Organ-preserving Approach Research Articles

What To Do With Suspected Nodal Regrowth on Magnetic Resonance Imaging During Follow-up in an Organ Preservation Approach for Rectal Cancer?

BACKGROUND: For nodal regrowth in patients with rectal cancer following watch-and-wait standardized protocols on diagnostic procedures and subsequent treatment are lacking. OBJECTIVE: Evaluate the diagnosis and treatment of suspected nodal regrowth following an organ preservation approach. SETTINGS: Patients were included from national and institutional watch-and-wait -databases. DESIGN: Thirty-five rectal cancer patients with suspected nodal regrowth on magnetic resonance imaging were retrospectively identified during watch-and-wait follow-up. PATIENTS: Twenty-seven of 35 patients followed watch-and-wait after neoadjuvant (chemo)radiotherapy and 8/35 followed watch-and-wait schedule after local excision for early rectal cancer. MAIN OUTCOME MEASURES: Diagnostic procedures, treatment and histopathological outcome. RESULTS: Median follow-up was 34 months. Median time from end of (chemo)radiotherapy or local excision to first detection of suspected nodal regrowth on magnetic resonance imaging following watch-and-wait was 9 and 10 months. After first detection, 17 of 35 patients underwent immediate treatment without further diagnostics, of whom 7 also had luminal regrowth. In 18 of 35 patients, additional diagnostic procedures were performed. In 4 of 18 patients, positron emission tomography-computed tomography or endorectal ultrasound-guided biopsy was performed and treatment was initiated based on increased nodal regrowth suspicion. In 14 of 18 patients, MRI was repeated after 8-12 weeks: growth of suspected lymph nodes was the most decisive factor to proceed to treatment. In 8 patients, repeated magnetic resonance imaging was combined with positron emission tomography-computed tomography and/or endorectal ultrasound-guided biopsy: in half of them it contributed to treatment initiation. In total, 34/35 patients were treated: 9 received (re-)irradiation and 33 underwent total mesorectal excision. In 27 of 33 patients, nodal regrowth was pathologically confirmed in the total mesorectal excision-resection specimen; 5 of 6 patients without nodal involvement had pathologically confirmed luminal regrowth. LIMITATIONS: Highly selected study population. CONCLUSIONS: During watch-and-wait follow-up of patients with rectal cancer in an organ preservation strategy, magnetic resonance imaging plays an important role in diagnosis of nodal regrowth. Repeated magnetic resonance imaging after an interval can be helpful in making treatment decisions, and the role of positron emission tomography-computed tomography and endorectal ultrasound-guided biopsy appears limited. See Video Abstract.

A Review of Neoadjuvant Therapy and the Watch-and-Wait Protocol in Rectal Cancer: Current Evidence and Future Directions.

The treatment of rectal cancer underwent a significant change with the introduction of total mesorectal excision (TME), which substantially improved recurrence rates. However, TME is associated with complications such as fecal incontinence and poor bladder control, especially in tumors located near the anal verge. The watch-and-wait (WW) protocol has emerged as an alternative for patients achieving a clinical complete response (cCR) following neoadjuvant radiochemotherapy. This narrative review, developed according to the Scale for the Assessment of Narrative Review Articles guidelines, evaluates neoadjuvant treatments and the WW protocol for rectal cancer. Literature was sourced from the PubMed database using specific search terms related to neoadjuvant therapy and the WW protocol, resulting in 63 articles selected for discussion. Neoadjuvant treatment, including chemoradiation and short-course radiotherapy, is indicated for T3 and T4 rectal adenocarcinomas. Studies like the German Rectal Cancer Study Group and the PRODIGE 23 trial have shown the benefits of preoperative treatment, including improved disease-free survival and reduced local recurrence rates. However, challenges in adopting the WW protocol include the risk of local regrowth and distant metastasis. Immune checkpoint inhibitors have shown promise in mismatch repair-deficient patients, yet the data are insufficient to fully endorse WW for these cases. The WW protocol is viable for selected rectal cancer patients, with ongoing debates regarding criteria for inclusion. Key challenges include accurately identifying cCR and managing patients with near-complete responses. MRI and endoscopic evaluation are crucial for assessing treatment response, although achieving a pathological complete response remains uncertain. The WW strategy offers a potential organ-preserving approach in rectal cancer management but requires careful patient selection and comprehensive risk-benefit discussions. Further research is needed to refine criteria for inclusion and optimize treatment protocols, enhancing outcomes while minimizing invasive interventions.

