An easy way to determine bone mineral density and predict pelvic insufficiency fractures in patients treated with radiotherapy for cervical cancer.

PURPOSE: The aim of this study was to investigate whether bone mineral density (BMD) as measured in planning computed tomographies (CTs) by a new method is a risk factor for pelvic insufficiency fractures (PIF) after radio(chemo)therapy (R(C)T) for cervical cancer. METHODS: 62 patients with cervical cancer who received definitive or adjuvant radio(chemo)therapy between 2013 and 2017 were reviewed. The PIF were detected on follow-up magntic resonance imaging (MRI). The MRI of the PIF patients was registered to the planning CT and the PIF contoured. On the contralateral side of the fracture, a mirrored structure of the fracture was generated (mPIF). For the whole sacral bone, three lumbar vertebrae, the first and second sacral vertebrae, and the PIF, we analyzed the BMD (mg/cm3), V50Gy, Dmean, and Dmax. RESULTS: Out of 62 patients, 6 (9.7%) had a fracture. Two out of the 6 patients had a bilateral fracture with only one of them being symptomatic. PIF patients showed a significantly lower BMD in the sacral and the lumbar vertebrae (p < 0.05). The BMD of the contoured PIF, however, when comparing to the mPIF, did not reach significance (p < 0.49). The difference of the V50Gy of the sacrum in the PIF group compared to the other (OTH) patients, i.e. those without PIF, did not reach significance. CONCLUSION: The dose does not seem to have a relevant impact on the incidence of PIF in our patients. One of the predisposing factors for developing PIF after radiotherapy seems to be the low BMD. We presented an easy method to assess the BMD in planning CTs.

Lumbar vertebral osteoradionecrosis: a rare case report with 10-year follow-up and brief literature review.

BACKGROUND: Osteoradionecrosis (ORN) is a complication that occurs after radiotherapy for head or neck malignancies. ORN of the spine is rare, with only few cases affecting the cervical spine reported to date. To our knowledge, no case of lumbar ORN has been reported. We report a rare case of ORN in the lumbar spine that occurred 2 years after radiotherapy and perform a literature review. CASE PRESENTATION: We present a case of lumbar ORN that occurred 2 years after radiotherapy for gallbladder carcinoma. The patient was successfully treated conservatively and followed up for > 10 years. CONCLUSIONS: ORN of the spine is a rare complication of radiotherapy. Spinal ORN is clinically described as a chronic disease with a slow onset. The most common presenting symptom of spinal ORN is pain. However, as ORN progresses, spinal kyphosis and instability can lead to neurological compression and thus to induced myelopathy or radiculopathy. Treatment of spinal ORN is comprehensive, including orthosis, medication, hyperbaric oxygen therapy, surgery, and new treatment combinations of pentoxifylline and tocopherol. The surgical rate for spinal ORN is relatively high.

Diagnostic Reference Levels for conventional radiography and fluoroscopy in Austria: Results and updated National Diagnostic Reference Levels derived from a nationwide survey.

OBJECTIVE: Evaluation and updating of Austrian National Diagnostic Reference Levels (NDRLs). METHODS: A nationwide survey on common conventional radiography and fluoroscopy examinations was conducted. In line with Austrian radiation protection standards, all relevant Austrian hospitals and radiology offices/centers were asked to report a minimum sample of 10 representative dose-area product (DAP) values together with patient weight and fluoroscopy time, if applicable. Examinations included for conventional radiography were skull, chest, abdomen, pelvis, lumbar spine and bedside chest x-ray, for fluoroscopy barium enema (single and double contrast) and swallowing (video). Participants were invited via e-mail, followed up by reminders to increase participation rates. Plausibility checks were performed to increase data quality. 3rd quartiles of facility median and mean DAP were calculated and compared to Austrian and international NDRLs. RESULTS: 59% of invited facilities submitted DAP data, 43% submitted additional data on patient weight and 41% on fluoroscopy time. DAP case numbers varied from 1005 to 2121 for conventional radiography and from 182 to 1380 for fluoroscopy. Average patient weight was 75 kg for conventional radiography and 77 kg for fluoroscopy. CONCLUSION: 3rd quartiles derived from the survey are substantially lower than the old Austrian NDRLs (valid till early 2018). Since 3rd quartiles correspond well to European NDRLs, the update would be in accordance with European DRL harmonisation efforts.

