Intraindividual comparison of preoperative (99m)Tc-MDP SPECT/CT and intraoperative and histopathological findings in patients with bisphosphonate- or denosumab-related osteonecrosis of the jaw

Development of a novel phantom for evaluating jawbone SPECT targeting medication-related osteonecrosis of the jaw

OBJECTIVE

We developed a new phantom for technical evaluation of jawbone single-photon emission computed tomography (SPECT) examinations for medication-related osteonecrosis of the jaw (MRONJ). In this study, we verified the utility of the phantom by determining optimal image reconstruction parameters.

METHODS

We evaluated the image quality and quantification in jawbone SPECT images obtained by different reconstruction parameters using the phantom. The phantom images were acquired using a SPECT/computed tomography (CT) system and then reconstructed using ordered-subset expectation maximization (OSEM) iterative reconstruction with resolution recovery as well as scatter and attenuation correction with various update numbers and Gaussian filter full width at half maximums (FWHMs). The percent contrast (%contrast) and absolute recovery coefficient were calculated to determine the optimal reconstruction parameters (OSEMjaw). Nineteen patients with a clinical diagnosis of MRONJ who underwent bone SPECT/CT were enrolled for the clinical study. The performance of OSEMjaw was verified by comparison with OSEMcurrent determined by a spherical phantom, using the correlation between the mean standardized uptake value (SUVmean) and clinical staging and visual assessment as endpoints.

RESULTS

In the phantom study, %contrast and absolute recovery coefficient increased with increasing update numbers. As the Gaussian filter FWHM increased, the quantitative accuracy and image sharpness decreased. The parameter determined by the phantom study (OSEMjaw) recommended 120 updates and no filter. In the clinical study, the mean and standard deviation of SUVmean obtained from OSEMjaw were 8.9 ± 1.4 for stage 1 lesions, 12.9 ± 4.1 for stage 2 lesions, and 13.8 ± 1.4 for stage 3 lesions. For OSEMcurrent, they were 5.4 ± 2.3 for stage 1 lesions, 8.3 ± 2.5 for stage 2 lesions, and 8.0 ± 0.9 for stage 3 lesions. The SUVmean obtained from OSEMjaw had a stronger correlation with clinical stage. Based on visual assessment, the quality of the SPECT images reconstructed by OSEMjaw (3.7 ± 0.9) was superior to that reconstructed by OSEMcurrent (2.9 ± 1.1).

CONCLUSIONS

We developed a novel phantom and adapted it for technical evaluation. This study demonstrated the utility of the developed phantom.

Determination of adequate bony resection margins in inflammatory jaw pathologies using SPECT-CT in primary mandibular reconstruction with virtually planned vascularized bone flaps

OBJECTIVES

In advanced stages of osteoradionecrosis, medication-related osteonecrosis of the jaw, and osteomyelitis, a resection of sections of the mandible may be unavoidable. The determination of adequate bony resection margins is a fundamental problem because bony resection margins cannot be secured intraoperatively. Single-photon emission computed tomography (SPECT-CT) is more accurate than conventional imaging techniques in detecting inflammatory jaw pathologies. The clinical benefit for virtual planning of mandibular resection and primary reconstruction with vascularized bone flaps has not yet been investigated. This study aimed to evaluate the determination of adequate bony resection margins using SPECT computed tomography (SPECT-CT) for primary microvascular reconstruction of the mandible in inflammatory jaw pathologies.

MATERIALS AND METHODS

The cases of 20 patients with inflammatory jaw pathologies who underwent primary microvascular mandibular reconstruction after the bony resection margins were determined with SPECT-CT were retrospectively analyzed. The bony resection margins determined by SPECT-CT were histologically validated. The sensitivity was calculated as the detection rate and the positive predictive value as the diagnostic precision. Radiological ossification of the vascularized bone flaps with the mandibular stumps was assessed at least 6 months after reconstruction. The clinical course was followed for 12 months.

RESULTS

The determination of adequate bony resection margins with SPECT-CT yielded a sensitivity of 100% and a positive predictive value of 94.7%. Of all the bony resection margins, 97.4% were radiologically sufficiently ossified with the vascularized bone flap and showed no complications in the clinical course.

CONCLUSIONS

SPECT-CT could increase the probability of determining adequate bony resection margins.

