Development and prospective in-patient proof-of-concept validation of a surface photogrammetry + CT-based volumetric motion model for lung radiotherapy

PURPOSE

We develop and validate a motion model that uses real-time surface photogrammetry acquired concurrently with four-dimensional computed tomography (4DCT) to estimate respiration-induced changes within the entire irradiated volume, over arbitrarily many respiratory cycles.

METHODS

A research, couch-mounted, VisionRT (VRT) system was used to acquire optical surface data (15 Hz, ROI = 15 × 20 cm² ) from the thoraco-abdominal surface of a consented lung SBRT patient, concurrently with their standard-of-care 4DCT. The end-exhalation phase from the 4DCT was regarded as reference and for each remaining phase, deformation vector fields (DVFs) with respect to the reference phase were computed. To reduce dimensionality, the first two principal components (PCs) of the matrix of nine DVFs were calculated. In parallel, ten phase-averaged VRT surfaces were created. Surface DVFs and corresponding PCs were computed. A principal least squares regression was used to relate the PCs of surface DVF to those of volume DVFs, establishing a relationship between time-varying surface and the underlying time-varying volume. Proof-of-concept validation was performed during each treatment fraction by concurrently acquiring 30 s time series of real-time surface data and "ground truth" kV fluoroscopic data (FL). A ray-tracing algorithm was used to create a digitally reconstructed fluorograph (DRF), and motion trajectories of high-contrast, soft-tissue, anatomical features in the DRF were compared with those from kV FL.

RESULTS

For five of the six fluoroscopic acquisition sessions, the model out-performed 4DCT in predicting contour Dice coefficient with respect to fluoroscopy-derived contours. Similarly, the model exhibited a marked improvement over 4DCT for patch positions on the diaphragm. Model patch position errors varied from 5 to -15 mm while 4DCT errors ranged between 5 and -22.4 mm. For one fluoroscopic acquisition, a marked change in the a priori internal-external correlation resulted in model errors comparable to those of 4DCT.

CONCLUSIONS

We described the development and a proof-of-concept validation for a volumetric motion model that uses surface photogrammetry to correlate the time-varying thoraco-abdominal surface to the time-varying internal thoraco-abdominal volume. These early results indicate that the proposed approach can result in a marked improvement over 4DCT. While limited by the duration of the fluoroscopic acquisitions as well as the resolution of the acquired images, the DRF-based proof-of-concept technique developed here is model-agnostic, and therefore, has the potential to be used as an in-patient validation tool for other volumetric motion models.

Barriers to screening and isoniazid preventive therapy for child contacts of tuberculosis patients

BACKGROUND

India's guidelines recommend tuberculosis (TB) screening of household contacts aged <6 years and isoniazid preventive therapy (IPT) for children without active disease. We evaluated the current status and barriers to screening and IPT provision among the child contacts of TB patients.

METHODS

Questionnaire and health record data were collected from index cases and health care providers (HCPs) at Sassoon General Hospital, Pune, India.

RESULTS

Of 80 adult TB cases, 24 (30%) reported that an HCP recommended TB screening of their child contacts; 49/178 (28%) child contacts were screened. Sixteen (33%) children had active TB, and 28 (85%) of those who screened negative were prescribed IPT. Nineteen (76%) HCPs reported recommending child contact screening. Only 8 (32%) reported ever prescribing IPT. Lack of TB screening and IPT provision for child contacts was associated with inadequate HCP counseling (aOR 19.5, P < 0.001), a non-parent index case (aOR 3.72, P = 0.008) and lack of postgraduate HCP qualification (aOR 19.12, P = 0.04).

CONCLUSIONS

TB screening and IPT provision for child contacts of adults with TB were infrequent. Many screened children had active TB. Universal, timely TB screening and IPT for exposed children are urgently needed to reduce pediatric TB in India.