Cortical Thinning and Structural Bone Changes in Non-Human Primates after Single-Fraction Whole-Chest Irradiation.

Stereotactic body radiation therapy (SBRT) is associated with an increased risk of vertebral compression fracture. While bone is typically considered radiation resistant, fractures frequently occur within the first year of SBRT. The goal of this work was to determine if rapid deterioration of bone occurs in vertebrae after irradiation. Sixteen male rhesus macaque non-human primates (NHPs) were analyzed after whole-chest irradiation to a midplane dose of 10 Gy. Ages at the time of exposure varied from 45-134 months. Computed tomography (CT) scans were taken 2 months prior to irradiation and 2, 4, 6 and 8 months postirradiation for all animals. Bone mineral density (BMD) and cortical thickness were calculated longitudinally for thoracic (T) 9, lumbar (L) 2 and L4 vertebral bodies; gross morphology and histopathology were assessed per vertebra. Greater mortality (related to pulmonary toxicity) was noted in NHPs <50 months at time of exposure versus NHPs >50 months ( P = 0.03). Animals older than 50 months at time of exposure lost cortical thickness in T9 by 2 months postirradiation ( P = 0.0009), which persisted to 8 months. In contrast, no loss of cortical thickness was observed in vertebrae out-of-field (L2 and L4). Loss of BMD was observed by 4 months postirradiation for T9, and 6 months postirradiation for L2 and L4 ( P < 0.01). For NHPs younger than 50 months at time of exposure, both cortical thickness and BMD decreased in T9, L2 and L4 by 2 months postirradiation ( P < 0.05). Regions that exhibited the greatest degree of cortical thinning as determined from CT scans also exhibited increased porosity histologically. Rapid loss of cortical thickness was observed after high-dose chest irradiation in NHPs. Younger age at time of exposure was associated with increased pneumonitis-related mortality, as well as greater loss of both BMD and cortical thickness at both in- and out-of-field vertebrae. Older NHPs exhibited rapid loss of BMD and cortical thickness from in-field vertebrae, but only loss of BMD in out-of-field vertebrae. Bone is sensitive to high-dose radiation, and rapid loss of bone structure and density increases the risk of fractures.

Evaluation of the effects of photobiomodulation on vertebras in two rat models of experimental osteoporosis.

The aim of this study was to evaluate the effects of photobiomodulation (PBM) on cancellous bone in rat models of ovariectomized induced osteoporosis (OVX-D) and glucocorticoid-induced osteoporosis (GIOP). The experiment comprised of nine groups. A group of healthy rats was used for baseline evaluations. The OVX-D rats were further divided into groups as follows: control rats with osteoporosis, OVX-D rats that received alendronate (1 mg/kg 60 days), OVX-D rats treated with pulsed wave laser (890 nm, 80 Hz, 900 s, 0.0061 W/cm2, 5.5 J/cm2, three times a week, 60 days), and OVX-D rats treated with alendronate + pulsed laser. Dexamethasone was administered to the remaining rats that were split into four groups: control, alendronate-treated rats, laser-treated rats, and GIOP rats treated with alendronate + laser. T12, L1, L2, and L3 vertebrae were subjected to laser. Results of the current study demonstrated that OVX-D and GIOP significantly decreased some stereological parameters, and type 1 collagen gene expression compared to the healthy group. There was a significant increase in osteoclast number in both OVX-D and glucocorticoid administration compared to the healthy group. However, the detrimental effect of the OVX-D procedure on bone was more serious than glucocorticoid administration. Results showed that laser alone had a detrimental effect on trabecular bone volume, and cortical bone volume in groups GIOP and OVX-D compared to those in the healthy group. Alendronate significantly improved total vertebral bone volume, trabecular bone volume, and cortical bone volume, in GIOP and OVX-D groups compared to the laser-treated groups. Furthermore, the alendronate + laser in OVX-D rats and GIOP rats produced significantly increased osteoblast number and type 1 collagen gene expression and caused a significant decrease in osteoclast number compared to the controls.

