Bilateral hearing loss preceding rhomboencephalitis - a hint for Kelch-like 11 syndrome.

BACKGROUND: Paraneoplastic neurological syndromes have diverse clinical presentations and offer an opportunity for early diagnosis of malignancy and treatment. Recently, a new paraneoplastic syndrome associated with seminoma was described, consisting of rhombencephalitis with antibodies targeting the Kelch-like protein 11 (KLHL11). Questions were raised as to the spectrum of clinical symptoms and strength of association to seminoma. METHODS: We present a 45-year-old man with bilateral sensorineural hearing loss, vertigo, and progressive ataxia. An extensive diagnostic workup led to the diagnosis of anti-KLHL11 paraneoplastic syndrome based on an immunofluorescence assay showing a typical pattern and a confirmatory serological assay. As a result, the patient underwent a meticulous search for an underlying seminoma. RESULTS: Although initially, all images were interpreted as negative, a revision of the positron emission tomography-CT (PET-CT) examination identified a small mediastinal suspicious mass. The mass was resected, and pathological examination confirmed it to be an extra-testicular seminoma. CONCLUSIONS: Patients presenting with progressive sensorineural hearing loss, vertigo, and ataxia should be evaluated for KLHL11 paraneoplastic syndrome. Furthermore, we support a strong association between anti-KLH11 rhombencephalitis and an underlying seminoma and recommend a thorough search for an undiagnosed germ cell tumor in these patients.

The Prognostic Value of Anti-PLA2R Antibodies Levels in Primary Membranous Nephropathy.

Anti-PLA2R antibodies (Ab) are a diagnostic and prognostic biomarker in primary membranous nephropathy (PMN). We assessed the relationship between the levels of anti-PLA2R Ab at diagnosis and different variables related to disease activity and prognosis in a western population of PMN patients. Forty-one patients with positive anti-PLA2R Ab from three nephrology departments in Israel were enrolled. Clinical and laboratory data were collected at diagnosis and after one year of follow-up, including serum anti-PLA2R Ab levels (ELISA) and glomerular PLA2R deposits on biopsy. Univariable statistical analysis and permutation-based ANOVA and ANCOVA tests were performed. The median [(interquartile range (IQR)) age of the patients was 63 [50-71], with 28 (68%) males. At the time of diagnosis, 38 (93%) of the patients had nephrotic range proteinuria, and 19 (46%) had heavy proteinuria (≥8 gr/24 h). The median [IQR] level of anti-PLA2R at diagnosis was 78 [35-183] RU/mL. Anti-PLA2R levels at diagnosis were correlated with 24 h proteinuria, hypoalbuminemia and remission after one year (p = 0.017, p = 0.003 and p = 0.034, respectively). The correlations for 24 h proteinuria and hypoalbuminemia remained significant after adjustment for immunosuppressive treatment (p = 0.003 and p = 0.034, respectively). Higher levels of anti-PLA2R Ab at diagnosis in patients with active PMN from a western population are associated with higher proteinuria, lower serum albumin and remission one year after the diagnosis. This finding supports the prognostic value of anti-PLA2R Ab levels and their possible use in stratifying PMN patients.

FDG PET/CT radiomics as a tool to differentiate between reactive axillary lymphadenopathy following COVID-19 vaccination and metastatic breast cancer axillary lymphadenopathy: a pilot study.

