Pelvic Insufficiency Fractures Research Articles

Insights into pelvic insufficiency fracture following pelvic radiotherapy for cervical cancer: a comparative review

BackgroundRadiotherapy (RT)-induced pelvic insufficiency fractures (PIF) are prevalent in patients with cervical cancer. Inconclusive studies on PIF after cervical irradiation create uncertainty. This review examined PIF after RT in cervical patients, including its pathobiology, likely locations of fractures, incidence, clinical symptoms, and predisposing factors. We further discussed study limitations and therapeutic possibilities of PIF.MethodsThe following online resources were searched for relevant articles: Google Scholar and PubMed. The keywords ‘pelvic insufficiency fractures’, ‘cervical carcinoma’ and ‘cervical cancer’, as well as ‘chemoradiotherapy’, ‘chemoradiation’, and ‘radiotherapy’, were some of the terms that were used during the search.ResultsPatients with PIF report pelvic pain after radiation treatment for cervical cancer; the incidence of PIF ranges from 1.7 to 45.2%. Evidence also supports that among all patients treated with pelvic radiation, those who experienced pelvic insufficiency fractures invariably had at least one sacral fracture, making it the most frequently fractured bone in the body. Menopausal status, weight, BMI, age, and treatments and diagnosis modalities can influence PIF during radiotherapy.ConclusionsIn conclusion, our comparative review of the literature highlights significant heterogeneity in various aspects of PIF following radiation for patients with cervical cancer. This diversity encompasses prevalence rates, associated risk factors, symptoms, severity, diagnosis methods, preventive interventions, and follow-up periods. Such diversity underscores the complexity of PIF in this population and emphasizes the critical need for further research to elucidate optimal management strategies and improve patient outcomes.

Pelvic insufficiency fracture in an osteoporotic 47-year-old female: a case report

Insufficiency fractures (IFs) represent a form of stress fractures frequently linked to osteoporosis and a lack of vitamin D. These fractures, which are not caused by trauma, typically manifest in the pelvis and spine, although occurrences in atypical locations are also relatively frequent. The primary methods for diagnosing IF involve using plain radiographs and magnetic resonance imaging scans, which are commonly employed imaging techniques. The management involves both medical and surgical methods, tailored as per the needs of the patient. 47-year-old female patient presented to the outpatient department with complaints of low back ache with waddling gait, with pain not responding to analgesics. Laboratory and radiological assessment revealed osteoporotic Insufficiency fracture in the pelvis which was managed with both surgical and medical methods, with surgical management involving percutaneous screw fixation of the fractures. Diagnosis of the osteoporotic insufficiency fractures at atypical locations can be extremely challenging because of the inconclusive radiographs and the lack of a perceptible trauma history and hence, can be missed at the initial presentation. The management includes both operative and non-operative modalities, best tailored as per the patient needs and expectations.

Is Nothing Sacrum? Identification and Treatment of Sacral Insufficiency Fractures

Sacral insufficiency fractures are an overlooked etiology of back pain that can also be difficult to diagnose radiographically. Advanced imaging, including MR and scintigraphy, are useful modalities for diagnosis, as these fractures are frequently missed on plain films. Management is often conservative to avoid surgical fixation, a rarely performed surgery due to its high morbidity. Radiologists are also able to provide symptomatic relief via sacroplasty, a minimally invasive, percutaneous, image-guided procedure first described in 2002. The most common sites of pelvic insufficiency fractures include the sacral ala and parasymphyseal region of the os pubis. The butterfly or “H-shaped” pattern is a classic sign of this fracture on scintigraphy, best appreciated posteriorly. MR is considered the gold standard in diagnosing insufficiency fractures and is characterized by low T1 band-like signal intensity with corresponding high T2/T2 short-tau inversion recovery (STIR) signal intensity. Such fractures can be treated via sacroplasty by carefully injecting polymethylmethacrylate bone cement via one or more trocar needles. Knowledge of sacral anatomy is critical during the procedure to not violate specific sacral zones or traverse any of the neural foramina.

