Dosimetric parameters predict radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma patients: A systematic review and meta-analysis.

This systematic review examines the role of dosimetric parameters in predicting temporal lobe necrosis (TLN) risk in nasopharyngeal carcinoma (NPC) patients treated with three-dimensional conformal RT (3D-CRT), intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). TLN is a serious late complication that can adversely affect the quality of life of NPC patients. Understanding the relationship between dosimetric parameters and TLN can guide treatment planning and minimize radiation-related complications. A comprehensive search identified relevant studies published up to July 2023. Studies reporting on dosimetric parameters and TLN in NPC patients undergoing 3D-CRT, IMRT, and VMAT were included. TLN incidence, follow-up duration, and correlation with dosimetric parameters of the temporal lobe were analyzed. The review included 30 studies with median follow-up durations ranging from 28 to 110 months. The crude incidence of TLN varied from 2.3 % to 47.3 % and the average crude incidence of TLN is approximately 14 %. Dmax and D1cc emerged as potential predictors of TLN in 3D-CRT and IMRT-treated NPC patients. Threshold values of >72 Gy for Dmax and >62 Gy for D1cc were associated with increased TLN risk. However, other factors should also be considered, including host characteristics, tumor-specific features and therapeutic factors. In conclusion, this systematic review highlights the significance of dosimetric parameters, particularly Dmax and D1cc, in predicting TLN risk in NPC patients undergoing 3D-CRT, IMRT, and VMAT. The findings provide valuable insights that can help in developing optimal treatment planning strategies and contribute to the development of clinical guidelines in this field.

Upfront neck dissection for treatment selection and improvement in quality of life as a novel treatment paradigm for deintensification in HPV+ OPSCC.

PURPOSE: Locoregionally advanced HPV+ oropharyngeal squamous cell carcinoma (OPSCC) has excellent cure rates, although current treatment regimens are accompanied by acute and long-term toxicities. We designed a phase II de-escalation trial for patients with HPV+OPSCC to evaluate the feasibility of an upfront neck dissection to individualize definitive treatment selection to improve quality of life without compromising survival. METHODS: Patients with T1-3, N0-2 HPV+ OPSCC underwent an upfront neck dissection with primary tumor biopsy. Patients with a single lymph node less than six centimeters, with no extracapsular spread(ECS), and no primary site adverse features underwent transoral surgery (Arm A). Patients who had two or more positive lymph nodes with no ECS, or those with primary site adverse features were treated with radiation alone (Arm B). Patients who had ECS in any lymph node were treated with chemoradiation (Arm C). The primary endpoint was quality of life at 1 year compared to a matched historical control. RESULTS: Thirty-four patients were enrolled and underwent selective neck dissection. Based on pathologic characteristics, 14 patients were assigned to arm A, 10 patients to arm B, and 9 to arm C. A significant improvement was observed in HNQOL compared to historical controls (-2.6 vs -11.9, p=0.034). With a median follow-up of 37 months, the 3-year overall survival was 100% and estimated 3-year estimated progression free survival was 96% (95% CI: 76-99%). CONCLUSION: A neck dissection driven treatment paradigm warrants further research as a de-intensification strategy.

Neurological complications of modern radiotherapy for head and neck cancer.

Radiotherapy is one of the mainstay treatment modalities for the management of non-metastatic head and neck cancer (HNC). Notable improvements in treatment outcomes have been observed in the recent decades. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and charged particle therapy, have significantly improved tumor target conformity and enabled better preservation of normal structures. However, because of the intricate anatomy of the head and neck region, multiple critical neurological structures such as the brain, brainstem, spinal cord, cranial nerves, nerve plexuses, autonomic pathways, brain vasculature, and neurosensory organs, are variably irradiated during treatment, particularly when tumor targets are in close proximity. Consequently, a diverse spectrum of late neurological sequelae may manifest in HNC survivors. These neurological complications commonly result in irreversible symptoms, impair patients' quality of life, and contribute to a substantial proportion of non-cancer deaths. Although the relationship between radiation dose and toxicity has not been fully elucidated for all complications, appropriate application of dosimetric constraints during radiotherapy planning may reduce their incidence. Vigilant surveillance during the course of survivorship also enables early detection and intervention. This article endeavors to provide a comprehensive review of the various neurological complications of modern radiotherapy for HNC, summarize the current incidence data, discuss methods to minimize their risks during radiotherapy planning, and highlight potential strategies for managing these debilitating toxicities.

