clinical outcomes after monofractionated radiosurgical treatment, including gamma knife radiosurgery (GKRS) and linear accelerator (Linac RS), or fractionated radiotherapy.

MATERIALS AND METHODS

The current review and meta-analysis adhered to the PRISMA guidelines. We performed a search in PubMed, Embase, and Medline based on the following mesh terms, used alone or in diverse combinations, in both title and abstract: "cavernous sinus," "meningioma," "radiosurgery," "gamma knife," "linac," "cyberknife," and "radiotherapy". We screened 425 studies. We selected 36 studies, matching all selection criteria: 24 for GK, 5 for Linac, and 7 for FRT.

RESULTS

Were included 2817 patients (GKRS, n = 2047, LinacRS, n = 350, FRT, n = 420). Half of patients benefited from upfront RS or FRT; the other half benefited from adjuvant RS or FRT (combined approach or tumor recurrence). The mean gross target volume (GTV) was smaller for RS as compared to FRT (p = 0.07). The median marginal doses were 13.9 Gy (range, 11 to 28) for GKRS and 14 Gy (range, 12.8 to 17.7) for LinacRS. For FRT, patients received a mean dose of 51.2 Gy (25.5 fractions, 1.85 Gy each). The mean overall follow-up values were 48 months (range, 15 to 89) for GKRS, 69 months (range, 46 to 87) for Linac, and 59.5 months (range, 33 to 83) for FRT. PFS at 5 years for GKRS, LinacRS, and FRT were respectively 93.6%, 95.6%, and 97.4% (p = 0.32, the Kruskal-Wallis). Monofractionated treatments (GKRS and LinacRS) induced more tumor volume regression than FRT (p = 0.001). Tumor recurrence or progression ranged between 3 and 5.8%, without statistically significant differences between modalities (p > 0.05). Trigeminal symptoms improved in approximately 54%, and III-IV-VI cranial nerves (CN) palsies improved in approximately 45%. After GKRS, visual acuity improved in 21% (not enough data available for other modalities). De novo deficits occurred in 5 to 7.5%. Adverse radiation effects appeared in 4.6 to 9.3% (all techniques pooled).

CONCLUSION

RS achieved a twice-higher rate of tumor volume regression than FRT. GKRS series reported an improvement in visual acuity in 21% of the cases. GKRS, Linac, and FRT provided similar clinical post therapeutic outcomes for the trigeminal and oculomotor CN.

MRI assessment of treatment delivery for interstitial photodynamic therapy of high-grade glioma in a preclinical model

BACKGROUND

High-grade gliomas are primary brain tumors that have shown increasing incidence and unfavorable outcomes. Local control is crucial to the management of this pathology. Photodynamic therapy (PDT), based on the light-induced activation of a photosensitizer (PS), achieves local treatment by inducing selective lesions in tumor tissue.

OBJECTIVES

Previous studies have reported the outcomes of PDT for glioblastoma via immunohistological data. Our study aimed to evaluate MRI findings, including diffusion, and perfusion sequences, compared with immunohistological data from the same population to address the efficiency of light fractionation.

MATERIALS AND METHODS

Twenty-six "nude" rats grafted with human U87 cells into the right putamen underwent PDT. After PS precursor (5-ALA) intake, an optical fiber was introduced into the tumor. The rats were randomized into the following groups: those without illumination and those that received two or five fractions of light. Treatment effects were assessed with early high-field MRI to measure the volume of necrosis and edema using diffusion and perfusion sequences; the MRI results were compared with immunohistology results, including necrosis and apoptosis markers.

RESULTS

Elevated diffusion values were observed on MRI in the centers of the tumors of the treated animals, especially in the 5-fraction group (P < 0.01). Perfusion was decreased around the treatment site, especially in the 5-fraction group (P = 0.024). The MRI findings were consistent with previously published histological data. The median volume of necrosis was significantly different between the sham group and treated groups, 0 mm³ versus 2.67 mm³ , P < 0.001. The same trend was previously observed in histology data when grading the absence or presence of necrosis and when the presence of necrosis was significantly more predominant for the treated group than for the untreated group (P < 001). Additionally, cell death represented by apoptosis marker data (TUNEL method) was significantly higher in the 5-fraction group than in the 2-fraction group (P = 0.01).

