Patterns of local recurrence after curative resection and reconstruction for oropharyngeal and oral cancers: Implications for postoperative radiotherapy target volumes

Target Delineation in Postoperative Radiation Therapy for Head and Neck Cancer After Flap Reconstruction

Delineation of the clinical target volume (CTV) after resection of head and neck cancer can be challenging, especially after flap reconstruction. The main area of contention is whether the entire flap should be included in the CTV. Several case series have reported marginal misses and intraflap failures when the entire flap was not routinely included in the CTV. On the other hand, available data have not convincingly demonstrated a detriment to long-term outcomes using intensity modulated radiotherapy after flap reconstruction. On the contrary, postoperative radiation can facilitate epilation and mucosalization of the flap tissue, reduce flap bulk, and improve long-term esthetic and functional outcomes. Therefore, our standard practice is to include the entire flap in the CTV. In certain scenarios, we may allow for a lower dose to part of flap distant from the resection bed than the flap-tumor bed junction, where recurrences are most likely. We provide three case vignettes describing such scenarios where sparing part of the flap, and more importantly, the nearby uninvolved native tissue, from high-dose radiation may be justified.

[Issues and implementation of postoperative radiotherapy after flap reconstructive surgery in head and neck cancers]

The management of head and neck cancers is multidisciplinary, often relying on the use of combined treatments to maximize the chances of cure. Combined treatments are however also responsible for cumulative side effects. The aim of reconstructive surgery with a flap is to restore a function lost with the loss of substance from the tumor resection. However, changes in reconstructive surgery have impact of postoperative radiotherapy planning. The optimization of imaging protocols for radiotherapy planning should make it possible to identify postoperative changes and to distinguish flaps from surrounding native tissues to delineate the flaps and document the spontaneous evolution of these flaps or dose-effect relationships in case of radiotherapy. Such changes include atrophy, fibrosis of soft tissue flaps and osteoradionecrosis of bone flaps. Radiotherapy optimization also involves standardization of the definition of target volumes in situations where a flap is present, a situation that is increasingly common in routine care. This evolution of practice, beyond the essential multidisciplinary consultation meetings defining treatment indications, requires a close radio surgical collaboration with respect to technical aspects of the two disciplines. Doing so, anticipation of relapse and toxicity profiles could possibly lead to propose strategies for personalized de-escalation of multimodal treatments through interdisciplinary trials.

Reconstructive flap surgery in head and neck cancer patients: an interdisciplinary view of the challenges encountered by radiation oncologists in postoperative radiotherapy

Background

Major advances have been made in reconstructive surgery in the last decades to reduce morbidity in head and neck cancer. Flaps are now present in 80% of patients with oral cavity cancer to cover anatomic, functional, and cosmetic needs. However, gaps in interdisciplinary innovation transfer from surgery to postoperative radiotherapy (poRT) remain challenging. We aimed to provide an interdisciplinary view of the challenges encountered by radiation oncologists in planning head and neck postoperative radiotherapy.

Methods

A systematic and critical review was conducted to address areas of optimization in surgery and radiology that may be relevant to poRT.

Results

Despite extensive surgical literature on flap techniques and salvage surgery, 13 retrospective series were identified, where flap outcomes were indirectly compared between surgery alone or poRT. These low-evidence studies suggest that radiotherapy accelerates flap atrophy, fibrosis, and osteoradionecrosis and deteriorates functional outcomes. Preliminary evidence suggests that tumor spread occurs at the flap-tissue junction rather than in the flaps. One prospective 15-patient study showed 31.3% vs. 39.2% flap volume reduction without or with poRT. In an international consensus, experts recognized the needs for optimized flap-sparing poRT against flap-related functional deterioration and bone damage. CT, MRI, and PET-CT modalities show potential for the delineation of the junction area between native tissues and flap for flap segmentation and to characterize flap-specific changes quantitatively and correlate them with patterns of relapse or complications.