OBJECTIVES: To evaluate if radiomics with machine learning can differentiate between F-18-fluorodeoxyglucose (FDG)-avid breast cancer metastatic lymphadenopathy and FDG-avid COVID-19 mRNA vaccine-related axillary lymphadenopathy. MATERIALS AND METHODS: We retrospectively analyzed FDG-positive, pathology-proven, metastatic axillary lymph nodes in 53 breast cancer patients who had PET/CT for follow-up or staging, and FDG-positive axillary lymph nodes in 46 patients who were vaccinated with the COVID-19 mRNA vaccine. Radiomics features (110 features classified into 7 groups) were extracted from all segmented lymph nodes. Analysis was performed on PET, CT, and combined PET/CT inputs. Lymph nodes were randomly assigned to a training (n = 132) and validation cohort (n = 33) by 5-fold cross-validation. K-nearest neighbors (KNN) and random forest (RF) machine learning models were used. Performance was evaluated using an area under the receiver-operator characteristic curve (AUC-ROC) score. RESULTS: Axillary lymph nodes from breast cancer patients (n = 85) and COVID-19-vaccinated individuals (n = 80) were analyzed. Analysis of first-order features showed statistically significant differences (p < 0.05) in all combined PET/CT features, most PET features, and half of the CT features. The KNN model showed the best performance score for combined PET/CT and PET input with 0.98 (± 0.03) and 0.88 (± 0.07) validation AUC, and 96% (± 4%) and 85% (± 9%) validation accuracy, respectively. The RF model showed the best result for CT input with 0.96 (± 0.04) validation AUC and 90% (± 6%) validation accuracy. CONCLUSION: Radiomics features can differentiate between FDG-avid breast cancer metastatic and FDG-avid COVID-19 vaccine-related axillary lymphadenopathy. Such a model may have a role in differentiating benign nodes from malignant ones. KEY POINTS: • Patients who were vaccinated with the COVID-19 mRNA vaccine have shown FDG-avid reactive axillary lymph nodes in PET-CT scans. • We evaluated if radiomics and machine learning can distinguish between FDG-avid metastatic axillary lymphadenopathy in breast cancer patients and FDG-avid reactive axillary lymph nodes. • Combined PET and CT radiomics data showed good test AUC (0.98) for distinguishing between metastatic axillary lymphadenopathy and post-COVID-19 vaccine-associated axillary lymphadenopathy. Therefore, the use of radiomics may have a role in differentiating between benign from malignant FDG-avid nodes.

Physiologic and hypermetabolic breast 18-F FDG uptake on PET/CT during lactation.

OBJECTIVE: To investigate the patterns of breast cancer-related and lactation-related 18F-FDG uptake in breasts of lactating patients with pregnancy-associated breast cancer (PABC) and without breast cancer. METHODS: 18F-FDG-PET/CT datasets of 16 lactating patients with PABC and 16 non-breast cancer lactating patients (controls) were retrospectively evaluated. Uptake was assessed in the tumor and non-affected lactating tissue of the PABC group, and in healthy lactating breasts of the control group, using maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), and breast-SUVmax/liver-SUVmean ratio. Statistical tests were used to evaluate differences and correlations between the groups. RESULTS: Physiological uptake in non-breast cancer lactating patients' breasts was characteristically high regardless of active malignancy status other than breast cancer (SUVmax = 5.0 ± 1.7, n = 32 breasts). Uptake correlated highly between the two breasts (r = 0.61, p = 0.01), but was not correlated with age or lactation duration (p = 0.24 and p = 0.61, respectively). Among PABC patients, the tumors demonstrated high 18F-FDG uptake (SUVmax = 7.8 ± 7.2, n = 16), which was 326-643% higher than the mostly low physiological FDG uptake observed in the non-affected lactating parenchyma of these patients (SUVmax = 2.1 ± 1.1). Overall, 18F-FDG uptake in lactating breasts of PABC patients was significantly decreased by 59% (p < 0.0001) compared with that of lactating controls without breast cancer. CONCLUSION: 18F-FDG uptake in lactating tissue of PABC patients is markedly lower compared with the characteristically high physiological uptake among lactating patients without breast cancer. Consequently, breast tumors visualized by 18F-FDG uptake in PET/CT were comfortably depicted on top of the background 18F-FDG uptake in lactating tissue of PABC patients. KEY POINTS: • FDG uptake in the breast is characteristically high among lactating patients regardless of the presence of an active malignancy other than breast cancer. • FDG uptake in non-affected lactating breast tissue is significantly lower among PABC patients compared with that in lactating women who do not have breast cancer. • In pregnancy-associated breast cancer patients, 18F-FDG uptake is markedly increased in the breast tumor compared with uptake in the non-affected lactating tissue, enabling its prompt visualization on PET/CT.