CLINICAL RELEVANCE

SPECT-CT could have a beneficial clinical impact in the context of primary microvascular bony reconstruction in inflammatory jaw pathologies.

Comparison of single photon emission computed tomography-computed tomography, computed tomography and magnetic resonance imaging of medication-related osteonecrosis of jaw by new calculated parameters

BACKGROUND

This study aimed to investigate parameters for medication-related osteonecrosis of jaw (MRONJ) patients using the bone SPECT/CT, especially bone mineral-based parameters.

METHODS

Sixty-three patients with MRONJ (43 osteoporosis and 20 bone metastasises) underwent CT, MRI and SPECT/CT. A commercially available software automatically detected lesion area and calculated the quantitative SPECT/CT parameters as bone mineral-based standardized uptake value (SUV).

RESULTS

Regarding stage of MRONJ patients, bone mineral based maximum SUV of stage 3 was significantly higher than stage 1, 2 (P=0.018). Regarding duration of medication therapy, bone mineral based maximum SUV 1 year or more was significantly higher than less than 1 year (P=0.019). Regarding present of periosteal bone proliferation on CT, bone mineral based maximum SUV was significantly higher than those of absent (P=0.029). Regarding spread of soft tissue inflammation on MRI, bone mineral based maximum SUV of 2 or more was significantly higher than those of less than 2 spaces (P=0.025). Regarding blood pool phase imaging with SPECT, bone mineral based maximum SUV of intense uptake was significantly higher than those of decrease uptake (P=0.002).

CONCLUSIONS

SPECT/CT bone mineral-based parameters indicated significant difference in staging, dosing period, periosteal bone proliferation on CT, spread of soft tissue inflammation on MRI, and blood phase imaging with SPECT. Bone SPECT/CT bone mineral-based parameters are helpful for the assessment of MRONJ.

Usefulness of quantitative bone SPECT/CT for evaluating medication-related osteonecrosis of the jaw treatment response

OBJECTIVE

For assessment of therapeutic response in medication-related osteonecrosis of the jaw (MRONJ) cases, the clinical usefulness of quantitative bone single-photon computed tomography-computed tomography (SPECT/CT) results was investigated.

MATERIALS AND METHODS

Sixteen patients (18 lesions) with a clinical diagnosis of MRONJ underwent bone SPECT/CT scanning before and during/after anti-inflammatory therapy given for 3 or more months. The GI-BONE software package was used to determine standard uptake values (SUVs), including maximum (SUVmax), peak (SUVpeak), and mean (SUVmean), and metabolic bone volume (MBV) and also total bone uptake (TBU). In both responders (downstage) and non-responders (upstage or no change), differences in quantitative values between the first and second SPECT/CT examinations were analyzed using a Wilcoxon test.

RESULTS

Following therapy, significant reductions in SUVmax, SUVpeak, SUVmean, MBV and TBU values for 11 lesions were noted in the responders after therapy (p = 0.003, p = 0.006, p = 0.004, p = 0.003, and p = 0.002, respectively). On the other hand, those for the seven lesions in the non-responder group were not significantly different (p = 0.17, p = 0.16, p = 0.26, p = 0.96, and p = 0.12, respectively). Results for SUVmax change showed sensitivity and specificity values of 45.5% and 85.7%, respectively, for differentiating responders from non-responders, with - 37.3% the optimal cutoff value. Those for MBV change were 72.7 and 85.7%, respectively, with - 29.4% the optimal cutoff value. Those for TBU change were 81.8% and 85.7%, respectively, with - 36.3% the optimal cutoff value.

CONCLUSION

The present findings showed that therapeutic response in MRONJ cases could be determined by use of quantitative SUV, MBV, and TBU values based on bone SPECT/CT findings.

Usefulness of quantitative bone SPECT/CT for medication-related osteonecrosis of the jaw in clinical settings

OBJECTIVE

This study was conducted to investigate the clinical utility of quantitative bone single-photon computed tomography-computed tomography (SPECT/CT) for detection and classification for medication-related osteonecrosis of the jaw (MRONJ).

