Quantitative Evaluation of Extramural Vascular Invasion of Rectal Cancer by Dynamic Contrast-Enhanced Magnetic Resonance Imaging

Role of molecular imaging in prognosis, diagnosis, and treatment of gastrointestinal cancers: An update on new therapeutic methods

One of the leading causes of cancer-related death is gastrointestinal cancer, which has a significant morbidity and mortality rate. Although preoperative risk assessment is essential for directing patient care, its biological behavior cannot be accurately predicted by conventional imaging investigations. Potential pathophysiological information in anatomical imaging that cannot be visually identified can now be converted into high-dimensional quantitative image features thanks to the developing discipline of molecular imaging. In order to enable molecular tissue profile in vivo, molecular imaging has most recently been utilized to phenotype the expression of single receptors and targets of biological therapy. It is expected that molecular imaging will become increasingly important in the near future, driven by the expanding range of biological therapies for cancer. With this live molecular fingerprinting, molecular imaging can be utilized to drive expression-tailored customized therapy. The technical aspects of molecular imaging are first briefly discussed in this review, followed by an examination of the most recent research on the diagnosis, prognosis, and potential future clinical methods of molecular imaging for GI tract malignancies.

Study on the diagnostic value of MDCT extramural vascular invasion in preoperative N staging of gastric cancer patients

BACKGROUND

To explore the diagnostic value of multidetector computed tomography (MDCT) extramural vascular invasion (EMVI) in preoperative N Staging of gastric cancer patients.

METHODS

According to the MR-defined EMVI scoring standard of rectal cancer, we developed a 5-point scale scoring system to evaluate the status of CT-detected extramural vascular invasion(ctEMVI), 0-2 points were ctEMVI-negative status, and 3-4 points were positive status for ctEMVI. Patients were divided into ctEMVI positive group and ctEMVI negative group. The correlation between ctEMVI and clinical features was analyzed. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of ctEMVI for pathological metastatic lymph nodes and N staging, The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of pathological N staging using ctEMVI and short-axis diameter were generated and compared.

RESULTS

The occurrence rate of lymphovascular invasion (LVI) and proportion of tumors with a greatest diameter > 6 cm in the ctEMVI positive group was higher than that in the ctEMVI negative group (P < 0.05). Spearman correlation analysis showed a positive correlation between ctEMVI and LVI, N stage, and tumor size (P < 0.05). For ctEMVI scores ≥ 3,The AUC of ctEMVI for diagnosing lymph node metastasis, N stage ≥ N2, and N3 stage were 0.857, 0.802, and 0.758, respectively. The sensitivity, NPV and accuracy of ctEMVI for diagnosing N stage ≥ N2 were superior to those of short-axis diameter (P < 0.05), while sensitivity, specificity, PPV, NPV, and accuracy of ctEMVI for diagnosing N3 stage were superior to those of short-axis diameter (P < 0.05).

CONCLUSION

ctEMVI has important value in diagnosing metastatic lymph nodes and advanced N staging. As an important imaging marker, ctEMVI can be included in the preoperative imaging evaluation of patients, providing important assistance for clinical guidance and treatment.

Results of a diagnostic imaging audit in a randomised clinical trial in rectal cancer highlight the importance of careful planning and quality control

BACKGROUND

Magnetic resonance (MR) imaging is the modality used for baseline assessment of locally advanced rectal cancer (LARC) and restaging after neoadjuvant treatment. The overall audited quality of MR imaging in large multicentre trials on rectal cancer is so far not routinely reported.

MATERIALS AND METHODS

We collected MR images obtained within the Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation (RAPIDO) trial and performed an audit of the technical features of image acquisition. The required MR sequences and slice thickness stated in the RAPIDO protocol were used as a reference.

