Spatial correlation between in vivo imaging and immunohistochemical biomarkers: A methodological study.

In this study, we present a method that enables voxel-by-voxel comparison of in vivo imaging to immunohistochemistry (IHC) biomarkers. As a proof of concept, we investigated the spatial correlation between dynamic contrast enhanced (DCE-)CT parameters and IHC biomarkers Ki-67 (proliferation), HIF-1α (hypoxia), and CD45 (immune cells). 54 whole-mount tumor slices of 15 laryngeal and hypopharyngeal carcinomas were immunohistochemically stained and digitized. Heatmaps of biomarker positivity were created and registered to DCE-CT parameter maps. The adiabatic approximation to the tissue homogeneity model was used to fit the following DCE parameters: Ktrans (transfer constant), Ve (extravascular and extracellular space), and Vi (intravascular space). Both IHC and DCE maps were downsampled to 4 × 4 × 3 mm[3] voxels. The mean values per tumor were used to calculate the between-subject correlations between parameters. For the within-subject (spatial) correlation, values of all voxels within a tumor were compared using the repeated measures correlation (rrm). No between-subject correlations were found between IHC biomarkers and DCE parameters, whereas we found multiple significant within-subject correlations: Ve and Ki-67 (rrm = -0.17, P < .001), Ve and HIF-1α (rrm = -0.12, P < .001), Ktrans and CD45 (rrm = 0.13, P < .001), Vi and CD45 (rrm = 0.16, P < .001), and Vi and Ki-67 (rrm = 0.08, P = .003). The strongest correlation was found between IHC biomarkers Ki-67 and HIF-1α (rrm = 0.35, P < .001). This study shows the technical feasibility of determining the 3 dimensional spatial correlation between histopathological biomarker heatmaps and in vivo imaging. It also shows that between-subject correlations do not reflect within-subject correlations of parameters.

Differential transcriptional invasion signatures from patient derived organoid models define a functional prognostic tool for head and neck cancer.

Clinical outcome for patients suffering from HPV-negative head and neck squamous cell carcinoma (HNSCC) remains poor. This is mostly due to highly invasive tumors that cause loco-regional relapses after initial therapeutic intervention and metastatic outgrowth. The molecular pathways governing the detrimental invasive growth modes in HNSCC remain however understudied. Here, we have established HNSCC patient derived organoid (PDO) models that recapitulate 3-dimensional invasion in vitro. Single cell mRNA sequencing was applied to study the differences between non-invasive and invasive conditions, and in a collective versus single cell invading PDO model. Differential expression analysis under invasive conditions in Collagen gels reveals an overall upregulation of a YAP-centered transcriptional program, irrespective of the invasion mode. However, we find that collectively invading HNSCC PDO cells show elevated levels of YAP transcription targets when compared to single cell invasion. Also, collectively invading cells are characterized by increased nuclear translocation of YAP within the invasive strands, which coincides with Collagen-I matrix alignment at the invasive front. Using gene set enrichment analysis, we identify immune cell-like migratory pathways in the single cell invading HNSCC PDO, while collective invasion is characterized by overt upregulation of adhesion and migratory pathways. Lastly, based on clinical head and neck cancer cohorts, we demonstrate that the identified collective invasion signature provides a candidate prognostic platform for survival in HNSCC. By uncoupling collective and single cell invasive programs, we have established invasion signatures that may guide new therapeutic options.

Comparative Performance Analysis of Idylla and Archer in the Detection of Gene Fusions in Spitzoid Melanocytic Tumors.

Melanocytic neoplasms with spitzoid histomorphology are often difficult to classify without identifying genetic drivers such as kinase fusions. Traditional diagnostic methods, such as immunohistochemistry, can yield inconclusive results, and advanced techniques such as the Archer fusion assay are often inaccessible and costly. The Idylla GeneFusion Assay might offer a rapid and cost-effective alternative. This study compared Idylla and Archer in identifying ALK, pan-NTRK, RET, and ROS1 gene fusions. Of the 147 samples where next-generation sequencing did not detect genetic drivers, 89 (60.5%) meeting the tissue requirements were further analyzed using Idylla (Cohort A). Idylla demonstrated a sensitivity of 75% and a specificity of 100% in detecting these fusions. Additionally, among 27 randomly selected cases (Cohort B) that failed to meet the inclusion criteria, Idylla maintained the same levels of sensitivity and specificity. Our findings also show that Idylla can be effectively conducted with isolated RNA, broadening its applicability beyond tissue samples. Although the Idylla assay may not replace more comprehensive molecular assays such as Archer, it could serve as a valuable initial screening tool in diagnosing spitzoid melanocytic tumors.