Update on olfactory neuroblastoma.

Olfactory neuroblastomas are uncommon malignancies that arise from olfactory receptor cells located high in the nasal cavity. Accurate diagnosis plays a crucial role in determining clinical results and guiding treatment decisions. Diagnosis can be a major challenge for pathologists, especially when dealing with tumours with poor differentiation. The discovery of several molecular and immunohistochemical markers would help to overcome classification difficulties. Due to the paucity of large-scale studies, standardisation of diagnosis, treatment and prediction of outcome remains a challenge. Surgical resection by endoscopic techniques with the addition of postoperative irradiation is the treatment of choice. In addition, it is advisable to consider elective neck irradiation to minimise the risk of nodal recurrence. Molecular characterisation will help not only to make more accurate diagnoses but also to identify specific molecular targets that can be used to develop personalised treatment options tailored to each patient. The present review aims to summarise the current state of knowledge on histopathological diagnosis, the molecular biology and management of this disease.

A Meta-analysis of Surgical Outcomes of T4a and Infranotch T4b Oral Cancers.

OBJECTIVE: To determine the overall surgical outcomes of infranotch T4b oral cancers and compare them with T4a oral cancers. METHODS: PubMed, EMBASE and Cochrane databases from 2000 to 2022 were systematically searched. Clinical studies reporting at least one outcome following curative surgery and adjuvant therapy for comparison of patients with either infranotch T4b (IN-T4b) or T4a tumour. The heterogeneity of the included studies was determined using Tau-squared, Chi-squared, and the Higgins I2 test. The random effects model was used to determine the log odds ratio (logOR). RESULTS: The systematic review comprised 11,790 patients from 16 included studies. Seven studies were included in the meta-analysis (n = 11,381). For IN-T4b patients, the pooled 2 and 5 year overall survival (OS) were 59.3% and 53.2%, 2 and 5 year disease-free survival (DFS) 57.9% and 48.4%, 2 and 5 year disease-specific survival (DSS) 72% and 68%, and 2 and 5 year local control (LC), 47% and 56%, respectively. There was no statistically significant difference in 2 year OS [logOR = 0.28 (-0.47, 1.03), p = 0.46, confidence interval (CI) = 95%], 5 year OS [logOR = 0.7 (-0.4, 1.8), p = 0.54, CI = 95%], 2 year DFS [logOR = 0.22 (-0.35, 0.79), p = 0.45, CI = 95%], 5 year DFS [logOR = 0.17 (-0.42, 0.77), p = 0.57, CI = 95%], 2 year LC [logOR = 0.47 (-0.33, 1.26), p = 0.25, CI = 95%] and 5 year LC [logOR = 0.34 (-0.31, 0.99), p = 0.31, CI = 95%] between IN-T4b and T4a oral cancers. CONCLUSION: Results of this meta-analysis suggest that IN-T4b oral cancers have similar outcomes to T4a oral cancers, which supports down-staging IN-T4b cancers to T4a cancers.

Survival Outcomes in T3 Laryngeal Cancers: Primary Total Laryngectomy vs. Concurrent Chemoradiation or Radiation Therapy-A Meta-Analysis.