Post-mastectomy surveillance of BRCA1/BRCA2 mutation carriers: Outcomes from a specialized clinic for high-risk breast cancer patients.

Female BRCA1/BRCA2 mutation carriers may elect bilateral risk-reducing mastectomy. There is a paucity of data on yield of imaging surveillance after risk-reducing mastectomy. This retrospective study focused on female BRCA1/BRCA2 mutation carriers who underwent bilateral mastectomy either as primary preventative, or as secondary preventative, after breast cancer diagnosis. All participants underwent breast imaging at 6- to 12-month intervals after mastectomy. Data on subsequent breast cancer diagnosis and timing were collected and compared between the groups. Overall, 184 female mutation carriers (134 BRCA1, 45 BRCA2, 5 both BRCA genes) underwent bilateral mastectomy after initial breast cancer diagnosis, between April 1, 2009 and August 31, 2018. During a mean follow-up of 6.2 ± 4.2 years, 13 (7.06%) were diagnosed with breast cancer; 12 ipsilateral (range: 0.4-28.8 years) and 1 contralateral breast cancer, 15.9 years after surgery. On the contrary, among asymptomatic BRCA1 (n = 40) and BRCA2 (n = 13) mutation carriers who underwent primary risk-reducing mastectomy (mean age at surgery 39.5 ± 8.4 years); none has developed breast cancer after a mean follow-up of 5.4 ± 3.4 years. BRCA1/BRCA2 mutation carriers with prior disease who underwent risk-reducing mastectomy after breast cancer diagnosis are still prone for developing ipsi or contralateral breast cancer, and therefore may benefit from continues clinical and imaging surveillance, unlike BRCA1/BRCA2 mutation carriers who undergo primary preventative bilateral mastectomy.

PSMA PET/CT to evaluate response to SBRT for prostate cancer bone metastases.

BACKGROUND: In the current study we evaluated 68Ga PSMA PET/ CT to measure local control of bone metastasis in oligometastatic prostate cancer patients treated with SBRT. MATERIALS AND METHODS: After the institutional review board approval, a retrospective review of medical records of consecutive prostate cancer patients treated between 2014 and 2018 was conducted. Only medical records of patients that were treated with SBRT for bone metastasis and had pre-and post-SBRT 68Ga PSMA PET/CT scans were included in our study. Data extracted from the medical files included patient-related (age), disease-related (Gleason score, site of metastasis), and treatment-related factors and outcomes. RESULTS: During the study period, a total of 12 patients (15 lesions) were included, with a median age of 73 years. The median follow-up was 26.5 months (range 13-45 months). Median time of 68Ga PSMA PET/ CT follow up was 17.0 months (range 3-39 months). The median pre-treatment PSA was 2 ng/mL (range 0.56-44 ng/mL) vs. post treatment PSA nadir of 0.01 ng/mL (0.01-4.32) with a median time to nadir of 7 months (range, 2-12). Local control was 93% during the follow up period and there was correlation with PS MA avidity on PE T. None patients developed recurrences in the treated bone. None of the patients had grade 3 or more toxicities during follow-up. CONCLUSIONS: SBRT is a highly effective and safe method for treatment of prostate cancer bone metastases. More studies are required to determine if SBRT provides greater clinical benefit than standard fractionation for oligometastatic prostate cancer patients. 68Ga PSMA PET/CT should be further investigated for delineation and follow-up.