Is precision medicine the solution to improve organ preservation in laryngeal/hypopharyngeal cancer? A position paper by the Preserve Research Group.

In locally advanced (LA) laryngeal/hypopharyngeal squamous cell carcinoma (LHSCC), larynx preservation (LP) strategies aim at the cure of the disease while preserving a functional larynx, thus avoiding total laryngectomy and the associated impact on the quality of life. In the last decades, apart from transoral and open-neck organ preservation approaches, several non-surgical regimens have been investigated: radiotherapy alone, alternate, concurrent or sequential chemoradiation, and bioradiotherapy. Despite major progress, the identification of reliable and effective predictors for treatment response remains a clinical challenge. This review examines the current state of LP in LA-LHSCC and the need for predictive factors, highlighting the importance of the PRESERVE trial in addressing this gap. The PRESERVE trial represents a pivotal initiative aimed at finding the optimal therapy for laryngeal preservation specific to each patient through a retrospective analysis of data from previous LP trials and prospectively validating findings. The goal of the PRESERVE trial is to develop a comprehensive predictive classifier that integrates clinical, molecular, and multi-omics data, thereby enhancing the precision and efficacy of patient selection for LP protocols.

The conundrum of total neoadjuvant therapy in rectal cancer.

Total neoadjuvant therapy (TNT) has fast become the paradigm in the management of rectal cancer. The widespread adoption of this approach across the world, not only for locally advanced cancers but even for cancers that otherwise would not merit chemotherapy, leads both to an increase in treatment-related toxicity for patients and burdens the healthcare services of the country. It is important to tailor treatment to each patient based not only on the tumour but, even more importantly, on the patient's expectations and goals. The intent of treatment while prescribing TNT needs to be clear, understanding that not all patients are suitable for an organ preservation (watch and wait) approach and that the survival benefits of TNT are not as obvious as most proponents believe.

Indian clinical practice consensus guidelines for the management of laryngeal cancer: Update 2022

In laryngeal cancer, the goal of treatment is to achieve maximum cure and preserve function of the larynx with good voice quality. In early disease, transoral laser microsurgery is the preferred choice of treatment. An option for treatment of carcinoma in situ is radiotherapy (RT). In locally advanced laryngeal carcinoma, concurrent chemoradiotherapy (CTRT) is an option. Induction therapy with docetaxel, cisplatin, and 5-flourouracil (TPF), followed by definitive RT or definitive CTRT can be one of the organ preservation approaches for patients undergoing total laryngectomy. For resectable locally advanced disease (T3, N0-3), surgery (laryngectomy with thyroidectomy, ipsilateral or bilateral neck dissection, and pretracheal and ipsilateral paratracheal lymph node dissection) with RT or CTRT should be considered.

Preoperative Intensified Chemoradiation with Intensity-Modulated Radiotherapy and Simultaneous Integrated Boost Combined with Capecitabine in Locally Advanced Rectal Cancer: Long-Term Outcomes of a Real-Life Multicenter Study