MATERIALS AND METHODS

Fifty-nine patients (69 lesions) clinically diagnosed as MRONJ by four specialists of Japanese Society of Oral Surgery according to the AAOMS diagnostic criteria and who underwent bone SPECT/CT were enrolled. One reader determined standard uptake values (SUVs), including maximum (SUVmax), peak (SUVpeak), and mean (SUVmean), as well as metabolic bone volume (MBV), representing total volume above threshold, and total bone uptake (TBU), calculated as MBV × SUVmean, using the GI-BONE software package. One-way repeated-measures analysis of variance and subsequent post hoc analysis were employed to compare quantitative values between clinical stages. To check reproducibility of values, another reader calculated these quantitative values.

RESULTS

Mean SUVmax values for stage 0 (n = 21), 1 (n = 13), 2 (n = 25), and 3 (n = 10) were 5.82 ± 3.20, 5.46 ± 3.79, 8.16 ± 3.93, and 10.57 ± 8.43, respectively, while values for MBV were 9.52 ± 6.33, 11.36 ± 7.32, 12.4 ± 8.21, and 17.84 ± 16.94, respectively, and for TBU were 40.60 ± 46.97, 53.70 ± 77.26, 62.37 ± 42.91, and 102.01 ± 74.52, respectively. There were significant differences for SUVmax, SUVpeak, and SUVmean between clinical stages (p = 0.024, p = 0.027, p = 0.039, respectively). Subsequent post hoc analysis showed that SUVmax and SUVpeak of stage 3 were significantly higher than those of stage 0 (p = 0.046, 0.045, respectively). MBV and TBU showed a tendency to increase with increased stage, though differences between stages were not significant (p = 0.15, p = 0.053, respectively). Little differences of mean SUVmax, SUVpeak, SUVmean, MBV, and TBU between two readers were observed (- 3.10%, - 0.26%, - 4.24%%, 0.69%, and - 3.42%, respectively). The intraclass correlation coefficients (ICCs) of SUVmax, SUVpeak, SUVmean, MBV, and TBU were 0.985, 0.990, 0.980, 0.994, and 0.994, respectively (almost perfect for all values).

CONCLUSION

As objective and reliable indicators, SUVmax and SUVpeak derived from quantitative bone SPECT/CT results are useful for detection of early status disease, as well as staging in MRONJ patients.

Quantitative Analysis of Multimodal Skeletal SPECT/CT Reconstructions in Diagnosing Medication-related Osteonecrosis of the Jaw

AIM

Our goal was to assess visual and quantitative aspects of multimodal skeletal SPECT/CT reconstructions (recon) in differentiating necrotic and healthy bone of patients with suspected MRONJ.

METHODS

Prior to surgery, 20 patients with suspected MRONJ underwent SPECT/CT of the jaw 3-4 hours after injection of Tc-99m-DPD (622±112.4 MBq). SPECT/CT data were reconstructed using the multimodal xSPECT Bone and xSPECT Quant algorithms as well as the OSEM-algorithm FLASH 3D. For analysis, we divided the jaw into 12 separate regions. Both xSPECT Bone and FLASH 3D datasets were scored on a four-point scale (VIS xSPECT; VIS F3D), based on the intensity of localized tracer uptake. In F3D and xSPECT Quant datasets, local tracer uptake of each region was recorded as semi-quantitative uptake ratio (SQR F3D) or SUVs, respectively. ROC analysis was performed. Postoperative histologic results served as gold standard.

RESULTS

VIS F3D, VIS xSPECT and SQR F3D did not differ significantly in diagnostic accuracy (VIS xSPECT sensitivity=0.64; specificity=0.89). Of the quantitative parameters, SUVpeak yielded the best interobserver reproducibility. SUVpeak was 9.9±7.1 (95%CI: 7.84-11.95) in MRONJ regions, as opposed 3.6±1.8 (95% CI:3.36-3.88) elsewhere, with a cutpoint of 4.5 (sensitivity=0.83; specificity=0.80). Absolute quantitation significantly surpassed VIS and SQR (p<0.05) in accuracy and interobserver agreement (SUVpeak: κ=0.92; VIS xSPECT: κ=0.61; SQR F3D κ=0.66).

CONCLUSION

Absolute quantitation proved significantly more accurate than visual and semi-quantitative assessment in diagnosing MRONJ, with higher interobserver agreement.