A Retrospective Analysis of the Safety and Activity of Lutetium-177-Prostate-Specific Membrane Antigen Radionuclide Treatment in Older Patients with Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Prostate cancer is a common malignancy of the elderly, and with the aging of the population, the need is growing for therapies suitable for this age group. Lutetium-177-prostate-specific membrane antigen (Lu-PSMA), a radiolabeled small molecule, binds with high affinity to prostate-specific membrane antigen, enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). In a recent single-arm phase II trial and a subsequent expansion cohort, a prostate-specific antigen (PSA) decline of ≥50% was observed in approximately 60% of patients receiving Lu-PSMA. Taking into account the specific challenges and potential toxicities of Lu-PSMA administration in elderly men, we sought to retrospectively analyze the safety and activity of Lu-PSMA in men aged older than 75 years with mCRPC. PATIENTS AND METHODS: The electronic medical records of 24 patients aged older than 75 years treated with Lu-PSMA "off-trial" were reviewed, and clinical data were extracted. Clinical endpoints were toxicity and activity, defined as a PSA decline ≥50%. Descriptive statistics were performed using Excel. RESULTS: The median age at treatment start was 81.7 years (range 75.1-91.9). The median number of previous treatment lines was four. The number of treatment cycles ranged from one to four; the mean administered radioactivity was 6 GBq per cycle. Treatment was generally tolerable; side effects included fatigue (n = 8, 33%), anemia (n = 7, 29%), thrombocytopenia (n = 5, 21%), and anorexia/nausea (n = 3, 13%). Clinical benefit was observed in 12 of 22 patients (54%); PSA decline above 50% was observed in 11 patients (48%) and was associated with significantly longer overall survival. CONCLUSION: Our results indicate that Lu-PSMA is safe and active in elderly patients with mCRPC. IMPLICATIONS FOR PRACTICE: Lutetium-177-prostate-specific membrane antigen (Lu-PSMA), a radiolabeled small molecule, binds with high affinity to prostate-specific membrane antigen, enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). The recently published single-arm phase II trial with Lu-PSMA, describing its safety and activity, did not include patients aged older than 75 years. In this study, Lu-PSMA activity was retrospectively analyzed in patients aged older than 75 years and results indicate that treatment was tolerable and similarly active in this age group, with no new emerging safety signals. Despite the small cohort size, this analysis suggests that Lu-PSMA can serve as an advanced palliative treatment line in mCRPC in elderly patients.

Brain 18F-FDG-PET: Utility in the Diagnosis of Dementia and Epilepsy.

BACKGROUND: The authors reviewed the two most common current uses of brain 18F-labeled fluoro-2-deoxyglucose positron emission tomography (FDG-PET) at a large academic medical center. For epilepsy patients considering surgical management, FDG-PET can help localize epileptogenic lesions, discriminate between multiple or discordant EEG or MRI findings, and predict prognosis for post-surgical seizure control. In elderly patients with cognitive impairment, FDG-PET often demonstrates lobar-specific patterns of hypometabolism that suggest particular underlying neurodegenerative pathologies, such as Alzheimer's disease. FDG-PET of the brain can be a key diagnostic modality and contribute to improved patient care.

Fat necrosis after abdominal surgery: A pitfall in interpretation of FDG-PET/CT.

OBJECTIVE: We describe FDG-PET/CT findings of postoperative fat necrosis in patients following abdominal surgery, and evaluate their changes in size and FDG uptake over time. METHODS: FDG-PET/CT scans from January 2007-January 2016 containing the term 'fat necrosis' were reviewed. Lesions meeting radiological criteria of fat necrosis in patients with prior abdominal surgery were included. RESULTS: Forty-four patients, 30 males, mean age 68.4 ± 11.0 years. Surgeries: laparotomy (n=37; 84.1 %), laparoscopy (n=3; 6.8 %), unknown (n=4; 9.1 %). CTs of all lesions included hyperdense well-defined rims surrounding a heterogeneous fatty core. Sites: peritoneum (n=34; 77 %), omental fat (n=19; 43 %), subcutaneous fat (n=8; 18 %), retroperitoneum (n=2; 5 %). Mean lesion long axis: 33.6±24.9 mm (range: 13.0-140.0). Mean SUVmax: 2.6±1.1 (range: 0.6-5.1). On serial CTs (n=34), lesions decreased in size (p=0.022). Serial FDG-PET/CT (n=24) showed no significant change in FDG-avidity (p=0.110). Mean SUVmax did not correlate with time from surgery (p=0.558) or lesion size (p=0.259). CONCLUSION: Postsurgical fat necrosis demonstrated characteristic CT features and may demonstrate increased FDG uptake. However, follow-up of subsequent imaging scans showed no increases in size or FDG-avidity. Awareness of this entity is important to avoid misinterpretation of findings as recurrent cancer. KEY POINTS: • Postsurgical fat necrosis may mimic cancer in FDG-PET/CT. • Follow-up of fat necrosis showed no increase in FDG intensity. • CT follow-up showed a decrease in lesion size. • FDG uptake did not correlate with time lapsed from surgery.