Conclusion

Flap management in poRT is insufficiently documented, but poRT seems to damage flaps. Current gaps in knowledge underscore the need for prospective flap assessment and interdisciplinary trials investigating flap morbidity minimization by flap-sparing poRT planning.

Outcomes among oropharyngeal and oral cavity cancer patients treated with postoperative volumetric modulated arctherapy

Background

Presently, there are few published reports on postoperative radiation therapy for oropharyngeal and oral cavity cancers treated with IMRT/VMAT technique. This study aimed to assess the oncological outcomes of this population treated with postoperative VMAT in our institution, with a focus on loco-regional patterns of failure.

Material and methods

Between 2011 and 2019, 167 patients were included (40% of oropharyngeal cancers, and 60% of oral cavity cancers). The median age was 60 years. There was 64.2% of stage IV cancers. All patients had both T and N surgery. 34% had a R1 margin, 42% had perineural invasion. 72% had a positive neck dissection and 42% extranodal extension (ENE). All patients were treated with VMAT with simultaneous integrated boost with three dose levels: 66Gy in case of R1 margin and/or ENE, 59.4-60Gy on the tumor bed, and 54Gy on the prophylactic areas. Concomittant cisplatin was administrated concomitantly when feasible in case of R1 and/or ENE.

Results

The 1- and 2-year loco-regional control rates were 88.6% and 85.6% respectively. Higher tumor stage (T3/T4), the presence of PNI, and time from surgery >45 days were significant predictive factors of worse loco-regional control in multivariate analysis (p=0.02, p=0.04, and p=0.02). There were 17 local recurrences: 11 (64%) were considered as infield, 4 (24%) as marginal, and 2 (12%) as outfield. There were 9 regional recurrences only, 8 (89%) were considered as infield, and 1 (11%) as outfield. The 1- and 2-year disease-free survival (DFS) rates were 78.9% and 71.8% respectively. The 1- and 2-year overall survival (OS) rates were 88.6% and 80% respectively. Higher tumor stage (T3/T4) and the presence of ENE were the two prognostic factors significantly associated with worse DFS and OS in multivariate analysis.

Conclusion

Our outcomes for postoperative VMAT for oral cavity and oropharyngeal cancers are encouraging, with high rates of loco-regional control. However, the management of ENE still seems challenging.

International assessment of interobserver reproducibility of flap delineation in head and neck carcinoma

Background: Several reports have suggested that radiotherapy after reconstructive surgery for head and neck cancer (HNC), could have deleterious effects on the flaps with respect to functional outcomes. To predict and prevent toxicities, flap delineation should be accurate and reproducible. The objective of the present study was to evaluate the interobserver variability of frequent types of flaps used in HNC, based on the recent GORTEC atlas.Materials and methods: Each member of an international working group (WG) consisting of 14 experts delineated the flaps on a CT set from six patients. Each patient had one of the five most commonly used flaps in HNC: a regional pedicled pectoralis major myocutaneous flap, a local pedicled rotational soft tissue facial artery musculo-mucosal (FAMM) (2 patients), a fasciocutaneous radial forearm free flap, a soft tissue anterolateral thigh (ALT) free flap, or a fibular free flap. The WG's contours were compared to a reference contour, validated by a surgeon and a radiologist specializing in HNC. Contours were considered as reproducible if the median Dice Similarity Coefficient (DSC) was > 0.7.Results: The median volumes of the six flaps delineated by the WG were close to the reference contour value, with approximately 50 cc for the pectoral, fibula, and ALT flaps, 20 cc for the radial forearm, and up to 10 cc for the FAMM. The volumetric ratio was thus close to the optimal value of 100% for all flaps. The median DSC obtained by the WG compared to the reference for the pectoralis flap, the FAMM, the radial forearm flap, ALT flap, and the fibular flap were 0.82, 0.40, 0.76, 0.81, and 0.76, respectively.Conclusions: This study showed that the delineation of four main flaps used for HNC was reproducible. The delineation of the FAMM, however, requires close cooperation between radiologist, surgeon and radiation oncologist because of the poor visibility of this flap on CT and its small size.