Morphology, Biology and Predation Capacity of Amphiareus constrictus (Stål) (Hemiptera: Anthocoridae)

A minute pirate bug, Amphiareus constrictus (Stål) (Hemiptera: Anthocoridae), the biology of which has been less studied, was successfully reared in the laboratory for more than 20 generations. Studies were conducted to understand its biology, life table parameters, and predatory potential. Besides the adult, the egg and all five nymphal instars are described with live images, which can serve as additional characters for identification. The biological parameters were studied at different temperatures. Rearing temperatures of 25 and 30°C were found to be suitable for hatching and nymphal survival to adult stage (88.5 and 75%, respectively). Life table parameters like net reproductive rate (R₀), precise intrinsic rate of increase (r_m), finite rate of increase (λ) and hypothetical F₂ females were higher at 25°C. A nymph could consume a total of 32.8 ± 1.8 Corcyra cephalonica Stainton eggs. Male and female adult consumed a total of 179.0 ± 15.6 and 388.5 ± 58.6 C. cephalonica eggs, respectively. The data generated through studies on biology, fertility, and predatory potential led to the standardization of a simple production protocol for A. constrictus utilizing the eggs of the rice moth C. cephalonica. Predatory potential studies on Tuta absoluta (Meyrick) indicated that a nymph could consume 154.8 eggs during nymphal duration. Male and female adults could consume 1280.5 and 1435 eggs, respectively. The mass-reared A. constrictus can be field evaluated against the tomato pinworm TT absoluta and the brown plant hopper Nilaparvata lugens Stål.

The optimal oral biopsy site for diagnosis of mucous membrane pemphigoid and pemphigus vulgaris

BACKGROUND

Accepted 'standard practice' for the diagnosis of immunobullous disease is a perilesional sample for direct immunofluorescence (DIF).

OBJECTIVES

To compare diagnostic outcomes of a normal buccal punch biopsy (NBPB) with a perilesional biopsy (PLB) for mucous membrane pemphigoid (MMP) and pemphigus vulgaris (PV).

METHODS

A retrospective analysis of 251 DIF-positive patients with MMP and 77 DIF-positive patients with PV was undertaken. Parameters analysed included the intraoral sites of involvement and histopathological, DIF and indirect immunofluorescence (IIF) findings.

RESULTS

For MMP, PLB was positive in 134 of 143 (93·7%) samples, compared with 129 of 144 (89·6%) by NBPB. The diagnostic sensitivities for PLB (81%, 39 of 48) and NBPB (77%, 37 of 48) among 48 patients who underwent both techniques were not significantly different (P = 0·62). In gingival-only MMP, PLB was positive in 63 of 69 (91%) and NBPB was positive in 63 of 75 (84%). For multisite MMP, PLB was positive in 71 of 74 (96%) and NBPB was positive in 66 of 69 (96%). In gingival-only MMP, biopsies from reflected alveolar mucosa in 17 consecutive patients were positive in 17 of 17 cases (100%). For PV, PLB was positive in 42 of 43 (98%), compared with 42 of 42 (100%) by NBPB. Histopathology was diagnostic in 93 of 134 (69·4%) cases of MMP and 38 of 41 (93%) cases of PV. IIF was positive in 126 of 197 (64·0%) MMP and 68 of 74 (92%) PV patient sera.

CONCLUSIONS

In the largest series of combined oral DIF results in patients with MMP and PV, we have shown that NBPB is equivalent to PLB for the diagnosis of PV and multisite MMP, and is more sensitive than both histology and IIF. What's already known about this topic? The variation in sensitivity of oral biopsy sites for direct immunofluorescence (DIF) in the diagnosis of oral MMP and PV has not been studied in detail in large series of patients. Biopsy can be challenging due to difficult access and fragility of the oral mucosa. The diagnostic biopsy technique is therefore critical. What does this study add? We have shown that a normal buccal punch biopsy (NBPB) from uninvolved oral mucosa is as sensitive as a perilesional biopsy (PLB) for diagnosis of oral PV, and superior to serology and histology. For multisite MMP, NBPB is equivalent to PLB and is more sensitive than serology and histology. The oral punch biopsy technique on uninvolved buccal mucosa tissue is a simple and safe practical method for diagnosing oral PV and MMP.