BACKGROUND: The management of cT3 laryngeal cancers remains controversial, with studies recommending surgical or non-surgical approaches. Despite the many papers that have been published on the subject, there is a lack of studies showing which treatment has better results in terms of survival. OBJECTIVE: To determine the difference in survival outcomes following total laryngectomy (TL), concurrent chemoradiation (CRT) or radiation therapy (RT) alone in T3 laryngeal cancers. METHODS: Search of PubMed, Scopus, and Google Scholar databases from 1995 to 2023 employing specific keywords and Boolean operators to retrieve relevant articles. Statistical analysis was conducted using a random-effects model, and heterogeneity was evaluated using the Q-test and I2 statistic. Funnel plot asymmetry was assessed using rank correlation and regression tests. RESULTS: The qualitative data synthesis comprised 10,940 patients from 16 included studies. TL was performed in 2149 (19.4%), CRT in 6723 (61.5%), RT in 295 (2.7%), while non-surgical treatment was not specified in 1773 (16.2%) patients. The pooled 2-year overall survival (OS) rates were TL = 73%, CRT = 74.7%, RT = 57.9%, 3-year OS rates were TL = 64.3%, CRT = 62.9%, RT = 52.4%, and 5-year OS rates were TL = 54.2%, CRT = 52.7%, RT = 40.8%. There was a significant heterogeneity in the included studies. There was no statistically significant difference in 2-year OS (logOR= -0.88 (95% confidence interval (CI): -1.99 to 0.23), p = 0.12), 3-year OS (logOR = -0.6 (95% CI: -1.34 to 0.15), p = 0.11), and 5-year OS (logOR = -0.54 (95% CI: -1.29 to 0.21), p = 0.16) between TL and CRT. Instead, there was significant difference in 2-year OS (logOR= -1.2383 (95% CI: -2.1679 to -0.3087), p = 0.009), 3-year OS (-1.1262 (95% CI: -1.6166 to -0.6358), p < 0.001), and 5-year OS (-0.99 (95% CI: -1.44 to -0.53)), p < 0.001) between TL and RT alone. CONCLUSIONS AND SIGNIFICANCE: TL followed with adjuvant (chemo)radiation on indication and CRT with salvage surgery in reserve appear to have similar OS outcomes. Both resulted in better OS outcomes compared to RT alone in the treatment of T3 laryngeal cancers. If patients are unfit for chemotherapy, making CRT impossible, surgery may become the choice of treatment.

Proton Beam Radiation Therapy for Oropharyngeal Squamous Cell Carcinoma.

Purpose: To discuss the role of proton beam therapy (PBT) in the treatment of patients with oropharyngeal squamous cell carcinoma (OPSCC). Materials and Methods: A review of the pertinent literature. Results: Proton beam therapy likely results in reduced acute and late toxicity as compared with intensity-modulated radiation therapy (IMRT). The extent of the reduced toxicity, which may be modest, depends on the endpoint and technical factors such as pencil beam versus passive scattered PBT and adaptive replanning. The disease control rates after PBT are likely similar to those after IMRT. Conclusion: Proton beam therapy is an attractive option to treat patients with OPSCC. Whether it becomes widely available depends on access.

Current management of xerostomia in head and neck cancer patients.

Radiotherapy (RT) continues to play a key role in the management of head and neck cancer (HNC). Xerostomia remains a principal detriment to the quality of life (QoL) for 80 % of surviving patients receiving head and neck radiation. Radiation-induced injury to the salivary glands is dose-dependent, and thus efforts have been focused on decreasing radiation to the salivary glands. Decreased saliva production reduces both short-term and long-term quality of life in head and neck survivors by impacting on taste and contributing to dysphagia. Several radioprotective agents to the salivary gland have been investigated. Although not widely practiced, surgical transfer of the submandibular gland prior to RT is the mainstay of surgical options in preventing xerostomia. This review focuses on the strategies to improve xerostomia following radiation therapy in head and neck cancers.

Management of Older Patients with Head and Neck Cancer: A Comprehensive Review.

The projected increase in life expectancy over the next few decades is expected to result in a rise in age-related diseases, including cancer. Head and neck cancer (HNC) is a worldwide health problem with high rates of morbidity and mortality. In this report, we have critically reviewed the literature reporting the management of older patients with HNC. Older adults are more prone to complications and toxicities secondary to HNC treatment, especially those patients who are frail or have comorbidities. Thus, this population should be screened prior to treatment for such predispositions to maximize medical management of comorbidities. Chronologic age itself is not a reason for choosing less intensive treatment for older HNC patients. Whenever possible, also older patients should be treated according to the best standard of care, as nonstandard approaches may result in increased treatment failure rates and mortality. The treatment plan is best established by a multidisciplinary tumor board with shared decision-making with patients and family. Treatment modifications should be considered for those patients who have severe comorbidities, evidence of frailty (low performance status), or low performance status or those who refuse the recommendations of the tumor board.

