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MR-guided high dose rate (HDR) brachytherapy for focal GTV boost in prostate cancer radiotherapy is an established technique. However, this is resource-intense, invasive and may be contraindicated in some patients. Linear accelerators with integrated MRI allow visualization of the GTV within the prostate, facilitating the use of External Beam Radiation Therapy (EBRT) to deliver GTV boost. This study compared patient-reported quality of life for the first 20 patients treated with these two techniques. Twenty intermediate risk prostate cancer patients who were enrolled and treated between May 2022 and August 2023 in prospective clinical trials were included in this study. Patients were stratified based on patient preference; 10 patients received GTV boost fraction using HDR brachytherapy and 10 patients were treated with EBRT using a 1.5T MR-Linac. For HDR treatment patients were positioned supine under general anesthesia while transperineal catheters were inserted under MRI guidance. For EBRT treatment patients were positioned supine with minimal immobilization and an empty bladder. All patients received 1 × 15 Gy to the GTV followed within 1 week by 5 × 6 Gy (alternate days) to the whole prostate. Both groups received their subsequent whole gland prostate treatment on the MR-Linac. Patient-reported quality of life was captured using The Expanded Prostate Cancer Index Composite (EPIC) survey. The questionnaire was administered at baseline and at one month follow-up. Results were analyzed using descriptive statistics. All patients completed treatment as planned and had minimum follow up of 1 month (range 1-6). The mean score and standard deviation collected from EPIC for bladder and bowel subscales at 1-month follow up were similar between those who received HDR and EBRT with 81.1(29.7) and 94.1 (13.9) vs 85.2(23.1) and 93.9(15.0) respectively. There were also no statistically significant differences when looking further at additional subsets, urinary function was 87.7(13.1) vs 89.8(8.3), p=1.0 for HDR and EBRT and urinary bother 74.2(21.8) vs 81.63(11.0), p=0.71. Bowel function was 94.3(6.2) vs 92.9(8.3), p=1.0 for HDR and EBRT and bowel bother 93.9(7.5) vs 94.8(8.8), p=0.62. The mean change in score from baseline assessment was –5.7 for urinary incontinence and –6.1 urinary irritative/obstructive and 0.8 in rectal subscales for HDR patients compared to 1.0, -1.9 and 0.0 for EBRT patients. These changes from baseline only exceeded the minimally important difference (MID) reported in literature for the urinary irritative/obstructive subscale and only in HDR patients. MRL focal boost to GTV region of the prostate was found to have a similar patient-reported quality of life compared to HDR focal boost at 1 month following completion of treatment, although patients receiving HDR reported a MID from baseline in urinary irritative/obstructive symptoms. A larger sample size may confirm these preliminary findings translate into differences in QOL. [ABSTRACT FROM AUTHOR]

Nonsurgical and minimally invasive approaches for early-stage peripheral lung cancer are needed to avoid the known morbidity of surgical resection, particularly in high-risk patients. We previously demonstrated the utility of multifunctional porphyrin-phospholipid nanoparticles (porphysomes) for fluorescence imaging and phototherapy after preferential accumulation into tumors. The objective of this study was to demonstrate the feasibility of porphysome-mediated imaging and photothermal therapy using a newly developed fiberscope and thoracoscope. To prepare this technology for clinical translation, we developed a porphysome-specific fiberscope (scanning fiber endoscope and porphysome-specific thoracoscope), both capable of detecting porphysome fluorescence, for image-guided transbronchial and transpleural photothermal therapy to treat endobronchial/peribronchial and subpleural tumors, respectively. These were tested in three animal models: human lung cancer xenografts (A549) in mice, orthotopic VX2 lung tumors in rabbits, and ex vivo pig lung into which A549 tumor tissue was transplanted. The scanning fiber endoscope, with a 1.2-mm diameter, is small enough to pass through the working channel of a conventional bronchoscope and could visualize porphysome-laden tumors located inside or close to the peripheral bronchial wall. The porphysome-specific thoracoscope system had high sensitivity for porphysome fluorescence and enabled image-guided thoracoscopic resection of porphysome-accumulating tumors close to the pleura. Porphysomes also enhanced the efficacy of scanning fiber endoscope-guided transbronchial photothermal therapy and porphysome-specific thoracoscope-guided transpleural photothermal therapy, resulting in selective and efficient tumor tissue ablation in the rabbit and pig models. These results support the potential for clinical translation of this novel platform to affect nonsurgical and minimally invasive treatment options for early-stage peripheral lung cancer. [ABSTRACT FROM AUTHOR]

