Predictive factors of posttreatment fracture by definitive radiotherapy for uterine cervical cancer

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

BACKGROUND

Radiotherapy (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.

METHODS

The 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.

RESULTS

Patients 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.

CONCLUSIONS

In 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.

Predictive Factors for Toxicity After Primary Chemoradiation for Locally Advanced Cervical Cancer: A Systematic Review

PURPOSE

Women with locally advanced cervical cancer (LACC) undergoing primary platinum-based chemoradiotherapy and brachytherapy often experience toxicities. Normal-tissue complication probability (NTCP) models quantify toxicity risk and aid in optimizing radiation therapy to minimize side effects. However, it is unclear which predictors to include in an NTCP model. The aim of this systematic review was to provide an overview of the identified predictors contributing to gastrointestinal (GI), genitourinary (GU), and vaginal toxicities and insufficiency fractures for LACC.

METHODS AND MATERIALS

A systematic search was performed and articles evaluating the relationship between predictors and toxicities in women with LACC treated with primary chemoradiation were included. The Quality In Prognosis Studies tool was used to assess risk of bias, with high-risk studies being excluded from further analysis. Relationships between dose-volume parameters, patient and treatment characteristics, and toxicity endpoints were analyzed.

RESULTS

Seventy-three studies were identified. Twenty-six had a low or moderate risk of bias and were therefore included. Brachytherapy-related dose-volume parameters of the GI tract, including rectum and bowel equivalent dose in 2 Gy fractions (EQD2) D2 cm3, were frequently related to toxicities, unlike GU dose-volume parameters. Furthermore, (recto)vaginal point doses predicted toxicities. Few studies evaluated external beam radiation therapy dose-volume parameters and identified rectum EQD2 V30 Gy, V40 Gy, and V55 Gy, bowel and bladder EQD2 V40 Gy as toxicity predictors. Also, total reference air kerma and vaginal reference length were associated with toxicities. Relationships between patient characteristics and GI toxicity were inconsistent. The extent of vaginal involvement at diagnosis, baseline symptoms, and obesity predicted GU or vaginal toxicities. Only 1 study evaluated insufficiency fractures and demonstrated lower pretreatment bone densities to be associated.

CONCLUSIONS

This review detected multiple candidate predictors of toxicity. Larger studies should consider insufficiency fractures, assess dose levels from external beam radiation therapy, and quantify the relationship between the predictors and treatment-related toxicities in women with LACC to further facilitate NTCP model development for clinical use.

Radiotherapy-related insufficiency fractures and bone mineral density: what is the connection?

Background

Radiotherapy-related insufficiency fractures (RRIFs) represent a common, burdensome consequence of pelvic radiotherapy. Their underlying mechanisms remain unclear, and data on the effect of osteoporosis are contradictory, with limited studies assessing bone mineral density (BMD) by dual-energy x-ray absorptiometry (DXA).

Methods

BMD by DXA (Hologic) scan and fracture risk following pelvic RRIF were retrospectively assessed in 39 patients (median age 68 years) at a tertiary cancer centre. Patient characteristics and treatment history are presented narratively; correlations were explored using univariate regression analyses.

Results

Additional cancer treatments included chemotherapy (n = 31), surgery (n = 20) and brachytherapy (n = 19). Median interval between initiation of radiotherapy and RRIF was 11 (7.5-20.8) and that between RRIF and DXA 3 was (1-6) months. Three patients had normal BMD, 16 had osteopenia and 16 osteoporosis, following World Health Organization classification. Four patients were <40 years at the time of DXA (all Z-scores > -2). Median 10-year risk for hip and major osteoporotic fracture was 3.1% (1.5-5.7) and 11.5% (7.1-13.8), respectively. Only 33.3% of patients had high fracture risk (hip fracture >4% and/or major osteoporotic >20%), and 31% fell above the intervention threshold per National Osteoporosis Guidelines Group (NOGG) guidance (2017). Higher BMD was predicted by lower pelvic radiotherapy dose (only in L3 and L4), concomitant chemotherapy and higher body mass index.

Conclusion

At the time of RRIF, most patients did not have osteoporosis, some had normal BMD and overall had low fracture risk. Whilst low BMD is a probable risk factor, it is unlikely to be the main mechanism underlying RRIFs, and further studies are required to understand the predictive value of BMD.

Sacral Insufficiency Fractures After Total Pubectomy for Osteomyelitis: A Case Series

OBJECTIVE

To document the incidence, risk factors, and prevalence of sacral insufficiency fractures (SIF) among patients who have undergone total pubectomy for osteomyelitis.

METHODS

A retrospective chart review was performed of patients undergoing total pubectomy for osteomyelitis at a single institution from 2016 to 2021. Descriptive statistics and univariate analysis were performed using the Wilcoxon rank-sum test and Fisher exact test as appropriate.

RESULTS

Sixteen patients underwent total pubectomy for osteomyelitis. The median age was 68 years. 12/16 (75%) had previously received pelvic radiotherapy. The median BMI was 27.8 kg/m². Eleven (68.75%) had postoperative pelvic imaging, of which 3 (27.3%) had a new SIF. One other patient had a SIF 3 days before pubectomy. Three SIFs were detected via MRI and one by CT scan. The median BMI of patients with SIF was significantly lower than those without SIF (22.4 v 30.5, p = 0.004). All patients with SIF presented with new pelvic or perineal pain without radiculopathy. Symptoms resolved for three patients with non-opioid analgesics, physical therapy, and/or a brief trial of opioids.

CONCLUSIONS

Sacral insufficiency fracture is a rare sequela of total pubectomy for osteomyelitis. Lower BMI is significantly associated with SIF perhaps due to reduced muscle mass or poor bone condition and, as a result, baseline pelvic instability. Medical management should be first-line therapy.