Soft-tissue sarcoma in adults: Imaging appearances, pitfalls and diagnostic algorithms

This article provides an overview of the current knowledge regarding diagnostic imaging of patients with soft-tissue sarcomas, which is a heterogeneous group of rare mesenchymal malignancies. After an initial contextualization, diagnostic flow-chart based on initial radiological findings of soft-tissue masses (with specific focus on adipocytic soft-tissue tumors [STTs], hemorragic STTs and retroperitoneal STTs) are provided considering relevant results from novel researches, guidelines, and experts' viewpoints, with the aim to help radiologists and clinicians in their practice. Particularly, the central place of sarcoma reference centers in the diagnostic and therapeutic management is highlighted, as well as the pivotal role that radiologists should play to correctly identify patients with soft-tissue sarcoma at the initial stage of the disease. Indications and methods for performing imaging-guided biopsies are also discussed, as well as clues to improve soft-tissue sarcoma grading with conventional and quantitative imaging.

The role of multiparametric ultrasound in the detection of clinically significant prostate cancer

PURPOSE

Transrectal ultrasound (US) imaging is paramount to the successful completion of prostate biopsies. Certain US features have been associated with prostate cancer (PCa), but their utility remains controversial. We explored the role of multiparametric US (mpUS) in the detection of clinically significant PCa.

METHODS

We performed a retrospective cohort study to contrast the findings of prostate MRI and mpUS. Patients who underwent MRI, US and biopsy between 2015 and 2021 were included. Biopsies were performed using a systematic approach (12 cores), as well as with MRI (4 cores/lesion) and US (1 core/lesion) targeting. The US features analyzed consisted of: calcifications, hypoechoic lesions and power or color Doppler positivity. Gleason 3 + 4 or higher was used as to define true positives. Measures of diagnostic accuracy were calculated for the different imaging modalities.

RESULTS

The final cohort included 74 patients, of which 24 (32.4%) had clinically significant PCa. The concordance between MRI and US was 63.5%. Seven individuals with discordant results had clinically significant PCa. MRI alone was more sensitive (87.5% vs 75%) but less specific (28% vs 32%) than US alone. An all-inclusive approach considering any suspicious US or MRI finding had a sensitivity of 95.8%. A more restrictive approach, targeting lesions noted in both US and MRI, yielded the highest specificity (50.0%) and accuracy (55.4%).

CONCLUSION

Biopsy targeting based on US findings can provide additional diagnostic information that may increase sensitivity or specificity. Additional research into this topic could open the door to a more personalized approach to prostate biopsy.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Accuracy and complications of percutaneous transthoracic needle lung biopsy for the diagnosis of malignancy in patients with idiopathic pulmonary fibrosis

OBJECTIVES

To determine the accuracy of CT-guided percutaneous transthoracic needle lung biopsy (PTNB) for the diagnosis of malignancy and the associated complication rates in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

This retrospective study included 91 CT-guided PTNBs performed in 80 patients with IPF from April 2003 through December 2016. Data regarding patients, target lesions, procedures, complications, and pathological reports were collected, and the final diagnosis was made. The diagnostic accuracy, sensitivity, specificity, percentage of nondiagnostic results, and complication rates were determined. Multivariable logistic regression analyses were performed to identify risk factors for nondiagnostic results and major complications.

RESULTS

Three biopsies (technical failure [n = 2] and undetermined final diagnosis [n = 1]) were excluded from the diagnostic accuracy calculation. The diagnostic accuracy, sensitivity, and specificity were 89% (78/88), 90% (62/69), and 84% (16/19), respectively. The percentage of nondiagnostic results was 34% (30/88). Lesion size ≤ 3 cm (odds ratio [OR], 8.8; 95% confidence interval [CI], 2.5-31.2; p = 0.001) and needle tip placement outside the target lesion (OR, 13.7; 95% CI, 1.4-132.2; p = 0.02) were risk factors for nondiagnostic results. The overall and major complication rates were 51% (46/91) and 12% (11/91), respectively. The presence of honeycombing along the path of the needle (OR, 11.2; 95% CI, 1.4-89.1; p = 0.02) was an independent risk factor for major complications.

CONCLUSIONS

CT-guided PTNB shows a relatively reasonable accuracy in diagnosing malignancy in patients with IPF. The complication rate may be high, especially when the needle passes through honeycomb lesions.

KEY POINTS

• In patients with idiopathic pulmonary fibrosis (IPF), CT-guided percutaneous transthoracic needle lung biopsy (PTNB) showed a relatively reasonable accuracy for the diagnosis of malignancy. • Target lesion size ≤ 3 cm and biopsy needle tip placement outside the target lesion were risk factors for nondiagnostic results of CT-guided PTNB. • The complication rate may be high, especially in cases where the biopsy needle passes through honeycomb lesions.