Salvage Surgery in Recurrent Oral Squamous Cell Carcinoma

More than half of patients with oral cancer recur even after multimodality treatment and recurrent oral cancers carry a poorer prognosis when compared to other sites of head and neck. The best survival outcome in a recurrent setting is achieved by salvage surgery; however, objective criteria to select an ideal candidate for salvage surgery is difficult to frame, as the outcome depends on various treatment-, tumor-, and patient-related factors. The following is summarizes various tumor- and treatment-related factors that guide our decision-making to optimize oncologic and functional outcomes in surgical salvage for recurrent oral cancers. Short disease-free interval, advanced tumor stage (recurrent and primary), extracapsular spread and positive tumor margins in a recurrent tumor, regional recurrence, and multimodality treatment of primary tumor all portend worse outcomes after surgical salvage. Quality of life after surgical intervention has shown improvement over 1 year with a drastic drop in pain scores. Various trials are underway evaluating the combination of immunotherapy and surgical salvage in recurrent head and neck tumors, including oral cavity, which may widen our indications for salvage surgery with improved survival and preserved organ function.

Molybdenum Diphosphide Nanorods with Laser-Potentiated Peroxidase Catalytic/Mild-Photothermal Therapy of Oral Cancer

Chemodynamic therapy (CDT) is an emerging treatment that usually employs chemical agents to decompose hydrogen peroxide (H₂O₂) into hydroxyl radical (•OH) via Fenton or Fenton-like reactions, inducing cell apoptosis or necrosis by damaging biomacromolecules such as, lipids, proteins, and DNA. Generally, CDT shows high tumor-specificity and minimal-invasiveness in patients, thus it has attracted extensive research interests. However, the catalytic reaction efficiency of CDT is largely limited by the relatively high pH at the tumor sites. Herein, a 808 nm laser-potentiated peroxidase catalytic/mild-photothermal therapy of molybdenum diphosphide nanorods (MoP₂ NRs) is developed to improve CDT performance, and simultaneously achieve effective tumor eradication and anti-infection. In this system, MoP₂ NRs exhibit a favorable cytocompatibility due to their inherent excellent elemental biocompatibility. Upon irradiation with an 808 nm laser, MoP₂ NRs act as photosensitizers to efficiently capture the photo-excited band electrons and valance band holes, exhibiting enhanced peroxidase-like catalytic activity to sustainedly decompose tumor endogenous H₂O₂ to •OH, which subsequently destroy the cellular biomacromolecules both in tumor cells and bacteria. As demonstrated both in vitro and in vivo, this system exhibits a superior therapeutic efficiency with inappreciable toxicity. Hence, the work may provide a promising therapeutic technique for further clinical applications.

Are Throat Pain and Otalgia Predictive of Perineural Invasion in Squamous Cell Carcinoma of the Oropharynx?

PURPOSE

Head and neck cancer is often associated with pain and perineural invasion (PNI). The purpose of this study was to determine the association of pain complaints and the microscopic identification of PNI in patients with oropharyngeal squamous cell carcinoma (OPSCC).

PATIENTS AND METHODS

A retrospective cohort study was performed including patients diagnosed with OPSCC from 2010 to 2019. Patients diagnosed and operated on with curative intent at 2 institutions were included. The primary predictor variable was pain (measured as no pain, ear pain, throat pain, or simultaneous pain). Other variables were patient demographics, p16 status, and TNM staging. The primary outcome variable was the histologic presence of PNI. Chi-square analysis was performed to test for any significant associations between pain, T stage, overall stage, and p16 status in relation to PNI outcome. Multivariate logistic regression analysis was used to control for cancer staging variables when testing the association between pain and PNI.

RESULTS

The final sample was composed of 157 subjects of whom 126 were men. The mean age was 59.7 years. Seventy-seven (49.0%) presented with no pain, while 35 (22.3%), 39 (24.8%), and 6 (3.8%) presented with both throat/ear pain, throat pain only, and ear pain only, respectively. Patients with simultaneous pain had 3.41 times higher odds of PNI compared to the no pain group (P = .02), although only pathologic T stage 4 and a diagnosis on the base of the tongue were independent postoperative predictors of PNI (P < .05).