Tumor immune microenvironment alterations using induction cetuximab in a phase II trial of deintensified therapy for p16-positive oropharynx cancer.

BACKGROUND: We sought to characterize early changes in CD8+ tumor-infiltrating lymphocytes and tumor transcriptomes after induction cetuximab in a cohort with p16-positive oropharyngeal cancer on a phase II clinical de-escalation trial. METHODS: Tumor biopsies were obtained before and 1 week after a single cetuximab loading dose in eight patients enrolled in a phase II trial of cetuximab and radiotherapy. Changes in CD8+ tumor-infiltrating lymphocytes and transcriptomes were assessed. RESULTS: One week after cetuximab, five patients (62.5%) had an increase in CD8+ cell infiltration with a median (range) fold change of +5.8 (2.5-15.8). Three (37.5%) had unchanged CD8+ cells (median [range] fold change of -0.85 [0.8-1.1]). In two patients with evaluable RNA, cetuximab induced rapid tumor transcriptome changes in cellular type 1 interferon signaling and keratinization pathways. CONCLUSIONS: Within 1 week, cetuximab induced measurable changes in pro-cytotoxic T-cell signaling and immune content.

Development and Clinical Implementation of an Automated Virtual Integrative Planner for Radiation Therapy of Head and Neck Cancer.

Purpose: Head and neck (HN) radiation (RT) treatment planning is complex and resource intensive. Deviations and inconsistent plan quality significantly affect clinical outcomes. We sought to develop a novel automated virtual integrative (AVI) knowledge-based planning application to reduce planning time, increase consistency, and improve baseline quality. Methods and Materials: An in-house write-enabled script was developed from a library of 668 previously treated HN RT plans. Prospective hazard analysis was performed, and mitigation strategies were implemented before clinical release. The AVI-planner software was retrospectively validated in a cohort of 52 recent HN cases. A physician panel evaluated planning limitations during initial deployment, and feedback was enacted via software refinements. A final second set of plans was generated and evaluated. Kolmogorov-Smirnov test in addition to generalized evaluation metric and weighted experience score were used to compare normal tissue sparing between final AVI planner versus respective clinically treated and historically accepted plans. A t test was used to compare the interactive time, complexity, and monitor units for AVI planner versus manual optimization. Results: Initially, 86% of plans were acceptable to treat, with 10% minor and 4% major revisions or rejection recommended. Variability was noted in plan quality among HN subsites, with high initial quality for oropharynx and oral cavity plans. Plans needing revisions were comprised of sinonasal, nasopharynx, P-16 negative squamous cell carcinoma unknown primary, or cutaneous primary sites. Normal tissue sparing varied within subsites, but AVI planner significantly lowered mean larynx dose (median, 18.5 vs 19.7 Gy; P < .01) compared with clinical plans. AVI planner significantly reduced interactive optimization time (mean, 2 vs 85 minutes; P < .01). Conclusions: AVI planner reliably generated clinically acceptable RT plans for oral cavity, salivary, oropharynx, larynx, and hypopharynx cancers. Physician-driven iterative learning processes resulted in favorable evolution in HN RT plan quality with significant time savings and improved consistency using AVI planner.

Randomized Phase II Study of Physiologic MRI-Directed Adaptive Radiation Boost in Poor Prognosis Head and Neck Cancer.

PURPOSE: We conducted a randomized phase II multicenter clinical trial to test the hypothesis that physiologic MRI-based radiotherapy (RT) dose escalation would improve the outcome of patients with poor prognosis head and neck cancer. PATIENTS AND METHODS: MRI was acquired at baseline and at RT fraction 10 to create low blood volume/apparent diffusion coefficient maps for RT boost subvolume definition in gross tumor volume. Patients were randomized to receive 70 Gy (standard RT) or 80 Gy to the boost subvolume (RT boost) with concurrent weekly platinum. The primary endpoint was disease-free survival (DFS) with significance defined at a one-sided 0.1 level, and secondary endpoints included locoregional failure (LRF), overall survival (OS), comparison of adverse events and patient reported outcomes (PRO). RESULTS: Among 81 randomized patients, neither the primary endpoint of DFS (HR = 0.849, P = 0.31) nor OS (HR = 1.19, P = 0.66) was significantly improved in the RT boost arm. However, the incidence of LRF was significantly improved with the addition of the RT boost (HR = 0.43, P = 0.047). Two-year estimates [90% confidence interval (CI)] of the cumulative incidence of LRF were 40% (27%-53%) in the standard RT arm and 18% (10%-31%) in the RT boost arm. Two-year estimates (90% CI) for DFS were 48% (34%-60%) in the standard RT arm and 57% (43%-69%) in the RT boost arm. There were no significant differences in toxicity or longitudinal differences seen in EORTC QLQ30/HN35 subscales between treatment arms in linear mixed-effects models. CONCLUSIONS: Physiologic MRI-based RT boost decreased LRF without a significant increase in grade 3+ toxicity or longitudinal PRO differences, but did not significantly improve DFS or OS. Additional improvements in systemic therapy are likely necessary to realize improvements in DFS and OS.