Contrast-enhanced ultrasonography to guide diagnostic and therapeutic interventional procedures

Although not necessary for the vast majority of ultrasound-guided procedures, intravenous contrast agents can be useful for procedures aimed at lesions that require contrast enhancement to be seen on ultrasonography. Using contrast-enhanced ultrasonography to guide procedures has two drawbacks: first, because enhancement from ultrasound contrast agents is short lived, it is often necessary to plan several injections; second, because the needle is poorly seen on contrast-enhanced ultrasonography, a dual image display format is necessary. Contrast-enhanced ultrasonography can be used for planning and monitoring diagnostic and therapeutic procedures, for guiding the procedures, and for follow-up. Using contrast-enhanced ultrasonography enables better results in both types of procedures; moreover, it can be used within cavities.

Diagnostic performance of 68Ga-PSMA-11 PET/MRI-guided biopsy in patients with suspected prostate cancer: a prospective single-center study

PURPOSE

Ultrasound-guided biopsy (US biopsy) with 10-12 cores has a suboptimal sensitivity for clinically significant prostate cancer (sigPCa). If US biopsy is negative, magnetic resonance imaging (MRI)-guided biopsy is recommended, despite a low specificity for lesions with score 3-5 on Prostate Imaging Reporting and Data System (PIRADS). Screening and biopsy guidance using an imaging modality with high accuracy could reduce the number of unnecessary biopsies, reducing side effects. The aim of this study was to assess the performance of positron emission tomography/MRI with ⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA-PET/MRI) to detect and localize primary sigPCa (ISUP grade group 3 and/or cancer core length ≥ 6 mm) and guide biopsy.

METHODS

Prospective, open-label, single-center, non-randomized, diagnostic accuracy study including patients with suspected PCa by elevation of prostate-specific antigen (PSA) level and a suspicious lesion (PIRADS ≥3) on multiparametric MRI (mpMRI). Forty-two patients underwent PSMA-PET/MRI followed by both PSMA-PET/MRI-guided and section-based saturation template biopsy between May 2017 and February 2019. Primary outcome was the accuracy of PSMA-PET/MRI for biopsy guidance using section-based saturation template biopsy as the reference standard.

RESULTS

SigPCa was found in 62% of the patients. Patient-based sensitivity, specificity, negative and positive predictive value, and accuracy for sigPCa were 96%, 81%, 93%, 89%, and 90%, respectively. One patient had PSMA-negative sigPCa. Eight of nine false-positive lesions corresponded to cancer on prostatectomy and one in six false-negative lesions was negative on prostatectomy.

CONCLUSION

PSMA-PET/MRI has a high accuracy for detecting sigPCa and is a promising tool to select patients with suspicion of PCa for biopsy.

TRIAL REGISTRATION

This trial was retrospectively registered under the name "Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) Guided Biopsy in Men with Elevated PSA" (NCT03187990) on 06/15/2017 ( https://clinicaltrials.gov/ct2/show/NCT03187990 ).

Multiparametric magnetic resonance imaging can exclude prostate cancer progression in patients on active surveillance: a retrospective cohort study

Objectives

To assess the ability of multiparametric MRI (mp-MRI) of the prostate to exclude prostate cancer (PCa) progression during monitoring patients on active surveillance (AS).

Methods

One hundred forty-seven consecutive patients on AS with mp-MRI (T2WI, DWI, DCE-MRI) at 3T were initially enrolled. Fifty-five received follow-up mp-MRI after a minimum interval of 12 months and subsequent targeted MR/US fusion-guided biopsy (FUS-GB) plus concurrent systematic transrectal ultrasound-guided (TRUS-GB) biopsy as reference standard. Primary endpoint was the negative predictive value (NPV) of the follow-up mp-MRI to exclude histopathologic tumor progression using PRECISE recommendations. Secondary endpoints were the positive predictive value (PPV), sensitivity, specificity, Gleason score (GS) upgrades, and comparison of biopsy method.

Results

Of 55 patients, 29 (53%) had a GS upgrade on re-biopsy. All 29 patients showed a tumor progression on follow-up mp-MRI. Fifteen of 55 patients (27%) displayed signs of tumor progression, but had stable GS on re-biopsy. None of the 11 patients (20%) without signs of progression on follow-up mp-MRI had a GS upgrade on re-biopsy. The NPV was 100%, PPV was 66%, sensitivity was 100%, and specificity 42%. FUS-GB resulted in GS upgrade significantly more often (n = 28; 51%) compared with TRUS-GB (n = 12; 22%; p < 0.001).

Conclusions

(Follow-up) Mp-MRI can reliably exclude PCa progression in patients on AS. Standard serial re-biopsies might be waived if follow-up mp-MRIs are stable. Over 60% of patients with signs of tumor progression on mp-MRI during AS had a GS upgrade on re-biopsy. Targeted re-biopsies should be performed if cancer progression or higher-grade PCa is suspected on mp-MRI.