Background: Despite the feasibility and promising activity data on intensity-modulated RT and simultaneous integrated boost (IMRT-SIB) dose escalation in preoperative chemoradiation (CRT) for locally advanced rectal cancer (LARC), few data are currently available on long-term outcomes. Patients and Methods: A cohort of 288 LARC patients with cT3-T4, cN0-2, cM0 treated with IMRT-SIB and capecitabine from March 2013 to December 2019, followed by a total mesorectal excision (TME) or an organ-preserving strategy, was collected from a prospective database of 10 Italian institutions. A dose of 45 Gy in 25 fractions was prescribed to the tumor and elective nodes, while the SIB dose was prescribed according to the clinical practice of each institution on the gross tumor volume (GTV). Concurrent capecitabine was administered at a dose of 825 mg/m2 twice daily, 7 days a week. The primary objective of the study was to evaluate long-term outcomes in terms of local control (LC), progression-free survival (PFS) and overall survival (OS). The secondary objective was to confirm the previously reported feasibility, safety and efficacy (pCR, TRG1-2 and downstaging rates) of the treatment in a larger patient population. Results: All patients received a dose of 45 Gy to the tumor and elective nodes, while the SIB dose ranged from 52.5 Gy to 57.5 Gy (median 55 Gy). Acute gastrointestinal and hematologic toxicity rates of grade 3–4 were 5.7% and 1.8%, respectively. At preoperative restaging, 36 patients (12.5%) with complete or major clinical responses (cCR or mCR) were offered an organ-preserving approach with local excision (29 patients) or a watch and wait strategy (7 patients). The complete pathologic response rate (pCR) in radically operated patients was 25.8%. In addition, 4 TME patients had pT0N1 and 19 LE patients had pT0Nx, corresponding to an overall pT0 rate of 31.3%. Of the 36 patients selected for organ preservation, 7 (19.5%) required the completion of TME due to unfavorable pathologic features after LE or tumor regrowth during W-W resulting in long-term rectal preservation in 29 of 288 (10.1%) of the total patient population. Major postoperative complications occurred in 14.2% of all operated patients. At a median follow-up of 50 months, the 5-year PFS and OS rates were 72.3% (95% CI: 66.3–77.4) and 85.9% (95% CI: 80.2–90.1), respectively. The 5-year local recurrence (LR) rate was 9.2% (95% CI: 6.0–13.2), while the distant metastasis (DM) rate was 21.3% (95% CI: 16.5–26.5). The DM rate was 24.5% in the high-risk subset compared to 16.2% in the low-intermediate risk group (p = 0.062) with similar LR rates (10% and 8%, respectively). On multivariable analysis, cT4 and TRG3–5 were significantly associated with worse PFS, OS and metastasis-free survival. Conclusions: Preoperative IMRT-SIB with the moderate dose intensification of 52.5–57.5 Gy (median 55 Gy) and the full dose of concurrent capecitabine confirmed to be feasible and effective in our real-life clinical practice. Organ preservation was shown to be feasible in carefully selected, responsive patients. The favorable long-term survival rates highlight the efficacy of this intensified treatment program. The incorporation of IMRT-SIB with a more effective systemic therapy component in high-risk patients could represent a new area of investigational interest.

Neoadjuvant BRAF Targeted Therapy for Ameloblastoma of the Mandible: an Organ Preservation Approach.

Ameloblastoma is a rare odontogenic neoplasm frequently located in the mandible. Standard treatment involves radical bone resection and immediate reconstruction, causing functional, aesthetic, and psychological impairments. The BRAF V600E mutation is present in about 80% of mandible ameloblastomas, and BRAF inhibitors have demonstrated sustained responses in unresectable cases. We identified ameloblastoma patients planned for ablative surgery and screened them for BRAF V600E mutation. Neoadjuvant BRAF inhibitors were offered to facilitate jaw preservation surgery. Retrospective data collection encompassed treatment regimens, tolerability, tumor response, and conversion to mandible preservation surgery. Between 2017 and 2022, eleven patients received Dabrafenib (n = 6)/Dabrafenib+Trametinib (n = 5). The median age was 19 years (10-83). Median treatment duration was 10 months (3-20). All patients achieved a radiological response (RR = 100%). Ten patients (91%) successfully converted to mandible preservation surgery with residual tumor enucleation. One patient attained complete radiological response, and surgery was not performed. Among the ten surgically treated patients, all exhibited a pathological response, with four achieving near complete response and six partial response. At a median follow-up of fourteen months (7-37) after surgery, one case of recurrence was observed. Grade 1-2 adverse events were reported in eight patients (73%), with a single case of grade 3 (hepatitis). Dose modification was necessary for three patients, and four experienced treatment interruptions, while one patient permanently discontinued therapy. Neoadjuvant BRAF inhibition may offer a safe and effective strategy for organ preservation in mandible ameloblastoma treatment.