High-dose (60 Gy) intensity-modulated radiotherapy with concurrent weekly cisplatin followed by intracavitary radiation in locally advanced cervical cancer: A phase II prospective clinical trial

ObjectiveRadiotherapy dose-escalation using intensity-modulated radiotherapy (IMRT) has been necessary to improve treatment results in cervical cancer. MethodsThis was a phase II prospective clinical trial. 88 patients with FIGO II-IVa cervical cancer were enrolled in a single center. They received high-dose (60 Gy) IMRT with weekly cisplatin to the primary tumor and clinically positive nodes followed by intracavitary radiation. The primary endpoint was 30-month PFS rate (Target; 82%, an increase of 20% compared to GOG 120 trial using standard-dose radiotherapy). Secondary endpoints were tumor response, toxicity, recurrence, distant metastasis, and overall survival. ResultsProgression-free survival rate at 30 months was 82.8%. Overall survival, locoregional recurrence, distant metastasis, and para-aortic recurrence rates at 30 months were 93.6%, 8.2%, 9.2%, and 2.4%, respectively. Forty-five (51.1%) of 88 patients achieved downstaging on MRI during radiotherapy and 80 (90.9%) patients had clinically complete response at three months after high-dose IMRT and intracavitary radiotherapy. The 30-month recurrence-free survival (92.9% vs. 73.1%, P = 0.009) and overall survival (100% vs. 87.0%, P = 0.006) were significantly higher in the downstaged group than in the non-downstaged group during radiotherapy. Grade 3 or higher hematologic toxicity was found in 11 (12.5%) patients and grade 3 or higher non-hematologic toxicity was found in 3 (3.4%) patients. Fourteen had chronic urinary (8.0%), intestinal (5.7%) toxicity, pelvic insufficiency fracture (2.3%) or vesicovaginal fistula (2.3%). ConclusionHigh-dose (60 Gy) IMRT with concurrent weekly cisplatin in locally advanced cervical cancer yielded favorable progression-free survival outcome. Tumor response during radiotherapy can be a significant prognostic factor for PFS.Clinical trial information: This prospective trial is registered at ClinicalTrials.gov Identifier: NCT02993653.

Pelvic insufficiency fractures and pelvic bone metastases after neoadjuvant (chemo)radiotherapy for rectal cancer

Background: Pelvic insufficiency fractures (PIFs) are a late complication of radiotherapy for pelvic malignancies. We evaluated the incidence, radiologic findings, clinical course, and outcome of PIFs in patients treated with neoadjuvant (chemo)radiotherapy ((C)RT) for rectal cancer. Material and methods: Data of patients diagnosed with rectal cancer from a large teaching hospital treated from 2002 to 2012 were extracted from the Dutch Cancer Registry. All hospital records were reviewed for the diagnosis of PIFs or pelvic bone metastases. An expert radiologist reassessed all imaging procedures of the lower back, abdomen, and pelvis. Results: A total of 513 rectal cancer patients were identified of whom 300 patients (58.5%) were treated with neoadjuvant (C)RT (long- vs. short-course radiotherapy: 91 patients [17.7%] vs. 209 [40.7%], respectively). Twelve PIFs were diagnosed initially according to hospital records and imaging reports of all 513 patients. These 12 patients were treated with neoadjuvant (C)RT. After reassessment of all pelvic imaging procedures done in this patient group (432 patients (84.2%)), 20 additional PIFs were detected in patients treated with neoadjuvant (C)RT, resulting in a 10.7% PIF rate in irradiated patients. One PIF was detected in the group of patients not treated with neoadjuvant (C)RT for rectal cancer. This patient had palliative radiotherapy for prostate cancer and is left out of the analysis. Median follow-up time of 32 PIF patients was 49 months. Median time between start of neoadjuvant (C)RT and diagnosis of PIF was 17 months (IQR 9–28). Overall median survival for patients with PIF was 63.5 months (IQR 44–120). Conclusion: PIFs are a relatively common late complication of neoadjuvant (C)RT for rectal cancer but are often missed or misdiagnosed as pelvic bone metastases. The differentiation of PIFs from pelvic bone metastases is important because of a different treatment and disease outcome.