Long-Term Bone Marrow Suppression During Postoperative Chemotherapy in Rectal Cancer Patients After Preoperative Chemoradiation Therapy.

PURPOSE/OBJECTIVE(S): To quantify ensuing bone marrow (BM) suppression during postoperative chemotherapy resulting from preoperative chemoradiation (CRT) therapy for rectal cancer. METHODS AND MATERIALS: We retrospectively evaluated 35 patients treated with preoperative CRT followed by postoperative 5-Fluorouracil and oxaliplatin (OxF) chemotherapy for locally advanced rectal cancer. The pelvic bone marrow (PBM) was divided into ilium (IBM), lower pelvis (LPBM), and lumbosacrum (LSBM). Dose volume histograms (DVH) measured the mean doses and percentage of BM volume receiving between 5-40 Gy (i.e.: PBM-V5, LPBM-V5). The Wilcoxon signed rank tests evaluated the differences in absolute hematologic nadirs during neoadjuvant vs. adjuvant treatment. Logistic regressions evaluated the association between dosimetric parameters and ≥ grade 3 hematologic toxicity (HT3) and hematologic event (HE) defined as ≥ grade 2 HT and a dose reduction in OxF. Receiver Operator Characteristic (ROC) curves were constructed to determine optimal threshold values leading to HT3. RESULTS: During OxF chemotherapy, 40.0% (n=14) and 48% (n=17) of rectal cancer patients experienced HT3 and HE, respectively. On multivariable logistic regression, increasing pelvic mean dose (PMD) and lower pelvis mean dose (LPMD) along with increasing PBM-V (25-40), LPBM-V25, and LPBM-V40 were significantly associated with HT3 and/or HE during postoperative chemotherapy. Exceeding ≥36.6 Gy to the PMD and ≥32.6 Gy to the LPMD strongly correlated with causing HT3 during postoperative chemotherapy. CONCLUSIONS: Neoadjuvant RT for rectal cancer has lasting effects on the pelvic BM, which are demonstrable during adjuvant OxF. Sparing of the BM during preoperative CRT can aid in reducing significant hematologic adverse events and aid in tolerance of postoperative chemotherapy.

[Effects of 1.8 mT sinusoidal alternating electromagnetic fields of different frequencies on bone biomechanics of young rats].

Objective: To study the effects of 1.8 mT sinusoidal electromagnetic fields of different frequencies on bone mineral density (BMD) and biomechanical properties in young rats. Methods: A total of 32 female SD rats (6-week-old) were randomly divided into 4 groups (8 in each):control group, 10 Hz group, 25 Hz group and 40 Hz group. The experimental groups were given 1.8 mT sinusoidal electromagnetic field intervention 90 min per day. The whole body BMD of rats was detected with dual-energy X-ray absorptiometry after 4 and 8 weeks of intervention. After 8 weeks of intervention, all rats were sacrificed, and the BMD of femur and lumbar vertebra, the length and diameter of femur, the width between medial and lateral malleolus were measured. Electronic universal material testing machine was used to obtain biomechanical properties of femur and lumbar vertebra, and micro CT scan was performed to observe micro structures of tibial cancellous bone. Results: Compared with the control group, rats in 10 Hz and 40 Hz groups had higher whole body BMD, BMD of femur, maximum load and yield strength of femur, as well as maximum load and elastic modulus of lumbar vertebra (all P<0.05). But no significant differences in the length and diameter of femur, and the width between medial and lateral malleolus were observed between control group and experimental groups (all P>0.05). Micro CT scan showed that the trabecular number and separation degree, bone volume percentage were significantly increased in 10 Hz and 40 Hz groups (all P<0.01). Rats in 25 Hz group also had higher BMD and better in biomechanical properties than control group, but the differences were not statistically significant (all P>0.05). Conclusion: 10 and 40 Hz of 1.8 mT sinusoidal electromagnetic field can significantly improve the bone density, microstructure and biomechanical properties in young rats.