CONCLUSION

Diffusion and perfusion MRI revealed histological lesions. Interstitial PDT (iPDT) induced specific lesions in the tumor tissue, which were observed with MRI and confirmed by histopathological analysis. Thus, MRI may provide a non-invasive and reliable tool to assess treatment outcomes after PDT. Lasers Surg. Med. 50:460-468, 2018. © 2017 Wiley Periodicals, Inc.

Interstitial photodynamic therapy and glioblastoma: Light fractionation in a preclinical model

BACKGROUND

Glioblastoma is a high-grade cerebral tumor with local recurrence and poor outcome. Photodynamic therapy (PDT) is a localized treatment based on the light activation of a photosensitizer (PS) in the presence of oxygen, which results in the formation of cytotoxic species. The delivery of fractionated light may enhance treatment efficacy by reoxygenating tissues.

OBJECTIVE

To evaluate the efficiency of two light-fractionation schemes using immunohistological data.

MATERIALS AND METHODS

Human U87 cells were grafted into the right putamen of 39 nude rats. After PS precursor intake (5-ALA), an optic fiber was introduced into the tumor. The rats were randomly divided into three groups: without light, with light split into 2 fractions and with light split into 5 fractions. Treatment effects were assessed using brain immunohistology.

RESULTS

Fractionated treatments induced intratumoral necrosis (P < 0.001) and peritumoral edema (P = 0.009) associated with a macrophagic infiltration (P = 0.006). The ratio of apoptotic cells was higher in the 5-fraction group than in either the sham (P = 0.024) or 2-fraction group (P = 0.01). Peripheral vascularization increased after treatment (P = 0.017), and these likely new vessels were more frequently observed in the 5-fraction group (P = 0.028).

CONCLUSION

Interstitial PDT with fractionated light resulted in specific tumoral lesions. The 5-fraction scheme induced more apoptosis but led to greater peripheral neovascularization. Lasers Surg. Med. 49:506-515, 2017. © 2016 Wiley Periodicals, Inc.

Acute clinical adverse radiation effects after Gamma Knife surgery for vestibular schwannomas

OBJECTIVE

Vestibular schwannomas (VSs) represent a common indication of Gamma Knife surgery (GKS). While most studies focus on the long-term morbidity and adverse radiation effects (AREs), none describe the acute clinical AREs that might appear on a short-term basis. These types of events are investigated, and their incidence, type, and outcomes are reported in the present paper.

METHODS

The included patients were treated between July 2010 and March 2016, underwent at least 6 months of follow-up, and presented with a disabling symptom during the first 6 months after GKS that affected their quality of life. The timing of appearance, as well as the type of main symptom and outcome, were noted. The prescribed dose was 12 Gy at the margin.

RESULTS

Thirty-five (22%) of 159 patients who fulfilled the inclusion criteria had acute clinical AREs. The mean followup period was 30 months (range 6–49.2 months). The mean time of appearance was 37.9 days (median 31 days; range 3–110 days). In patients with de novo symptoms, the more frequent symptoms were vertigo (n = 4; 11.4%) and gait disturbance (n = 3; 8.6%). The exacerbation of a preexisting symptom was more frequently related to hearing loss (n = 10; 28.6%), followed by gait disturbance (n = 7; 20%) and vertigo (n = 3, 8.6%). In the univariate logistic regression analysis, the following factors were statistically significant: age (p = 0.002; odds ratio [OR] 0.96), hearing at baseline by Gardner-Robertson (GR) class (p = 0.006; OR 0.21), pure tone average at baseline (p = 0.006; OR 0.97), and Koos grade at baseline (with Koos Grade I used as a reference) (for Koos Grade II, OR 0.17 and p = 0.002; for Koos Grade III, OR 0.42 and p = 0.05). The following were not statistically significant but showed a tendency toward significance: the number of isocenters (p = 0.06; OR 0.94) and the maximal dose received by the cochlea (p = 0.07; OR 0.74). Fractional polynomial regression analysis showed a nonlinear relationship between the outcome and the radiation dose rate (minimum reached at a cutoff of 2.5 Gy/minute) and the maximal vestibular dose (maximum reached at a cutoff of 8 Gy), but the small sample size precludes a detailed analysis of the former. The clinical acute AREs disappeared in 32 (91.4%) patients during the first 6 months after appearance. Permanent and somewhat disabling morbidity was found in 3 cases (1.9% from the whole series): 1 each with complete hearing loss (GR Class I before and V after), hemifacial spasm (persistent but alleviated), and dysgeusia.

