Artificial intelligence in brachytherapy: a summary of recent developments

Artificial intelligence (AI) applications, in the form of machine learning and deep learning, are being incorporated into practice in various aspects of medicine, including radiation oncology. Ample evidence from recent publications explores its utility and future use in external beam radiotherapy. However, the discussion on its role in brachytherapy is sparse. This article summarizes available current literature and discusses potential uses of AI in brachytherapy, including future directions. AI has been applied for brachytherapy procedures during almost all steps, starting from decision-making till treatment completion. AI use has led to improvement in efficiency and accuracy by reducing the human errors and saving time in certain aspects. Apart from direct use in brachytherapy, AI also contributes to contemporary advancements in radiology and associated sciences that can affect brachytherapy decisions and treatment. There is a renewal of interest in brachytherapy as a technique in recent years, contributed largely by the understanding that contemporary advances such as intensity modulated radiotherapy and stereotactic external beam radiotherapy cannot match the geometric gains and conformality of brachytherapy, and the integrated efforts of international brachytherapy societies to promote brachytherapy training and awareness. Use of AI technologies may consolidate it further by reducing human effort and time. Prospective validation over larger studies and incorporation of AI technologies for a larger patient population would help improve the efficiency and acceptance of brachytherapy. The enthusiasm favoring AI needs to be balanced against the short duration and quantum of experience with AI in limited patient subsets, need for constant learning and re-learning to train the AI algorithms, and the inevitability of humans having to take responsibility for the correctness and safety of treatments.     

Coagulopathy Disproportionately Predisposes to Lobar Intracerebral Hemorrhage

Background

Anticoagulation increases the risk of intracerebral hemorrhage (ICH), yet whether different underlying disease processes are equally affected is unknown. We tested the hypothesis that coagulopathy, measured by admission international normalized ratio (INR), disproportionately increases the risk for lobar hemorrhages.

Methods

Patients with primary ICH were enrolled into a registry between December 2006 and February 2012 with prospective data acquisition and systematic follow up. Logistic regression was used to test whether lobar versus deep ICH location was independently associated with INR, and then whether INR had an influence on mortality. Spearman’s correlation coefficient was used to test for an association between INR and hematoma volume separately in the lobar and deep ICH groups.

Results

221 patients were studied. Patients with lobar ICH were older (71 vs. 62 years old, p < 0.001) and more likely to have prior ICH (10 vs. 0 %, p < 0.001). INR >1.4 was observed on admission more frequently in lobar versus deep ICH (19 vs. 8 %, p = 0.02). Lobar ICH location was independently associated with INR >1.4 (OR: 2.51, 95 % CI: 1.03–6.14, p = 0.043). ICH volume correlated with INR in lobar ICH (p = 0.009), but not deep ICH (p = 0.8). Death at 1 month was independently associated with INR >1.4 (OR: 7.6, 95 % CI: 2.4–24.1, p = 0.001) after correction for the ICH Score.

Conclusions

Abnormal coagulation occurs disproportionally in lobar versus deep ICH, and is associated with larger ICH volumes and higher mortality. These findings suggest a unique risk interaction between coagulopathy and underlying brain pathology due to cerebral amyloid angiopathy.     

Amyloidosis Cutis Dyschromica: A Rare Reticulate Pigmentary Dermatosis

We are reporting a rare case of amyloidosis cutis dyschromica in a 41-year-old man. This is a rare form of primary cutaneous amyloidosis characterized by reticulate pigmentation with hypopigmented and hyperpigmented macules, onset in childhood, familial tendency in some, occasional mild itching and deposition of amyloid in the papillary dermis. Our case also had multiple bilaterally symmetrical hyperpigmented keratotic papules abutting the axillary vault resembling those seen in Dowling–Deogs disease. The other unusual feature in this patient was the strong family history of vitiligo, which we are unable to explain. We have also tried to explain the mechanism leading to the hyperpigmentation and hypopigmentation in amyloidosis cutis dyschromica.     

PET imaging of oncogene overexpression using 64Cu-vasoactive intestinal peptide (VIP) analog: comparison with 99mTc-VIP analog.