Abstract 109: Myeloid Syk-PI3Kg-HIF axis inhibits anti-tumor adaptive immunity: In silico design of a “first in class” novel dual-Syk/PI3K inhibitor, SRX3207, to block the immunosuppressive tumor microenvironment

Introduction: Macrophages (MΘs) play important roles in the initiation and progression of solid tumors and in establishing an immunosuppressive tumor microenvironment (TME) that dampens effective anti-tumor immune responses in cancer. Hence, targeting signaling pathways in MΘs that promote tumor immunosuppression will provide therapeutic benefit. Syk kinase is a well-established cytoplasmic protein tyrosine kinase that has been extensively studied in adaptive immune responses, but its role in macrophage-mediated inflammatory responses and innate immune responses remains poorly understood. The role of PI3Kγ in tumor growth and immunosuppression has been recently established by our and other groups. Our current study examines whether targeting two crucial signaling entities, which promote macrophage-mediated anti-inflammatory responses viz. Syk kinase and PI3K, would maximally activate the anti-tumor immune response.

Methodology: 1) We generated myeloid-specific conditional Syk k/o mice to investigate if the deletion of Syk has any role in a) macrophage polarization in vitro and in vivo; b) tumor growth in various syngeneic mouse models including LLC, B16, CT26, and MC38 carcinoma; c) tumor immunosuppression including polarization of macrophages into immunosuppressive phenotype, infiltration of myeloid-derived suppressor cells, regulatory T cells; and d) infiltration and activation of CD8+T cells in the TME. 2) We used commercially available Syk inhibitor, R788, to study the role of Syk in the control of the aforementioned phenotypes. 3) We used computational chemistry methods to develop a novel chemotype, SRX3207, which inhibits both PI3K and Syk (with a single molecule) as a strategy for combinatorial activation of anti-cancer immunity.

Results: Our results suggest that macrophage, Syk, functions upstream of Rac2 GTPase and PI-3K to modulate integrin (αvβ3/αvβ5&α4β1)-mediated polarization of immunosuppressive macrophages and tumor growth in in vivo syngeneic tumor models. Genetic or pharmacological blockade of Syk in MΘs promotes a pro-inflammatory MΘ phenotype, restores CD8+ T cell activity, destabilizes HIF under hypoxia, and stimulates an antitumor immune response. Moreover, Syk-regulated immune response gene signature predicts survival in cancer patients. Novel dual-Syk/PI3K inhibitor, SRX3207, shows great efficacy in various syngeneic tumor models with no toxicity.

Conclusions: Our results validate the concept of combined Syk and PI3K inhibition as an effective approach to treat macrophage-driven, devastating cancers. This study will open new avenues to explore this chemotype in combination with other immuno-oncologic agents as the majority of cancer patients do not respond to single agent anti-PD1 or other checkpoint inhibitors currently in clinical use.

Citation Format: Shweta Joshi, Kevin Liu, Muamera Zulcic, Alok Singh, Timothy Pham, Christopher K. Glass, Andrew Sharabi, Guillermo A. Morales, Joseph R. Garlich, Donald Durden. Myeloid Syk-PI3Kg-HIF axis inhibits anti-tumor adaptive immunity: In silico design of a “first in class” novel dual-Syk/PI3K inhibitor, SRX3207, to block the immunosuppressive tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 109.

Evaluating the role of dithiolane rich fraction of Ferula asafoetida (apiaceae) for its antiproliferative and apoptotic properties: in vitro studies

Asafoetida resin has been reported for various biological activities but its use has been widely restricted owing to its pungent smell and pool water solubility.

AIM

In vitro study of the anticancer potential of microwave-extracted essential oil (EO) of Ferula asafoetida.