Gynecological Lymphoma: A Case Series and Review of the Literature.

OBJECTIVE: The aim of the study was to evaluate the radiological characteristics of gynecological lymphoproliferative disease (LPD) and specific imaging features that may suggest the diagnosis. METHODS: Two readers conducted a retrospective evaluation of imaging studies of 13 female patients presenting with a gynecological LPD. A literature review was also performed. RESULTS: Of the 13 evaluated women, 9 had ovarian involvement, 3 had cervical involvement, and 1 had uterine involvement. The most common lesion characteristics were homogenous masses (11), with mild contrast enhancement (9), followed by soft-tissue necrosis (4), prominent blood vessels displaced by the lesions (4), linear arrangement of cysts at the periphery of the ovaries (3), and "touching" ovaries in all cases of bilateral ovarian involvement. CONCLUSIONS: A solid large homogeneous mass with mild contrast enhancement should alert the radiologist to the possibility of the differential diagnosis of LPD. Radiologists should be "the gatekeepers" by raising this possibility to avoid unnecessary surgery and enable appropriate treatment.

Correlations Between Core Needle Biopsy and Excisional Biopsy Findings in Suspected Breast Lesions: A Single Center Study.

BACKGROUND: When a breast lesion is suspected based on a physical exam, mammography, or ultrasound, a stereotactic core needle biopsy (CNB) is usually performed to help establish a definitive diagnosis. CNBs are far less invasive than excisional biopsies, with no need for general anesthetics or hospitalization, and no recovery period. However, since only samples of the mass are removed in a CNB and not the whole mass, sampling errors can occur. OBJECTIVES: To compare the degree of agreement between the pathological data from CNBs and excisional biopsies from a single tertiary referral hospital. METHODS: The concordance of pathological data was compared in patients who underwent CNBs and had their surgical procedures at the same medical center. RESULTS: From the 894 patients who underwent CNBs, 254 (28.4%) underwent subsequent excisional biopsies at our medical center. From the total of 894 patients, 227 (25.3%) who underwent a CNB were diagnosed with a malignancy, with the rest of the CNBs being diagnosed as benign pathologies. The pathological findings in the CNBs and in the excisional biopsies concurred in 232/254 (91.3%) of the cases. CONCLUSIONS: A CNB to confirm mammographic or clinical findings of breast lesions is an accurate method to establish a pathological diagnosis of breast lesions. The accuracy is higher for invasive carcinomas than for non-invasive cancers. Excisional biopsies are necessary for lesions with anticipated sampling errors or when the core needle biopsy findings are discordant with clinical or mammographic findings.

The PET-CT Radiological Appearance of Facial Cosmetic Injections: A Pitfall in the Evaluation of the Oncological Patient.

BACKGROUND: Facial rejuvenation using different dermal and sub-dermal injectable compounds is a popular cosmetic procedure which may pose a diagnostic dilemma to the radiologist. OBJECTIVES: To describe the appearance of cosmetic facial fillers on PET-CT. METHODS: All PET-CT exams performed between January 2015 and May 2017 in which findings suggestive of prior facial filler procedures was evident and where anamnestic confirmation with the patient was possible were reviewed. RESULTS: We describe five females who had undergone facial filler procedures leading to calcifications around the mouth and nasolabial triangle. CONCLUSIONS: Familiarity with the appearance of such cosmetic procedures on PET-CT is of paramount importance in order to avoid misinterpretation of the findings leading to unnecessary apprehension and work-up.