CONCLUSIONS

Acute effects after radiosurgery for VS are not rare. They concern predominantly de novo vertigo and gait disturbance and the exacerbation of preexistent hearing loss. In de novo vestibular symptoms, a vestibular dose of more than 8 Gy is thought to play a role. In most cases, none of these effects are permanent, and they will ultimately improve or disappear with steroid therapy. Permanent AREs remain very rare.

Internal and external spheno-orbital meningioma varieties: different outcomes and prognoses

BACKGROUND

Internal variation among spheno-orbital meningiomas (SOM) is surgically challenging. Optic canal invasion management is discussed.

METHOD

This retrospective study includes 70 patients with SOM who underwent surgery between 1995 and 2012. Preoperative ophthalmological, neurological and aesthetic clinical signs were collected. All patients benefitted from repeated tomography and magnetic resonance imaging (MRI). The surgical team consisted of a neurosurgeon and a plastic surgeon. In the majority of cases, resection was followed by bone reconstruction using an autologous iliac crest graft. The extent of resection was evaluated on the dural and osseous sides. Early clinical outcomes, long-term follow-up, recurrence and adjuvant therapies were reported.

RESULTS

The mean age was 52 years old, and 91 % of the patients were women. Initial symptoms primarily included proptosis (65 %), decreased visual acuity (39 %) and soft tissue tumefaction (16 %). We classified 40 cases as the internal variety when considering the inner third of the greater wing of the sphenoid, optic canal, anterior clinoid process or cavernous sinus. The remaining cases were described as the external variety. The complete resection rates for the internal and external varieties were 12 % and 61 %, respectively (P < 0.001). In total, 90 % of cases were grade I meningiomas. For grade I, we reported 30 % recurrence, and 50 % of these cases recurred in the first 2 years. Grade II cases without early adjuvant radiotherapy increased at 2 years. We did not observe any difference in recurrence rate among grade I tumours with or without tumour remnants. At the end of follow-up, visual acuity was stabilised or increased in 88 % of patients. In addition, 14 % of patients experienced persistent pain at the location of the iliac harvesting site.

CONCLUSIONS

The internal SOM variety exhibited a reduced total resection rate and a shorter progression-free survival (PFS). Unroofing of the optic canal extended PFS. Among grade I cases, the persistence of a negligible tumour remnant did not alter the probability of recurrence. For superior grades, radiotherapy must be administered in addition to surgery as soon as possible. SOMs require prolonged follow-up. Autologous iliac reconstruction is related to substantial morbidity and could be replaced by prosthetic bone three-dimensional reconstruction.

Predictors of functional outcomes and recurrence of chronic subdural hematomas

We aimed to evaluate the functional outcome and risk factors of recurrence in patients operated on for a chronic subdural hematoma (CSH), and discuss systematic early postoperative CT scans. CSH is a very common disease in neurosurgical practice, especially in elderly patients who are treated with anticoagulation. The challenge is to rapidly restore the independence of these patients. We retrospectively analyzed data from 164 consecutive surgical procedures performed on 140 CSH patients, including recurrent surgery, at our institution from June 2011 to June 2012. Pre- and postoperative CT scans, and medical records, were systematically reviewed using the institutional computing database. A poor functional outcome was defined by a modified Rankin scale (mRS) score>2 at 3 months. Among the 140 patients (mean age 76 years; 64% men), a single burr hole craniostomy was performed in 122 patients, and a craniotomy in 18. A poor functional outcome was recorded in 39 patients (28%; 95% confidence interval [CI] 20-35%). In multivariate analyses, an increased risk of poor functional outcome was associated with age >75 years (odds ratio [OR] 5.88; 95% CI 1.96-17.63), residual hematoma thickness >14 mm (OR 3.79; 95% CI 1.47-9.77), and GCS<15 (OR, 2.96; 95% CI, 1.18-7.40). Recurrences occurred in 24 patients (17%; 95% CI 11-23%), with a median delay to reintervention of 13 days. The independent predictors of CSH recurrence were preoperative anticoagulant therapy (OR 3.68; 95% CI 1.13-12.00), and persistence of mass effect on the postoperative CT scan (OR 5.61; 95% CI 1.52-20.66). Three months after surgical treatment, more than one quarter of the CSH patients had a mRS⩾3. The loss of independence was associated with older age, initial GCS<15, and residual hematoma thickness postoperatively. Anticoagulant therapy and persistence of postoperative mass effect heightened the risk of recurrence.