T4 larinks kanseri için tedavi seçimi: kemoradyoterapi ile organ koruyucu yaklaşım mümkün mü yoksa multimodalite tedavi daha mı etkili?

Aims: Organ-preserving approach is recommended as an evidence-based treatment option for advanced laryngeal cancer (LC) with similar survival results. However, the organ-preserving approach in T4 disease is controversial, and surgical treatment is primarily preferred. Today, chemoradiotherapy (CRT) is applied to T4 LC patients who are inoperable for medical or surgical reasons and upon the request of the patient who refuses the recommended surgical treatment. The aim of this study was to evaluate the treatment outcomes in patients with T4 LC who underwent CRT for these conditions and received adjuvant radiotherapy (RT)/CRT as the standard treatment regimen after surgery.
 Methods: A retrospective review of T4 LC patients treated with CRT (17 patients) and adjuvant RT/CRT (26 patients) between 2015 and 2021 was conducted. Overall survival (OS), local regional recurrence-free survival (LRRFS), and disease-free survival (DFS) were compared between the groups. The organ preservation rate was determined for the CRT group.
 Results: The median follow-up time for the entire cohort was 41 months, the 5-y OS, LRRFS, and DFS were 55.9%, 51.4%, and 51.9%, respectively. Statistically significant difference was found between the treatment groups in terms of 5-y OS, LRRFS, and DFS rates, and survival was found to be decreased in the CRT group (35.3% vs. 70.2%, p=0.007; 22.1% vs. 75.1%, p= 0.001; 22.1% vs. 75.7%, p=0.001). With respect to other clinicopathological factors, age was the only significant factor in on OS in multivariate analysis, whereas tumor size, nodal stage, and ECE (in the postoperative RT group, except LRRFS) were linked with OS, LRRFS, and DFS rates. Among the patients who underwent CRT, OS was found to be better in the group applied due to the patient’s request compared to the patients referred for RT due to medical or surgical inoperability, and in multivariate analysis, the indication for RT remained an independent predictor of OS. In addition, the 3-y organ preservation rate was 81.5% in the CRT group.
 Conclusion: The surgical arm had statistically significantly superior results in terms of OS, LRRFS, DFS compared to the CRT group. However, it is also noteworthy that OS was better in cases where RT is applied at the patient’s request without inoperable disease. In addition, laryngeal protection was observed to a large extent in the CRT arm.

Induction chemotherapy-based organ-preservation protocol improve the function preservation compared with immediate total laryngectomy for locally advanced hypopharyngeal cancer-Results of a matched-pair analysis.

We performed a paired analysis to compare the therapeutic effect between the induction chemotherapy-based organ-preservation approach and immediate total laryngectomy in hypopharyngeal squamous cell carcinoma patients requiring total laryngectomy. 351 patients who were treated with organ-preservation approach were compared with 110 patients who were treated with total laryngectomy. The main measures and outcomes were progression-free survival (PFS), overall survival (OS), and larynx function preservation survival (LFPS). No statistical difference was observed for 3-, 5-, and 10-year PFS and OS in two groups. In the organ-preservation group, the 3-, 5-, and 10-year LFPS was 30.7%, 23.3%, and 16.6%, respectively. The LFPS of Stage III > Stage IV, N0 > N1 > N2 > N3, T2 > T3 > T4, CR > PR > SD > PD patients (all p values <0.05). Survival outcomes did not significantly differ between the two groups. The organ-preservation approach allowed more than 70% of the survivors to retain their larynx function.

Restaging MRI of Rectal Adenocarcinoma after Neoadjuvant Chemoradiotherapy: Imaging Findings and Potential Pitfalls