[Determination of Bone SPECT Image Reconstruction Conditions in the Head and Neck Region]

PURPOSE

Quantitative analysis using a standardized uptake value (SUV) has become possible for single-photon emission computed tomography-computed tomography (SPECT-CT) of bone. However, previous research was targeted to the trunk area, and there are few studies for the head and neck region. Therefore, the purpose of this study was to determine the optimal image reconstruction conditions for bone SPECT of the head and neck using a phantom study.

METHOD

The radioactivity concentration of the ^99mTc solution enclosed in the cylindrical phantom was set to the same count rate as in clinical cases, and six hot spheres (10, 13, 17, 22, 28, 37 mm) with four times the concentration were placed within it. The image reconstruction was 3D-OSEM, and the reconstruction conditions were varied by the number of iterative updates and the width of the Gaussian filter. Quantitative evaluations of the image quality were performed using the % contrast, background variability, and SUV for the hot spheres and background. A visual evaluation was performed by four observers to determine the optimal image reconstruction conditions for bone SPECT of the head and neck region.

RESULT

The concentration of the ^99mTc solution enclosed in the phantom was 6.95 (kBq/ml). Based on the results of the quantitative and visual evaluations, the optimal image reconstruction conditions were iterative updates=60 (subset: 10, iteration: 6) and a Gaussian filter of 7.8 mm.

CONCLUSION

The optimal image reconstruction conditions were subset=10, iterations=6, and a Gaussian filter of 7.8 mm.

Effect of morphological findings in computed tomography on the quantitative values in single-photon emission computed tomography for patients with antiresorptive agent-related osteonecrosis of the jaw: a cross-sectional study

OBJECTIVE

Quantitative analyses of gamma-ray accumulation in single-photon emission computed tomography (SPECT), and the evaluation of antiresorptive agent-related osteonecrosis of the jaw (ARONJ) have been reported recently. However, the relationship between the quantitative parameters calculated from SPECT and the detailed morphological changes observed in computed tomography (CT) remains unclear. This study aimed to investigate patients' characteristics and morphological changes observed on CT, and their effects on the quantitative values in SPECT.

METHODS

From April 2017 to March 2019, patients diagnosed with ARONJ at our hospital were enrolled. The data obtained before September 2017 were reviewed retrospectively, and other data were collected prospectively. CT scans were evaluated for internal texture, sequestrum formation, periosteal reaction, cortical perforation, bone expansion, and pathological fracture. For quantitative assessment, the ratio of the maximum standardized uptake value (SUV) to the mean SUV in the temporal bone (rSUVmax) was calculated from SPECT images. The factors affecting rSUVmax were investigated by multiple regression analysis. The statistical significance level was set at α = 0.05.

RESULTS

Overall, 55 lesions of 42 patients (median age and interquartile range, 75 [67-80 years], 27 female) were evaluated. Male sex (p = 0.007) and bilateral location (p < 0.0001) were selected as variables in the multivariate analysis. Adjusted coefficient of determination R2 was 0.59 (p < 0.0001).

CONCLUSION

Sex and horizontal progression of the disease may affect individually calibrated SUVs in SPECT for patients with ARONJ.

A critical assessment of the medication-related osteonecrosis of the jaw classification in stage I patients: a retrospective analysis

Objectives

It is unclear whether the extent of intraoral mucosa defects in patients with medication-related osteonecrosis of the jaw indicates disease severity. Therefore, this study investigated whether mucosal lesions correlate with the true extent of osseous defects in stage I patients.

Materials and Methods

Retrospectively, all patients with stage I medication-related osteonecrosis of the jaw who underwent surgical treatment between April 2018 and April 2019 were enrolled. Preoperatively, the extent of their mucosal lesions was measured in clinical evaluations, and patients were assigned to either the visible or the probeable bone group. Intraoperatively, the extent of necrosis was measured manually and with fluorescence.

Results

Fifty-five patients (36 female, 19 male) with 86 lesions (46 visible bone, 40 probeable bone) were enrolled. Intraoperatively, the necrotic lesions were significantly larger (P<0.001) than the preoperative mucosal lesions in both groups. A significant (P<0.05) but very weak (R2<0.2) relationship was noted between the extent of the mucosal lesions and the necrotic bone area.

Conclusion

Preoperative mucosal defects (visible or probeable) in patients with medication-related osteonecrosis of the jaw do not indicate the extent of bone necrosis or disease severity.