Sinonasal mucosal melanoma in The Netherlands between 2001 and 2021: a clinical and epidemiological overview of 320 cases.

PURPOSE: Sinonasal mucosal melanoma (SNMM) is a rare malignancy, characterised by high (local) recurrence rates and poor survival. Comprehensive understanding of tumour etiology is currently lacking, which complicates adequate tumour treatment. Besides examining trends in incidence, this study aims to assess the association between clinical characteristics, treatment practices and patient outcomes, with the objective of establishing a baseline from which SNMM management can be enhanced. METHODS: All newly diagnosed SNMM cases in The Netherlands between 2001 and 2021 were included using data from The Netherlands Cancer Registry (NCR). RESULTS: A total of 320 patients were included. The annual incidence rate for the overall population was stable over the inclusion period with an annual percentage change (APC) of only - 0.01%. The 5-year overall survival (OS) and relative survival (RS) were 24.5 and 32.4%, respectively. Relative survival did not increase over time. The addition of adjuvant radiotherapy to surgery was not associated with a higher OS and RS compared to surgery alone. CONCLUSION: Sinonasal mucosal melanoma is a rare disease with stable incidence rates in the Netherlands between 2001 and 2021. There has been no improvement in survival over the course of the inclusion period. The study reaffirms that adjuvant radiotherapy does not seem to improve patient outcomes. Given the generally poor outcomes for SNMM patients, novel therapeutic options ought to be considered in order to improve care.

Pros and cons of artificial intelligence implementation in diagnostic pathology.

The rapid introduction of digital pathology has greatly facilitated development of artificial intelligence (AI) models in pathology that have shown great promise in assisting morphological diagnostics and quantitation of therapeutic targets. We are now at a tipping point where companies have started to bring algorithms to the market, and questions arise whether the pathology community is ready to implement AI in routine workflow. However, concerns also arise about the use of AI in pathology. This article reviews the pros and cons of introducing AI in diagnostic pathology.

Squamous cell carcinoma of the nasal vestibule in the Netherlands: A clinical and epidemiological review of 763 cases (2008-2021).

BACKGROUND: Squamous cell carcinoma of the nasal vestibule (SCCNV) is a rare disease, distinctly different in presentation, treatment, and outcome from squamous cell carcinoma (SCC) of the nasal cavity and paranasal sinuses. However, these are often not analyzed separately. METHODS: The Netherlands Cancer Registry (NCR) and pathology reports from the Dutch Nationwide Pathology Databank (PALGA) were used to identify all newly diagnosed SCCNV cases in the Netherlands between 2008 and 2021. RESULTS: A total of 763 patients were included. The yearly incidence rate displayed a significant downward trend with an annual percentage change (APC) of -3.9%. The 5-year overall survival (OS) and disease-free survival were 69.0% and 77.2%, respectively. The 5-year relative survival was 77.9% and improved slightly over the inclusion period. OS for patients who were staged cT3 appeared to be worse than those staged cT4a, calling the applicability of the TNM-classification into question. CONCLUSION: SCC of the nasal vestibule is rare, with declining incidence rates. Introducing a specific topography code for SCCNV is recommended to enhance registration accuracy. The TNM classification seems poorly applicable to SCCNV, suggesting the need to explore alternative staging methods.

Improved delineation with diffusion weighted imaging for laryngeal and hypopharyngeal tumors validated with pathology.

