Assessment of organ doses, peak skin doses and effective doses in patients undergoing anterior cervical discectomy and fusion utilising VirtualDose-IR software.

In this study, the effect of patient- and procedure-related parameters on organ doses (ODs), peak skin dose (PSD) and effective dose (E) during anterior cervical discectomy and fusion (ACDF) was evaluated. Patient- and procedure-related parameters, as well as fluoroscopy time, kerma-area product (KAP), cumulative air-kerma (Kair) and incident Kair, were analysed for 50 ACDF procedures performed with a mobile C-arm. These parameters were inserted in VirtualDose-IR software implementing sex-specific and body mass index (BMI)-adjustable anthropomorphic phantoms to calculate OD, PSD and E. The BMI, gender and type of implants did not significantly affect KAP, incident Kair, PSD and E. However, the type of fusion significantly affected the E. The single fusions in C5/C6 resulted in significantly higher KAP, incident Kair and E than C4/C5 levels, while those performed in C6/C7 resulted in significantly higher E and PSD than C4/C5 levels. The thyroid, oesophagus and salivary glands received the largest doses in all groups studied. The BMI did not significantly affect ODs. The salivary glands absorbed significantly higher doses in males than females, while the extrathoracic region's dose significantly increased for multi- than single-level fusions. The fusions in C6/C7 resulted in significantly higher oesophagus and thyroid doses than C3/C4 and C4/C5 levels, as well as fusions performed in C5/C6 compared with C4/C5 levels. The data presented here could be used by the neurosurgeons as a comparator for future studies in optimising radiation protection during ACDF procedures in the operating theatre by keeping the ODs, PSD and E as low as reasonably practicable.

Lumbar discectomy and fusion: Organs' dose and effective dose estimation using Monte Carlo simulation.

In this study, the effect of patient- and procedure-related parameters on organs' dose (OD), peak skin dose (PSD) and effective dose (ED) during lumbar discectomy and fusion (LDF) was assessed. Intra-operative parameters obtained from 102 LDFs were inserted into VirtualDose-IR software implementing sex-specific and BMI-adjustable anthropomorphic phantoms for dosimetric calculations. Fluoroscopy time (FT), kerma-area product (KAP), cumulative and incident air-kerma (Kair) were also recorded from the dosimetric report of the mobile C-arm. An increase in KAP, Kair, PSD and ED was found for male or higher BMI patients, multi-level or fusion or L5/S1 procedures. However, a significant difference was found only for PSD and incident Kair between normal and obese patients and for FT between discectomy and discectomy and fusion procedures. The spleen, kidneys and colon received the highest doses. The BMI have a significant impact only for kidneys, pancreas, and spleen doses when comparing obese to overweight and for urinary bladder when comparing overweight to normal patients. Multi-level and fusion procedures resulted in significantly higher doses for lungs, heart, stomach, adrenals, gallbladder and kidneys, while pancreas and spleen doses significantly increased only for multi-level procedures. Additionally, a significant increase was found only for urinary bladder, adrenals, kidneys, and spleen ODs when comparing L5/S1 and L3/L4 levels. The mean ODs were lower compared to the literature. These data may aid neurosurgeons in optimising exposure techniques during LDF to keep patients' dose as low as is practicably possible.

PATIENT SIZE INDICES AND DOSE IN FLUOROSCOPICALLY GUIDED LUMBAR DISCECTOMY AND FUSION: A PRELIMINARY STUDY.