Clinical curative effect of percutaneous vertebroplasty combined with 125I-seed implantation in treating spinal metastatic tumor.

This paper selected and studied 15 in-hospital patients to analyze and discuss the clinical curative effect of percutaneous vertebroplasty (PVP) combined with (125)I-seed implantation in treating spinal metastatic tumor. The evaluation of clinical curative effects was based on the observation of several factors, namely recovery conditions of vertebral body's leading edge and middle section before and after surgery, improvements of kyphosis Cobb angle, visual analog scale (VAS), and Barthel Index (BI). The paper found significant difference between preoperative VAS and postoperative VAS, and the same situation occurred to BI. However, compared to the loss rate of vertebral body's leading edge and middle section and the improvement of Cobb angle before operative, postoperative loss rate and Cobb angle did not show statistical difference. Thus the conclusion is that PVP combined with (125)I-seed implantation is a minimally invasive surgery for effectively treating spinal metastatic tumor, which does well in rapidly releasing pains, improving patients' daily life activities and life qualities.

The advantage of 3D conformal treatment of lumbar spine metastases in comparison to traditional PA or AP-PA techniques: restoring an intermediate niche of therapeutic sophistication.

BACKGROUND: To evaluate the effect of the 3D radiation field design on normal tissues compared with commonly used appositional fields in patients with lumbar spine metastases. METHODS AND MATERIALS: Ten comparative treatment plans for radiation of lumbar spine metastases were compared for posterior and anterior- posterior fields with 3D plans. RESULTS: The PTV coverage in all comparative plans was similar. V 15 of the bowel in 3D, AP-PA and PA plans was 6.7 Gy (SD 6.47), 39.8 Gy (SD 11.4) and 37.3 Gy (SD15.7), respectively (p < 0.0001). The mean dose to both kidneys was 9.6 Gy (SD 4.8), 4.1 Gy (SD 3.9) and 4.6 Gy (SD 4.4) for appropriate plans (p = 0.002). Maximal dose to the spinal cord was 30.6 Gy (SD 2.1), 33.1 Gy (SD 9.8) and 37.7 Gy (SD 2) for 3D, AP-PA and PA plans. CONCLUSION: 3D conformal treatment planning of lumbar vertebral metastases was significantly better in term of bowel and spinal cord exposure compared to AP-PA and PA techniques. The exposure of the kidneys in 3D plans, while greater than in the comparative plans, did not violate accepted dose-volume thresholds.

Randomized, double-blinded, placebo-controlled, trial of risedronate for the prevention of bone mineral density loss in nonmetastatic prostate cancer patients receiving radiation therapy plus androgen deprivation therapy.