Do various imaging modalities provide potential early detection and diagnosis of medication-related osteonecrosis of the jaw? A review

OBJECTIVE

Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities' usage and findings of MRONJ to provide possible approaches for early detection.

METHODS

Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.

RESULTS

Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T₁WI and hyperintense on T₂WI and STIR when necrotic bone shows hypointensity on all T₁WI, T₂WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.

CONCLUSION

Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

Retrospective analysis of bacterial colonization of necrotic bone and antibiotic resistance in 98 patients with medication-related osteonecrosis of the jaw (MRONJ)

OBJECTIVES

The aim of our study was to describe microbial flora associated with MRONJ and characterize the susceptibility of pathogens to help guide an effective empiric antibiotic treatment in these patients.

MATERIALS AND METHODS

A retrospective, single-center analysis was performed, using 116 bone samples from 98 patients. The bone samples were homogenized and subjected to routine culture methods. Growing bacteria were differentiated to the species level using whole-cell mass spectrometry and subjected to susceptibility testing.

RESULTS

A highly diverse microbial flora was detected in necrotic bone, with a simultaneous presence of two or more bacterial species in 79% of all patients. In at least 65% of samples, gram-negative isolates were detected. Therefore, bacterial species resistant against β-lactamase inhibitors were present in at least 70% of all patients.

CONCLUSIONS

The empiric choice of antibiotics in MRONJ patients should consider the high rate of gram-negative bacteria and resistance against β-lactam antibiotics.

CLINICAL RELEVANCE

According to recent guidelines and recommendations, systemic antibiotic treatment is a key component in the treatment of all stage 2 and 3 MRONJ patients. We recommend using fluoroquinolones for empiric treatment and emphasize the use of bacterial cultivation and susceptibility testing to enable an effective antibiotic treatment.

The role, efficacy and outcome measures for teriparatide use in the management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a complex disease which can be associated with multiple morbidities and is challenging to treat. This review evaluates the literature on the role and efficacy of teriparatide (TPTD) as a treatment for MRONJ. The clinical, radiological, histopathological and serological parameters used to assess treatment response have been described. Electronic databases were searched to retrieve articles (April 2005 and April 2020) based on strict inclusion criteria. Seventeen articles were included in this review. Of the 91 patients treated; only six received TPTD as a standalone treatment. There were significant variations in defining treatment outcomes and measuring treatment response. The longest follow-up period was 26 months, and 12 studies failed to report follow-up. The overall quality of evidence is weak with potential for a high risk of bias, making it difficult to determine the efficacy of TPTD and its long-term effects. However, TPTD may play a role in the treatment of intractable MRONJ in osteoporotic patients or those unfit for surgery. Therefore, randomized clinical trials on larger patient cohorts with long-term follow-up is required to confirm efficacy, safety and inform treatment indications for TPTD in the treatment of MRONJ.

Monitoring indices of bone inflammatory activity of the jaw using SPECT bone scintigraphy: a study of ARONJ patients

Development of quantitative analysis software has enabled application of several standardised uptake values (SUV) for bone analysis in single photon emission computed tomography (SPECT). The present retrospective study aimed to develop a reliable method of monitoring bone inflammatory activity in antiresorptive agent-related osteonecrosis of the jaw (ARONJ) using SPECT quantitative analysis software. Fifteen ARONJ patients underwent SPECT before and after anti-inflammatory therapy. We calculated the mean maximum SUV (SUVmax) of the bilateral cranial bones using quantitative analysis software and used this as the control [C]. We attempted to adjust the SUVmax of the lesion [L] as follows: adjusted SUVmax (aSUVmax) = [L] - [C]. The optimum threshold to calculate the metabolic bone volume (MBV) (cm³) was [C] + 3. The threshold values obtained for each case were input to calculate MBV at each osteomyelitis site. Retrospectively, we compared aSUVmax and MBV of each patient's ARONJ before and after anti-inflammatory therapy. The patients' high aSUVmax or large MBV of the ARONJ reduced rapidly, reflecting individual clinical findings after treatment. Application of SPECT quantitative analysis software to monitor bone inflammatory activity in ARONJ could improve the prognosis-deciding abilities of clinicians and enable them to treat ARONJ effectively.