The purpose of this study was to assess the feasibility of PET imaging of oncogene VPAC1 receptors overexpressed in human breast cancer cells. METHODS: Vasoactive intestinal peptide (VIP) analog (TP3982) was synthesized to harbor a carboxy-terminus lysine (Lys) residue separated from VIP-asparagine (Asn(28)) by 4-aminobutyric acid (Aba) as a spacer. Lys was derivatized with diaminopropionic acid coupled to a pair of dibenzoylthioglycolic acid residues as protecting groups. The analog was labeled with (64)Cu at pH 9 ((64)Cu-TP3982) and (99m)Tc at pH 12 ((99m)Tc-TP3982). (99m)Tc-TP3982 and VIP derivatized with Aba-GAGG and labeled with (99m)Tc ((99m)Tc-TP3654) were used as reference agents. Smooth muscle relaxivity assays performed with each derivative and compared with unaltered VIP(28) demonstrated functional integrity. In vitro stability of (64)Cu-TP3982 was determined by challenging the complex with 100-mol excess of diethylenetriaminepentaacetic acid (DTPA), human serum albumin (HSA), and cysteine. In vivo stability was determined in urine and serum for up to 24 h. The mass of the Cu-TP3982 complex was determined by mass spectrometry. Human T47D breast tumor xenografts were grown in athymic nude mice. Planar scintigraphic imaging was performed at 4 and 24 h after the intravenous administration of (99m)Tc-TP3982 and (99m)Tc-TP3654 and PET imaging was performed using a small animal MOSAIC PET scanner, also at 4 and 24 h after injection of (64)Cu-TP3982. Tissue-distribution studies were also performed. In a separate experiment, receptors were blocked by intravenous injection of authentic VIP(28) 30 min before the administration of (64)Cu-TP3982 and tissue distribution was examined. RESULTS: (64)Cu-TP3982 labeling yields were 98% +/- 1.2% and those for (99m)Tc-TP3982 and (99m)Tc-TP3654 were 98.2% +/- 1.1% and 97% +/- 1.6%, respectively. The biologic activity of both VIP analogs was uncompromised. When (64)Cu-TP3982 was challenged with 100-mol excess of DTPA, HSA, or cysteine, >98% radioactivity remained as (64)Cu-TP3982. In vivo, >98% of (64)Cu circulating in plasma remained as (64)Cu-TP3982. Of the (64)Cu excreted in urine 4, 20, and 24 h after injection, >98%, 89.9% +/- 0.9%, and 85% +/- 3%, respectively, were bound to TP3982. The mass of Cu-TP3982 as determined by surface-enhanced laser desorption/ionization time of flight (SELDI-TOF) was 4,049.7 Da. Four hours after receptor blocking with VIP(28), there was a significant reduction in uptake of all tissues except in the liver. With (64)Cu-TP3982, the 4-h postinjection tumor uptake was 10.8 +/- 2.1 %ID/g versus 0.5 +/- 0.02 %ID/g and 0.24 +/- 0.08 %ID/g for (99m)Tc-TP3982 and (99m)Tc-TP3654, respectively. Twenty-four hours after injection, the corresponding numbers were 17 +/- 0.7 %ID/g, 0.77 +/- 0.1 %ID/g, and 0.23 +/- 0.1 %ID/g. The severalfold greater uptake (21.2-74) of (64)Cu-TP3982 is attributable to the in vivo stability of the agent. CONCLUSION: The results suggest that the uncompromised biologic activity and the significantly greater tumor uptake of (64)Cu-TP3982, combined with the high sensitivity and enhanced resolution of PET imaging, make (64)Cu-TP3982 highly desirable for further studies in PET imaging of oncogene receptors overexpressed in breast and other types of cancers.     

Would a Massive Intra-abdominal Malignant Peripheral Nerve Sheath Tumor with Growth into the Inguinal Canal and Scrotum Preclude Surgical Option? A Case Report and Review of Literature

Malignant peripheral nerve sheath tumors (MPNST) are rare spindle-cell sarcomas derived from Schwann cells or pluripotent cells of the neural crest accounting for less than 10 % of all soft tissue sarcomas. They arise from major or minor peripheral nerve fibers or their sheaths. The World Health Organization coined the term MPNST for tumors of neurogenic origin with similar biological behavior replacing all the previous heterogeneous and, often, confusing nomenclature including malignant schwannoma, malignant neurilemmoma, and neurofibrosarcoma. The retroperitoneum and the lower extremities are the most common sites, but MPNST may arise anywhere in the body. Its location in the retroperitoneum in a patient without neurofibromatosis is an exceedingly rare occurrence. Imaging is routinely performed to assess the extent of the disease and to plan surgical resection. Surgical resection is the first line of therapy, ideally with total removal of the tumor. Owing to a high risk of recurrence with incomplete resection, postoperative irradiation and chemotherapy are necessary; however, they are often used as adjuvant therapy even if the tumor is completely resected.     

Open Classic Latarjet Procedure Performed Using Freehand Technique—Surgical Technique and Outcome

IntroductionLatarjet procedure is commonly performed for recurrent anterior shoulder instability with glenoid side bone loss. Classic Latarjet procedure can be performed using specially designed drill guides, jigs, or by freehand technique. Here we have described a technical note on classic Latarjet procedure performed with freehand technique utilizing simple rulers and caliper. The functional and radiological outcomes of our patients have also been analysed.Material and Methods149 open classic Latarjet procedures were performed using our technique between March 2015 and July 2018. The mean age of the patients was 32.95 years (Range 22–59 years). The functional outcome of the patients was measured using Western Ontario Shoulder Instability (WOSI) and Oxford Shoulder Instability Score (OSIS) at 2 years of follow-up. Screw and graft positioning were studied in 24 consecutive patients with a postoperative computed tomography (CT) scan.ResultsThere was no incidence of recurrent subluxation or dislocation post-surgery. Mean OSIS score increased from 15.63 ± 3.20 preoperatively to 42.44 ± 3.88 postoperatively (p value < 0.05). WOSI score decreased significantly from 62.54% ± 8.24 to 10.26 ± 6.33 postoperatively at 2-year follow-up (p value < 0.05). Postoperative CT scan also showed satisfactory screw placement in all patients.ConclusionOpen Latarjet procedure performed using freehand technique provides good functional and radiological outcomes in patients with recurrent anterior shoulder instability with glenoid side bone loss.Supplementary InformationThe online version contains supplementary material available at 10.1007/s43465-021-00385-7.     