Objectives Localization and resection of nonvisible, nonpalpable pulmonary nodules during video-assisted thoracoscopic surgery are challenging. Our study was to determine the feasibility and safety of indocyanine green fluorescence localization and resection of small nodules using a near-infrared fluorescence thoracoscope. Methods Twenty patients with undiagnosed peripheral nodules smaller than 3 cm scheduled for computed tomography–guided microcoil placement followed by video-assisted thoracoscopic surgery wedge resection were enrolled. After microcoil deployment, 100 to 150 μL of diluted indocyanine green was injected percutaneously near the nodule. The nodule initially was localized solely by using a near-infrared thoracoscope to visualize indocyanine green fluorescence. Thoracoscopic instruments were used to determine the staple line. Wedge resection was performed after confirmation of the location of the microcoil using fluoroscopy. Results Twenty patients underwent near-infrared, image-guided, video-assisted thoracoscopic surgery resection. The median computed tomography tumor size was 1.2 cm. The median depth from the pleural surface was 1.4 cm (range, 0.2-4.8 cm). The median computed tomography–guided intervention time was 35 minutes, and video-assisted thoracoscopic surgery procedural time was 54 minutes. Indocyanine green fluorescence was clearly identified in 18 of 20 patients (90%). The surgical margins were all negative on final pathology without the need for additional resection. The final diagnoses included 18 primary lung cancers, 1 metastatic lung cancer, and 1 benign lung tumor. Conclusions Computed tomography–guided percutaneous indocyanine green injection and intraoperative near-infrared localization of small nodules are safe and feasible. These offer surgeons the ease of localization through direct indocyanine green fluorescence imaging without the use of fluoroscopy and may be a complementary technique to preoperative microcoil placement for nonvisible, nonpalpable intrapulmonary nodules. [ABSTRACT FROM AUTHOR]

Background Video-assisted thoracoscopic wedge resection of multiple small, non-visible, and nonpalpable pulmonary nodules is a clinical challenge. We propose an ultra-minimally invasive technique for localization of pulmonary nodules using the electromagnetic navigation bronchoscope (ENB)-guided transbronchial indocyanine green (ICG) injection and intraoperative fluorescence detection with a near-infrared (NIR) fluorescence thoracoscope. Methods Fluorescence properties of ICG topically injected into the lung parenchyma were determined using a resected porcine lung. The combination of ENB-guided ICG injection and NIR fluorescence detection was tested using a live porcine model. An electromagnetic sensor integrated flexible bronchoscope was geometrically registered to the three-dimensional chest computed tomographic image data by way of a real-time electromagnetic tracking system. The ICG mixed with iopamidol was injected into the pulmonary nodules by ENB guidance; ICG fluorescence was visualized by a near-infrared (NIR) thoracoscope. Results The ICG existing under 24-mm depth of inflated lung was detectable by the NIR fluorescence thoracoscope. The size of the fluorescence spot made by 0.1 mL of ICG was 10.4 ± 2.2 mm. An ICG or iopamidol spot remained at the injected point of the lung for more than 6 hours in vivo. The ICG fluorescence spot injected into the pulmonary nodule with ENB guidance was identified at the pulmonary nodule with the NIR thoracoscope. Conclusions The ENB-guided transbronchial ICG injection and intraoperative NIR thoracoscopic detection is a feasible method to localize multiple pulmonary nodules. [ABSTRACT FROM AUTHOR]

