Retreatment of Recurrent or Second Primary Head and Neck Cancer After Prior Radiation: Executive Summary of the American Radium Society® (ARS) Appropriate Use Criteria (AUC): Expert Panel on Radiation Oncology - Head and Neck Cancer

Proton therapy re-irradiation outcomes and genomic landscape of patients with recurrent head and neck cancer

INTRODUCTION

Re-irradiation (re-RT) for recurrent head and neck cancer (rHNC) is challenging. We describe clinical outcomes and toxicity of proton therapy (PT) for recurrent HNC, and report genomic alterations associated with patterns of failure.

MATERIALS & METHODS

We performed a retrospective analysis of rHNC patients treated with PT. Outcomes were estimated using the Kaplan-Meier method. Univariate (UVA) and multivariate analyses (MVA) were performed to assess multiple patient factors. Next-generation sequencing and genomic analyses were performed on available samples.

RESULTS

Eighty-nine patients treated with PBS-PT for rHNC with a median follow-up of 12 mo (0-71 mo) were included. The 1- and 2-y local control (LC) rates were 80.8 % (95 % CI: 70.8-90.8) and 66.2 % (95 % CI: 50.7-81.7), and 1- and 2-y distant metastasis-free survival (DMFS) were 41.0 % (95 % CI: 30.0-52.0) and 26.3 % (95 % CI: 15.7-36.9). The median overall survival (OS) was 13 mo (95 % CI: 9.3-16.7). On UVA and MVA, smaller gross tumor volume (GTV) was associated with improved OS (HR 1.002, P = 0.004), DMFS (HR 1.002, P = 0.004), and PFS (HR 1.002, P = 0.014). There were 35 late Gr3 + toxicity events (30.3 %). Patients with higher candidate gene-specific mutation burden (genes with [OR] > 2, P < 0.05) had inferior PFS. TP53, NOTCH4, and ARID1B mutations were associated with inferior DMFS (OR > 2, P < 0.05).

CONCLUSIONS

PBS-PT is effective at achieving LC for rHNC with favorable toxicity. Distant metastases are common, and associated with TP53, NOTCH4, and ARID1B mutations. Inclusion of genomic alterations in the clinical decision process may be warranted.

Re-irradiation of recurrent head and neck cancers using pulsed reduced dose rate radiotherapy: An institutional series

PURPOSE/OBJECTIVE(S)

Pulsed reduced dose rate (PRDR) radiation (RT) is a re-irradiation (Re-RT) technique that potentially overcomes dose/volume constraints in the setting of previous RT. There is minimal data for its use for recurrent or secondary primary head and neck squamous cell carcinoma (HNSCC). In this study, we report preliminary data from our institution of a consecutive cohort of HNSCC patients who received PRDR Re-RT.

MATERIALS/METHODS

Nine patients received PRDR Re-RT from August 2020 to January 2023 and had analyzable data. Intensity modulated RT was used for treatment delivery and a wait time between 20 cGy arc/helical deliveries was used to achieve the effective low dose rate. Data collected included patient demographic information, prior interventions, diagnosis, radiation therapy dose and fractionation, progression free survival, overall survival, and toxicity rates.

RESULTS

The median time to PRDR-RT from completion of initial RT was 13 months (range, 6-50 months). All but one patient underwent salvage surgery prior to PRDR-RT. The median follow-up after Re-RT was 7 months. The median OS from PRDR-RT was 7 months (range, 1-32 months). Median PFS was 7 months (range, 1-32 months). One patient (11.1 %) had acute grade 3 toxicity, and two patients (22.2 %) had late grade 3 toxicities. There were no grade 4+ toxicities.

CONCLUSION

PRDR Re-RT is a feasible treatment strategy for patients with recurrent or second primary HNSCC. Initial findings from this retrospective review suggest reasonable survival outcomes and potentially improved toxicity; prospective data is needed to establish the safety and efficacy of this technique.

Effectiveness and risk of second primary malignancies after radiotherapy in major salivary gland carcinomas: A retrospective study using SEER database

OBJECTIVE

To investigate the effectiveness of radiotherapy and its association with second primary malignancies (SPMs) risk in major salivary gland carcinomas (MSGCs) patients.