OBJECTIVE: This study aims to determine the added value of a geometrically accurate diffusion-weighted (DW-) MRI sequence on the accuracy of gross tumor volume (GTV) delineations, using pathological tumor delineations as a ground truth. METHODS: Sixteen patients with laryngeal or hypopharyngeal carcinoma were included. After total laryngectomy, the specimen was cut into slices. Photographs of these slices were stacked to create a 3D digital specimen reconstruction, which was registered to the in vivo imaging. The pathological tumor (tumorHE) was delineated on the specimen reconstruction. Six observers delineated all tumors twice: once with only anatomical MR imaging, and once (a few weeks later) when DW sequences were also provided. The majority voting delineation of session one (GTVMRI) and session two (GTVDW-MRI), as well as the clinical target volumes (CTVs), were compared to the tumorHE. RESULTS: The mean tumorHE volume was 11.1 cm3, compared to a mean GTVMRI volume of 18.5 cm3 and a mean GTVDW-MRI volume of 15.7 cm3. The median sensitivity (tumor coverage) was comparable between sessions: 0.93 (range: 0.61-0.99) for the GTVMRI and 0.91 (range: 0.53-1.00) for the GTVDW-MRI. The CTV volume also decreased when DWI was available, with a mean CTVMR of 47.1 cm3 and a mean CTVDW-MRI of 41.4 cm3. Complete tumor coverage was achieved in 15 and 14 tumors, respectively. CONCLUSION: GTV delineations based on anatomical MR imaging tend to overestimate the tumor volume. The availability of the geometrically accurate DW sequence reduces the GTV overestimation and thereby CTV volumes, while maintaining acceptable tumor coverage.

Diagnostic and Treatment-Related Challenges in Sinonasal Teratocarcinosarcoma: A Report of Three Cases.

Background: Sinonasal teratocarcinosarcoma is a rare, aggressive malignancy located almost exclusively in the nasal cavity, paranasal sinuses, or anterior skull base. Histopathological diagnosis can be challenging due to the heterogeneous composition. Methods: Retrospective analysis of 3 patients with sinonasal teratocarcinosarcoma diagnosed and treated at the University Medical Center Utrecht was conducted. Results: Patients presented with nasal obstruction, epistaxis, headaches, or behavioral changes. All three patients had locally advanced disease, and one had lymph node metastases. Two patients underwent surgery followed by radiotherapy, and one underwent neoadjuvant chemotherapy followed by surgery. The follow-up duration ranged from 3 to 32 months. All three patients died due to progression of their disease. Conclusion: Sinonasal teratocarcinosarcoma is characterized by rapid, aggressive local expansion. The prognosis is poor due to a high risk of metastases and locally recurrent disease. Multimodality treatment consisting of surgery, followed by (chemo)-radiotherapy, is essential for optimizing outcomes. Neoadjuvant therapy offers a promising treatment option.

Using Intratumor Heterogeneity of Immunohistochemistry Biomarkers to Classify Laryngeal and Hypopharyngeal Tumors Based on Histologic Features.

Haralick texture features are used to quantify the spatial distribution of signal intensities within an image. In this study, the heterogeneity of proliferation (Ki-67 expression) and immune cells (CD45 expression) within tumors was quantified and used to classify histologic characteristics of larynx and hypopharynx carcinomas. Of 21 laryngectomy specimens, 74 whole-mount tumor slides were scored on histologic characteristics. Ki-67 and CD45 immunohistochemistry was performed, and all sections were digitized. The tumor area was annotated in QuPath. Haralick features independent of the diaminobenzidine intensity were extracted from the isolated diaminobenzidine signal to quantify intratumor heterogeneity. Haralick features from both Ki-67 and CD45 were used as input for a principal component analysis. A linear support vector machine was fitted to the first 4 principal components for classification and validated with a leave-one-patient-out cross-validation method. Significant differences in individual Haralick features were found between cohesive and noncohesive tumors for CD45 (angular second motion: P =.03, inverse difference moment: P =.009, and entropy: P =.02) and between the larynx and hypopharynx tumors for both CD45 (angular second motion: P =.03, inverse difference moment: P =.007, and entropy: P =.005) and Ki-67 (correlation: P =.003). Therefore, these features were used for classification. The linear classifier resulted in a classification accuracy of 85% for site of origin and 81% for growth pattern. A leave-one-patient-out cross-validation resulted in an error rate of 0.27 and 0.35 for both classifiers, respectively. In conclusion, we show a method to quantify intratumor heterogeneity of immunohistochemistry biomarkers using Haralick features. This study also shows the feasibility of using these features to classify tumors by histologic characteristics. The classifiers created in this study are a proof of concept because more data are needed to create robust classifiers, but the method shows potential for automated tumor classification.

A closer look at the resection margins of buccal mucosa cancer: Their influence on local recurrence free survival.