Rectal adenocarcinoma constitutes about one-third of all colorectal adenocarcinoma cases. Rectal MRI has become mandatory for evaluation of patients newly diagnosed with rectal cancer because it can help accurately stage the disease, impact the choice to give neoadjuvant therapy or proceed with up-front surgery, and even direct surgical dissection planes. Better understanding of neoadjuvant chemoradiotherapy effects on rectal tumors and recognition that up to 30% of patients can have a pathologic complete response have opened the door for the nonsurgical "watch-and-wait" management approach for rectal adenocarcinoma. Candidates for this organ-preserving approach should have no evidence of malignancy on all three components of response assessment after neoadjuvant therapy (ie, digital rectal examination, endoscopy, and rectal MRI). Hence, rectal MRI again has a major role in directing patient management and possibly sparing patients from unnecessary surgical morbidity. In this article, the authors discuss the indications for neoadjuvant therapy in management of patients with rectal adenocarcinoma, describe expected imaging appearances of rectal adenocarcinoma after completion of neoadjuvant therapy, and outline the MRI tumor regression grading system. Since pelvic sidewall lymph node dissection is associated with a high risk of permanent genitourinary dysfunction, it is performed for only selected patients who have radiologic evidence of sidewall lymph node involvement. Therefore, the authors review the relevant lymphatic compartments of the pelvis and describe lymph node criteria for determining locoregional nodal spread. Finally, the authors discuss limitations of rectal MRI, describe several potential interpretation pitfalls after neoadjuvant therapy, and emphasize how these pitfalls may be avoided. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Evaluation of Endoscopic Response Using Deep Neural Network in Esophageal Cancer Patients Who Received Neoadjuvant Chemotherapy.

We previously reported that endoscopic response evaluation can preoperatively predict the prognosis and distribution of residual tumors after neoadjuvant chemotherapy (NAC). In this study, we developed artificial intelligence (AI)-guided endoscopic response evaluation using a deep neural network to discriminate endoscopic responders (ERs) in patients with esophageal squamous cell carcinoma (ESCC) after NAC. Surgically resectable ESCC patients who underwent esophagectomy following NAC were retrospectively analyzed in this study. Endoscopic images of the tumors were analyzed using a deep neural network. The model was validated with a test data set using 10 newly collected ERs and 10 newly collected non-ER images. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the endoscopic response evaluation by AI and endoscopists were calculated and compared. Of 193 patients, 40 (21%) were diagnosed as ERs. The median sensitivity, specificity, PPV, and NPV values for ER detection in 10 models were 60%, 100%, 100%, and 71%, respectively. Similarly, the median values by the endoscopist were 80%, 80%, 81%, and 81%, respectively. This proof-of-concept study using a deep learning algorithm demonstrated that the constructed AI-guided endoscopic response evaluation after NAC could identify ER with high specificity and PPV. It would appropriately guide an individualized treatment strategy that includes an organ preservation approach in ESCC patients.

Downstaging of Rectal Cancer Following Neoadjuvant Chemoradiotherapy; How Far Could Functional MRI Support Organ Preservation Approach

Downstaging of Rectal Cancer Following Neoadjuvant Chemoradiotherapy; How Far Could Functional MRI Support Organ Preservation Approach

Quality-of-life outcomes in older patients with early-stage rectal cancer receiving organ-preserving treatment with hypofractionated short-course radiotherapy followed by transanal endoscopic microsurgery (TREC): non-randomised registry of patients unsuitable for total mesorectal excision