METHODS

Cohort 1 included 7274 surgically treated MSGC patients from the Surveillance, Epidemiology, and End Results database, assessing the effectiveness of radiotherapy. Cohort 2 (n = 4213) comprised patients with ≥5-year survival in Cohort 1 to study SPMs.

RESULTS

Radiotherapy decreased overall survival in MSGCs patients, but improved it in high-grade MSGCs. Cumulative SPMs incidences at 25 years were 16.5% in the radiotherapy (RT) group compared to 14.5% in the non-radiotherapy (NRT) group. For second head and neck carcinomas (SHNCs), incidences were 3.4% in RT versus 1.6% in NRT. Radiotherapy increased the relative risks of tumors, particularly SHNCs (RR = 1.78). The 10-year OS rates of SHNCs after radiotherapy were significantly lower.

CONCLUSION

Radiotherapy improves survival in advanced-stage MSGCs but increases the risk of developing SPMs, particularly SHNCs.

Stereotactic ablative radiotherapy for treating primary head and neck cancer and locoregional recurrence: A comprehensive review of the literature

Introduction

Although stereotactic ablative radiotherapy (SABR) has advance to standard-of-care for many different indications like lung and liver malignancies, it still remains in its infancy for treating head and neck cancer. Nevertheless there is a growing body of experience and evidence, which is summarized in this review Methods A thorough search of the literature was performed and critically reviewed both for SABR as a primary treatment as well as for treating locoregionally recurrent disease in a pre-irradiated field.

Results

There exist only few prospective data published so far for treating head and neck cancer with SABR. In the primary situation especially implementing SABR as a boost after definitive radiotherapy or a single-modality for locally limited, small glottic cancer appear promising. On the other hand, SABR can be a useful modality for treating local recurrence in a pre-irradiated field. However, caution is needed in the case of proximity to a pre-irradiated carotid artery or other serial organs at risk. Usually only limited gross volumes are treated with 3-6 fractions every other day and a cumulative dose of 24-44 Gy in dedicated radiosurgery platforms or modern linacs with the possibility of online image-guidance and adequate immobilsation.

Conclusions

SABR is an innovative, effective and promising treatment modality for small targets, especially in near proximity to organs at risk or in a pre-irradiated region. Prospective trials are further needed for this technique to become standard-of care.

Stereotactic Body Radiation Therapy in Recurrent Head and Neck Cancer: Where Do We Stand?

This review explores the difficulties encountered in the management of head and neck cancer (HNC), with special attention to the challenges presented by locoregional recurrences, which impact a substantial number of patients. While maximal surgical resection remains the gold standard for treatment, surgery is often not feasible due to various factors. In such cases, reirradiation has emerged as a potential strategy, albeit with a heightened risk of severe toxicity. Stereotactic Body Radiation Therapy (SBRT) is introduced as a promising approach for unresectable recurrent HNC. SBRT offers precise radiation doses and shorter treatment durations, making it a potentially optimal treatment modality. Despite the growing interest in SBRT, there is a lack of consensus guidelines for its use in HNC, particularly in India. Nevertheless, recommendations are provided for the benefit of SBRT in reirradiation settings, considering factors like tumour size, dose, and treatment duration. The article highlights the safety and effectiveness of SBRT-based reirradiation with existing evidence. The literature review discusses various studies and their findings, emphasizing the importance of high-dose SBRT for improved overall survival. The article also explores the combination of SBRT with systemic therapy as a potential synergistic approach to enhance patient outcomes. In conclusion, SBRT shows promise as a valuable therapeutic tool for patients with inoperable recurrent HNC, offering acceptable safety. However, further research and well-designed trials are needed to optimize its use and identify the most suitable patient cohorts. Establishing comprehensive working guidelines and a nationwide prospective database will be crucial in advancing this treatment approach.

Adjuvant Reirradiation With Proton Therapy in Head and Neck Squamous Cell Carcinoma

Purpose

For patients with head and neck squamous cell carcinoma (HNSCC), locoregional failure and second primary tumors are common indications for adjuvant reirradiation (re-RT). Given an absence of clear consensus on the role of adjuvant re-RT, we sought to assess histopathologic risk factors of patients with HNSCC and their resulting outcomes after adjuvant re-RT with proton therapy.