MATERIALS AND METHODS

The phytochemical investigation and in vitro cytotoxicity assessment was carried out in two human liver cancer cell lines. The expression of NFKB1, TGFB1, TNF, CASP3 was analyzed by reverse transcription polymerase chain reaction.

RESULTS

Ferula asafoetida EO contains high concentrations of dithiolane, which possess antiproliferative activity in human liver carcinoma cell lines (HepG2 and SK-Hep1) in a dose-dependent manner. The bioactive compounds in F. asafoetida are capable of induction of apoptosis and altered NF-kB and TGF-β signalling with increase in caspase-3 and TNF-α expression.

CONCLUSION

Further elucidation of bioactive molecules and underlying mechanisms could lead to potential intervention in liver cancer in animal models. The safety and efficacy as well as the mode of EO action in animal models would be highly crucial.

SF2523: Dual PI3K/BRD4 Inhibitor Blocks Tumor Immunosuppression and Promotes Adaptive Immune Responses in Cancer

Macrophages (MΘs) are key immune infiltrates in solid tumors and serve as major drivers behind tumor growth, immune suppression, and inhibition of adaptive immune responses in the tumor microenvironment (TME). Bromodomain and extraterminal (BET) protein, BRD4, which binds to acetylated lysine on histone tails, has recently been reported to promote gene transcription of proinflammatory cytokines but has rarely been explored for its role in IL4-driven MΘ transcriptional programming and MΘ-mediated immunosuppression in the TME. Herein, we report that BET bromodomain inhibitor, JQ1, blocks association of BRD4 with promoters of arginase and other IL4-driven MΘ genes, which promote immunosuppression in TME. Pharmacologic inhibition of BRD4 using JQ1 and/or PI3K using dual PI3K/BRD4 inhibitor SF2523 (previously reported by our group as a potent inhibitor to block tumor growth and metastasis in various cancer models) suppresses tumor growth in syngeneic and spontaneous murine cancer models; reduces infiltration of myeloid-derived suppressor cells; blocks polarization of immunosuppressive MΘs; restores CD8⁺ T-cell activity; and stimulates antitumor immune responses. Finally, our results suggest that BRD4 regulates the immunosuppressive myeloid TME, and BET inhibitors and dual PI3K/BRD4 inhibitors are therapeutic strategies for cancers driven by the MΘ-dependent immunosuppressive TME.

Abstract P5-14-07: Accuracy of psychosocial assessments in an online surgical decision aid developed for early breast cancer patients with resource and educational constraints

Background: Women with early breast cancer routinely face a choice between breast conservation therapy and mastectomy, and assume agency through shared decision making. However, for women with lower socioeconomic power or education, barriers such as access to understandable information, involvement of family in decision making, and a decreased sense of autonomy inhibits this agency. To better empower this population, a simple to understand, online, self-administered, conjoint analysis based decision aid called “Navya Patient Preference Tool” (PPT) is developed to be used outside the physician encounter. PPT is unique in its incorporation of several psychological scales that assess potential confounders of participation in shared decision making.

Methodology: This is a pre-planned analysis of the reliability and validity of the psychological scales used in all three arms of an IRB approved randomized controlled trial to assess PPT. Women with operable node negative breast cancer eligible for BCT or MRM at one of Asia's largest academic tertiary cancer centers were eligible. PPT trial consists of an initial conjoint analysis questionnaire analyzing implicit preferences for breast conservation given to the intervention arms. The following psychological scales were given to all patients regardless of randomization: Autonomy Preference Index (API), Traditional-Egalitarian Gender Roles (TEGR), Caregiving Role, Brief Resiliency Scale (BRS), Appearances Scale, and Decisional Conflict Scale (DCS). Cronbach's alpha as a measure of internal reliability for all scales, and correlations of scores with known demographic trends as a measure of external validity are calculated.