Patient dose values varied significantly during interventional procedures, mainly due to the patient size, operators' choices and clinical complexity. In this study, the effect of applying a previously described and validated size-correction method to normalise kerma-area product (KAP) and average KAP rate values of the whole procedure (KAP rate) and isolate variations in dose due to the patient size and complexity, during lumbar discectomy and fusion (LDF) procedures, was investigated. Fluoroscopy time (FT), KAP, KAP rate and patient size data (weight, height and equivalent diameter) were recorded, for 96 patients who underwent single or multilevel LDF procedures by three senior neurosurgeons, defining three different patient groups (surgeon 1, surgeon 2, surgeon 3). Simple linear regression and coefficients of determination were used to investigate the relationship between uncorrected and corrected KAP and KAP rate values and patient size indices in these groups. The results showed that the size correction decreased the influence of patient size and could contribute to the isolation of the variations in patient dose due to the patient size. From this point of view, dose surveys during lumbar spine interventions may include dosimetric data from all patients independently of their body size and not only for standard-sized patients, providing the advantage of accessible data collection for the establishment of local dose reference levels and optimisation purposes, within the framework of the radiation protection program in the Neurosurgery Department.

DO THE BMI AND SURGEON INFLUENCE THE PATIENT DOSE IN FLUOROSCOPICALLY GUIDED LUMBAR DISCECTOMY AND FUSION?☆.

A survey was conducted to evaluate the role of the surgeon and the patients' body size, on patient radiation dose in fluoroscopically guided lumbar discectomy and fusion (LDF) procedures. Fluoroscopy time (FT), kerma area product (KAP), cumulative dose (CD), as well as anatomical and technical data were recorded for 100 patients, who underwent single or multi-level posterior LDF, which was carried out by three senior neurosurgeons utilising a C-arm fluoroscopy system. The patients were divided into three groups based on the body mass index (BMI) values (normal, overweight, obese) and the neurosurgeon that performed each procedure (surgeon 1, surgeon 2, surgeon 3). Entrance surface dose (ESD) was estimated based on KAP values and exposure data, while the effective dose (ED) was estimated utilising the KAP values and appropriate conversion coefficients. The mean FT, KAP, CD, ESD and ED values were 11.7 s, 0.65 Gy cm2, 2.96 mGy, 11.7 mGy and 0.08 mSv for normal patients, 22.1 s, 0.94 Gy cm2, 4.27 mGy, 21.4 mGy and 0.11 mSv for overweight patients and 67.7 s, 3.59 Gy cm2, 17.79 mGy, 107.2 mGy and 0.44 mSv for obese patients. The corresponding values were 21.5 s, 0.77 Gy cm2, 3.51 mGy, 17.5 mGy, 0.09 mSv for the first, 23.0 s, 1.44 Gy cm2, 6.52 mGy, 30.2 mGy, 0.18 mSv for the second and 14.2 s, 0.64 Gy cm2, 2.91 mGy, 17.0 mGy, 0.08 mSv for the third surgeon. Overweight patients received 83% and 38% higher ESD and ED, while obese patients 816% and 450%, compared to normal patients, respectively. The CD values should be implemented with caution, as a skin dose indicator, for all patient sizes. The weight-FT product could be useful in estimating KAP during LDF procedures. The third surgeon achieved the lowest dose values. Although the first surgeon had the same FT with the second surgeon, the corresponding dose values were decreased by 50%. The differences in FT, KAP, CD and ED values among the groups of patients studied were not statistically significant (Kruskal-Wallis test, p > 0.05), although the p-values were close to the threshold of statistical significance. The pairwise comparisons showed statistically significant differences for KAP, CD and ED values between obese and normal patients and between surgeon 1 and surgeon 3 (Mann-Whitney test, p < 0.05). The ESD values showed statistically significant differences among the BMI-based groups and among the surgeon-based groups studied (Kruskal-Wallis test, p < 0.05). This fact can be attributed to the better implementation of the fluoroscopy system technical parameters concerning the patients' size, clinical conditions and complexity of the procedures. Training and awareness of neurosurgeons on radiation protection issues are of critical importance; however, further studies should be performed towards optimisation procedures regarding patient dose.

Institutional (local) diagnostic reference levels in fluoroscopically guided spine surgery.