BACKGROUND: The adequate surgical margin for local control of buccal mucosa squamous cell carcinoma (BMSCC) is under debate. This study investigates surgical margins and other factors associated with local recurrence free survival (LRFS) in a large cohort of BMSCC patients. METHODS: Multiple factors were evaluated retrospectively in 97 patients with BMSCC. Cox-regression and Kaplan-Meier curves were used for analysis. RESULTS: The local recurrence rate was 23%. The tumor-free margin was <5.0 mm in 89% of the patients and the deep margin was significantly more often inadequate. Multivariate analysis associated pT3-classification, former smokers, tumor-free margin status, and postoperative (chemo)radiation (PO(ch)RT) with local recurrence. Re-resections did not improve LRFS in patients with <5.0 mm tumor-free margins. CONCLUSIONS: Adequate tumor-free margins are pivotal for LRFS of BMSCC. PO(ch)RT, not re-resection, can improve LRFS in patients with <5.0 mm tumor-free margins.

Validation of automated positive cell and region detection of immunohistochemically stained laryngeal tumor tissue using digital image analysis.

Objectives: This study aimed to validate a digital image analysis (DIA) workflow for automatic positive cell detection and positive region delineation for immunohistochemical hypoxia markers with a nuclear (hypoxia-inducible factor 1α [HIF-1α]) and a cytoplasmic (pimonidazole [PIMO]) staining pattern. Materials and methods: 101 tissue fragments from 44 laryngeal tumor biopsies were immunohistochemically stained for HIF-1α and PIMO. QuPath was used to determine the percentage of positive cells and to delineate positive regions automatically. For HIF-1α, only cells with strong staining were considered positive. Three dedicated head and neck pathologists scored the percentage of positive cells using three categories (0: <1%; 1: 1%-33%; 2: >33%;). The pathologists also delineated the positive regions on 14 corresponding PIMO and HIF-1α-stained fragments. The consensus between observers was used as the reference standard and was compared to the automatic delineation. Results: Agreement between categorical positivity scores was 76.2% and 65.4% for PIMO and HIF-1α, respectively. In all cases of disagreement in HIF-1α fragments, the DIA underestimated the percentage of positive cells. As for the region detection, the DIA correctly detected most positive regions on PIMO fragments (false positive area=3.1%, false negative area=0.7%). In HIF-1α, the DIA missed some positive regions (false positive area=1.3%, false negative area=9.7%). Conclusions: Positive cell and region detection on biopsy material is feasible, but further optimization is needed before unsupervised use. Validation at varying DAB staining intensities is hampered by lack of reliability of the gold standard (i.e., visual human interpretation). Nevertheless, the DIA method has the potential to be used as a tool to assist pathologists in the analysis of IHC staining.

Ultrasound-guided resection for squamous cell carcinoma of the buccal mucosa: A feasibility study.

BACKGROUND: Image-guided surgery could help obtain clear (≥5.0 mm) resection margins. This feasibility study investigated ultrasound-guided resection accuracy of buccal mucosa squamous cell carcinoma (BMSCC). METHODS: MRI and ultrasound measurements of tumor thickness were compared to histology in 13 BMSCC-patients. Ultrasound measured margins (at five locations) on the specimen were compared to the corresponding histological margins. RESULTS: Accuracy of in- and ex-vivo ultrasound (mean deviation from histology: 1.6 mm) for measuring tumor thickness was comparable to MRI (mean deviation from histology: 2.6 mm). The sensitivity to detect clear margins using ex-vivo ultrasound was low (48%). If an ex-vivo ultrasound cutoff of ≥7.5 mm would be used, the sensitivity would increase to 86%. CONCLUSIONS: Ultrasound-guided resection of BMSCC's is feasible. In- and ex-vivo ultrasound measure tumor thickness in BMSCC accurately. We recommend ≥7.5 mm resection margins on ex-vivo ultrasound to obtain histological clear margins. Additional research is required to establish the effect of 7.5 mm ultrasound cutoff.

Long-term oncological follow-up after mold-based pulsed dose rate brachytherapy for early stage squamous cell carcinoma of the nasal vestibule: A single center experience of 68 patients over a 17-year period.