PURPOSE: Androgen deprivation therapy (ADT) has been used as an adjuvant treatment to radiation therapy (RT) for the management of locally advanced prostate carcinoma. Long-term ADT decreases bone mineral density (BMD) and increases the risk of osteoporosis. The objective of this clinical trial was to evaluate the efficacy of risedronate for the prevention of BMD loss in nonmetastatic prostate cancer patients undergoing RT plus 2 to 3 years of ADT. METHODS AND MATERIALS: A double-blinded, placebo-controlled, randomized trial was conducted for nonmetastatic prostate cancer patients receiving RT plus 2 to 3 years of ADT. All had T scores > -2.5 on dual energy x-ray absorptiometry at baseline. Patients were randomized 1:1 between risedronate and placebo for 2 years. The primary endpoints were the percent changes in the BMD of the lumbar spine at 1 and 2 years from baseline, measured by dual energy x-ray absorptiometry. Analyses of the changes in BMD and bone turnover biomarkers were carried out by comparing mean values of the intrapatient changes between the 2 arms, using standard t tests. RESULTS: One hundred four patients were accrued between 2004 and 2007, with 52 in each arm. Mean age was 66.8 and 67.5 years for the placebo and risedronate, respectively. At 1 and 2 years, mean (±SE) BMD of the lumbar spine decreased by 5.77% ± 4.66% and 13.55% ± 6.33%, respectively, in the placebo, compared with 0.12% ± 1.29% at 1 year (P=.2485) and 0.85% ± 1.56% (P=.0583) at 2 years in the risedronate. The placebo had a significant increase in serum bone turnover biomarkers compared with the risedronate. CONCLUSIONS: Weekly oral risedronate prevented BMD loss at 2 years and resulted in significant suppression of bone turnover biomarkers for 24 months for patients receiving RT plus 2 to 3 years of ADT.

Severe spinal deformity and multiple vertebral collapses in juvenile Cushing Syndrome: a case report.

Cushing's Syndrome (CS) is rare in adolescence but the pathological effects of excessive circulating glucocorticoids concentration on bone during the developmental age still represent a challenge for orthopedists. Only few reports describe the gravity of early developed damages of spine in young affected by CS. A 18-years-old woman suffering from Cushing's Disease presented after many years treatment of the primary disease referring severe back pain and worsening back deformity. Radiological investigations showed vertebral collapses a devastating thoraco-lumbar scoliosis of 80° Cobb. Lumbar dual X-ray absorptiometry Z-score values were very low and consistent with severe osteoporosis. The patient was treated with bracing, antiresorptive therapy, calcium and vitamin D supplementation, and followed-up with imaging investigations to screen for further fractures. The bone mineral density will be monitored until its normalization will allow to plane surgical treatment in case of progression of spinal deformity and collapses. Early diagnosis and treatment of hypercortisolism, periodical clinical and radiographic follow-up, and treatment for the bone damage are mandatory to prevent the devastating sequelae of secondary osteoporosis.

Effects of pulsed electromagnetic fields on bone mass and Wnt/ß-catenin signaling pathway in ovariectomized rats.

BACKGROUND AND AIMS: The therapeutic effects of pulsed electromagnetic fields (PEMFs) on osteoporosis have been documented. However, the precise mechanisms by which PEMFs elicit these favorable biological responses are still not fully understood. This study aimed to systematically investigate the effects of PEMFs on bone mass and Wnt/ß-catenin signaling pathway in ovariectomized rats. METHODS: Thirty 3-month-old female Sprague Dawley rats were randomly assigned to one of three groups: sham-operated control (sham), ovariectomy (OVX), and ovariectomy with PEMFs treatment (PEMFs). One week following ovariectomy surgery, rats in the PEMFs group were exposed to PEMFs for 40 min/day, 5 days/week, for 12 weeks. RESULTS: After 12-week interventions, serum 17ß-estradiol and bone-specific alkaline phosphatase levels increased in the PEMFs group. Bone mineral density of the femur and the fifth lumbar vertebral body also increased in the PEMFs group. Histomorphometrical studies showed that PEMFs improved trabecular area, trabecular width, and trabecular number by 77.50%, 17.38% and 51.06%, respectively, and reduced trabecular separation by 44.28% compared with the OVX group. Biomechanical studies showed that PEMFs increased maximum load and energy to failure in the fifth lumbar vertebral body. Quantitative real-time RT-PCR analysis showed that PEMFs increased the mRNA expressions of Wnt3a, low-density lipoprotein receptor-related protein 5(LRP5), ß-catenin, c-myc and runt-related gene 2 (Runx2), and reduced dickkopf1 (DKK1) in ovariectomized rats. However, mRNA expression of Axin2 was not affected by PEMFs. CONCLUSIONS: PEMFs can prevent ovariectomy-induced bone loss and deterioration of bone microarchitecture and strength, at least partly, through activation of Wnt/ß-catenin signaling pathway.

