Real-time FDG PET/CT-guided bone biopsy in a patient with two primary malignancies

PET-based Quantitative Techniques in Assessing Efficacy of Interventional Radiology Procedures in Oncology

Interventional radiology (IR) is a super specialised branch where imaging modalities are employed to guide disease specific diagnostic and therapeutic interventions. IR interventions have gained popularity in various oncological and non-oncological indications due to it's ability to effectively diagnose the disease and direct specific targeted treatment. Hybrid imaging using PET CT and PET MRI combines the best of morphological and functional informations and offers improved sensitivity and specificity for detection of lesion; helps in accurate mapping of tumour burden, thereby aiding in planning curative vs palliative intent intervention; more accurate response evaluation to plan redo session in cases of residual / recurrent disease or for follow up evaluation and for prognostication and predicting response. Albeit visual analysis of PET images by specialist is most commonly performed for reading PET scans, PET has a remarkable capability to provide quantitative information. The present review provides a comprehensive assessment of the role of various aspects of quantitative PET parameters in assessing the efficacy of IR interventions. The insights provided will help clinicians, researchers, and medical professionals understand the role of PET imaging in advancing patient care and enhancing the therapeutic outcomes of IR procedures.

Clinical application of real-time PET/CT guided targeted retroperitoneal masses biopsy in diagnosing malignant tumors

OBJECTIVE

To explore the feasibility, safety, and clinical application value based on the fusion image of 18 F-FDG PET/CT, for guiding retroperitoneal puncture biopsy technology and to determine the diagnosis of retroperitoneal masses in diagnosing malignant tumors.

METHODS

From March 2019 to January 2023, 42 patients underwent 18 F-FDG PET/CT imaging and were found to have retroperitoneal lesions that required definite diagnosis; 22 were male, 20 were female, and the average age was(59.17 ± 13.23) years. According to the fused 18 F-FDG PET/CT tomographic image, the target point with the highest metabolic activity, the safest, and expected maximum sample size was selected. CT scans were acquired with the same machine and fused with 18 F-FDG PET, guiding the puncture biopsy needle to approach the expected target zone, enabling timely delivery of pathological and immunohistochemical examination of the biopsy. Success rate, total examination time, biopsy operation time, complications, CT radiation dose, pathological, and immunohistochemical results were recorded.

RESULTS

All 42 patients were sampled successfully with the successful rate being 100%. The site of sampling of 42 patients accurately targeted the highest metabolic activity, the safest, and the expected maximum sample size. All 42 patients received clear diagnosis (25 cases of malignant tumors and cases of 17 benign tissues). 15 cases of patients had a change in clinical diagnosis, accounting for 35.7% of all patients, and affecting subsequent treatment plans. The average total examination time for patients was (41.3 ± 7.3) minutes, and the biopsy operation time was (29.1 ± 8.7) minutes. The effective radiation dose generated by the entire examination generated by CT guidance was (2.0 ± 0.5) mSv; no severe complications occurred in the patients.

CONCLUSION

Real-time-guided retroperitoneal puncture biopsy based on 18 F-FDG PET/CT fusion image is safe, accurate, and feasible, and can provide patients of retroperitoneal mass with clear pathological diagnosis and immunohistochemical evaluation.

Feasibility of a multimodal (18)F-FDG-directed lymph node surgical excisional biopsy approach for appropriate diagnostic tissue sampling in patients with suspected lymphoma

Background

¹⁸F-FDG PET/CT imaging is widely utilized in the clinical evaluation of patients with suspected or documented lymphoma. The aim was to describe our cumulative experience with a multimodal ¹⁸F-FDG-directed lymph node surgical excisional biopsy approach in patients with suspected lymphoma.

Methods

Thirteen patients (mean age 51 (±16;22–76) years), with suspected new or suspected recurrent lymphoma suggested by ¹⁸F-FDG-avid lesions seen on prior diagnostic whole-body PET/CT imaging, were injected IV with ¹⁸F-FDG prior to undergoing same-day diagnostic lymph node surgical excisional biopsy in the operating room. Various ¹⁸F-FDG detection strategies were used on the day of surgery, including, (1) same-day pre-resection patient PET/CT; (2) intraoperative gamma probe assessment; (3) clinical scanner specimen PET/CT imaging of whole surgically excised tissue specimens; (4) specimen gamma well counts; and/or (5) same-day post-resection patient PET/CT.