Methods and Materials

We conducted a retrospective analysis of patients with HNSCC who underwent salvage surgery at our institution followed by adjuvant re-RT with proton therapy over 1.5 years. All included patients received prior radiation therapy. The Kaplan-Meier method was used to evaluate locoregional recurrence-free survival and overall survival.

Results

The cohort included 22 patients, with disease subsites, including oropharynx, oral cavity, hypopharynx, larynx, and nasopharynx. Depending on adverse pathologic features, adjuvant re-RT to 66 Gy (32% of cohort) or 60 Gy (68%), with (59%) or without (41%) concurrent systemic therapy was administered. The majority (86%) completed re-RT with no reported treatment delay; 3 patients experienced grade ≥3 acute Common Terminology Criteria for Adverse Events toxicity and no patient required enteral feeding tube placement during re-RT. Median follow-up was 21.0 months (IQR, 11.7-25.2 months). Five patients had biopsy-proven disease recurrences a median of 5.9 months (IQR, 3.8-9.7 months) after re-RT. Locoregional recurrence-free survival was 95.2%, 70.2%, 64.8% at 6, 12, and 24 months, respectively. OS was 100%, 79.2%, and 79.2% at 6, 12, and 24 months, respectively. Four patients had osteoradionecrosis on imaging a median of 13.2 months (IQR, 8.7-17.4 months) after re-RT, with 2 requiring surgical intervention.

Conclusions

Adjuvant re-RT for patients with HNSCC was well-tolerated and offered reasonable local control in this high-risk cohort but appears to be associated with a risk of osteoradionecrosis. Additional study and longer follow-up could help define optimal patient management in this patient population.

Preclinical Evaluation of the ATR Inhibitor BAY 1895344 as a Radiosensitizer for Head and Neck Squamous Cell Carcinoma

PURPOSE

Despite aggressive multimodal treatment that typically includes definitive or adjuvant radiation therapy (RT), locoregional recurrence rates approach 50% for patients with locally advanced human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). Thus, more effective therapeutics are needed to improve patient outcomes. We evaluated the radiosensitizing effects of ataxia telangiectasia and RAD3-related (ATR) inhibitor (ATRi) BAY 1895344 in preclinical models of HNSCC.

METHODS AND MATERIALS

Murine and human HPV-negative HNSCC cells (MOC2, MOC1, JHU-012) were treated with vehicle or ATRi with or without 4 Gy. Checkpoint kinase 1 phosphorylation and DNA damage (γH2AX) were evaluated by Western blot, and ATRi half-maximal inhibitory concentration was determined by MTT assay for HNSCC cells and immortalized murine oral keratinocytes. In vitro radiosensitization was tested by clonogenic assay. Cell cycle distribution and mitotic catastrophe were evaluated by flow cytometry. Mitotic aberrations were quantified by fluorescent microscopy. Tumor growth delay and survival were assessed in mice bearing MOC2 or JHU-012 transplant tumors treated with vehicle, ATRi, RT (10 Gy × 1 or 8 Gy × 3), or combined ATRi + RT.

RESULTS

ATRi caused dose-dependent reduction in checkpoint kinase 1 phosphorylation at 1 hour post-RT (4 Gy) and dose-dependent increase in γH2AX at 18 hours post-RT. Addition of RT to ATRi led to decreased BAY 1895344 half-maximal inhibitory concentration in HNSCC cell lines but not in normal tissue surrogate immortalized murine oral keratinocytes. Clonogenic assays demonstrated radiosensitization in the HNSCC cell lines. ATRi abrogated the RT-induced G2/M checkpoint, leading to mitosis with unrepaired DNA damage and increased mitotic aberrations (multinucleated cells, micronuclei, nuclear buds, nucleoplasmic bridges). ATRi and RT significantly delayed tumor growth in MOC2 and JHU-012 in vivo models, with improved overall survival in the MOC2 model.

CONCLUSIONS

These findings demonstrated that BAY 1895344 increased in vitro and in vivo radiosensitivity in HPV-negative HNSCC preclinical models, suggesting therapeutic potential warranting evaluation in clinical trials for patients with locally advanced or recurrent HPV-negative HNSCC.