Pelvic insufficiency fractures after intensity modulated radiation therapy combined with chemotherapy for cervix carcinoma: Incidence and impact of bone mineral density

Background and PurposeThe aim of this study was to evaluate the incidence and predictive factors of Pelvic Insufficiency Fractures (PIFs) occurring after Intensity Modulated Radiation Therapy (IMRT) combined with chemotherapy for locally advanced cervical cancer (CC).Material and methodsMedical records of patients receiving radio-chemotherapy with IMRT between 2010 and 2020 for advanced CC were reviewed. PIFs were detected during follow-up on pelvic Magnetic Resonance Imaging (MRI) or Computed Tomography (CT). The cumulative incidence rate of PIFs and its confidence interval were calculated at 2 and 5 years of follow-up. Pre-therapeutic Bone Mineral Density (BMD) (g/cm3) was evaluated on CT simulation for sacrum and the fourth lumbar (L4) vertebrae. Sacrum dosimetric parameters (V30Gy, V40Gy, D50%, Dmean) were analyzed.Results136 patients were included. The median follow-up was 4.4 years. Median dose of D50% and V40Gy sacrum were 35.2 Gy (20.6–46.4) and 32.2% (7.2–73.4) respectively. The 2-year and 5-year cumulative incidence rates were 15.7% (95% CI: 9.88–22.71) and 22% (95% CI: 14.58–30.45) respectively. Median time interval between RT completion and PIFs’ detection was 11.5 months (IQR: 7.4–22.3). Univariate analysis showed that older age (p < 0.01), postmenopausal status at baseline (p < 0.01), and lower sacral and spinal BMD at baseline (respectively p < 0.001 and p < 0.01) were significantly associated to all sites of PIFs, and lower sacral BMD with sacral fractures (p < 0.001).ConclusionPost-IMRT PIFs were detected in 18.4% of patients with locally advanced CC. Individual predisposing factors as older age, postmenopausal status, decreased bone density on the CT simulation were mainly predictive.

Pelvic Insufficiency Fractures in Patients with Rheumatoid Arthritis: A single Case Report

Pelvic Insufficiency Fractures in Patients with Rheumatoid Arthritis: A single Case Report

Pelvic insufficiency fractures revisited

Objectives: There has been a significant increase in insufficiency fractures of the pelvis. Early diagnosis is essential to decrease morbidity and mortality. We describe the incidence of demographics of insufficiency fractures in different parts of the pelvis. Material and Methods: A retrospective search of the radiology database for insufficiency fractures was performed at a tertiary orthopedic center. We analyzed the location of insufficiency fractures and demographics. Results: There were 323 insufficiency fractures, with the majority being in the sacrum and pelvis. Insufficiency fractures of pubis, acetabulum and sacrum were in relatively older patients. Conclusion: Early diagnosis and management are crucial.

Prediction of Patients at Risk of Pelvic Insufficiency Fractures Following Pelvic Radiotherapy

<h3>Purpose/Objective(s)</h3> Radiotherapy-induced pelvic insufficiency fractures (PIFs), historically under-reported, can lead to significant morbidity. Using deep-learning techniques, this study develops a fully automated predictive tool to identify patients who are at high-risk of developing PIFs following radiotherapy for gynecological cancer. <h3>Materials/Methods</h3> Retrospective clinical, dosimetry and imaging data from 330 patients receiving pelvic radiotherapy for any primary gynecological cancer between January 2012 and January 2021 was collected (study approved by local ethical committee). Patient electronic records were reviewed; PIFs were diagnosed radiologically using computed tomography (CT) and magnetic resonance imaging (MRI). An auto-segmentation model for the sacrum and whole pelvis on CT-imaging was developed using a UNETR architecture to aid evaluation of pelvic radiotherapy dose and CT density. The model was validated by comparing the derived dose-volume histograms (DVHs) with those derived from manual contours. Chi-squared and Mann-Whitney tests were performed to determine associations between derived potential risk factors and PIF. Using Elastic Net Logistic Regression modelling a predictive tool to identify patients at risk of developing PIF was developed and internally validated. <h3>Results</h3> Among the 330 patients, the median follow-up was 36.6 months, and median age was 65 years. The PIF incidence was 10.9% and median interval from radiotherapy to PIF was 16 months. 86% of fractures occurred in the sacrum, 56% of patients had multiple fractures and 64% of patients were symptomatic. The auto-contouring tool of the sacrum and whole pelvis was clinically validated and, against gold-standard contours, achieved a mean DICE coefficient of 0.94, Average Surface Distance (ASD) of 0.65, and maximum absolute error for DVH curves of 3.1%. Univariant analysis found that site of primary disease, body mass index, prior diagnosis of osteopenia or osteoporosis, use of concurrent chemotherapy, V_55Gy (volume of the sacrum and whole pelvis receiving 55 Gy), and lower CT density were statistically associated with the development of PIF (p<0.05). The fully automated predictive tool to identify patients at risk of PIF using solely imaging and dosimetry data had similar accuracy to models including additional clinical features; both had a receiver-operating-characteristic (ROC) area-under-the-curve (AUC) of 0.761. The prediction tool has a sensitivity of 66%, specificity of 72% and a negative predictive value of 95%. <h3>Conclusion</h3> PIF is not uncommon in this setting, often symptomatic and strongly associated with low bone density on CT. Prediction and prevention of PIF would have an immense impact on patients and healthcare systems. We propose an automated predictive tool to identify patients at high risk, for whom effective prophylactic treatments are needed.