RESULTS

Out of 920 participants of the RAPIDO study, MR investigations of 668 and 623 patients in the baseline and restaging setting, respectively, were collected. Of these, 304/668 (45.5%) and 328/623 (52.6%) MR images, respectively, fulfilled the technical quality criteria. The main reason for non-compliance was exceeding slice thickness 238/668, 35.6% in the baseline setting and 162/623, 26.0% in the restaging setting. In 166/668, 24.9% and 168/623, 27.0% MR images in the baseline and restaging setting, respectively, one or more of the required pulse sequences were missing.

CONCLUSION

Altogether, 49.0% of the MR images obtained within the RAPIDO trial fulfilled the image acquisition criteria required in the study protocol. High-quality MR imaging should be expected for the appropriate initial treatment and response evaluation of patients with LARC, and efforts should be made to maximise the quality of imaging in clinical trials and in clinical practice.

CRITICAL RELEVANCE STATEMENT

This audit highlights the importance of adherence to MR image acquisition criteria for rectal cancer, both in multicentre trials and in daily clinical practice. High-resolution images allow correct staging, treatment stratification and evaluation of response to neoadjuvant treatment.

KEY POINTS

- Complying to MR acquisition guidelines in multicentre trials is challenging. - Neglection on MR acquisition criteria leads to poor staging and treatment. - MR acquisition guidelines should be followed in trials and clinical practice. - Researchers should consider mandatory audits prior to study initiation.

Biodegradable magnesium screw, titanium screw and direct embedding fixation in pedicled vascularized iliac bone graft transfer for osteonecrosis of the femoral head: a randomized controlled study

BACKGROUND

The use of degradable magnesium screws to fix the bone flap implanted in the treatment of femoral head necrosis has achieved preliminary good therapeutic results. However, there is no conclusive evidence in the study to demonstrate whether biodegradable magnesium screws promote angiogenesis and no comparison has been made between degradable magnesium screws and traditional screws.

OBJECTIVE

To investigate the clinical efficacy and safety of biodegradable magnesium screws in pedicled vascularized iliac bone graft transfer (PVIBGT) for osteonecrosis of the femoral head (ONFH).

MATERIALS AND METHODS

A total of thirty-six patients (37 hips) with ONFH were recruited from March 2020 to July 2022. The study used a single-blind method, and patients who underwent PVIBGT were randomized into three groups: 12 patients (12 hips) were fixed with biodegradable magnesium screws (Group A), 12 patients (13 hips) were fixed with titanium screws (Group B), 12 patients (12 hips) were directly embedded (Group C). The operating time and the length of stay were recorded. Harris scores, radiological examinations (X-ray, CT, DCE-MRI), blood and serum tests were conducted before and after surgery. The gas yield and degradation rates of the magnesium screws were measured at the 3-months and 6-months post-operative follow-ups in Group A.

RESULTS

There was no statistically significant difference among these three groups in terms of types, gender, age, course of disease, surgical side, operation time, the length of stay (P > 0.05). All patients were followed up for 6 months. The mean Harris scores were higher in all groups 6 months after surgery (P < 0.05). The rates of excellent and good outcomes were 66.7%, 46.2%, and 33.3% in Groups A, B, and C, respectively. PVIBGT and magnesium screws can improve the blood supply of the femoral head via DCE-MRI evaluation. Two patients with poor incision healing received prompt treatment and subsequently recovered well. No adverse events, such as hip infection or deep vein thrombosis, were reported in the patients. The patients had good biocompatibility of magnesium screws, and no fracture of the magnesium screws was observed in Group A. Liver and kidney functions (including serum magnesium) were within normal ranges. The area of the intermuscular air space was 0 cm² in follow-ups. The degradation rate of the biodegradable magnesium screws was approximately 10.32% at the 3-months follow-up and 13.72% at the 6-months follow-up.

CONCLUSIONS

PVIBGT has a positive effect, especially with regard to improving blood supply of the femoral head. The fixation of biodegradable magnesium screws is reliable and safe in PVIBGT, and promote angiogenesis.