CONCLUSIONS

Our study demonstrates that otalgia is a preoperative predictor of PNI in OPSCC and also demonstrates a trend of increasing pain complaints with PNI.

Prognostic Value of Perineural Invasion in Oral Tongue Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVES

A significant number of recently published research has outlined the contribution of perineural invasion (PNI) to clinical outcomes in oral tongue squamous cell carcinoma (OTSCC), but some results remain conflicting. This study aimed to determine whether patients with OTSCC with PNI have a worse prognosis than those without PNI.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were queried for potentially eligible articles published up to December 2020. The primary outcomes were the hazard ratio (HR) for locoregional recurrence, overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS). The random-effect model was used in all analyses.

RESULTS

Seventeen studies (4445 patients) were included. Using adjusted HRs, the presence of PNI was associated with a higher risk of locoregional recurrence (HR=1.73, 95%CI: 1.07-2.79, P=0.025, I2 = 33.1%, Pheterogeneity=0.224), worse OS (HR=1.94, 95%CI: 1.39-2.72, P<0.001, I2 = 0.0%, Pheterogeneity=0.838), worse DFS (HR=2.13, 95%CI: 1.53-2.96, P<0.001, I2 = 48.4%, Pheterogeneity=0.071), and worse CSS (HR=1.93, 95%CI: 1.40-2.65, P<0.001, I2 = 25.5%, Pheterogeneity=0.251). PNI had an impact on locoregional recurrence in early-stage OTSCC but not in all stages, and on OS, DFS, and CSS in all-stage and early-stage OTSCC. The sensitivity analyses showed that the results were robust.

CONCLUSION

The presence of PNI significantly affects the locoregional recurrence and survival outcomes among patients with OTSCC.

Recommendations for postoperative radiotherapy in head & neck squamous cell carcinoma in the presence of flaps: A GORTEC internationally-reviewed HNCIG-endorsed consensus

INTRODUCTION

Head and neck reconstructive surgery using a flap is increasingly common. Best practices and outcomes for postoperative radiotherapy (poRT) with flaps have not been specified. We aimed to provide consensus recommendations to assist clinical decision-making highlighting areas of uncertainty in the presence of flaps.

MATERIAL AND METHODS

Radiation, medical, and surgical oncologists were assembled from GORTEC and internationally with the Head and Neck Cancer International Group (HNCIG). The consensus-building approach covered 59 topics across four domains: (1) identification of postoperative tissue changes on imaging for flap delineation, (2) understanding of tumor relapse risks and target volume definitions, (3) functional radiation-induced deterioration, (4) feasibility of flap avoidance.

RESULTS

Across the 4 domains, international consensus (median score ≥ 7/9) was achieved only for functional deterioration (73.3%); other consensus rates were 55.6% for poRT avoidance of flap structures, 41.2% for flap definition and 11.1% for tumor spread patterns. Radiation-induced flap fibrosis or atrophy and their functional impact was well recognized while flap necrosis was not, suggesting dose-volume adaptation for the former. Flap avoidance was recommended to minimize bone flap osteoradionecrosis but not soft-tissue toxicity. The need for identification (CT planning, fiducials, accurate operative report) and targeting of the junction area at risk between native tissues and flap was well recognized. Experts variably considered flaps as prone to tumor dissemination or not. Discrepancies in rating of 11 items among international reviewing participants are shown.

CONCLUSION

International GORTEC and HNCIG-endorsed recommendations were generated for the management of flaps in head and neck radiotherapy. Considerable knowledge gaps hinder further consensus, in particular with respect to tumor spread patterns.