Results

Same-day ¹⁸F-FDG injection dose was 14.8 (±2.4;12.5-20.6) millicuries or 548 (±89;463–762) megabecquerels. Sites of ¹⁸F-FDG-avid lesions were 4 inguinal, 3 cervical, 3 abdominal/retroperitoneal, 2 axillary, and 1 gluteal region subcutaneous tissue. Same-day pre-resection patient PET/CT was performed on 6 patients. Intraoperative gamma probe assessment was performed on 13 patients. Clinical scanner PET/CT imaging of whole surgically excised tissue specimens was performed in 10 cases. Specimen gamma well counts were performed in 6 cases. Same-day post-resection patient PET/CT imaging was performed on 8 patients. Time from ¹⁸F-FDG injection to same-day pre-resection patient PET/CT, intraoperative gamma probe assessment, and same-day post-resection patient PET/CT were 76 (±8;64–84), 240 (±63;168–304), and 487 (±104;331–599) minutes, respectively. Time from ¹⁸F-FDG injection to clinical scanner PET/CT of whole surgically excised tissue specimens was 363 (±60;272–446) minutes. Time from ¹⁸F-FDG injection to specimen gamma well counts was 591 (±96;420–689) minutes. Intraoperative gamma probe assessment successfully identified ¹⁸F-FDG-avid lesions in 12/13 patients. Histopathologic evaluation confirmed lymphoma in 12/13 patients and benign disease in 1/13 patients.

Conclusions

A multimodal approach to ¹⁸F-FDG-directed lymph node surgical excisional biopsy for suspected lymphoma is technically feasible for guiding appropriate diagnostic tissue sampling of lymph nodes seen as ¹⁸F-FDG-avid lesions on diagnostic ¹⁸F-FDG PET/CT imaging.

18F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals derived from a single-institution 18F-FDG-directed surgery experience: feasibility and quantification of 18F-FDG accumulation within 18F-FDG-avid lesions and background tissues

Background

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is a well-established imaging modality for a wide variety of solid malignancies. Currently, only limited data exists regarding the utility of PET/CT imaging at very extended injection-to-scan acquisition times. The current retrospective data analysis assessed the feasibility and quantification of diagnostic ¹⁸F-FDG PET/CT oncologic imaging at extended injection-to-scan acquisition time intervals.

Methods

¹⁸F-FDG-avid lesions (not surgically manipulated or altered during ¹⁸F-FDG-directed surgery, and visualized both on preoperative and postoperative ¹⁸F-FDG PET/CT imaging) and corresponding background tissues were assessed for ¹⁸F-FDG accumulation on same-day preoperative and postoperative ¹⁸F-FDG PET/CT imaging. Multiple patient variables and ¹⁸F-FDG-avid lesion variables were examined.

Results

For the 32 ¹⁸F-FDG-avid lesions making up the final ¹⁸F-FDG-avid lesion data set (from among 7 patients), the mean injection-to-scan times of the preoperative and postoperative ¹⁸F-FDG PET/CT scans were 73 (±3, 70-78) and 530 (±79, 413-739) minutes, respectively (P < 0.001). The preoperative and postoperative mean ¹⁸F-FDG-avid lesion SUV_max values were 7.7 (±4.0, 3.6-19.5) and 11.3 (±6.0, 4.1-29.2), respectively (P < 0.001). The preoperative and postoperative mean background SUV_max values were 2.3 (±0.6, 1.0-3.2) and 2.1 (±0.6, 1.0-3.3), respectively (P = 0.017). The preoperative and postoperative mean lesion-to-background SUV_max ratios were 3.7 (±2.3, 1.5-9.8) and 5.8 (±3.6, 1.6-16.2), respectively, (P < 0.001).

Conclusions

¹⁸F-FDG PET/CT oncologic imaging can be successfully performed at extended injection-to-scan acquisition time intervals of up to approximately 5 half-lives for ¹⁸F-FDG while maintaining good/adequate diagnostic image quality. The resultant increase in the ¹⁸F-FDG-avid lesion SUV_max values, decreased background SUV_max values, and increased lesion-to-background SUV_max ratios seen from preoperative to postoperative ¹⁸F-FDG PET/CT imaging have great potential for allowing for the integrated, real-time use of ¹⁸F-FDG PET/CT imaging in conjunction with ¹⁸F-FDG-directed interventional radiology biopsy and ablation procedures and ¹⁸F-FDG-directed surgical procedures, as well as have far-reaching impact on potentially re-shaping future thinking regarding the “most optimal” injection-to-scan acquisition time interval for all routine diagnostic ¹⁸F-FDG PET/CT oncologic imaging.