Four magnetic resonance imaging surveillance-detected breast cancer cases in cancer-free BRCA1/2 mutation carriers

Background Hereditary breast and ovarian cancer (HBOC) syndrome is a susceptibility syndrome for cancers, such as breast and ovarian cancer, and BRCA1/2 are its causative genes. Annual breast-enhanced magnetic resonance imaging (MRI) is recommended for BRCA1/2 mutation carriers aged over 25 years as a secondary prevention of breast cancer. However, breast MRI surveillance is rarely performed in Japan, and only four cases of breast cancer diagnosis triggered by MRI surveillance have been reported. Case presentation At our hospital, MRI triggered the diagnosis of breast cancer in four cancer-free BRCA1/2 mutation carriers. In one of our four cases, although MRI showed only a 3-mm focus, we could diagnose breast cancer by shortening the surveillance interval considering the patient’s high-risk for developing breast cancer. Conclusions Image-guided biopsy, including MRI-guided biopsy, depending on the size of the lesion, and shorter surveillance intervals are useful when there are potentially malignant findings on breast MRI surveillance for cancer-free patients with HBOC.

The role of cochlear implant positioning on MR imaging quality: a preclinical in vivo study with a novel implant magnet system

Purposes To investigate the effects for Ultra 3D cochlear implant (CI) positioning on MR imaging quality, looking at a comprehensive description of intracranial structures in cases of unilateral and bilateral CI placement. Methods Four CI angular positions (90°, 120°, 135° and 160°) at 9 cm distance from the outer-ear canal were explored. The 1.5 T MRI assessment included our institutional protocol for the investigation of brain pathologies without gadolinium application. Three investigators (two experienced neuroradiologists and one experienced otoneurosurgeon) independently evaluated the MR findings. A 4-point scale was adopted to describe 14 intracranial structures and to determine which CI positioning allowed the best image quality score and how bilateral CI placement modified MRI scan visibility. Results A high positive correlation was found between the three blinded observers. Structures situated contralateral from the CI showed high-quality values in all four placements. Structures situated ipsilaterally provided results suitable for diagnostic purposes for at least one position. At 90°, artifacts mainly involved brain structures located cranially and anteriorly (e.g., temporal lobe); on the contrary, at 160°, artifacts mostly influenced the posterior fossa structures (e.g., occipital lobe). For the bilateral CI condition, MR imaging examination revealed additional artifacts involving all structures located close to either CI, where there was a signal void/distortion area. Conclusions Suitable unilateral CI positioning can allow the visualization of intracranial structures with sufficient visibility for diagnostic purposes. Bilateral CI positioning significantly deteriorates the anatomical visibility. CI positioning might play a crucial role for patients who need post-operative MRI surveillance.

RADI-23. Exploring the optimal timing of routine initial surveillance MRI following treatment of brain metastases with stereotactic radiosurgery: a comparison of two approaches

Purpose To measure the value of early initial surveillance MRI scans in patients with brain metastases undergoing stereotactic radiosurgery (SRS), as MRI scans are a significant cost and patient stressor. Methods We identified a retrospective cohort of patients with brain metastases treated with SRS and followed at a single institution with scheduled 6-week or 12-week initial surveillance MRI. Imaging interval was based on policy of different providers. Outcome measures included new/progressive lesions, salvage treatment, detection of new lesions before symptoms, and use of surgical resection. Results Two hundred patients were included: 100 consecutive patients scanned with 6-week and 12-week imaging. Eighty-seven and 74 patients in each group had available follow-up imaging and were analyzed. Median time to MRI was 6.7 weeks and 13.5 (p<.001). No difference in primary site, prior SRS, number of treated brain metastases, or use of targeted therapy/immune checkpoint inhibitors was detected. A lower percentage of patients with 6-week MRI had controlled extracranial disease at initial treatment (30% vs 47%,p=.003). Twenty-eight percent with 6-week MRI had findings concerning for new/progressive disease, compared to 47% with 3-month MRI (p=0.01). Fifteen percent (10/87) with 6-week MRI underwent intervention (i.e. SRS, whole brain radiotherapy, or surgery) compared to 34% (20/74) with 12-week MRI (p=0.004). Of patients receiving SRS, a higher percentage had new/worsening neurologic symptoms (45% vs 30%) at follow-up although a lower percentage had new lesions >1cm (20% vs 50%) when discovered. One patient in each group underwent surgical salvage. Conclusion While shorter 6-week interval MRI surveillance post-SRS may detect new/progressive disease less frequently than 12-week MRI surveillance intervals, short interval MRI may be more likely to detect new/progressive lesions before symptoms develop. Surgical salvage was uncommon with either schedule. Further study may identify a high-risk subgroup who would benefit from early surveillance.

In regards to Chu et al.: Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer

We read the article entitled “Patterns of brain metastasis immediately before prophylactic cranial irradiation (PCI): implications for PCI optimization in limited-stage small cell lung cancer” with great interest. In that study, the author reported about the importance of PCI timing in limited stage small cell lung cancer (LS-SCLC) in the era of MRI surveillance. In addition, the authors raise the issue of neurotoxicity of PCI. In this letter, we aimed to clarify the value of PCI in LS-SCLC and present ongoing trials regarding PCI and MRI surveillance in SCLC. As a result, we see the need for the development of a prediction tool to estimate the risk of intracranial relapse in LS-SCLC after chemoradiotherapy in order to support shared decision making through improved guidance.

Routine use of both mammography and MRI surveillance in patients with previous ‘mammogram occult’ breast cancer: experience from a tertiary centre

BackgroundTo evaluate the role of combined MRI and mammogram follow-up in patients with previous ‘mammographically occult’ breast cancer.MethodsBetween 2011 and 2016, examinations of all patients undergoing routine surveillance following previous ‘mammogram occult’ breast cancer were evaluated. Patients had both MRI and mammograms on the same day with an interval of 12–18 months between consecutive pairs. Total number of recalls on both imaging modalities and the outcome of those recalls was recorded. There were six median examinations per patient.ResultsThere were a total of 325 examinations of 54 patients. There were 96 mammograms/MRI pairs and 87 lone MRI and 46 lone mammograms. There were a total of 26 recalls in 21 patients. MRI had specificity (95% CI) of 89.99 (85.67 to 93.11) compared to mammograms 96.27 (92.53 to 98.25). The diagnostic OR with 95% CI was 19.40 (3.70 to 101.57) vs 6.72 (1.43 to 31.58) of mammograms and MRI, respectively. Three of seven cancers presented symptomatically.ConclusionsMRI surveillance leads to higher recalls and false positives compared to mammograms in this specific subgroup of high-risk patients. Large proportion of cancers presented symptomatically, stressing the importance of remaining vigilant of breast symptoms despite imaging surveillance.