High-Risk, Advanced-Stage Hodgkin Lymphoma: The Impact of Combined Escalated BEACOPP and ABVD Treatment in Patients Who Rapidly Achieve Metabolic Complete Remission on Interim FDG-PET/CT Scan.

The escalated BEACOPP (escBEACOPP) regimen improves the outcome of patients with advanced-stage Hodgkin lymphoma (HL) but is associated with cumbersome toxicity. We analyzed the survival outcome of high-risk, advanced-stage HL patients treated with response-adapted therapy. escBEACOPP was administered for 2 cycles, and after complete remission (CR) or partial remission (PR) was observed on FDG-PET/CT, treatment was de-escalated to 4 cycles of ABVD. Sixty-nine patients were evaluated, of them 45 participated in the multicenter, phase II prospective study between 2001 and 2007. Sixty patients had an international prognostic score ≥3. At a median follow-up of 5.6 years, 4 patients had died, 2 of them due to advanced HL. After the initial 2 cycles of escBEACOPP, 52 (75%) patients were in CR and 17 (25%) had a PR. Progression-free survival and overall survival (OS) were 79 and 93%, respectively. OS was predicted from the results of early-interim FDG-PET/CT: 98% of the patients in CR and 79% of those with a PR (p = 0.015). Hematological toxicity was more frequent during the first 2 cycles of escBEACOPP than in the ABVD phase. In conclusion, this retrospective analysis indicates that combined escBEACOPP-ABVD therapy is well tolerated and efficacious in HL patients who achieve negative early-interim PET results, while a positive PET result partially identified those with a worse prognosis.

The impact of R-VACOP-B and interim FDG-PET/CT on outcome in primary mediastinal large B cell lymphoma.

The choice of a rituximab-based regimen and the prognostic significance of interim 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in primary mediastinal large B cell lymphoma (PMBCL) are debatable. We evaluated the clinical features and outcomes of 95 consecutive patients with PMBCL who were treated between 1985 and 2009. Forty-three patients received rituximab-based chemotherapy, R-VACOP-B (N = 30) or R-CHOP21 (N = 13), whereas 52 patients were treated with VACOP-B (N = 47) or CHOP21 (N = 5). Radiotherapy was not given. Patients who received rituximab had a 5-year progression-free survival (PFS) of 79 % and overall survival (OS) of 97 % compared with 58 % (p = 0.06) and 88 % (p = 0.2), respectively, without rituximab. Five-year PFS in patients treated with R-VACOP-B, R-CHOP21, VACOP-B, and CHOP21 were 83, 69, 62, and 20 %, respectively (p = 0.039). However, direct comparison showed that the difference between PFS rates in patients receiving R-VACOP-B compared to R-CHOP21 was not statistically significant (p = 0.3). None of the standard clinical risk factors predicted for PFS and OS in patients receiving rituximab (R)-chemotherapy. Mid-interim FDG-PET/CT scans were performed in 30/43 patients who received R-chemotherapy. The negative predictive values of mid-PET activity were high (100 % for R-VACOP-B and 86 % for R-CHOP21) while the positive predictive values (PPV) were relatively low (30 and 75 %, respectively). Despite the low PPV, the 5-year PFS for mid-PET-negative patients (N = 16) was significantly higher (94 %) than that for mid-PET-positive (N = 14) patients (57 %, p = 0.015). This retrospective analysis demonstrates that the superiority of VACOP-B over CHOP21 for treatment of PMBCL disappeared once rituximab was added. The potential benefit of using interim PET activity as a guide for continuing therapy in patients with PMBCL remains unclear due to the relatively low PPV.

Use of titanium spiral tacks for long-term oophoropexy before pelvic irradiation.