Brachytherapy (BT) boost to the whole-gland (i.e., clinical target volume [CTV]) improves oncological outcomes in prostate cancer patients, albeit with higher likelihood of genitourinary (GU) and gastrointestinal (GI) toxicities. Magnetic resonance (MR) imaging can unveil the gross tumour volume (GTV) with high sensitivity and specificity (i.e., 86% (CI 82-89%) and 99% (CI 98-99%), respectively) in patients with localized disease, which also correlates with the most common area of local recurrence after radiation treatment. To improve the therapeutic index of BT boost, one potential approach is circumscribing it to the MR-depicted GTV (i.e., focal BT boost). Another approach is the use of rectal spacers, which significantly decrease the occurrence of radiation-related toxicities. However, their use is limited in ultrasound-guided BT given their echogenic noise limiting visualization of prostate and catheters. An MR-guided BT setting can converge the benefits of improved soft-tissue resolution and rectal spacers in the absence of device-related imaging artifacts. Herein, we present the results of a prospective study using rectal spacers for MR-guided focal BT boost combined with stereotactic body radiotherapy (SBRT) to the prostate. Patients with localized prostate cancer and visible GTV on MR were enrolled in a prospective study (NCT00913939). All patients underwent insertion of rectal spacer under ultrasound guidance. Subsequently, patients received MR-guided HDR BT boost (15Gy in 1 fraction), followed by SBRT to prostate (33Gy to CTV, 30Gy to PTV, in 5 fractions). The present study reports on the first 73 patients enrolled. Seventy-three patients are included in this analysis, with a median follow-up of 42 months (IQR 30-57). Most patients (47/73; 64.4%) had Grade Group 2 disease; while 37 (50.7%) and 27 (37%) were respectively categorised as NCCN favourable and unfavourable intermediate-risk, and 9 (12.3%) high-risk disease. Thirty percent of patients received combinatorial ADT for a medial duration of 6 months (IQR 6-20). Median number of BT catheters were 5 (IQR 4-7). Acute Grade 1 GI and GU toxicities were seen in 22 (30.1%) and 66 (90.4%) of patients, respectively. Only one case reported Grade 2 acute GU toxicity (dysuria). Late (i.e., 3-months after treatment) Grade 1 GI and GU toxicities were observed in 4 (5.5%) and 29 (39.7%) cases, respectively. There was a single case of late Grade 2 GU toxicity (haematuria). No incidence of acute or late Grade 3-4 toxicities was observed. Seven (9.6%) biochemical recurrence events were recorded, with an associated BCR-free survival of 83.7% at 5 years. Among those with BCR, 6 cases had recurrence localization by imaging: two local recurrences alone (both intra-prostatic outside the focal boost volume), while four had regional and/or distant recurrences. MR-guidance allows the incorporation of rectal spacers to the BT treatment paradigm, which together with the use of focal BT boost combined with SBRT renders a favourable therapeutic index for men with localized prostate cancer. [ABSTRACT FROM AUTHOR]

Magnetic resonance image-guided brachytherapy is essential in the management of locally advanced cervical cancer. This study compares disease and toxicity outcomes in cervical cancer patients treated with 24 Gy/3 fractions (Fr) versus the conventional 28 Gy/4 Fr. This retrospective study included 241 consecutive patients with International Federation of Gynecology and Obstetrics 2018 stage IB to IVA cervical cancer treated with definitive chemoradiation between April 2014 and March 2021. Disease-free survival (DFS) was estimated using the Kaplan-Meier method and compared using the log-rank test. Cumulative incidence of local failure (LF), distant failure (DF), and G2+ gastrointestinal (GI), urinary and vaginal toxicity were estimated using the cumulative incidence function with death as a competing risk and compared using Gray's test. Of the 241 patients, 42% received 24 Gy/3 Fr and 58% received 28 Gy/4 Fr. With a median follow-up of 3.2 (range, 0.2-9.2) years, there were 14 local, 41 regional nodal, and 51 distant failures in 63 (26%) patients. No significant differences were found between the 24 Gy/3 Fr and 28 Gy/4 Fr groups in 3-year DFS (77% vs 68%, P =.21), the 3-year cumulative incidence of LF (5% vs 7%, P =.57), DF (22% vs 25%, P =.86), G2+ GI toxicity (11% vs 20%, P =.13), or G2+ vaginal toxicity (14% vs 17%, P =.48), respectively. The 3-year cumulative G2+ urinary toxicity rate was lower in the 24 Gy/3 Fr group (9% vs 23%, P =.03). Patients with cervical cancer treated with 24 Gy/3 Fr had similar DFS, LF, DF, GI, and vaginal toxicity rates and a trend toward a lower G2+ urinary toxicity rate compared with those treated with 28 Gy/4 Fr. A less resource-intensive brachytherapy fractionation schedule of 24 Gy/3 Fr is a safe alternative to 28 Gy/4 Fr for definitive treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