Supervised machine learning-based classification scheme to segment the brainstem on MRI in multicenter brain tumor treatment context

PURPOSE

To constrain the risk of severe toxicity in radiotherapy and radiosurgery, precise volume delineation of organs at risk is required. This task is still manually performed, which is time-consuming and prone to observer variability. To address these issues, and as alternative to atlas-based segmentation methods, machine learning techniques, such as support vector machines (SVM), have been recently presented to segment subcortical structures on magnetic resonance images (MRI).

METHODS

SVM is proposed to segment the brainstem on MRI in multicenter brain cancer context. A dataset composed by 14 adult brain MRI scans is used to evaluate its performance. In addition to spatial and probabilistic information, five different image intensity values (IIVs) configurations are evaluated as features to train the SVM classifier. Segmentation accuracy is evaluated by computing the Dice similarity coefficient (DSC), absolute volumes difference (AVD) and percentage volume difference between automatic and manual contours.

RESULTS

Mean DSC for all proposed IIVs configurations ranged from 0.89 to 0.90. Mean AVD values were below 1.5 cm(3), where the value for best performing IIVs configuration was 0.85 cm(3), representing an absolute mean difference of 3.99% with respect to the manual segmented volumes.

CONCLUSION

Results suggest consistent volume estimation and high spatial similarity with respect to expert delineations. The proposed approach outperformed presented methods to segment the brainstem, not only in volume similarity metrics, but also in segmentation time. Preliminary results showed that the approach might be promising for adoption in clinical use.

Anorexia: an early sign of fourth ventricle astrocytoma in children

INTRODUCTION

Paediatric low-grade astrocytomas of the fourth ventricle are rare tumours, generally revealed by hydrocephalus. However, some patients present with a history of severe anorexia. It might be a harbinger, which if recognized, could lead to earlier diagnosis. We decided to examine our database in order to evaluate the incidence and signification of anorexia in this context.

METHODS

Retrospective monocentric study of cases of low-grade astrocytomas of the fourth ventricle operated between 1991 and 2012 in our paediatric neurosurgery department. We particularly observed the clinical presentation and long-term clinical, oncological and radiological evolution. Non-parametrical tests were used (Mann-Whitney, Fisher).

RESULTS

We reviewed 34 cases, 31 pilocytic astrocytomas and 3 diffuse astrocytomas, 16 boys and 18 girls, (M/F ratio 0.89). Mean age at diagnosis was 8 years old. Seven presented with notable anorexia, the average BMI in this group was ≤2 standard deviation (SD); with clinical signs evolving for 11.5 months. Twenty-seven children had no anorexia; average BMI in this group was +1 SD, with clinical evolution for 6 months on an average of p < 0.05. We found no significant difference regarding hydrocephalus or tumour location. In all children with anorexia, body mass index improved markedly in the postoperative follow-up, which lasted, on average, for 6 years.

CONCLUSION

Anorexia with stunted body weight curve is a non-exceptional presentation in children with low-grade astrocytomas of the fourth ventricle. Unexplained or atypical anorexia with negative etiologic assessment should prompt cerebral imaging. Clinical improvement after surgical resection, could suggest a possible interaction between tumour tissue and appetite-suppressing peptide secretion.