Proton Therapy for Squamous Cell Carcinoma of the Head and Neck: Early Clinical Experience and Current Challenges.

Proton therapy (PT) is a promising development in radiation oncology, with the potential to further improve outcomes for patients with squamous cell carcinoma of the head and neck (HNSCC). By utilizing the finite range of protons, healthy tissue can be spared from beam exit doses that would otherwise be irradiated with photon-based treatments. Current evidence on PT for HNSCC is limited to comparative dosimetric analyses and retrospective single-institution series. As a consequence, the recognized indications for the reimbursement of PT remain scarce in most countries. Nevertheless, approximately 100 PT centers are in operation worldwide, and initial experiences for HNSCC are being reported. This review aims to summarize the results of the early clinical experience with PT for HNSCC and the challenges that are currently faced.

Randomized trial of laryngeal organ preservation evaluating two cycles of induction chemotherapy with platinum, docetaxel, and a novel Bcl-xL inhibitor.

BACKGROUND: Single cycle induction chemotherapy (IC) with platinum and 5-flurouracil (PF) and treatment based on clinical response predicts organ preservation in laryngeal cancer. Other agents offer intriguing alternatives with potentially increased ease of administration, reduced risk for severe toxicities, and increased platinum sensitivity. METHODS: We report the results of a phase II bioselection trial in advanced resectable laryngeal cancer utilizing an IC regimen of two cycles of platinum plus docetaxel (TP) with a Bcl-2 inhibitor. The primary endpoint was organ preservation rate at 12 weeks post chemoradiation. RESULTS: Fifty-four patients were enrolled. Response to IC was 72%. The organ preservation rate was 59% with a laryngectomy free survival of 46%. Induction related grade ≥3 toxicities were observed in 56% of patients with two grade 5 events. CONCLUSIONS: Two cycles of TP IC plus a Bcl-2 inhibitor did not improve laryngeal preservation compared to a single cycle of PF.

Stricter Postoperative Oropharyngeal Cancer Radiation Therapy Normal Tissue Dose Constraints Are Feasible.

PURPOSE: Although dose de-escalation is one proposed strategy to mitigate long-term toxicity in human papillomavirus associated oropharyngeal cancer, applying more stringent normal tissue constraints may be a complementary approach to further reduce toxicity. Our study demonstrates that in a postoperative setting, improving upon nationally accepted constraints is achievable and leads to reductions in normal tissue complication probabilities (NTCP) without compromising disease control. METHODS AND MATERIALS: We identified 92 patients at our institution between 2015 and 2019 with p16+ oropharyngeal cancer who were treated with adjuvant volumetric modulated arc therapy. We included patients treated to postoperative doses and standard volumes (including bilateral neck). Doses delivered to organs at risk were compared with recommended dose constraints from a recent cooperative group head and neck cancer trial of radiation therapy to 60 Gy. We applied validated and published NTCP models for dysphagia, dysgeusia, esophagitis, oral mucositis, and xerostomia relevant to oropharyngeal cancer. RESULTS: Achievable and delivered mean doses to most normal head and neck tissues were well below national recommended constraints. This translates to notable absolute NTCP reductions for salivary flow (10% improvement in contralateral parotid, 35% improvement in submandibular gland), grade ≥ 2 esophagitis (23% improvement), grade ≥ 3 mucositis (17% improvement), dysgeusia (10% improvement), and dysphagia (8% improvement). Locoregional control at a median follow-up of 26.3 months was 96.7%, with only 3 patients experiencing locoregional recurrence (1 local, 2 regional). CONCLUSIONS: Modern radiation therapy planning techniques allow for improved normal tissue sparing compared with currently established dose constraints without compromising disease control. These improvements may lead to reduced toxicity in a patient population expected to have favorable long-term outcomes. Stricter constraints can be easily achieved and should be used in conjunction with other evolving efforts to mitigate toxicity.