Quantitative evaluation of anti-resorptive agent-related osteonecrosis of the jaw using bone single photon emission computed tomography in clinical settings: relationship between clinical stage and imaging

OBJECTIVE

This study aimed to use quantitative values, calculated from bone single photon emission computed tomography (SPECT) imaging, to estimate the reliability of progression evaluation for anti-resorptive agent-related osteonecrosis of the jaw (ARONJ).

METHODS

The study population consisted of 21 patients (23 lesions), clinically diagnosed with mandibular ARONJ, who underwent SPECT/CT scanning. Diagnosis and staging of ARONJ were performed according to the American Association of Oral and Maxillofacial Surgeons (AAOMS) definition and the recommendations of the International Task Force on ONJ. Hybrid SPECT/CT imaging quantitative analyses were performed on a workstation. Each volume of interest (VOI) was semi-automatically placed over a lesion with areas of high tracer accumulation, using the GI-BONE^® software default threshold method settings. Additionally, control VOI was manually set over an unaffected area. Measured parameters included standardized uptake values (SUV)-maximum (SUV_max) and mean (SUV_mean), metabolic bone volume (MBV)-the total volume above the threshold, and total bone uptake (TBU) as calculated by MBV × SUV_mean. We also calculated the SUV ratio (rSUV) between the lesion and control area, factoring for differences in individual bone metabolism; the ratios were termed rSUV_max and rSUV_mean, accordingly. The product of multiplying the rSUV_mean by MBV of a lesion was defined as the ratio of TBU (rTBU). Quantitative values were compared between clinical stages by the Kruskal-Wallis test and subsequent post hoc analysis.

RESULTS

MBVs (cm³) were: median, [IQR] Stage 1, 8.28 [5.62-9.49]; Stage 2, 15.28 [10.64-24.78]; and Stage 3, 34.61 [29.50-40.78]. MBV tended to increase with stage increase. Furthermore, only MBV showed a significant difference between clinical stages (p < 0.01). Subsequent post hoc analysis showed no significant difference between stages 1 and 2 (p = 0.12) but a significant difference between stages 2 and 3 (p = 0.048). rSUVmax and rTBU tended to increase with stage increase, but the differences between the stages were not significant (p = 0.10 and p = 0.055, respectively).

CONCLUSION

MBV, which includes the concept of volume, showed significant differences between clinical stages and tended to increase with the stage increase. As an objective and reliable indicator, MBV might be an adjunct diagnostic method for staging ARONJ.

A comparative effectiveness pilot study of teriparatide for medication-related osteonecrosis of the jaw: daily versus weekly administration

We studied the effectiveness of teriparatide (TPTD) for treating medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis and examined differences in the clinical outcomes following daily versus weekly TPTD. The outcomes were significantly improved in the entire patient series and the daily group.

PURPOSE

Teriparatide (TPTD) treatment for Stage II-III medication-related osteonecrosis of the jaw (MRONJ) in osteoporotic patients has yielded promising results in uncontrolled studies. The daily administration and the weekly administration of TPTD have been reported to improve outcomes in MRONJ. Herein, we sought to identify differences in the clinical outcomes of MRONJ patients treated with daily TPTD versus weekly TPTD.

METHODS

We enrolled 13 patients and randomly assigned them to receive either of two treatments: 1×/week 56.5-μg TPTD injection for 6 months (weekly group; n = 6 patients after 1 dropout), or 20-μg TPTD injection daily for 6 months (daily group; n = 6 patients). Patients in both groups received conventional therapy plus intensive antibiotic therapy as necessary. We compared the changes in the patients' clinical stage of MRONJ, bone metabolism, percentage of bone formation, and bone turnover markers between the weekly and daily groups.

RESULTS

TPTD treatment with MRONJ led to partial remission or complete remission in 5 daily-group patients and 3 weekly-group patients. The MRONJ stage was significantly improved from baseline to 6 months of treatment in the entire series of 12 patients (p = 0.008); the weekly group did not show significant improvement, but the daily group did (p = 0.01).

CONCLUSIONS

This study provides the first comparison of clinical outcomes between MRONJ patients who received daily or weekly TPTD injections. Six months of treatment with TPTD realized a significant improvement of MRONJ stage in both the entire patient series and the daily group.