Low contralateral failure rate with unilateral proton beam radiotherapy for oropharyngeal squamous cell carcinoma: A multi-institutional prospective study from the proton collaborative group

INTRODUCTION

Unilateral radiation therapy is appropriate for select patients with oropharyngeal squamous cell carcinoma (OPSCC). The use of proton beam therapy (PBT) in the unilateral setting decreases the dose to the contralateral neck and organs at risk. This study aims to evaluate contralateral recurrences in patients who received ipsilateral PBT.

METHODS

We evaluated the Proton Collaborative Group database for patients treated with PBT for head and neck squamous cell carcinoma between the years 2015-2020 at 12 institutions. Dosimetric analysis was performed in five cases.

RESULTS

Our analysis included 41 patients that received ipsilateral PBT with a mean follow-up of 14.7 months. 37% patients (n = 15) were treated for recurrent disease, and 63% (n = 26) were treated for de novo disease. Oropharyngeal sites included tonsillar fossa (n = 30) and base of tongue (n = 11). The median dose and BED delivered were 69.96 CGE and 84 Gy, respectively. Eight (20%) patients experienced at least one grade 3 dysphagia (n = 4) or esophagitis (n = 4) toxicity. No grade ≥ 4 toxicities were reported. There was one (2.4%) failure in the contralateral neck. The 1-year locoregional control was 88.9% and the freedom from distant metastasis was 95.5% (n = 2). The dosimetric analysis demonstrated similar ipsilateral level II cervical nodal region doses, whereas contralateral doses were higher with photon plans, mean: 15.5 Gy and 0.7CGE, D5%: 25.1 Gy and 6.6CGE.

CONCLUSIONS

Our series is the first to report outcomes for patients with OPSCC receiving unilateral PBT. The contralateral neck failure rate was excellent and comparable to failure rates with photon irradiation.

Reirradiation of head and neck squamous cell carcinomas: a pragmatic approach-part I: prognostic factors and indications to treatment

INTRODUCTION

Reirradiation (reRT) of locally recurrent/second primary tumors of the head and neck region is a potentially curative treatment for patients not candidate to salvage surgery. Aim of the present study is to summarize available literature on both prognostic factors and indications to curative reRT in this clinical setting.

MATERIALS AND METHODS

A narrative review of the literature was performed on two topics: (1) patients' selection according to prognostic factors and (2) dosimetric feasibility of reRT. Postoperative reRT and palliative intent treatments were out of the scope of this work.

RESULTS

Patient-tumor and treatment-related prognostic factors were analyzed, together with dosimetric parameters concerning target volume and organs at risk. Based on available evidence, a stepwise approach has been proposed aiming to provide a useful tool to identify suitable candidates for curative reRT in clinical practice. This was then applied to two clinical cases, proposed at the end of this work.

CONCLUSION

A second course of RT in head and neck recurrence/second primary tumors is a personalized approach that can be offered to selected patients only in centers with expertise and dedicated equipment following a multidisciplinary team discussion.

[Therapy of tumor recurrences or secondary carcinomas in pretreated area is not compatible with the primary therapy in non-previously treated tissue - an overview]

There are different initial situations in the treatment of local or locoregional recurrences, secondary carcinomas or residual squamous cell carcinomas of the head and neck region after primary therapy. The majority of patients with locoregional recurrences have had prior treatment consisting of surgery and/or postoperative radiotherapy or radiochemotherapy or primary radiotherapy or radiochemotherapy. In any case, it is a matter of new tumor growth in a previously treated area, which must be taken into account for the therapy decision. The biological backgrounds are diverse and are described in more detail and clinically classified in the present work.

MRI sequence optimisation methods to identify cranial nerve course for radiotherapy planning

INTRODUCTION

Magnetic resonance imaging (MRI) is being increasingly used to improve radiation therapy planning by allowing visualisation of organs at risk that cannot be well-defined on computed tomography (CT). Diagnostic sequences are increasingly being adapted for radiation therapy planning, such as the use of heavily T2-weighted 3D SPACE (Sampling Perfection with Application optimised Contrasts using different flip angle Evolution) sequence for cranial nerve identification in head and neck tumour treatment planning.