Retrospective-prospective study of safety and efficacy of sofosbuvir-based direct-acting antivirals in HIV/HCV-coinfected participants with decompensated liver disease pre– or post–liver transplant

Direct-acting antiviral (DAA) therapy has transformed the management of human immunodeficiency virus (HIV) and hepatitis C (HCV) coinfected patients with advanced liver disease. STOP-Coinfection was a multicenter prospective and retrospective, open-label study using sofosbuvir-based DAA therapy to treat HIV/HCV-coinfected participants pre– or post–liver transplant (LT). Sixty-eight participants with end-stage liver disease (Child-Turcotte-Pugh score ≥7 and Model for End-Stage Liver Disease score 6–29) were enrolled, 26 had hepatocellular carcinoma. Forty-two participants were treated pre–LT and 26 post–LT. All participants completed therapy without need for dose reduction or transfusion; eight required two or more courses of therapy. Ninety-three percent achieved a sustained virologic response and DAA therapy was well tolerated. Despite HCV cure, 12 end-stage liver disease participants required subsequent LT, 7 for decompensated liver disease. Thirteen participants died, 10 with decompensated liver disease pre–LT and three post–LT. Overall, transplant free survival was 42.8% at 4 years and post–LT survival was 87.9% at 5 years. We conclude that sofosbuvir-based DAA therapy is safe and highly effective in HCV-HIV patients with decompensated liver disease and post–LT, with post–LT survival rates comparable to other indications. This removes one of the last barriers to liver transplantation in this challenging cohort of recipients.     

甲状腺影像报告和数据系统在超声检查甲状腺结节中的应用

目的 探讨甲状腺影像报告和数据系统(thyroid imaging reporting and data system,TI-RADS)在超声检查甲状腺结节中的诊断价值.方法 收集292例(423个)甲状腺结节患者的超声资料,以组织病理学结果为参照标准,采用TI-RADS分级诊断标准进行回顾性评价.结果 423个甲状腺结节中,TI-RADS分级为1～5级者其恶性结节所占百分率分别为0(0/129)、6.3%(11/176)、33.3%(10/30)、86.8%(46/53)和100%(35/35).对甲状腺良性结节超声检查TI-RADS分级的灵敏度、特异度、正确率、阳性预测值和阴性预测值分别为96.3%(309/321)、83.3%(85/102)、93.1%(394/423)、94.8%(309/326)和87.6%(85/97),阳性似然比、阴性似然比及Youden指数分别为5.77、0.04和79.6%.TI-RADS分级的良、恶性结节在形态、边界、内部回声、回声质地、内部构成和钙化灶方面所占比例的差异均有统计学意义(P<0.001).结论 在甲状腺结节的超声检查中,应用TI-RADS分级诊断标准对临床诊断和治疗具有重要的指导价值.     

Comparison of warfarin versus aspirin for the prevention of recurrent stroke or death: subgroup analyses from the Warfarin-Aspirin Recurrent Stroke Study

Background and Purpose: We performed a combination of prespecified and exploratory subgroup analyses to detect any treatment differences among various baseline subgroups in the Warfarin-Aspirin Recurrent Stroke Study (WARSS) cohort. Methods: The WARSS compared the efficacy of adjusted-dose warfarin (INR 1.4-2.8) to aspirin (325 mg/day) for recurrent ischemic stroke or death within 2 years. The effect of warfarin and aspirin was compared among prespecified and exploratory subgroups with respect to sociodemographic and vascular risk factors, stroke subtype, arterial territory, and infarct topography. Hazard ratios and 95% confidence intervals comparing warfarin to aspirin were calculated using Cox proportional hazards models. Differences in hazard ratios were tested using interaction terms. Results: No treatment differences between warfarin and aspirin were found across multiple prespecified subgroups. In a multivariate model, warfarin was associated with greater hazard among patients with moderate stroke severity (HR 1.63, 95% CI 1.005-2.64, p = 0.047) and a greater benefit among those with posterior circulation location without brainstem infarction (HR 0.54, 95% CI 0.33-0.88, p = 0.013). In post-hoc analyses of the cryptogenic subgroup, warfarin was associated with worse outcomes among patients with moderate stroke severity and better outcomes among those without baseline hypertension or with posterior circulation infarcts sparing the brainstem. Conclusions: In the WARSS, the majority of subgroup analyses showed no benefit of warfarin over aspirin. Warfarin benefit was limited to brainstem-sparing posterior circulation infarcts and select cryptogenic stroke subgroups. Pending future clinical trial evidence to the contrary, antiplatelets are recommended for survivors of noncardioembolic stroke.