Pelvic Insufficiency Fractures and Bone Pain after Radiation Therapy for Anal Cancer: Relation to Pelvic Bone Dose-Volume Parameters

PurposeChemoradiation therapy is the primary treatment for anal cancer. Radiation therapy (RT) can weaken the pelvic bone structure, but the risk of pelvic insufficiency fractures (PIFs) and derived pain in anal cancer is not yet established. We determined the frequency of symptomatic PIFs after RT for anal cancer and related this to radiation dose to specific pelvic bone substructures. Methods and MaterialsIn a prospective setting, patients treated with RT for anal cancer had magnetic resonance imaging 1 year after RT. PIFs were mapped to 17 different bone sites, and we constructed a guideline for detailed delineation of pelvic bone substructures. Patients were interviewed regarding pain and scored according to Common Terminology Criteria for Adverse Effects. Dose-volume relationships for specific pelvic bone substructures and PIFs were determined for V20 to V40 Gy mean and maximum doses. ResultsTwenty-seven patients were included, and 51.9% had PIFs primarily located in the alae of the sacral bone. Patients with PIFs had significantly more pelvic pain (86% vs 23%, P = .001) and 43% had grade 2 bone pain. Dose-volume parameters for sacral bone and sacral alae were significantly higher in patients with PIFs (P < .05). V30 Gy (%) for sacral bone and alae implied an area under the curve of 0.764 and 0.758, respectively, in receiver operating characteristic analyses. ConclusionsWe observed a high risk of PIFs in patients treated with RT for anal cancer 1 year after treatment. A significant proportion had pain in the sites where PIFs were most frequently found. Radiation dose to pelvic bone substructures revealed relation to risk of PIFs and can be used for plan optimization in future clinical trials.

Effects of dose and dose-averaged linear energy transfer on pelvic insufficiency fractures after carbon-ion radiotherapy for uterine carcinoma

Background and PurposeThe correlation between dose-averaged linear energy transfer (LETd) and its therapeutic or adverse effects, especially in carbon-ion radiotherapy (CIRT), remains controversial. This study aimed to investigate the effects of LETd and dose on pelvic insufficiency fractures after CIRT. Material and MethodsAmong patients who underwent CIRT for uterine carcinoma, 101 who were followed up for > 6 months without any other therapy were retrospectively analyzed. The sacrum insufficiency fractures (SIFs) were graded according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity criteria. The correlations between the relative biological effectiveness (RBE)-weighted dose, LETd, physical dose, clinical factors, and SIFs were evaluated. In addition, we analyzed the association of SIF with LETd, physical dose, and clinical factors in cases where the sacrum D50% RBE-weighted dose was above the median dose. ResultsAt the last follow-up, 19 patients developed SIFs. Receiver operating characteristic curve analysis revealed that the sacrum D50% RBE-weighted dose was a valuable predictor of SIF. Univariate analyses suggested that LETd V10 keV/µm, physical dose V5 Gy, and smoking status were associated with SIF. Cox regression analysis in patients over 50 years of age validated that current smoking habit was the sole risk factor for SIF. Therefore, LETd or physical dose parameters were not associated with SIF prediction. ConclusionThe sacrum D50% RBE-weighted dose was identified as a risk factor for SIF. Additionally, neither LETd nor physical dose parameters were associated with SIF prediction.