Results: Of the 102 patients enrolled, 30 completed PPT in English, 39 in Hindi, and 33 in Marathi, (vernaculars). 69/102 were in middle and lower socioeconomic groups (Kuppuswamy Index). 53/102 had completed less than high school education. Internal reliability of all scales were high, with Cronbach's alpha above 0.7: API 0.74, TEGR 0.78, Caregiving 0.7, BRS 0.7, Appearance 0.84. DCS was highly reliable at 0.91, and is the primary outcome measure for the RCT. Correlations in the dataset met those expected in real world data, suggesting external validity. For e.g., education was inversely correlated with traditional gender roles on TEGR (R -0.4, p &lt;0.01), and positively correlated with resilience on BRS (R 0.228, p &lt;0.05). Individual scale items that are unrealistic were not chosen by any of the 102 respondents (e.g.,. My doctor should not participate in my medical decisions), substantiating nuanced reading. 85% of patients “Strongly Agreed” on a 1-5 Likert scale that “The survey questions were easy to understand” (mean score 1.18/5. SD 0.4).

Conclusions: Women with limited education and low socioeconomic status complete the online, self administered PPT outside of a physician encounter, with high internal reliability and external validity. Decision Aids such as Navya PPT, which account for psychosocial confounders of agency, have the potential to benefit women otherwise marginalized from shared decision making.

Citation Format: Joshi S, Ramarajan L, Ramarajan N, Srivastava G, Begum F, Deshpande O, Tondare A, Nair N, Parmar V, Gupta S, Badwe RA. Accuracy of psychosocial assessments in an online surgical decision aid developed for early breast cancer patients with resource and educational constraints [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-14-07.

Abstract P6-19-06: Breast conservation surgery in male breast cancer: A systematic literature review

BACKGROUND

Male breast cancer (BC) incidence is low and management is extrapolated from female BC. Breast conservation surgery (BCS) is commonly used for female BC, however, mastectomy remains the most frequently used surgical procedure for male breast cancer. We performed a literature review to assess the use of BCS in male BC as well as outcomes following BCS.

METHODS

A systematic literature review identified peer-reviewed articles in PubMed evaluating male BC and surgery. Abstracts were screened to identify studies that measured overall survival (OS), disease-free survival (DFS), or local recurrence (LR) in patients undergoing BCS. For all studies, we extracted the total number of patients and number of BCS cases. Of patients undergoing BCS, we further extracted mean age, mean follow-up time, clinical stage, type of axillary surgery [sentinel lymph node biopsy (SLNB), axillary lymph node dissection (ALND)], radiation therapy, hormonal therapy, and chemotherapy. Weighted averages, based on number of patients in each study, were performed for LR, DFS and 5-year OS. The time period for LR and DFS was the duration of follow-up time for each study.

RESULTS

The literature search yielded 4341 articles. Twelve studies published from 1998 to 2016 met the inclusion criteria and were selected for the systematic literature review. Among the 12,616 male breast surgery cases included, 1,633 (12.9%) underwent BCS. Only patients who underwent BCS were included in our analysis. The mean follow-up time was 54.4 months and mean age was 62.4 with stage II as the most common presentation. Two studies reported that 50-71.4% of patients underwent SLNB and 4 studies reported ALND in 14.3-100%. Seven studies reported that adjuvant radiation therapy was administered in 12.0-100% of 474 total patients undergoing BCS. Four studies reported use of hormonal therapy in 73.8-100% of patients. Four studies reported use of chemotherapy in 25-66.7% of patients. Seven studies reported LR among 122 patients, with a weighted average 11.8%. Four studies reported on 5-year OS in 1511 patients, with a weighted average of 85.8%.

CONCLUSION

While less commonly used than mastectomy, BCS can be considered a safe alternative in the surgical treatment of male BC. We have demonstrated that the use of adjuvant radiation following BCS is variable in this patient group. Future research should focus on better standardization of local therapy for male BC and improved reporting of outcomes.

Citation Format: Fisher CS, de la Cruz L, Joshi S, Mah T-J, Blankenship S, Thiruchelvam P. Breast conservation surgery in male breast cancer: A systematic literature review [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-19-06.