High dose-rate brachytherapy (HDR-BT) combined with external beam radiotherapy (EBRT) is a widely accepted treatment for patients with clinically localized prostate cancer. A significant impact on sexual health related quality of life (sHRQoL) is reported in published series. The etiology is probably multifactorial, including baseline factors, trauma and dose to the neurovascular bundles (NVB). Magnetic resonance imaging (MRI) enables the visualization and proper localization of the NVB. Herein we aim to analyze the long-term sHRQoL after MRI-guided whole gland HDR-BT boost for prostate cancer and to assess the impact of the dose to the NVB and other factors on sHRQoL. Sixty-one patients were treated with a single 15 Gy MRI-guided HDR-BT followed by EBRT as part of a prospective phase II trial approved by the local Research Ethic Board (09-0026-C). For this analysis, patients who received over 12 months of androgen deprivation therapy (ADT) and / or patients with a baseline erectile dysfunction were excluded. The left and right NVB were delineated in retrospect on T2-weighted images. Sexual HRQoL was prospectively collected using the expanded prostate index composite (EPIC) questionnaire at baseline, 1month, 3 months, 6 months, 12 months and Q12 monthly thereafter until 60 months. A minimally important difference (MID) was defined as a deterioration of sHRQoL scores at 3 months ≥ 0.5 standard deviation of baseline score. Linear and logistic regression models were used. Twenty-eight patients met the criteria to be included in this analysis. A short course of ADT was given to 15 patients. the mean baseline sexual HRQOL score was 48.1 (SD=27.1): 41.9 (SD=28.5) for sexual function and 63.8 (SD=37.9) for sexual bother (37.9). At 12, 24, 36 and 60 months the mean sexual score was 37.5 (SD=26.3), 47(SD=24.3), 45.1 (SD=20.4) and 36.8 (SD=29.1), p>0.05. A MID was reported by 50% of patients at 60 months. The mean sHRQoL score at 60 months of patients who had a short course of ADT was 44.1 (SD=27.1) versus 32.2 (SD=31.1), p >0.05.The mean delineated volume of the NVB was 0.35 cc ± 0.12 on the right and 0.36 cc ± 0.13 on the left. The median number of needles used was 18 [interquartile range(IQR):17-19]. The median dose max to the left NVB is 20.9 Gy (17.4-22.8) and to the right NVB is 21.1 Gy (19.0-24.0). the median dose to the penile bulb was 5.4 Gy (4.2-7.8).There was no association found between any of the baseline or dosimetric parameters with the deterioration sHRQoL. Fifty percent of prostate cancer patients treated with MRI-guided HDR-BT followed by EBRT reported a MID in their sHRQoL at 5 years after. The dose received by the NVB bilaterally was consistently higher than 120% of the prescription dose. A short course of ADT was not associated with a worse sHRQoL score at 5 years. Further studies should focus on using MRI to accurately delineate the NVB and assess the feasibility and impact of limiting the dose to the NVB. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) has the potential to simplify and optimize various steps of the brachytherapy workflow, and this literature review aims to provide an overview of the work done in this field. We conducted a literature search in June 2022 on PubMed, Embase, and Cochrane for papers that proposed AI applications in brachytherapy. A total of 80 papers satisfied inclusion/exclusion criteria. These papers were categorized as follows: segmentation (24), registration and image processing (6), preplanning (13), dose prediction and treatment planning (11), applicator/catheter/needle reconstruction (16), and quality assurance (10). AI techniques ranged from classical models such as support vector machines and decision tree-based learning to newer techniques such as U-Net and deep reinforcement learning, and were applied to facilitate small steps of a process (e.g., optimizing applicator selection) or even automate the entire step of the workflow (e.g., end-to-end preplanning). Many of these algorithms demonstrated human-level performance and offer significant improvements in speed. AI has potential to augment, automate, and/or accelerate many steps of the brachytherapy workflow. We recommend that future studies adhere to standard reporting guidelines. We also stress the importance of using larger sample sizes and reporting results using clinically interpretable measures. [ABSTRACT FROM AUTHOR]