Impact of radiotherapy on bone health in women with rectal cancer – A prospective cohort study

IntroductionPelvic radiotherapy (RT) increases the risk of pelvic insufficiency fractures. The aim was to investigate if RT is associated with changes in serum bone biomarkers in women with rectal cancer, and to examine the incidence of radiation-induced bone injuries and the association with bone biomarkers. Material and methodsWomen diagnosed with rectal cancer stage I-III, planned for abdominal surgery ± preoperative (chemo) RT, were prospectively included and followed one year. Serum bone biomarkers comprised sclerostin (regulatory of bone formation), CTX (resorption), BALP and PINP (formation). A subgroup was investigated with annual pelvic magnetic resonance imaging (MRI). The association between RT and bone biomarkers was explored in regression models. ResultsOf 134 included women, 104 had surgery with preoperative RT. The formation markers BALP and PINP increased from baseline to one year in the RT-exposed group (p < 0.001, longitudinal comparison). In the adjusted regression analysis, the mean increase in PINP was higher in the RT-exposed than the unexposed group (17.6 (3.6–31.5) μg/L, p = 0.013). Sclerostin and CTX did not change within groups nor differed between groups. Radiation-induced injuries were detected in 16 (42%) of 38 women with available MRI. At one year, BALP was higher among women with than without bone injuries (p = 0.018, cross-sectional comparison). ConclusionsPreoperative RT was associated with an increase in the formation marker PINP, which could represent bone recovery following RT-induced injuries, commonly observed in participants evaluated with MRI. These findings should be further explored in larger prospective studies on bone health in rectal cancer patients.

MP25-17 PELVIC INSUFFICIENCY FRACTURE—AN UNDERRECOGNIZED CAUSE OF PAIN AFTER PUBECTOMY

You have accessJournal of UrologyCME1 May 2022MP25-17 PELVIC INSUFFICIENCY FRACTURE—AN UNDERRECOGNIZED CAUSE OF PAIN AFTER PUBECTOMY Molly DeWitt-Foy, Ranveer Vasdev, and Sean Elliott Molly DeWitt-FoyMolly DeWitt-Foy More articles by this author , Ranveer VasdevRanveer Vasdev More articles by this author , and Sean ElliottSean Elliott More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002568.17AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Pubectomy is traditionally used in repair of complex pelvic fracture urethral injuries (PFUI) but is now increasingly used in the management of pubic osteomyelitis that results from prostate cancer treatment. Classically, pubectomy after PFUI is thought to not disrupt the stability of the pelvic ring. However, this has not been studied in detail in patients with osteomyelitis, who often have comorbid conditions that may alter said stability and increase risk of fracture.). Our aim is to document the incidence, presentation and risk factors of sacral insufficiency fracture (SIF) in patients who have undergone pubectomy for osteomyelitis. METHODS: Retrospective chart review was performed of patients undergoing pubectomy for osteomyelitis at a single institution from 2016-2021. Descriptive statistics and univariate analysis were performed using R. Wilcoxon rank-sum test and Fisher exact test were used as appropriate. RESULTS: Sixteen patients underwent pubectomy for osteomyelitis, all after prostate radiotherapy. Mean age was 68 years and mean BMI 28.5. Six (37.5%) underwent cystectomy with urinary diversion at the time of pubectomy, 4 (23.5%) had cystectomy prior to pubectomy. Eleven (68.7%) had postoperative cross-sectional pelvic imaging, of which 3 (25%) were found to have a new SIF; one additional patient had SIF prior to pubectomy. Three SIFs were detected on MRI and one on CT scan. All patients were symptomatic of SIF, most commonly with new pelvic or perineal pain. The median BMI of patients with SIF was significantly lower than those without SIF (22.4 v 30.5, p value=0.004). Age, chronic kidney disease, bone metastasis, hyperbaric oxygen, diabetes, and androgen deprivation therapy were not significantly associated with risk of SIF. CONCLUSIONS: Sacral insufficiency fracture is a rarely described sequela of pubectomy for osteomyelitis. Lower BMI is significantly associated with SIF, perhaps indicative of overall frailty. Source of Funding: NA © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e435 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Molly DeWitt-Foy More articles by this author Ranveer Vasdev More articles by this author Sean Elliott More articles by this author Expand All Advertisement PDF DownloadLoading ...