Patient dose measurements in diagnostic radiology procedures in Montenegro.

It was the aim of the study presented here to estimate for the first time patient dose levels in conventional diagnostic radiology in Montenegro. Measurements of patient dose in terms of entrance surface air kerma (ESAK) and kerma-area product (KAP) were performed on at least 10 patients for each examination type, in each of five randomly selected health institutions in Montenegro, so that a total of 872 patients for 16 different examination categories were included in the survey (817 patients for 1049 radiographies and 55 fluoroscopy patients). Exposure settings and individual data were recorded for each patient. Mean, median and third quartile values ESAK of patient doses are reported. The estimated mean ESAK values obtained are as follows: 4.7 mGy for pelvis anteroposterior (AP), 4.5 mGy for lumbar spine AP, 7.8 mGy for lumbar spine lateral (LAT), 3.1 mGy for thoracic spine AP and 4.3 mGy for thoracic spine LAT. When compared with the European diagnostic reference values, the mean ESAK for all studied examination types are found to be below the reference levels, except in chest radiography. Mean ESAK values for chest radiography are 0.9 mGy for posteroanterior (PA) projection and 2.0 mGy for LAT. The results exhibit a wide range of variation. For fluoroscopy examinations, the total KAP was measured. The mean KAP value per procedure for barium meal is found to be 22 Gy cm(2), 41 Gy cm(2) for barium enema and 19 Gy cm(2) for intravenous urography. Broad dose ranges for the same types of examinations indicate the necessity of applying practice optimisation in diagnostic radiology and establishment of national diagnostic reference levels.

Heavy ion irradiation and unloading effects on mouse lumbar vertebral microarchitecture, mechanical properties and tissue stresses.

Astronauts are exposed to both musculoskeletal disuse and heavy ion radiation in space. Disuse alters the magnitude and direction of forces placed upon the skeleton causing bone remodeling, while energy deposited by ionizing radiation causes free radical formation and can lead to DNA strand breaks and oxidative damage to tissues. Radiation and disuse each result in a net loss of mineralized tissue in the adult, although the combined effects, subsequent consequences for mechanical properties and potential for recovery may differ. First, we examined how a high dose (2 Gy) of heavy ion radiation ((56)Fe) causes loss of mineralized tissue in the lumbar vertebrae of skeletally mature (4 months old), male, C57BL/6 mice using microcomputed tomography and determined the influence of structural changes on mechanical properties using whole bone compression tests and finite element analyses. Next, we tested if a low dose (0.5 Gy) of heavy particle radiation prevents skeletal recovery from a 14-day period of hindlimb unloading. Irradiation with a high dose of (56)Fe (2 Gy) caused bone loss (-14%) in the cancellous-rich centrum of the fourth lumbar vertebra (L4) 1 month later, increased trabecular stresses (+27%), increased the propensity for trabecular buckling and shifted stresses to the cortex. As expected, hindlimb unloading (14 days) alone adversely affected microarchitectural and mechanical stiffness of lumbar vertebrae, although the reduction in yield force was not statistically significant (-17%). Irradiation with a low dose of (56)Fe (0.5 Gy) did not affect vertebrae in normally loaded mice, but significantly reduced compressive yield force in vertebrae of unloaded mice relative to sham-irradiated controls (-24%). Irradiation did not impair the recovery of trabecular bone volume fraction that occurs after hindlimb unloaded mice are released to ambulate normally, although microarchitectural differences persisted 28 days later (96% increase in ratio of rod- to plate-like trabeculae). In summary, (56)Fe irradiation (0.5 Gy) of unloaded mice contributed to a reduction in compressive strength and partially prevented recovery of cancellous microarchitecture from adaptive responses of lumbar vertebrae to skeletal unloading. Thus, irradiation with heavy ions may accelerate or worsen the loss of skeletal integrity triggered by musculoskeletal disuse.