To demonstrate the feasibility of treating cervical cancer patients with MRI-guided brachytherapy (MRgBT) using 24 Gy in 3 fractions (F) versus a standard, more resource-intensive regimen of 28 Gy in 4F, and its ability to meet EMBRACE II planning aims. A retrospective review of 224 patients with FIGO Stage IB–IVA cervical cancer treated with 28 Gy/4F (n = 91) and 24 Gy/3F (n = 133) MRgBT between 2016-2021 was conducted. Multivariable linear regression models were fitted to compare dosimetric parameters between the two groups, adjusting for CTV HR and T stage. Most patients had squamous cell carcinoma, T2b disease, and were treated with intracavitary applicator plus interstitial needles (96%). The 28 Gy/4F group had higher CTV HR (median 28 vs. 26 cm3, p = 0.04), CTV IR D 98% (mean 65.5 vs. 64.5 Gy, p = 0.03), rectum D 2cm3 (mean 61.7 vs. 59.2 Gy, p = 0.04) and bladder D 2cm3 (81.3 vs. 77.9 Gy, p = 0.03). There were no significant differences in the proportion of patients meeting the EMBRACE II OAR dose constraints and planning aims, except fewer patients treated with 28 Gy/4F met rectum D 2cm3 < 65 Gy (73 vs. 85%, p = 0.027) and ICRU rectovaginal point < 65 Gy (65 vs. 84%, p = 0.005). Cervical cancer patients treated with 24 Gy/3F MRgBT had comparable target doses and lower OAR doses compared to those treated with 28 Gy/4F. A less-resource intense fractionation schedule of 24 Gy/3F is an alternative to 28 Gy/4F in cervix MRgBT. [ABSTRACT FROM AUTHOR]

To report acute toxicity and health-related quality of life (HRQoL) outcomes of a phase II clinical trial of magnetic resonance imaging (MRI)-guided prostate high-dose-rate brachytherapy (HDR-BT) combined with external beam radiotherapy. Patients with intermediate- and high-risk prostate cancer (PCa) were eligible. Treatment consisted of a single 15 Gy MRI-guided HDR-BT followed by external beam radiotherapy (37.5–46 Gy depending on their risk category). Dosimetry, toxicity and HRQoL outcomes were collected prospectively at baseline, 1 and 3 months using Common Terminology Criteria for Adverse Events Version 4.0 and the expanded PCa index composite, respectively. General linear mixed modeling was conducted to assess the changes in expanded PCa index composite domain scores over time. A minimally important difference was defined as a deterioration of HRQoL scores at 3 months compared to baseline ≥ 0.5 standard deviation. A p value ≤ 0.05 was considered statistically significant. Sixty-one patients were included. Acute grade (G)2 urinary toxicity was observed in 18 (30%) patients while 1 (2%) patient had G3 toxicity, and none had G4 toxicity. Two patients had an acute urinary retention. G2 gastrointestinal toxicity was reported by 5 (8%) patients with no G3–4. Compared to baseline, urinary HRQoL scores significantly declined at 1 month (p < 0.001) but recovered at 3 months (p > 0.05). Bowel (p < 0.001) and sexual (p < 0.001) domain scores showed a significant decline over the 3-month follow-up period. At 3 months, 44%, 49% and 57% of patients reported a minimally important difference respectively in the urinary bowel and sexual domains. MRI-guided HDR-BT boost is a safe and well tolerated treatment of intermediate- and high-risk PCa in the acute setting. A longer follow-up and a comparison to ultrasound-based HDR-BT are needed to assess the potential benefit of MRI-guided prostate HDR-BT. [ABSTRACT FROM AUTHOR]

To assess the impact of the dose to the bladder neck (BN) on acute urinary toxicity (AUT) and health-related quality of life (uHRQoL) in patients with prostate cancer treated with MRI-guided high-dose-rate brachytherapy combined to external beam radiotherapy. Sixty-one patients were treated with a single 15-Gy MRI-guided high-dose-rate brachytherapy followed by external beam radiotherapy as part of a prospective Phase II trial. The BN was delineated in retrospect on T2-weighted images. AUT and uHRQoL data were collected prospectively using Common Terminology Criteria for Adverse Events version 4.0 and the expanded prostate index composite. A minimally important difference (MID) was defined as a deterioration of uHRQoL scores at 3 months ≥ 0.5 standard deviation of baseline score. Linear and logistic regression models were used. The median BN volume was 0.6 cc. The median BN and urethral maximum dose (BNDmax and UDmax) were 22 Gy and 20 Gy, respectively. BNDmax was significantly associated with UDmax (p = 0.03). AUT Grade 2 + was observed in 32% of patients. Among those, 4 patients had an acute urinary retention (AUR). No Grade 4 + toxicity was reported. At 3 months, 47% of patients reported an MID in urinary uHRQoL. None of the dosimetric parameters including BNDmax was associated with acute Grade 2 + urinary toxicity or MID. However, 3 of 4 patients with AUR had a BNDmax in the highest quartile; >175% of prescription dose. Although a high BN dose was observed in patients who had an AUR, the predictive value of this parameter is yet to be determined in a larger cohort. [ABSTRACT FROM AUTHOR]