PURPOSE: Cancer of the nasal vestibule is a rare type of malignancy constituting less than one percent of all head and neck cancers. These tumors are typically diagnosed at an early stage. Both surgery and radiotherapy provide excellent oncological results, but esthetic results are better after radiotherapy. The aim of this study was to evaluate the long-term oncological follow-up after brachytherapy for early stage squamous cell carcinoma of the nasal vestibule. METHODS AND MATERIALS: Retrospective analysis of patients with carcinoma of the nasal vestibule who were treated with primary brachytherapy in the Utrecht University Medical Center. RESULTS: In this single center experience over a 17-year period 68 patients with early stage squamous cell carcinoma of the nasal vestibule were treated with brachytherapy. Two patients had lymph node metastases at first clinical presentation. Median follow-up duration was 46.5 months. Five-year locoregional recurrence-free survival, disease-specific survival, and overall survival were 91.1%, 96.1%, and 66.2%, respectively. All recurrences occurred within the first 3 years of follow-up. CONCLUSIONS: Brachytherapy offers excellent oncological outcomes and is a safe and effective treatment for early stage carcinoma of the nasal vestibule. Recurrences typically occur within 3 years after treatment.

PRAME Staining in Sinonasal Mucosal Melanoma: A Single-Center Experience.

BACKGROUND: Sinonasal mucosal melanoma (MM) is a rare, aggressive melanoma subtype. Complete surgical excision, with or without adjuvant radiotherapy, remains the cornerstone of treatment and yields adequate locoregional control. Metastatic MM is managed similarly to metastatic cutaneous melanoma but with poorer survival. PReferentially expressed Antigen in MElanoma (PRAME) has been identified as a potential diagnostic marker and therapeutic target in the treatment of cutaneous melanoma. METHODS: Retrospective analysis of the clinical characteristics and immunohistochemical features of all sinonasal MM patients referred to the department of Head and Neck Surgical Oncology, UMC Utrecht Cancer Center, between 2011 and 2021 was performed. Single nucleotide polymorphism (SNP) array and next-generation sequencing (NGS) were performed in selected cases. RESULTS: A total of 26 patients with an MM were included. The median follow-up duration was 15 months. At the end of follow-up, 13 patients had died due to progression of their disease, and one patient died of intercurrent disease. PRAME immunohistochemistry was performed in 23 out of 26 cases, all displaying PRAME expression. In two cases PRAME expression was present both within the melanoma cells and in melanocytes in adjacent mucosa. SNP array showed ≥ 5 copy number variants (CNV) in all tested cases, with a median of 29.5 CNVs (IQR 23.25-40). The three most common mutations identified by NGS were NRAS (7 cases) and NF1 (2 cases). CONCLUSION: We show that expression of PRAME is common in sinonasal MM, making PRAME a useful ancillary diagnostic tool and a potential therapeutic target in sinonasal MM. The demonstrated occurrence of extensive presence of PRAME-positive melanocytes in the surrounding mucosa of sinonasal MM might explain the multifocal nature of melanoma in the (sinonasal) mucosa, and would be an extra argument for a PRAME targeting treatment in preventing local disease recurrence.

The prognostic role of tumor associated macrophages in squamous cell carcinoma of the head and neck: A systematic review and meta-analysis.

Head and neck squamous cell carcinoma (HNSCC) is an immunogenic cancer type, and tumor associated macrophages (TAMs) are a major component of the tumor microenvironment (TME). In this systematic review and meta-analysis, studies assessing tumor infiltration with CD68+, iNOS+, HLA-DR+, CD11b+, CD163+, CD206+, and CD204+TAMs were included, and correlation to survival hazard was studied. A low number of CD68+TAMs correlated to better overall survival (OS) in multivariate analysis (HR 1.36 95 %CI (1.07-1.72) P = .01). CD68+TAMs did not correlate to disease free survival (DFS), disease specific survival (DSS), progression free survival (PFS), or recurrence free survival (RFS). A low number of CD163+TAMs correlated to better OS in uni- and multivariate analysis (resp. HR 2.65 95 %CI (1.57-4.46) P = .01 and HR 2.42 95 %CI (1.72-3.41) P < .001). A low number of CD163+TAMs also correlated to better DFS and PFS, whereas a low number of CD204+TAMs only correlated to PFS. While IHC analysis of pan macrophage marker CD68 and M2-like marker CD163 both show prognostic utility in OS, CD163 is a stronger prognosticator, as indicated by multivariate meta-analysis. CD163+TAMs also correlate to DFS and PFS; outcomes that are more relevant to patients, thus showing promising results for future clinical implementation.