Three-dimensional radiologic-pathologic correlation of medication-related osteonecrosis of the jaw using 3D bone SPECT/CT imaging

OBJECTIVES

The aim of this study was to assess a three-dimensional (3D) correlation between preoperative 3D bone single photon emission CT (SPECT)/CT, which allows the visualization of radiotracer uptake on 3D volume-rendered CT images, and histopathological characteristics in the medication-related osteonecrosis of the jaw (MRONJ).

METHODS

We conducted a full histopathological assessment of the resected jaws in four patients with Stage 2 or 3 MRONJ. The pathologic results were classified as follows: necrosis without any tissue vascularity (N + V-), necrosis with both vascularity and acute inflammatory cell infiltration due to bacterial infection (N + V+I+), necrosis with regenerative vasculature but no inflammatory cell infiltration (N + V+I-), and chronic inflammation without massive necrosis (N-V +I+). These classifications were correlated with imaging results.

RESULTS

The N + V- areas visually represented the area of necrotic bone exposed to the oral cavity and were consistent with defect area of radioisotope uptake in SPECT/CT. The N + V- areas were surrounded by the N + V+I + areas where increased radiotracer uptake was clearly seen. Also, abnormal uptake was found in both of the N + V+I- and N-V +I+ areas. The extensive surgical resections from necrotic core to bloody viable margins were performed in all cases, although one had the recurrence of MRONJ at the margin showing abnormal uptake that histologically represented the N + V+I- area.

CONCLUSIONS

Radiologic-pathologic correlation of MRONJ could be achieved using 3D SPECT/CT. The presence of regenerative vascularity with necrosis or inflammation seemed to determine bone metabolism in MRONJ. The recurrence of MRONJ was observed in one case, and 3D SPECT/CT had preoperatively depicted the recurrence site.

Comparative evaluation of SPECT/CT and CBCT in patients with mandibular osteomyelitis and osteonecrosis

OBJECTIVES

Therapy of osteomyelitis and osteonecrosis very often requires surgery. Proper preoperative radiological evaluation of a lesion's localization and extent is a key in planning surgical bone resection. This study aims to assess the differences between single-photon emission computed tomography and cone beam computed tomography when detecting an osteomyelitis/osteonecrosis lesion as well as the lesion's qualitative parameters, extent, and localization.

MATERIAL AND METHODS

Identification of candidates was performed retrospectively following a search for patients with histologically or clinically confirmed osteomyelitis or osteonecrosis. They were matched with a list of patients whose disease extent and localization had been evaluated using single-photon emission computed tomography and cone beam computed tomography in the context of clinical investigations. Subsequently, two experienced examiners for each imaging technique separately performed de novo readings. Detection rate, localization, extent, and qualitative parameters of a lesion were then compared.

RESULTS

Twenty-one patients with mandibular osteomyelitis and osteonecrotic lesions were included. Cone beam computed tomography detected more lesions than single-photon emission computed tomography (25 vs. 23; 100% vs. 92%). Cone beam computed tomography showed significantly greater depth, area, and volume, whereas length and width did not differ statistically between the two groups.

CONCLUSION

Both single-photon emission computed tomography and cone beam computed tomography could sensitively detect osteomyelitis/osteonecrosis lesions. Only single-photon emission computed tomography showed metabolic changes, whereas cone beam computed tomography seemed to display anatomic morphological reactions more accurately. The selection of the most adequate three-dimensional imaging and the correct interpretation of preoperative imaging remains challenging for clinicians.

CLINICAL RELEVANCE

In daily clinical practice, three-dimensional imaging is an important tool for evaluation of osteomyelitis/osteonecrosis lesions. In this context, clinicians should be aware of differences between single-photon emission computed tomography and cone beam computed tomography when detecting and assessing an osteomyelitis/osteonecrosis lesion, especially if a surgical bone resection is planned.

Meth Mouth-A Growing Epidemic in Dentistry?