In this study, institutional (local) diagnostic reference levels (LDRLs) and action levels (ALs) for spine interventional procedures are reported. Fluoroscopy time (FT), kerma area product (KAP), cumulative dose (CD), as well as anatomical, clinical and technical factors affecting procedure complexity were recorded for 156 patients who underwent cervical and thoraco-lumbar interventions. Patient entrance surface dose (ESD), effective dose (ED), thyroid absorbed dose and gonadal dose were also estimated, based on KAP measurements. The LDRLs and ALs were calculated as the 75th and 10th percentile of FT, KAP and CD values for the total group of patients, as well as utilizing the weight banding method and the size correction method. For the total distribution of patients, the LDRLs for cervical and thoraco-lumbar interventions are 0.15min and 0.29min for FT values, 0.10Gycm2 and 0.71Gycm2 for KAP values, as well as 0.47mGy and 3.24mGy for CD values, respectively. The corresponding ALs are 0.03min and 0.03min, 0.01Gycm2 and 0.07Gycm2, as well as 0.05mGy and 0.33mGy for FT, KAP and CD values, respectively. The age and treated levels had a significant influence on the reference dose values only for cervical interventions, whereas none of the other included factors showed statistically significant association for both cervical and thoraco-lumbar interventions. The weight banding method resulted to reference values comparable to those obtained for the whole group of patients, while the size correction method resulted to lower values. The mean ESD values were 1.58mGy (range 0.02-13.58mGy) for cervical and 23mGy (range 0.004-390.3mGy) for thoraco-lumbar interventions. The corresponding mean ED values were 0.012mSv (range 0.001-0.097mSv) and 0.124mSv (range 0.00002-2.11mSv), respectively. The mean thyroid and gonadal doses were 0.14mGy (range 0.002-1.12mGy) and 0.044mGy (range 0.000003-1.56mGy), respectively. The LDRLs and ALs reported could contribute in the effort for establishing national DRLs and for increasing neurosurgeons awareness regarding patient dose and radiation protection issues during spine interventional procedures.

Therapeutic management of intraventricular cavernoma: case series and review of the literature.

Intraventricular cavernoma (IVC) is a rare intracranial vascular malformation and only 100 cases of IVC have been described in the literature. Although IVCs share some common characteristics with intraparenchymal cavernomas, they also have some distinct features involving structure, clinical symptoms, radiologic appearance, and onset of symptoms. This review presents our experience, consisting of five IVC cases over a period of 11 years. We describe the symptoms leading to hospital admission, the main radiologic findings, the management of each ICV case, and the patients' clinical status after surgery. We also reviewed the international literature on IVC, presenting the main demographic characteristics, their most common location in the ventricular system, and the main signs and symptoms. Finally, we present the management options according to the current literature, the advantages and disadvantages of every management option, accompanied by a brief follow-up of most IVC cases, whether the cavernoma was treated surgically or conservatively.

Destructive cervical spine osteoblastoma at C5 in a young patient initially presenting with quadriparesis: case report and review of the literature.

BACKGROUND: Osteoblastomas are rare benign bone tumors that are mostly found in the posterior spinal elements; about 20% are located in the cervical spine. OBJECTIVE: The case of a destructive cervical osteoblastoma at C5 is reported in a 19-year-old man who initially presented with spastic quadriparesis. CASE REPORT: A 19-year-old man was self-referred, reporting symptoms in keeping with a progressive spastic quadriparesis, which had suddenly developed 6 days earlier. Preceding symptoms included mild non-specific neck pain for 3 weeks. The patient was afebrile, and no ambulatory X-ray study had been performed until the time of referral. A cervical spine computed tomography (CT) scan revealed a lytic lesion involving the spinal process and the pedicles of the C5 vertebra. Cervical spine magnetic resonance imaging performed on an inpatient basis revealed a well-circumscribed, destructive lesion of the C5 vertebra, measuring approximately 3 cm. The spinal cord was significantly compressed. The patient underwent open surgical resection of the tumor through a midline posterior approach. Histopathology of the tumor specimen was in keeping with a diagnosis of osteoblastoma. CONCLUSION: Neuroimaging should be performed with either conventional plain X-ray study, which seems to be sufficient in patients presenting with non-specific symptomatology related to cervical spine damage, or with advanced techniques in the case of patients with persistent neck pain or neurological deficit.