Long Term Risk of Pelvic Insufficiency Fractures and Lower Extremity Edema After Definitive Chemoradiation for Squamous Cell Carcinoma of the Anal Canal

Definitive chemoradiation is the standard of care of treatment of squamous cell carcinomas (SCC) of the anal canal. While this treatment is effective, definitive chemoradiation is associated with significant acute and late toxicities. In this study, we seek to evaluate the incidence and identify risk factors of radiotherapy (RT) induced pelvic insufficiency fractures and lower extremity (LE) edema.We performed a single-institution retrospective analysis of 185 patients treated with chemoradiation for anal SCC between 2007-2019. Median age was 61 (range: 15-92); 9.8% were metastatic and 34.1% were men. All patients received concurrent chemotherapy, including 160 patients treated with concurrent 5-fluorouracil /MMC, 12 treated with 5-fluorouracil /Cisplatin, 9 patients treated with 5FU alone, 2 treated with FOLFOX alone, and 2 treated with Carboplatin/Paclitaxel. Median dose to the pelvis was 54 Gy. RT modalities included IMRT/VMAT (N = 157), pencil beam proton beam (N = 17), 3D-CRT (N = 6), and multi-modalities (N = 5). Patient medical charts and imaging were reviewed for patient/treatment characteristics, and to determine incidence of development of post-RT related insufficiency fractures and LE. Pelvic insufficiency fractures were all confirmed radiographically with CT or MRI pelvis. Patients with baseline LE edema were excluded from the analysis of post-RT related LE edema. Cox univariate analysis was performed to identify predictors of pelvic fracture.Median follow-up was 59 months. Among 185 patients, 11 (6%) patients developed pelvic insufficiency fractures at a median time of 11 months (range: 2.7-60) since completion of RT treatment (range: 2-60). Treatment for pelvic insufficiency fractures included narcotics (n = 3), and no patient required sacroplasty. All but 1 of the patients who developed pelvic insufficiency fractures were women. However, gender (P = 0.12) and menopausal status (P = 0.87) were not significant on univariate analysis. On univariate analysis, only treatment with IMRT/VMAT (HR 2.33, P = 0.02) predicted for higher risk of development of pelvic insufficiency fracture. Among patients without baseline LE edema, 5.95% of patients developed LE or pelvic edema after completion of RT at a median of 3 months post-treatment (range: 0-42). Of these, 7 patients developed LE edema, 1 developed vulvar edema, and 1 patient developed scrotal edema. All patients had grade 1+ edema.RT related pelvic insufficiency fractures and LE edema are rare after chemoradiation to the pelvis, and often are incidental findings appreciated radiographically. IMRT/VMAT may be associated with higher risk of pelvic insufficiency fractures.

Bone Mineral Density Changes Within and Outside of RT Fields Used to Treat Cervical Cancer