Older patients with early-stage rectal cancer are under-represented in clinical trials and, therefore, little high-quality data are available to guide treatment in this patient population. The TREC trial was a randomised, open-label feasibility study conducted at 21 centres across the UK that compared organ preservation through short-course radiotherapy (SCRT; 25 Gy in five fractions) plus transanal endoscopic microsurgery (TEM) with standard total mesorectal excision in adults with stage T1-2 rectal adenocarcinoma (maximum diameter ≤30 mm) and no lymph node involvement or metastasis. TREC incorporated a non-randomised registry offering organ preservation to patients who were considered unsuitable for total mesorectal excision by the local colorectal cancer multidisciplinary team. Organ preservation was achieved in 56 (92%) of 61 non-randomised registry patients with local recurrence-free survival of 91% (95% CI 84-99) at 3 years. Here, we report acute and long-term patient-reported outcomes from this non-randomised registry group. Patients considered by the local colorectal cancer multidisciplinary team to be at high risk of complications from total mesorectal excision on the basis of frailty, comorbidities, and older age were included in a non-randomised registry to receive organ-preserving treatment. These patients were invited to complete questionnaires on patient-reported outcomes (the European Organisation for Research and Treatment of Cancer Quality of Life [EORTC-QLQ] questionnaire core module [QLQ-C30] and colorectal cancer module [QLQ-CR29], the Colorectal Functional Outcome [COREFO] questionnaire, and EuroQol-5 Dimensions-3 Level [EQ-5D-3L]) at baseline and at months 3, 6, 12, 24, and 36 postoperatively. To aid interpretation, data from patients in the non-randomised registry were compared with data from those patients in the TREC trial who had been randomly assigned to organ-preserving therapy, and an additional reference cohort of aged-matched controls from the UK general population. This study is registered with the ISRCTN registry, ISRCTN14422743, and is closed. Between July 21, 2011, and July 15, 2015, 88 patients were enrolled onto the TREC study to undergo organ preservation, of whom 27 (31%) were randomly allocated to organ-preserving therapy and 61 (69%) were added to the non-randomised registry for organ-preserving therapy. Non-randomised patients were older than randomised patients (median age 74 years [IQR 67-80] vs 65 years [61-71]). Organ-preserving treatment was well tolerated among patients in the non-randomised registry, with mild worsening of fatigue; quality of life; physical, social, and role functioning; and bowel function 3 months postoperatively compared with baseline values. By 6-12 months, most scores had returned to baseline values, and were indistinguishable from data from the reference cohort. Only mild symptoms of faecal incontinence and urgency, equivalent to less than one episode per week, persisted at 36 months among patients in both groups. The SCRT and TEM organ-preservation approach was well tolerated in older and frailer patients, showed good rates of organ preservation, and was associated with low rates of acute and long-term toxicity, with minimal effects on quality of life and functional status. Our findings support the adoption of this approach for patients considered to be at high risk from radical surgery. Cancer Research UK.

A nationwide validation of the prognostic impact of pathological response and the distribution of recurrence patterns in responders after neoadjuvant chemotherapy for esophageal squamous cell carcinoma.

We previously reported that postoperative recurrence in responders occurred in the regional field mostly as a solitary lesion without distant failure. However, further validation is necessary due to the low percentage of pathological responders, especially those with pCR. This study aimed to validate the prognostic impact of pathological response and the distribution of residual tumors in pathological responders using a nationwide database from 85 Japanese esophageal centers. We retrospectively reviewed patients with esophageal squamous cell carcinoma (ESCC) who underwent subtotal esophagectomy at 85 authorized institutes for esophageal cancer between 2010 and 2015. The recurrence free survival (RFS), overall survival (OS), and recurrent tumor patterns were compared among the pathological responses. Of 4781 patients initially enrolled, 3840 were selected for subsequent analysis, including 237 patients with pathological complete response (pCR, 6%). The RFS and OS were significantly correlated with pathological response. When the recurrence pattern was classified into regional or distant recurrence, the incidence of distant failure was significantly lower in patients with pCR in cT1/2. Three percent of all patients with pCR in cT1/2 encountered postoperative recurrence in distant organs. The prognostic impact of pathological response was reproduced in the nationwide data. pCR in ESCC patients with cT1/2 provides a favorable prognosis with less incidence of distant failure. This finding may contribute to selecting appropriate candidates for an organ preservation approach based on the response to induction therapy.

Step-by-Step Guide to Surface Mold Applicator-Based Brachytherapy in a Case of Early Carcinoma Penis: An Organ-Preserving Approach

Purpose In this report we discuss an individually customized surface mold applicator technique to treat a case of early carcinoma penis. This case report is one of its kind which describes the brachytherapy treatment planning based on orthogonal X-ray technique. Material and methods T1N0 disease with squamous cell carcinoma histology involving the foreskin of penis and abutting the glans penis was treated by surface mold applicator technique. Impression of the organ was taken using alginate. Cast was prepared from the impression using Type 4 gypsum. The acrylic mold-based applicator was fabricated on the cast. The catheters were positioned and fixed on the acrylic mold. The organ is placed in the mold-based applicator and the catheters are reconstructed on two-dimensional imaging. The brachytherapy is delivered by the 18-channel high-dose rate Oncentra brachytherapy using Ir192 source. The dose given was 45 Gy in 15 fractions, twice daily more than 6 hours apart. Results Patient was reviewed after 6 weeks for follow-up and there was complete regression of the ulcer. At present, patient is on follow-up for the last 10 months and is now disease-free. Conclusion With judicious patient selection, surface mold brachytherapy is an attractive alternative to the interstitial brachytherapy. It is comfortable for the patient, is easily repeatable, and is time saving in high work load and limited resource settings. Early results with this technique are promising.