BACKGROUND: Ovarian transposition before planned pelvic irradiation can preserve ovarian function in young patients with pelvic malignancies. The transposed ovaries are fixed to the posterolateral abdominal wall. We described the use of a titanium spiral tack as a fixation device and compared it with other methods of oophoropexy. METHODS: Medical and surgical records of all consecutive patients who underwent oophoropexy in our institution between 2007 and 2013 were reviewed. Demographic and clinical data were summarized; follicle-stimulating hormone values, recorded; and imaging scans, reviewed. RESULTS: Oophoropexy was performed in 30 patients: 28 with cervical carcinomas and 2 with pelvic sarcomas. The procedure was done through laparoscopy in 13 patients and through laparotomy in 17. Titanium spiral tack was used for ovarian fixation in 14 patients, Vicryl suturing in 14, and in 2 cases the ovaries were pulled up through a retroperitoneal tunnel and fixed to the peritoneum with sutures. Titanium spiral tack fixation took a few seconds to perform. There were no immediate intraoperative or postoperative complications. Ovarian function was preserved in 15 patients (7/14 with spiral tack, 6/14 with sutures, and in both patients with retroperitoneal tunneling). Postoperative imaging results showed that all ovaries retained their extrapelvic location for a median period of 11.6 months (range, 2.3-63 months). CONCLUSIONS: Spiral tack is a simple, reliable method for oophoropexy before pelvic irradiation. Its efficacy is comparable with that of suture fixation, with the added advantage of ultrashort operative time. It is therefore worth considering as an alternative to suturing.

Early prediction of urinary retention following radical hysterectomy by 18F-FDG PET/CT imaging.

BACKGROUND: Radical hysterectomy for early cervical cancer is associated with postoperative bladder dysfunction. Postoperative imaging by 18F-FDG PET/CT scanning is often performed to rule out recurrence. Since women are instructed to empty the bladder before imaging, we aim to study if scanned abnormal residual bladder volume is associated with future urinary symptoms. METHODS: Women who underwent radical hysterectomy for cervical cancer between July 2010 and January 2019 were included in the study. Multi-Modality Tumor Tracking® (MMTT) was used to measure residual urinary volume on 18F-FDG PET/CT scans before and after hysterectomy. Demographic, clinical parameters, and urinary tract signs and symptoms, were evaluated among the cohort. RESULTS: Overall, 64 patients were included. Among those, in 24 (38%) the bladder volume reached ≥150 cm3 on postoperative 18F-FDG PET/CT scans. Of these, 9 (37.5%) had voiding difficulties of some degree. In 3 (12.5%) women, the 18F-FDG PET/CT scan has preceded their complaints of voiding difficulties by 2-4 months. Of the 40 women (62%) whose postoperative bladder volumes were <150 cm3, only 1 (2.5%) had urinary retention. Rate of symptomatic voiding difficulties was higher in the post-void volume ≥150 cm3 group; 13 (54.1%) vs. 6 (15.0%), P<0.002, Odds Ratio 95% Confidence Interval 6.6 (2.0-21.8), P=0.001. CONCLUSIONS: Measuring bladder volume on postoperative 18F-FDG PET/CT may facilitate early identification of urinary retention, possibly enabling early treatment and possibly preventing complications.

Deep inspiratory breath hold assisted by continuous positive airway pressure ventilation for lung stereotactic body radiotherapy.