In the past two decades, the synthetic style and fashion drug “crystal meth” (“crystal”, “meth”), chemically representing the crystalline form of the methamphetamine hydrochloride, has become more and more popular in the United States, in Eastern Europe, and just recently in Central and Western Europe. “Meth” is cheap, easy to synthesize and to market, and has an extremely high potential for abuse and dependence. As a strong sympathomimetic, “meth” has the potency to switch off hunger, fatigue and, pain while simultaneously increasing physical and mental performance. The most relevant side effects are heart and circulatory complaints, severe psychotic attacks, personality changes, and progressive neurodegeneration. Another effect is “meth mouth”, defined as serious tooth and oral health damage after long-standing “meth” abuse; this condition may become increasingly relevant in dentistry and oral- and maxillofacial surgery. There might be an association between general methamphetamine abuse and the development of osteonecrosis, similar to the medication-related osteonecrosis of the jaws (MRONJ). Several case reports concerning “meth” patients after tooth extractions or oral surgery have presented clinical pictures similar to MRONJ. This overview summarizes the most relevant aspect concerning “crystal meth” abuse and “meth mouth”.

Antiresorptive treatment-associated ONJ

Osteonecrosis of the jaw (ONJ) is a severe complication of therapy with antiresorptive agents (e.g. bisphosphonates and denosumab), which are used to manage bone metastases from cancer, to reduce the incidence of skeletal-related events. Available data indicate that 0-27, 5% of patients exposed to antiresorptive agents may develop ONJ, depending on the number of infusions and the duration of therapy. Besides antiresorptive therapy, a number of risk factors for osteonecrosis have been identified. Oral surgical procedures, tooth extractions and infection to the jawbones are considered the main risk factors for developing ONJ, when receiving antiresorptive therapy. However, a growing number of patients develop ONJ without apparent risk factors, raising concern for other predisposing factors. Jaw bone necrosis may be irreversible, resulting in a chronic disease with negative impact on the quality of patients' lives. The role of risk reduction strategies like meticulous dental screening and optimal oral hygiene is fundamental for preventing development of ONJ. ONJ is usually treated conservatively to relieve the symptoms and manage jaw bone necrosis. In certain cases, surgical intervention is required. Future research should emphasize individual predisposition to ONJ, more effective preventive measures and more efficient therapeutic procedures.

Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

Identifying MRONJ-affected bone with digital fusion of functional imaging (FI) and cone-beam computed tomography (CBCT): case reports and hypothesis

Surgical debridement of medication-related osteonecrosis of the jaw (MRONJ) lesions is far less predictable than lesion resection. Margins for surgical debridement are guided by surrogate markers of bone viability, such as bleeding and bone fluorescence, which limit debridement to visibly necrotic bone. In contrast, surgical resection is extensive, including a substantial portion of surrounding bone. The concept that the MRONJ lesion is a composite of affected but viable ("compromised") and necrotic bone is supported by histopathological data. Hence, removing only the necrotic bone during lesion debridement could inadvertently leave behind residual compromised bone in the lesion, subsequently contributing to persistence or reestablishment of the lesion. Using 2 case reports, this manuscript illustrates a novel assessment of the MRONJ lesion to enable demarcation of both the compromised and necrotic portions of the lesion. This assessment uses tumor-surveillance functional bone imaging data that may already be available for cancer patients with MRONJ and fuses these data digitally with computed tomography/cone-beam computed tomography imaging of the jaw obtained during MRONJ assessment. If validated, preoperative functional imaging-based assessment of the MRONJ lesion could enable surgeons to eliminate both the compromised and nonviable portions of the lesion precisely with conservative debridement, matching surgical resection in outcome.

Osteoradionecrosis and medication-related osteonecrosis of the jaw: similarities and differences

The purpose of this study was to compare medication-related osteonecrosis of the jaw (MRONJ) with osteoradionecrosis (ORN). Group 1 comprised 74 MRONJ patients (93 lesions) and group 2 comprised 59 ORN patients (69 lesions). Patient characteristics, clinical presentation of the lesions, the presence of complications, and the relationship with previous dental extractions were analyzed for both groups. Significant differences were found between the groups with regard to the characteristics of the patient populations, extraction as the precipitating event, the type of initial complaint, the prevalence of pain, and the location of the lesions. In the ORN group, significantly more patients complained of pain (P=0.0108) compared with the MRONJ group. Furthermore, significantly more pathological fractures (P<0.0001) and skin fistulae (P<0.0001) occurred in the ORN group. The treatment was more often conservative in the MRONJ group than in the ORN group (61.3% vs. 36.2%). Despite similarities in terms of imaging, risk factors, prevention, and treatment, MRONJ and ORN are two distinct pathological entities, as highlighted by the differences in patient characteristics, the initial clinical presentation, course of the disease, and outcome.