Postoperative radiotherapy after flap reconstructive surgery in patients with head and neck cancer: A retrospective monocentric study with flap delineation to assess toxicity and relapse

PURPOSE

Flaps are increasingly used during reconstructive surgery of head and neck cancers to improve functional outcomes. There are no guidelines as to whether the whole flap or its anastomotic border should be included in the primary tumour target volume of postoperative radiotherapy to prevent local relapses. Relapse and toxicity rates can increase substantially if the whole flap received full dose. Our aim was to determine whether flaps were included in the primary tumour target volume and to report the patterns of relapse and toxicity.

MATERIALS AND METHODS

Consecutive patients in 2014 through 2016, with or without a flap, receiving postoperative radiotherapy were selected in a retrospective monocentric control study. Flaps were homogenously delineated blind to treating radiation oncologists using a flap-specific atlas. Tumour recurrence, acute and late toxicity were evaluated using univariate and propensity score analyses.

RESULTS

A hundred patients were included; 54 with a flap. Median flap volume included in the tumour volume was 80.9%. Twelve patients experienced local recurrences: six with a flap, among whom two within their flap (3.7%). Patients with flaps had larger median tumour volumes to be irradiated (25cm³ versus 58cm³, p<0.001) and higher acute/late toxicity rates (p<0.001) even after adjustment on biases (more advanced T stage, oral cavity, active smoking in patients with flaps). Locoregional recurrence and survival rates were similar between patients with/without a flap.

CONCLUSION

Recurrences within a flap were rare in this series when including the whole flap body in the 60Gy-clinical target volume but inclusion of the flap in the primary tumour target volume increased toxicity. Multicentric studies are warranted.

[Impact of reconstructive or minimal invasive surgery on the assessment of current definitions of postoperative clinical target volume for head and neck cancers]

Advances in the reconstructive surgery and minimally invasive endonasal endoscopic surgery of head and neck is poorly evaluated in terms of their impact on radiotherapy planning and outcomes. These surgical advances have resulted in reduced morbidity with equivalent or better tumor control. In the absence of a recommendation on how to delineate target volumes in patients with flaps or to consider margins after endoscopic endonasal surgery, radiotherapy practices are inevitably heterogeneous. Efforts are needed to increase the therapeutic index of postoperative radiotherapy in these situations. We analysed the rare existing literature and outlined a preliminary basis for a recommendation. Strengthening of multidisciplinarity to accurately define target volumes in these complex and relatively new situations, and "delineation concertation meetings" between radiologists, surgeons and radiation oncologists could probably contribute to improved outcomes.

Are Oral Pain and Otalgia Predictive of Perineural Invasion in Squamous Cell Carcinoma of the Oral Tongue?

PURPOSE

Tongue cancer is often associated with pain and perineural invasion. The purpose of the present study was to determine the association between tongue pain and otalgia and the microscopic identification of perineural invasion (PNI) in patients with squamous cell carcinoma of the tongue (SCCOT).

PATIENTS AND METHODS

A retrospective cohort study was performed of patients with a diagnosis of SCCOT from January 2013 through June 2019. Patients without a history of head and neck cancer, who had SCCOT diagnosed and treated surgically by a single surgeon, were included in the present study. The primary predictor variables were tongue pain and otalgia (presence vs absence of both). Other variables included patient demographic data and TNM stage. The primary outcome variable was the histologic presence of PNI. A χ² analysis was performed to test for any significant associations between pain, T stage, and overall stage in relation to PNI outcome. Multivariate logistic regression analysis was used to control for cancer staging variables when testing the association between pain and PNI.

RESULTS

The sample included 128 subjects, of whom 76 were men. Their mean age was 60 years. Most patients (n = 97; 75.8%) complained of tongue pain and a few (n = 50; 39.1%) complained of otalgia. The patients with otalgia had a 3.15 times greater odds of PNI when controlling for T stage (P = .016) and 3.68 times greater odds of PNI when controlling for overall stage (P = .007). Increasing T stage and overall stage-with the exception of stage II-were also significantly associated with PNI (P ≤ .05).

CONCLUSIONS

Our study has demonstrated a statistically significant association between preoperative otalgia and PNI in a consecutive group of patients presenting with newly diagnosed SCCOT.