Pelvic insufficiency fractures and decreased bone mineral density (BMD) can occur in women treated with radiotherapy (RT) for gynecologic cancers. The purpose of this study was to compare the magnitude of BMD changes inside and outside of the radiation field in patients treated with radiation +/- chemotherapy for cervical cancer.In an IRB-approved prospective study, women (N = 78) with cervical cancer were assessed with serial tomographic scans and dual-energy x-ray absorptiometry (DXA) scans to evaluate the incidence of pelvic fractures (previously reported) and post-treatment BMD changes. Patients were treated with definitive RT or chemoradiation (CRT) at a single institution between 09/2008 and 07/2015. DXA scans were obtained at baseline (before CRT), 3 months, 1 year, and 2 years after completion of therapy. Serial BMD values at L1, L2, L3 and L4 were extracted from DXA reports. Patients with a pre-treatment history of pelvic fractures, bone metastases, or pelvic RT were excluded. The current analysis focused on a subset of 78 patients whose RT fields had upper borders below L1 and above L4, permitting a comparison of BMD changes in the field (L4) with those in a vertebral body outside the field (L1). Linear mixed models (LMM) were performed to examine the impact of radiotherapy on BMD change over time, and were adjusted for covariates (age, menopausal status, BMI, number of chemotherapy cycles).The median age of 78 patients was 45.5 years (range 23-88); all received RT and 76/78 (97.5%) received concurrent CRT. Treatment was associated with a significant decline in BMD in all 4 lumbar vertebral bodies over time, P < 0.05 with nadir at 3 months (L4) and 1 year (L1). By pairwise comparisons at 3 months and 2 years after treatment, BMD in L4 (inside RT field, P = 0.037) significantly improved while BMD in L1 (outside RT field) did not significantly change. After controlling for covariates noted above, there was no significant difference in BMD between 3 months and 2 years. Levels of C-terminal telopeptide of type I collagen (P = 0.018), bone alkaline phosphatase (P < 0.001), and number of chemotherapy cycles (P = 0.031) were significant predictors of L1 BMD loss. A trend of higher BMD at all time points was found for patients who were premenopausal versus postmenopausal at study entry. At 1- and 2-years of follow-up, trends towards BMD at levels higher than baseline were seen for patients who received hormone replacement therapy (HRT) after RT.Significant BMD loss following radiation treatment in all lumbar vertebrae (both in and out of field) was observed. On multivariate analysis, in-field vertebral bodies experienced no additional significant BMD decline earlier than those out-of-field, suggesting multifactorial contributors to bone density loss. HRT may improve BMD recovery and emphasizes the need for HRT after radiotherapy in appropriate premenopausal women.J. Wu: None. D.S. Lakomy: None. B. Fellman: None. M.P. Salcedo: IGCS-International Gynecologic Cancer Society, Brazilian Federation of Gynecology and Obstetricians (FEBRASGO)/BRAZIL (Federação Brasileira de Ginecologia e Obstetricia, FEBRASGO). A. Sood: Consultant; Kiyatec, Astra Zeneca. Stock; BioPath. sponsored research; M-Trap. A. Jhingran: American Board of Radiology. A.H. Klopp: Research Grant; MD Anderson Cancer Center SPORE Grant. R.B. Iyer: None. C. Jimenez: None. L. Colbert: None. K. Schmeler: None. P.J. Eifel: Travel Expenses; National Cancer Center Network. Stock; Apple Computer. L.L. Lin: Employee; VA Hospital. Research Grant; AstraZeneca. Travel Expenses; AstraZeneca.

101: A Single Institution Retrospective Study of Pelvic Insufficiency Fractures Following Curative-Intent Pelvic Intensity-Modulated Radiation Therapy for Gynecologic, Gastrointestinal and Genitourinary Cancers

101: A Single Institution Retrospective Study of Pelvic Insufficiency Fractures Following Curative-Intent Pelvic Intensity-Modulated Radiation Therapy for Gynecologic, Gastrointestinal and Genitourinary Cancers

PET/MRI is useful for early detection of pelvic insufficiency fractures after radiotherapy for cervical cancer.

Radiotherapy (RT) is used to manage cervical cancer, and pelvic insufficiency fracture (PIF) is known as a late complication of RT. The present study identified risk factors for PIF after radiotherapy for cervical cancer, and investigated its incidence rate. It also considered the usefulness of positron emission tomography/magnetic resonance imaging (PET/MRI) in PIF diagnosis. A total of 149 patients with cervical cancer who received definitive or adjuvant RT with/without concurrent chemotherapy between January 2013 and December 2018 were investigated in the present study and followed up for more than one month after RT at Kobe University Hospital. The median follow-up period was 32 months (range, 1–87 months), and the median age of all patients was 66 years (age range, 34–90 years). Computed tomography (CT), MRI, PET/CT or PET/MRI were used for image examination. Among the 149 patients, 31 (20.8%) developed PIF. The median age of these patients was 69 years (age range, 44–87 years). Univariate analysis using the log-rank test demonstrated that age (≥60 years) was significantly associated with PIF. The median maximum standardized uptake value of PIF sites on PET/CT was 4.32 (range, 3.04–4.81), and that on PET/MRI was 3.97 (range, 1.21–5.96) (P=0.162). Notably, the detection time of PIF by PET/MRI was significantly earlier compared with PET/CT (P<0.05). The incidence of PIF after RT for cervical cancer was 20.8%, and age was significantly associated with risk factors for such fractures. Taken together, these results suggest that PET/MRI, which offers the advantage of decreased radiation exposure to the patient, is useful for diagnosing PIF and can detect it earlier than PET/CT imaging.