Use of spinal cord stimulator for treatment of lumbar radiculopathy in a patient with severe kyphoscoliosis.

Spinal cord stimulation (SCS) has been a therapeutic option for chronic pain for over 40 years with a common indication being failed back surgery syndrome (FBSS). This case reports the successful implantation of a spinal cord stimulator in a patient with FBSS and kyphoscoliosis for treatment of radicular pain. Technical considerations and anatomical difficulties that may be encountered during placement with kyphoscoliosis will be discussed. This patient had failed other therapies including oral medications, epidural steroid injections, spinal surgeries, and physical and aquatic therapies. On physical examination the patient had a severely deformed lumbar spine. Careful review of the spine radiographs and CT scan revealed lead placement might be possible at the level of T12-L1 or L1-2. A Medline search did not reveal a case of kyphoscoliosis with radicular pain treated with SCS. After a successful percutaneous trial, a SCS was implanted. Fourteen weeks later, the patient reported being pain free with an increased physical activity level and opioid discontinuation. Technical considerations with kyphoscoliosis may discourage pain physicians from attempting SCS. This case illustrates that with careful selection, some of these patients may be candidates for SCS with good results.

Diagnosis and minimally invasive treatment of lumbar discogenic pain--a review of the literature.

Diagnosis and treatment of lumbar discogenic pain due to internal disc disruption (IDD) remains a challenge. It accounts for 39% of patients with low back pain. The mechanism of discogenic pain remains unclear and its clinical presentation is atypical. Magnetic resonance imaging (MRI) can find high-intensity zone as an indirect indication of IDD. However, relative low sensitivity (26.7% to 59%) and high false-positive (24%) and false-negative (38%) rates reduce the value of MRI in screening for the existence of painful IDD. Provocative discography can provide unique information about the pain source and the morphology of the disc. It may also provide information for selecting appropriate treatment for the painful annular tear. Adjunctive therapies, including nonsteroidal anti-inflammatory drugs, physical therapy, rehabilitation, antidepressants, antiepileptics, and acupuncture, have been used for low back pain. The value of these treatments for discogenic pain is yet to be established. Intradiscal steroid injection has not been proved to provide long-term benefits. Intradiscal electrothermal therapy may offer some pain relief for a group of well-selected patients. No benefits have been found for the intradiscal radiofrequency thermocoagulation. A block in the ramus communicans may interfere with the transition of painful information from the discs to the central nervous system. Disc cell transplantation is in the experimental stage. It has the potential to become a useful tool for the prevention and treatment of discogenic pain. Minimally invasive treatments provide alternatives for discogenic pain with the appeal of cost-effectiveness and, possibly, less long-term side effects. However, the value of most of these therapies is yet to be established. More basic science and clinical studies are needed to improve the clinical efficacy of minimally invasive treatments.

The effect of laser irradiation for nucleus pulposus: an experimental study.

BACKGROUND: The radicular pain caused by disc herniation can be explained by two mechanisms: the compression of the nerve root by the herniated disc or the irritation of the nerve root due to chemical factors. Percutaneous laser disc decompression (PLDD) was introduced for the treatment of lumbar disc hernias in the 1980s. Decompression of the nerve root is assumed to be an effective therapeutic mechanism for PLDD. However, laser irradiation might reduce the chemical factors that cause nerve root irritation by altering intra-disc proteins. We used nerve conduction velocities (NCV) and levels of two chemical factors to evaluate the differences between the two groups in this in vivo study. METHODS: All rabbits had the nerve root in contact with the leakage from the nucleus pulposus. One group underwent laser irradiation for the leaking nucleus pulposus including the incision site of the disc and nucleus pulposus itself. The levels of two chemical factors, prostaglandin E2 and phospholipase E2, in the intervertebral disc were measured before and after laser irradiation. RESULTS: NCV in the laser-irradiated group was significantly faster than in the non-laser-irradiated group. The levels of chemical factors were significantly reduced after laser irradiation. CONCLUSIONS: One of the mechanisms thought to be responsible for PLDD's effectiveness is a decrease in the chemical factors through protein alteration in the intervertebral disc by laser irradiation.