Radiculopathy after lumbar discectomy due to intraspinal retained Surgicel: clinical and magnetic resonance imaging evaluation.

BACKGROUND CONTEXT: Lumbar radiculopathy after lumbar spine surgery is an alerting sign usually caused by either a recurrent disc herniation or epidural hematoma. However, pressure on a spinal nerve root may also be exerted by a retained piece of Surgicel used to achieve hemostasis during lumbar spine surgical procedures. PURPOSE: To describe a case of lumbar radiculopathy that was caused by a piece of Surgicel left in the spinal canal after operation for lumbar disc herniation. STUDY SETTING: A case report of a retained piece of Surgicel being the cause of S1 radiculopathy. METHODS: Patient interview, medical records, imaging studies, and literature review. RESULTS: A 29-year-old man developed acute left S1 radiculopathy after a successful hemilaminectomy and discectomy operation for a L5-S1 disc herniation. In the magnetic resonance imaging studies that were performed, a postoperative hematoma could not be excluded and a reoperation revealed compression from Surgicel that was used for hemostasis. The patient was free of symptoms after reoperation. CONCLUSIONS: This case depicts the difficulty in distinguishing-by means of magnetic resonance imaging-nerve root compression caused by a postoperative hematoma and a recurrent disc herniation, from that caused by a retained Surgicel. Therefore, hemostatic agents should be meticulously used in spine surgery.

Patient outcome at long-term follow-up after aggressive microsurgical resection of cranial base chondrosarcomas.

OBJECTIVE: To evaluate patient clinical outcome and survival at long-term follow-up after aggressive microsurgical resection of chondrosarcomas of the cranial base. METHODS: Over a 20-year period, 47 patients underwent 72 operative procedures for resection of cranial base chondrosarcomas. Thirty-three patients were previously untreated, whereas 14 patients previously had undergone surgery or radiation. Twenty-three patients had a single operation and 24 underwent staged (more than one) operations because of extensive disease. Patients who underwent subtotal resection also underwent radiotherapy or radiosurgery. Patients were evaluated at follow-up clinically and by imaging studies. RESULTS: Gross total resection was accomplished in 29 (61.7%) patients, and subtotal resection was accomplished in 18 patients (38.3%). The resection was better in patients who underwent a primary operation (gross total resection, 68.8 versus 46.7%) rather than a reoperation. Patients who underwent incomplete resection underwent postoperative radiotherapy, which included proton beam radiotherapy (15.6%), radiosurgery (68%), and fractionated radiation (15.6%). There were no operative deaths. Postoperative complications (cerebrospinal fluid leakage, quadriparesis, infections, cranial nerve palsies, etc.) were observed in 10 patients (18%). The follow-up ranged from 2 to 255 months, with an average of 86 months. At the conclusion of study, 36 (76.6%) patients were alive, and 21 (44.7%) patients were alive without disease. Recurrence-free survival was 32% at 10 years in all patients, 42.3% in primary patients and 13.8% in those who underwent reoperation. The Karnofsky performance score was 82.4 +/- 9.8 before surgery, 85 +/- 12.5 at 1 year after surgery, and 85.3 +/- 5.8 at the latest follow-up. Two patients died as a result of radiotherapy complications (malignancy, radiation necrosis). CONCLUSION: Cranial base chondrosarcomas can be managed well by complete surgical resection or by a combination of surgery and radiotherapy. The study cannot comment about the efficacy of radiotherapy. Approximately half of the patients survived without recurrence at long-term follow-up (>132 mo). The functional status of the surviving patients was excellent at follow-up.

Giant osteoma of the frontoethmoidal sinus associated with two cerebral abscesses.

A 36-year-old woman presented with severe frontal headache, fever, left palpebral swelling, and proptosis. Radiographic studies showed a giant frontoethmoidal osteoma, that extended intracranially into the frontal lobe and was associated with two abscesses, one within the lesion and the other in the right frontal lobe. The tumour was excised and the abscesses drained. The patient made a full recovery.