Tissue Engineering & New TechnologiesP-36722453-225Sialoendoscopy in oral and maxillofacial surgery

<h3>Objectives</h3> The inflammatory pathology of the salivary glands constitutes one of the most frequent pathologies in maxillofacial diseases. In most cases it has an obstructive origin due to the presence of lithiasis in the path of the excretory duct. Other cases are not due to lithiasis inflammatory disease (recurrent sialadenitis). The emergence and development of sialoendoscopy allows the minimally invasive treatment of these patients with promising results, reducing morbidity, lowering health costs and accelerating the recovery of patients with this pathology. We present our experience in the implementation of this technique in an oral and maxillofacial surgery department. <h3>Results</h3> We present 31 cases of inflammatory glandular disease from September 2018 to September 2021, 25 cases of lithiasis origin, treated by endoscopic lithectomy and 6 cases of chronic non lithiasis sialadenitis treated by means of washes with serum and dilators. In 23 of the 25 cases of lithiasis origin, the lithectomy was achieved with no complications. The cases of failure of the procedure were a lithiasis of 10mm of diameter. The range value of lithiasis diameter was from 3.4 to 8.7mm, and the mean value was 6.3mm. In the cases of non-lithiasis origin the procedure allowed an improvement of its symptomatology. The complications were temporal glandular swelling in 23 cases and post surgical ductal stenosis in 1 case. <h3>Conclusion</h3> Sialoendoscopy can be served as an organ-preserving approach for diagnosis and treatment of inflammatory (obstructive and not obstructive) salivary diseases.

Abstract 2549: Immune microenvironment landscape shows treatment-specific differences in rectal cancer patients

Abstract Introduction: Neoadjuvant therapy is the backbone of modern rectal cancer treatment. More intensive therapy leads to higher complete responses, which means an organ-preservation approach can be used. Insights in the biology of tumor response are essential for a successful implementation of such strategies, as different treatments may lead to specific tumor responses. In this study we aim to explore treatment-specific responses of tumor microenvironment and how these are related to patient outcome. Methods: Patients with adenocarcinoma of the rectum who had received one of five different treatment regimens between 2015-2019 were included; no neo-adjuvant therapy (NT), neo-adjuvant chemotherapy (CT), neo-adjuvant radiochemotherapy (RCT), neo-adjuvant radiotherapy with a long interval (LRT) or short interval (SRT). In order to minimize heterogeneity we excluded cT1 tumors, cT4 tumors as well as stage IV rectal cancers. Consecutive slides were stained for HE, LC3-II (autophagy stain) and a multiplex immunofluorescence VECTRA panel for CD8, CD3, CD20, Foxp3, CD11c and pan-CK AE 1/3. Tumor response was scored by two independent investigators. Results: A total of 80 rectal cancer patients were included. Median age was slightly biased, with older patients in the SRT groups and younger patients in the CT group (p=0.03). Less regression and more lymph-node involvement was seen among the CT group, while higher angioinvasion and lymph node involvement was seen in the SRT group. A fragmented pattern of response was more prevalent in CT and RCT treated patients (&amp;gt;73% of cases), whereas a shrinkage pattern of response was predominant in RTL treated patients (64% of cases). Furthermore, autophagic activity in tumor cells was increased in RCT treated patients, especially compared to NT and CT. When analyzing the tumor immunophenotype, differences were found according to specific treatment regimens. RCT treated patients seemed to have lower stromal CD4+ cells, Foxp3+ cells and CD11c+ cells. The latter were found to be especially decreased in treatments will longer intervals (CT, RCT, LTR) compared to those with no treatment or immediate surgery (NT and SRT). The specific relations within the network of immune cells and how these relate to autophagy and the patterns of response are currently being evaluated. Thus, further results will follow shortly. Conclusions: We demonstrated treatment-specific differences in the immune microenvironment landscape of rectal cancer patients. We found higher autophagic activity in patients who received RT treatment, especially significant in the RCT group. Lower immune cell density was observed in longer wait intervals, stressing the importance of immune recovery. Understanding the immune landscape after a specific therapy will shed light on to future treatment decisions, as using immunotherapy in combination with established treatments is the future of personalized therapy. Citation Format: Cristina Graham Martinez, Yari F. H. C. Barella, Sonay Kus Öztürk, Mark A. Gorris, Corrie A. Marijnen, Iris D. Nagtegaal. Immune microenvironment landscape shows treatment-specific differences in rectal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2549.