A phase Ib/II study of regorafenib and paclitaxel in patients with beyond first-line advanced esophagogastric carcinoma (REPEAT).

Purpose: Regorafenib monotherapy, a multikinase inhibitor of angiogenesis, tumor microenvironment, and tumorigenesis, showed promising results in gastric cancer. We aimed to assess the tolerability of regorafenib and paclitaxel in patients with advanced esophagogastric cancer (EGC) refractory to first-line treatment, and explore potential biomarkers. Methods: Patients received paclitaxel (80 mg/m2) on days 1, 8, and 15 of a 28-day cycle and regorafenib (80/120/160 mg) on days 1-21 in the dose-escalation cohort, and the maximum-tolerated dose (MTD) in the dose-expansion cohort. Exploratory, overall survival (OS) and progression-free survival (PFS) were compared to a propensity-score matched cohort receiving standard second-/third-line systemic treatment. Paclitaxel pharmacokinetics were assessed using samples from day 1 (D1) and day 15 (D15). We performed enzyme-linked immunosorbent assay measurements of galectin-1, RNA sequencing, and shallow whole-genome sequencing of metastatic tumor biopsies for biomarker analyses. Results: In the dose-escalation cohort (n = 14), the MTD of regorafenib was 120 mg. In all, 34 patients were enrolled in the dose-expansion cohort. Most common toxicities (all grades; grade ⩾ 3) were fatigue (79%; 4%) and sensory neuropathy (63%; 4%). Best responses achieved were partial response (28%) and stable disease (54%). Median OS and PFS were 7.8 and 4.2 months, respectively (median follow-up: 7.8 months). OS (p = 0.08) and PFS (p = 0.81) were not significantly improved compared to the matched cohort. Paclitaxel concentrations were significantly increased with regorafenib (D15) compared with paclitaxel only (D1; p < 0.05); no associations were observed with toxicity or efficacy. An increase in circulating galectin-1 compared to baseline was associated with shorter OS (p < 0.01). Enrichment of angiogenesis-related gene expression was observed in short survivors measured by RNA sequencing. Chromosome 19q13.12-q13.2 amplification was associated with shorter OS (p = 0.02) and PFS (p = 0.02). Conclusion: Treatment with regorafenib and paclitaxel is tolerable and shows promising efficacy in advanced EGC refractory to first-line treatment. Galectin-1 and chromosome 19q13.12-q13.2 amplification could serve as negative predictive biomarkers for treatment response. Registration: Clinicaltrials.gov, NCT02406170, https://clinicaltrials.gov/ct2/show/NCT02406170.

Application and accuracy of ultrasound-guided resections of tongue cancer.

OBJECTIVES: Surgical removal of squamous cell carcinoma of the tongue (SCCT) with tumour-free margin status (≥5 mm) is essential for loco-regional control. Inadequate margins (<5 mm) often indicate adjuvant treatment, which results in increased morbidity. Ultrasound (US)-guided SCCT resection may be a useful technique to achieve more adequate resection margins compared to conventional surgery. This study evaluates the application and accuracy of this technique. METHODS: Forty patients with SCCT were included in a consecutive US cohort. During surgery, the surgeon aimed for a 10-mm echographic resection margin, while the tumour border and resection plane were captured in one image. Ex-vivo US measurements of the resection specimen determined whether there was a need for an immediate re-resection. The margin status and the administration of adjuvant treatment were compared those of with a consecutive cohort of 96 tongue cancer patients who had undergone conventional surgery. A receiver operating characteristic analysis was done to assess the optimal margin of ex-vivo US measurements to detect histopathologically inadequate margins. RESULTS: In the US cohort, the frequency of free margin status was higher than in the conventional cohort (55% vs. 16%, p < 0.001), and the frequency of positive margins status (<1 mm) was lower (5% vs. 15%, respectively, p < 0.001). Adjuvant radiotherapy was halved (10% vs. 21%), and the need for re-resection was comparable (10% vs. 9%). A cut-off value of 8 mm for ex-vivo measurements prevented histopathologically inadequate margins in 76%. CONCLUSION: US-guided SCCT resections improve margin status and reduce the frequency of adjuvant radiotherapy.