PH-0114 Pelvic insufficiency fractures detected by MRI one-year after chemoradiotherapy for anal cancer.

PH-0114 Pelvic insufficiency fractures detected by MRI one-year after chemoradiotherapy for anal cancer.

Radiotherapy-Associated Pelvic Insufficiency Fracture Treated by Romosozumab: Course of L1 and L5 Vertebral Body CT Attenuation

Background: Radiotherapy is a risk factor for osteoporosis and insufficiency fractures via osteoblast apoptosis and vascular injury. PTH analogs teriparatide and abaloparatide are contraindicated in patients with prior exposure to radiotherapy crossing bone due to the increased risk of osteosarcoma. Patients with radiotherapy-associated fractures or osteoporosis were eligible only for antiresorptive agents until romosozumab was recently FDA-approved. Current International Society for Clinical Densitometry (ISCD) guidelines include assessment of “opportunistic CT” as a surrogate for DXA scan using L1 vertebral body attenuation: >150 Hounsfield units (HU) is normal and <100 HU signifies osteoporosis.Clinical Case: A 60 year old female patient with history of endometrial cancer diagnosed at age of 57 and treated with hysterectomy and bilateral salpingo-oophorectomy, chemotherapy, then pelvic radiotherapy, was referred to endocrinology for pelvic insufficiency fractures evaluation. Two years after completing chemoradiotherapy, she complained of right groin and low back pain with difficulty walking. MRI pelvis showed bilateral sacral ala and right pubic ramus insufficiency fractures. She had normal serum mineral concentration, 25-OH vitamin D sufficiency, normal PTH, eGFR, liver function tests and 24-hour urine calcium excretion. Screening for celiac disease and multiple myeloma was negative. DXA scan BMD T-score showed osteoporosis, -3.0 at the right femoral neck. L1-L4 T-score was +0.4 but unreliable due to presence of degenerative changes. Four months after onset of pain, patient started romosozumab 210mg SQ monthly for a total of 12 doses, after which she started oral alendronate. Pain essentially resolved within 6 months of romosozumab therapy. C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP) were obtained at baseline, 3 and 12 months after romosozumab initiation. CTX was 362, 247 and 258 pg/mL (reference range, >49 years: not established), and P1NP was 82, 178 and 62 mcg/L (reference range, 20 - 108), respectively. Attenuation of L1 and L5 vertebral body was measured using CT abdomen and pelvis scans before and 5 months after radiotherapy, and before and after completion of romosozumab therapy. L1 attenuation measured 161, 132, 127 and 179 HU, and L5 measured 150, 46, 50 and 86 HU, respectively.Conclusion: Pelvic radiotherapy was associated with a decline in L1 CT attenuation and even greater magnitude of decrease at L5. Romosozumab was associated with clinical improvement, restoration of L1 CT attenuation and diminishment of regain at L5. Although L5 attenuation has not been previously assessed for osteoporosis, this site may be of predictive value in patients who receive pelvic radiotherapy.

Pelvic Insufficiency Fractures in Cervical Cancer After Radiation Therapy: A Meta-Analysis and Review.

The aim of the study was to estimate the prevalence of pelvic insufficiency fractures (PIFs) after radiation therapy (RT) in patients with cervical cancer. A total of 3,633 patients from 15 cohort studies were included. Proportion meta-analysis was performed to estimate prevalence and subgroup analysis was performed according to imaging modalities for diagnosis of PIF. For continuous variables (age and length of follow-up), meta-regression analysis was performed. Pooled prevalence estimate of PIF was 14% (95% CI=10-19). Incidence of PIF was higher in studies that used MRI as a diagnostic tool (17%, 95% CI=12-22) than non-MRI (8%, 95% CI=2-14). In meta-regression, we found a significant association of prevalence of PIF with age (p=0.021) but not with length of follow-up (p=0.118). PIF after RT in patients with cervical cancer is not rare. Physicians need to pay attention to PIFs, especially in patients with high-risk factors for osteoporotic fracture.