Neoadjuvant and adjuvant therapy for local excision of rectal cancer

Local excision (LE) for early-stage rectal cancer is an attractive option compared to total mesorectal excision (TME), as it avoids many of the significant comorbidities and adverse functional outcomes associated with TME. However, LE for tumors with high-risk histopathologic features can lead to unacceptably high rates of local and distant recurrence. Neoadjuvant or adjuvant chemoradiotherapy can mitigate those risks in certain clinical settings and may expand the number of patients who can be safely treated with an organ-preserving approach. In this chapter, we will explore the available date supporting the use of neoadjuvant and adjuvant chemoradiation (CRT) for the treatment of high-risk early-stage rectal cancer and will discuss future studies that aim to answer some of the ongoing clinical questions related to this practice.

The robotic-assisted extended "Sistrunk" approach for tumors of the upper aerodigestive tract with limited transoral access: First description of oncological and functional outcomes.

We report on the first clinical experience with the robotic‐assisted extended “Sistrunk” approach (RESA) for access to constrained spaces of the upper aerodigestive tract. This prospective case cohort study include six patients that underwent RESA if transoral exposure could not be achieved. Three patients received previous radiation. Patients were postoperatively followed until week 16 for perioperative complications, surgical margins, and functional outcomes. In all patients RESA allowed adequate exposure and resection with negative margins. Three patients who underwent salvage surgery experienced a minor or intermediate grade postoperative bleeding. No patient developed a pharyngocutaneous fistula. Three patients recovered their swallowing to their preoperative status and the remaining three experienced an improvement. All patients experienced complete recovery of their voice. RESA has the potential to provide a new organ preservation approach for head and neck cancer (HNC) not amenable to transoral exposure and thus warrants further prospective clinical studies.

Image-guided high-dose-rate brachytherapy for rectal cancer: technical note and first clinical experience on an organ-preserving approach

PurposeAs the population ages, the incidence of rectal cancer among elderly patients is rising. Due to the risk of perioperative morbidity and mortality, alternative nonoperative treatment options have been explored in elderly and frail patients who are clinically inoperable or refuse surgery.MethodsHere we present technical considerations and first clinical experience after treating a cohort of six rectal cancer patients (T1‑3, N0‑1, M0; UICC stage I-IIIB) with definitive external-beam radiation therapy (EBRT) followed by image-guided, endorectal high-dose-rate brachytherapy (HDR-BT). Patients were treated with 10–13 × 3 Gy EBRT followed by HDR-BT delivering 12–18 Gy in two or three fractions. Tumor response was evaluated using endoscopy and magnetic resonance imaging of the pelvis.ResultsMedian age was 84 years. All patients completed EBRT and HDR-BT without any high-grade toxicity (> grade 2). One patient experienced rectal bleeding (grade 2) after 10 weeks. Four patients (67%) demonstrated clinical complete response (cCR) or near cCR, there was one partial response, and one residual tumor and hepatic metastasis 8 weeks after HDR-BT. The median follow-up time for all six patients is 42 weeks (range 8–60 weeks). Sustained cCR without evidence of local regrowth has been achieved in all four patients with initial (n)cCR to date.ConclusionPrimary EBRT combined with HDR-BT is feasible and well tolerated with promising response rates in elderly and frail rectal cancer patients. The concept could be an integral part of a highly individualized and selective nonoperative treatment offered to patients who are not suitable for or refuse surgery.