Evaluation of temperature distributions in cadaveric lumbar spine during nucleoplasty.

In this study, temperature maps were obtained throughout human cadaveric disc specimens (n = 6) during a simulated Nucleoplasty treatment. The procedure was performed using the Perc-DL SpineWand (ArthroCare, Sunnyvale, CA) inserted through a 17 gage needle into the human cadaveric disc. The device uses a dual mode heating technique which employs a high voltage radio frequency (RF) plasma field to vaporize tissue (Coblation), followed by bipolar RF current heating for thermal coagulation. The device, with a distal 's-curve', is manipulated manually to create a series of six channels at a 60 degrees angular spacing within a period of 3 min. A computer-controlled, motorized translational system was used to reproducibly mimic the insertion (Coblation) and retraction (rf-coagulation) performed during clinical implementation, with rotation performed manually between each Coblation/coagulation cycle. Transient temperature data were obtained using five multi-junction thermocouple probes (5-8 junctions spaced at either 2 or 5 mm intervals, with 0.33 or 0.56 mm probe diameter) spaced throughout the desired heating volume. Transient temperature curves were obtained from 26+ points throughout the disc, and the data used to calculate accumulated thermal doses. Transient peaks of 80-90 degrees C were recorded within the discs, with temperatures greater than 60-65 degrees C measured within a radial distance of 3-4 mm from the introducer (applicator centreline). Accumulated thermal doses of t43 > 250 min were produced at radial distances of up to 6 mm from the introducer. Gross inspection of the discs revealed a narrow region of coagulation along the insertion length. Given these radial thermal penetrations and the possibility for unpredictable positioning during current clinical implementation, high temperatures and lethal thermal doses in small regions outside of the nucleus, or within the bone endplates, may be possible in clinical implementation.

One year comparison between two add-back therapies in patients treated with a GnRH agonist for symptomatic endometriosis: a randomized double-blind trial.

BACKGROUND: It has been proposed that hormonal supplementation during prolonged GnRH agonist therapy prevents hypoestrogenic side effects, including bone loss. The optimal combination for long-term treatments with safe metabolic profile remains questionable. A norprogesterone derivative, promegestone, was assessed for the first time in a double-blind trial. METHODS: Seventy-eight patients with endometriosis with rAFS (Revised American Society for Reproductive Medicine) scores of III-IV were randomly assigned to monthly leuprorelin 3.75 mg (1 year) which, after the third injection was used in combination with promegestone 0.5 mg (P) plus either estradiol placebo (PL) or estradiol 2 mg (E) per day. Bone mineral density (BMD) was determined at baseline, 6 and 12 months, and biological and clinical quarterly assessments were performed. Analysis was by the intention to treat method. RESULTS: At month 12, BMD changes from baseline were -6.1 +/- 3.7 and -4.9 +/- 4.0% in the PL-P group, at the spine and hip, respectively. This bone loss was prevented in the E-P group: -1.9 +/- 3.1 and -1.4 +/- 2.3%, respectively (P < 0.0001 inter-group comparisons). The BMD decrease in the E-P group was explained by the changes occurring during the first 6 months of treatment. There was no deleterious change in lipid parameters. Clinical improvement was observed without an inter-group difference. CONCLUSIONS: Estradiol 2 mg and promegestone 0.5 mg per day is an effective and safe add-back therapy, which can be proposed for prolonged leuprorelin treatment over 6 months in severe endometriosis.

Lumbar intervertebral thermal therapies.

In hopes of improving outcomes for patients with discogenic pain, less invasive techniques that reduce trauma and shorten the recovery period have been developed. This article attempts to present a comprehensive description of minimally invasive techniques, specifically heat treatments, for lumbar disc disease. The goal is to inform and educate the reader on the various thermal therapies available for lumbar disc disease by evaluating the scientific data in an objective manner.