Key Points

• None of the patients with unsuspicious mp-MRI had a GS upgrade in re-biopsy and mp-MRI might replace serial biopsies in these cases

• More than 60% of patients with mp-MRI signs of tumor progression had subsequent Gleason score (GS) upgrades

• Targeted re-biopsies should be performed in case of higher GS cancer suspicion on mp-MRI

Diagnostic performance of imaging-guided core needle biopsy of the mesentery and peritoneum

OBJECTIVE

To evaluate the diagnostic performance of imaging-guided core needle biopsy of nodules and diffuse infiltration of the omentum or of the peritoneum.

MATERIAL AND METHODS

We retrospectively evaluated 57 patients who underwent core needle biopsy of the peritoneum or of the omentum between March 2014 and January 2017. We used computed tomography (CT) to plan the biopsy. Biopsies were guided by CT or ultrasonography (US). We classified the results as diagnostic (benign / malignant) or inconclusive (inadequate sample). We calculated the sensitivity, specificity, positive-predictive value, and negative predictive value. We analyzed whether the specimen was diagnostic depending on the imaging technique used (CT or US) and on the type of omental or peritoneal involvement from which the specimen was obtained (mass, nodule, or diffuse involvement).

RESULTS

All (100%) the percutaneous biopsies were diagnostic. The sensitivity of the technique was 98.18% and the specificity was 100%. The positive predictive value was 100% and the negative predictive value was 50%. Both the specimens obtained under CT guidance (n=10) and those obtained under US guidance (n=47) were diagnostic. Likewise, biopsies of masses (n=24), of nodules (n=17), and even of diffuse infiltration (n=16) of the peritoneum or omentum enabled the histologic diagnosis. The rate of complications was 1.75% (one death).

CONCLUSION

Percutaneous core needle biopsy has high sensitivity regardless of the imaging technique used to guide the technique (CT or US) and of the type of lesion biopsied (mass, nodule, diffuse infiltration). It is a useful technique with a very low rate of complications, although severe complications can occur.

Higher number of transrectal ultrasound guided prostate biopsy cores is associated with higher blood loss and perioperative complications in robot assisted radical prostatectomy

INTRODUCTION

The local inflammatory process after prostate biopsies can have a negative impact on functional outcomes of radical prostatectomy. There is no evidence in literature demonstrating its impact on radical prostatectomy.

OBJECTIVES

To evaluate the impact of the number of TRUS core biopsies in the surgical morbidity and rate of positive margin on robot assisted radical prostatectomy (RARP).

MATERIAL AND METHODS

A prospectively maintained database of 2,054 RARPs in a single institution. Patients were further grouped into 2 groups based on the number of TRUS biopsy cores (G1≤12 cores; G2>12 cores). Multivariable logistic regression model was applied to analyze the impact of number of cores on complications.

RESULTS

A total number of 1,042 patients in the group 1 (≤12 cores) and 1,012 patients in the group 2 (>12 cores) were included. The rate of perioperative complications increased with higher number of biopsies (G1 6.4 vs. G2 8.5%; P=.03), but high grade complication (Clavien 3-4) were similar (G1 1.4 vs. G2 2.2%; P=.16). Positive surgical margin rates were similar in both groups (G1 11.8 vs. 9.98%; P=.2). At the multivariable logistic regression analysis shown that G2 had a 39% (OR 0.645) higher rate to experience perioperative complications during RARP.

CONCLUSION

Higher number of TRUS biopsy cores (>12) is associated to higher blood loss and perioperative complications during RARP. Careful preoperative evaluation for those patients underwent multiple biopsies or saturation protocols is mandatory. Application of longer intervals (>6 weeks) between biopsy and surgery may be advisable to minimize potential risks of surgical complications in patients may benefit from RARP. Further studies are still necessary to confirm these results.

The role of transrectal ultrasound in the diagnosis of prostate cancer: new contributions

Objective

The present study was aimed at evaluating the contribution of transrectal prostate ultrasound in the screening for prostate neoplasias and in the guidance of prostate biopsies.

Materials and Methods

Prospective study developed over a one-year period. All the patients with indication for prostate biopsy were evaluated. Regardless of PSA values, the patients underwent ultrasound in order to identify suspicious nodules (confirmed by two observers). Sextant biopsy was subsequently performed. In cases of finding suspicious nodules, an additional puncture directed to such nodules was done.

Results

In a total of 155 cases the prevalence of malignancy was of 53%. Suspicious nodules were detected in 34 patients, and 25 where malignant (positive predictive value of 74%). The specificity and sensitivity for suspicious nodules were 88% and 31% respectively. Comparatively with the randomly obtained sextant specimens, the rate of findings of neoplasia was higher in the specimens obtained with puncture directed to the nodule (p = 0.032). No statistically significant difference was observed in the Gleason score for both types of specimens (p = 0.172).

Conclusion

The high positive predictive value and the high rate of findings of neoplasia in specimens of suspicious nodules should be taken into consideration in the future. The authors suggest a biopsy technique similar to the one described in the present study (sextant biopsy plus puncture directed to the suspicious nodule).