Imaging findings after radiofrequency ablation of adrenal tumors

Percutaneous image-guided radiofrequency ablation for adrenal tumours: a systematic review

AIM

To undertaken a systematic review of the technical success and technique efficacy rates of percutaneous image-guided radiofrequency ablation (RFA) for adrenal tumours.

MATERIALS AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies from inception to the third week of January 2020. Only studies reporting effectiveness rates of percutaneous RFA for adrenal tumours were included. Data regarding sample size, tumours, effectiveness rates, outcomes, and complications were extracted in duplicate and recorded.

RESULTS

A total of 15 studies evaluating 292 individuals with 305 tumours were included. Patient selection criteria included age ≥18 years, contraindication to surgical intervention, and no uncorrected coagulopathy. Cumulative technical success, primary technique efficacy, and secondary technique efficacy rates were 99%, 95.1% and 100%, respectively, indicating optimal immediate control of adrenal tumours. Technical success and technique efficacy rates of primary adrenal tumours were higher than adrenal metastases; however, formal statistical analyses were precluded due to lack of comparative studies. Local tumour progression rates for adrenal metastases were 20.3% at 3 months, 26.3% at 6 months, and 29.3% at 12 months. Overall survival rates for adrenal metastases were 81.8% at 6 months, 59.6% at 12 months, and 62.9% at 18 months. The intraprocedural complication rate was 30.2%, with the most frequency reported complication being procedural hypertensive crisis.

CONCLUSION

The findings of this study suggest percutaneous image-guided RFA is a safe and efficacious procedure. Further studies are warranted to define patient selection criteria and long-term outcomes.

Radiofrequency ablation for adenoma in patients with primary aldosteronism and hypertension: ADERADHTA, a pilot study

OBJECTIVE

To evaluate the efficacy and the feasibility of radiofrequency ablation to treat aldosterone-producing adenomas.

METHODS

In an open prospective bicentric pilot study, patients with hypertension on ambulatory blood pressure measurement, a primary aldosteronism, an adenoma measuring less than 4 cm, and confirmation of lateralization by adrenal venous sampling were recruited. The primary endpoint, based on ABPM performed at 6 months after the radiofrequency ablation, was a daytime SBP/DBP less than 135/85 mmHg without any antihypertensive drugs or a reduction of at least 20 mmHg for SBP or 10 mmHg for DBP.

RESULTS

Thirty patients have been included (mean age = 51 ± 11 years; 50% women). Mean baseline daytime SBP and DBP were 144 ± 19 / 95 ± 15 mmHg and 80% received at least two antihypertensive drugs. At 6 months: 47% (95% CI 28-66) of patients reached the primary endpoint, mean daytime SBP and DBP were 131 ± 14 (101-154)/87 ± 10 (71-107) mmHg; 43% of them did not take any antihypertensive drug and 70% of them did not take potassium supplements. Few complications were recorded: four cases of back pain at day 1 postablation; three limited pneumothoraxes, which resolved spontaneously; one lesion of a polar renal artery.

CONCLUSION

Radiofrequency ablation for hypertensive patients with aldosterone-producing adenomas seems to be an emerging promising alternative to surgery. Its efficacy and its feasibility have to be confirmed in a larger sample of patients.

Percutaneous Adrenal Radiofrequency Ablation: A Short Review for Endocrinologists

Image-guided radiofrequency ablation (RFA) has been accepted as a minimally invasive treatment for adrenal tumors in patients who are unable to undergo adrenalectomy. Accordingly, this treatment has become more readily available for treating functioning or non-functioning adrenal masses. Thus, endocrinologists need a better understanding of percutaneous RFA of adrenal tumors. The purpose of this review is to briefly describe the basic mechanism of RFA, indications and contraindications, patient preparation prior to RFA, type of complications, how to avoid complications, RFA procedures, and treatment outcomes.

Radiofrequency Ablation of Functioning Adrenal Adenomas: Preliminary Clinical and Laboratory Findings

PURPOSE

To evaluate clinical and laboratory findings in patients undergoing radiofrequency (RF) ablation for functioning adrenal adenomas.

MATERIALS AND METHODS

Eleven adult patients, nine with Conn syndrome and two with Cushing syndrome, underwent percutaneous computed tomography-guided RF ablation for benign adrenal neoplasms. Systolic, diastolic, and mean blood pressure and the number of classes of antihypertensive drugs used by each patient were analyzed before and 1, 4, and 12 weeks after the procedure. Serum hormone levels were analyzed within 30 days before and 12 weeks after the procedure.

RESULTS

Of the nine patients with Conn syndrome, eight showed normal serum aldosterone levels after the procedure and one patient had a nodule located very close to the inferior vena cava, resulting in incomplete ablation. The two patients with Cushing syndrome had normal serum and salivary cortisol levels after the procedure. Mean aldosterone concentration at baseline was 63.3 ng/dL ± 28.0 and decreased to 13.3 ng/dL ± 13.5 at 12 weeks postoperatively (P = .008). Systolic, diastolic, and mean blood pressures decreased significantly in the first week after the procedure (P < .001) and remained stable during further follow-up.

CONCLUSIONS

In patients with Conn syndrome or Cushing syndrome, percutaneous RF ablation of functioning adrenal adenomas may result in normalization of hormone secretion, improvement in blood pressure, and reduced need for antihypertensive drugs.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

Morphologic Change in Computed Tomography of Aldosterone-Producing Adenoma after Radiofrequency Ablation

Objective

To evaluate the morphologic changes of aldosterone-producing adenoma (APA) on computed tomography (CT) before and after radiofrequency ablation (RFA) and to assess the factors that are important in determining successful complete ablation of these tumours.

Method

Between August 2004 and August 2011, 24 consecutive patients with APA undergoing CT-guided percutaneous RFA were identified from our prospective database. The pre-RFA and post-RFA CT appearances of these APAs that showed positive biochemical response were reviewed retrospectively for their 3-dimensional size, tumour volume, and CT attenuation in terms of Hounsfield units (HU). A comparison of these parameters before and after RFA was performed.

Results

In this study, there were 23 APAs in these 24 patients that showed biochemical cure of primary aldosteronism after RFA. When comparing post-RFA to pre-RFA CTs, there was no significant change in tumour size (14.5 mm vs 14.6 mm: P = .83) and tumour volume (1.55 cm3 vs 1.59 cm3; P = .41) after RFA. In nonenhanced CT images, there was no significant reduction in HU from pre-RFA to post-RFA measurements (4.4 HU vs 7.9 HU; P = .52). In contrast-enhanced CTs, there was a significant drop in HU after RFA (from 48.3 HU to 14.7 HU; P = .03). None of the included cases showed a focal region of contrast enhancement to suggest residual tumour.

Conclusion

A change in tumour size, tumour volume, and HU in nonenhanced CT were unreliable in defining radiologic treatment success. Only changes in HU in contrast-enhanced CT was useful in confirming a positive treatment response after RFA for APA.

Ablative therapies in adrenal tumors: primary and metastatic

A large number of adrenal tumors are now identified either incidentally or associated with a metastatic workup for cancer. While the vast majority of these lesions are benign, those that prove to be primary or secondary cancers are traditionally treated with surgical resection. A wide variety of alternative, less invasive therapies exist. One of these, thermal ablation, is examined herein.