PURPOSE: Continuous positive airway pressure (CPAP) ventilation hyperinflates the lungs and reduces diaphragmatic motion. We hypothesized that CPAP could be safely combined with deep inspiratory breath hold (CPAP-DIBH) during lung stereotactic radiotherapy (SBRT). MATERIAL AND METHODS: Patients with stage-1 lung cancer or lung metastasis treated with CPAP-DIBH SBRT between 3/2017-5/2021 were analyzed retrospectively. Patient characteristics, treatment parameters, duration of breath holds in all sessions and tolerance to CPAP-DIBH were recorded. Local control (LC) was assessed from CT or PET-CT imaging. The distances between the tumor and mediastinal organs at risk (OAR) in centrally located tumors using either free breathing (FB) or CPAP-DIBH were compared. Toxicity was graded retrospectively. RESULTS: Forty-five patients with 71 lesions were treated with CPAP-DIBH SBRT. Indications for CPAP-DIBH were prior radiation (35/71, 65%), lower lobe location (34/71, 48%), multiple lesions (26/71, 36.6%) and proximity to mediastinal OAR (7/71, 10%). Patient characteristics were: F:M 43%: 57%; mean gross tumor volume 4.5cm3 (SD 7.9), mean planning target volume 20cm3 (SD 27), primary: metastatic lesions (7%:93%). Mean radiation dose was 52.5 Gray (SD3.5). Mean lung volume was 5292cm3 (SD 1106). Mean duration of CPAP-DIBH was 41.3s (IQR 31-46.8). LC at 2 years was 89.5% (95% CI 76-95.5). In patients with central lesions, the distance between the tumor and mediastinal OAR increased from 0.84cm (SD 0.65) with FB to 1.23cm (SD 0.8) with CPAP-DIBH (p=0.002). Most patients tolerated CPAP well and completed all treatments after starting therapy. Three patients did not receive treatment: 2 were unable to tolerate CPAP and 1 had syncope (pre-existing). Toxicity was grade 2 in 4/65 (6%) and grade 3 in 1/65 (1.5%). There was no grade 2 or higher esophageal or tracheal toxicities. CONCLUSION: CPAP-DIBH assisted lung SBRT was tolerated well and was associated with minimal toxicity and favorable LC. This technique may be considered when treating multiple lung lesions, lesions located in the lower lobes or adjacent to mediastinal OAR.

The Role of 68 Ga-FAPI PET/CT in Detection of Metastatic Lobular Breast Cancer.

PURPOSE: Invasive lobular breast cancer (ILC) may be hard to detect using conventional imaging modalities and usually shows less avidity to 18 F-FDG PET/CT. 68 Ga-fibroblast activation protein inhibitor (FAPI) PET/CT has shown promising results in detecting non- 18 F-FDG-avid cancers. We aimed to assess the feasibility of detecting metastatic disease in patients with non- 18 F-FDG-avid ILC. METHODS: This prospective study included patients with metastatic ILC, infiltrative to soft tissues, which was not 18 F-FDG avid. The patients underwent 68 Ga-FAPI PET/CT for evaluation, which was correlated with the fully diagnostic CT performed at the same time. RESULTS: Seven women (aged 57 ± 10 years) were included. Among the 30 organs and structures found to be involved by tumor, the number of findings observed by FAPI PET/CT was significantly higher than that observed by CT alone ( P = 0.022), especially in infiltrative soft tissue and serosal locations. CONCLUSIONS: This small pilot trial suggests a role for 68 Ga-FAPI PET/CT in ILC, which needs to be confirmed by subsequent trials.

The Role of 68 Ga-FAPI PET/CT in Breast Cancer Response Assessment and Follow-Up.

PURPOSE: 68 Ga-fibroblast activation protein inhibitor (FAPI), a new PET/CT radiotracer targeting cancer-associated fibroblasts in tumor microenvironment, can detect many types of cancer. We aimed to assess whether it can also be used for response assessment and follow-up. METHODS: We followed up patients with FAPI-avid invasive lobular breast cancer (ILC) before and after treatment changes and correlated qualitative maximal intensity projection images and quantitative tumor volume with CT results and blood tumor biomarkers. RESULTS: Six consenting ILC breast cancer patients (53 ± 8 years old) underwent a total of 24 scans (baseline for each patient and 2-4 follow-up scans). We found a strong correlation between 68 Ga-FAPI tumor volume and blood biomarkers ( r = 0.7, P < 0.01), but weak correlation between CT and 68 Ga-FAPI maximal intensity projection-based qualitative response assessment. CONCLUSIONS: We found a strong correlation between ILC progression and regression (as assessed by blood biomarkers) and 68 Ga-FAPI tumor volume. 68 Ga-FAPI PET/CT could possibly be used for disease response assessment and follow-up.