Imaging response assessment for predicting outcomes after bioselection chemotherapy in larynx cancer: A secondary analysis of two prospective trials.

BACKGROUND AND PURPOSE: Bioselection with induction chemotherapy in larynx cancer is associated with excellent larynx preservation and disease-specific survival but requires visual inspection of the primary tumor. We retrospectively compare clinical and imaging response in bioselected patients to develop predictive models of surgeon-assessed response (SR), laryngectomy-free survival (LFS), and overall survival (OS) in bioselected patients. MATERIALS AND METHODS: In a secondary analysis of patients on two single-institution bioselection trials, model building used a regularized regression model (elastic-net) and applied nested cross-validation. Logistic regression-based model was used to predict SR and Cox proportional hazard-based models were used to predict LFS and OS. RESULTS: In 115 patients with a median age of 57 years, most patients had supraglottic tumors (73.0%) and T3/T4 disease (94.8%). Definitive treatment was chemoradiation in 76.5% and laryngectomy in 23.5%. Change in primary tumor (OR = 5.78, p < 0.001) and N-classification (OR = 1.64, p = 0.003) predicted SR (AUC 0.847). Change in tumor volume (HR = 0.58, p < 0.001) predicted LFS (c-index 0.724). N-classification (HR = 1.48, p = 0.04) and pre-chemotherapy tumor volume (HR = 1.30, p = 0.174) predicted OS (c-index 0.552). CONCLUSIONS: Imaging offers a non-invasive opportunity to evaluate response to induction chemotherapy, complementary to surgeon assessment. Further evaluation of approaches to bioselection that optimize generalizability of this paradigm are needed, and clinical trials utilizing imaging to predict outcomes including LFS are warranted.

Electrochemotherapy in Mucosal Cancer of the Head and Neck: A Systematic Review.

Electrochemotherapy (ECT) is a local ablative treatment that is based on the reversible electroporation and intracellular accumulation of hydrophilic drug molecules, which greatly increases their cytotoxicity. In mucosal head and neck cancer (HNC), experience with ECT is limited due to the poor accessibility of tumors. In order to review the experience with ECT in mucosal HNC, we undertook a systematic review of the literature. In 22 articles, published between 1998 and 2020, 16 studies with 164 patients were described. Curative and palliative intent treatment were given to 36 (22%) and 128 patients (78%), respectively. The majority of tumors were squamous cell carcinomas (79.3%) and located in the oral cavity (62.8%). In the curative intent group, complete response after one ECT treatment was achieved in 80.5% of the patients, and in the palliative intent group, the objective (complete and partial) response rate was 73.1% (31.2% and 41.9%). No serious adverse events were reported during or soon after ECT and late effects were rare (19 events in 17 patients). The quality-of-life assessments did not show a significant deterioration at 12 months post-ECT. Provided these preliminary data are confirmed in randomized controlled trials, ECT may be an interesting treatment option in selected patients with HNC not amenable to standard local treatment.

Contemporary management of the neck in nasopharyngeal carcinoma.

Up to 85% of the patients with nasopharyngeal carcinoma present with regional nodal metastasis. Although excellent nodal control is achieved with radiotherapy, a thorough understanding of the current TNM staging criteria and pattern of nodal spread is essential to optimize target delineation and minimize unnecessary irradiation to adjacent normal tissue. Selective nodal irradiation with sparing of the lower neck and submandibular region according to individual nodal risk is now emerging as the preferred treatment option. There has also been continual refinement in staging classification by incorporating relevant adverse nodal features. As for the uncommon occurrence of recurrent nodal metastasis after radiotherapy, surgery remains the standard of care.