METHODS

A 3D isotropic T2 SPACE sequence used for cranial nerve identification was adapted for radiation therapy purposes. Distortion was minimised using a spin-echo-based sequence, 3D distortion correction, isocentre scanning and an increased readout bandwidth. Radiation therapy positioning was accounted for by utilising two small flex, 4-channel coils. The protocol was validated for cranial nerve identification in clinical applications and distortion minimisation using an MRI QA phantom.

RESULTS

Normal anatomy of the cranial nerves CI-CIX, were presented, along with a selection of clinical applications and abnormal anatomy. The usefulness of cranial nerve identification is discussed for several case studies, particularly in proximity to tumours extending into the base of skull region. In-house testing validated that higher bandwidths of 600 Hz resulted in minimal displacement well below 1 mm.

CONCLUSION

The use of MRI for radiation therapy planning allows for greater individualisation and prediction of patient outcomes. Dose reduction to cranial nerves can decrease late side effects such as cranial neuropathy. In addition to current applications, future directions include further applications of this technology for radiation therapy treatments.

Predictors of toxicity after curative reirradiation with intensity modulated radiotherapy or proton therapy for recurrent head and neck carcinoma: new dose constraints for pharyngeal constrictors muscles and oral cavity

BACKGROUND

Our study aims to identify predictive factors of moderate to severe (grade ≥ 2) late toxicity after reirradiation (reRT) of recurrent head and neck carcinoma (HNC) and explore the correlations between dose organs at risk (OAR) and grade ≥ 2 toxicity.

MATERIAL AND METHODS

Between 09/2007 and 09/2019, 55 patients were re-irradiated with IMRT or proton therapy with curative intent for advanced HNC. Our study included all patients for whom data from the first and second irradiations were available. Co-variables, including interval to reRT, size of re-irradiated PTV, and dose to OAR, were analyzed as potential predictors for developing moderate to severe long-term toxicity with death as a competing risk. Receiver-operator characteristics (ROC) analysis assessed the association between dose/volume parameters and the risk of toxicity.

RESULTS

Twenty-three patients participated in our study. After a median follow-up of 41 months, 65% of the patients experienced grade ≥ 2 late toxicity. The average dose to pharyngeal constrictor muscles (PCM) at the time of reRT showed an association with the risk of grade ≥ 2 dysphagia: AUC = 0.78 (95% CI: 0.53-1), optimal cut-off value = 36.7 Gy (sensitivity 62%/specificity 100%). The average dose to the oral cavity at the time of reRT showed an association with the risk of grade ≥ 2 dysgeusia: AUC = 0.96 (0.89-1), optimal cut-off value = 20.5 Gy (sensitivity 100%/specificity 88%).

CONCLUSION

Our analysis depicted an association between the dose to OAR and the risk of developing moderate to severe dysphagia and dysgeusia and proposed new dose constraints for PCM (36.7 Gy) and oral cavity (20.5 Gy).

Curative high-dose reirradiation for patients with recurrent head and neck adenoid cystic carcinomas: outcomes and analysis of patterns of failure

BACKGROUND

To investigate the outcomes of patients who underwent curative reirradiation (reRT), with intensity-modulated radiation therapy (IMRT) or proton therapy (PT) for unresectable recurrent or second primary head and neck adenoid cystic carcinoma (HNACC).

METHODS

Ten patients, mostly KPS 90%, were reirradiated (3/10 with IMRT and 7/10 with PT) at a median maximum dose to the CTV of 64.2 Gy from July 2011 to November 2021. Locations at the time of reRT were mainly the sinus (4/10) and the salivary glands (including the parotid and submandibular gland, 3/10). CTCAEv5 was used to assess acute and late toxicities. Follow-up was the time between the end of reRT and the date of last news.

RESULTS

The median time between the two irradiations was 53.5 months (IQR: 18-84). After a median follow-up of 26 months (range, 12.5-51.8 months), six patients had developed a locoregional recurrence (LR), of which four occurred within the previously irradiated volume. Two and three-year locoregional failure-free survival (LFFS) and overall survival (OS) were 55.6% [95%CI: 31-99.7%], and 41% [18.5-94%] and 66.7% [42-100%] and 44.4% [21.4-92.3%], respectively. LFFS and OS were significantly better in the subgroup of sinus tumors (p = .013) and the subgroup of patients re-irradiated more than two years after the first course of irradiation (p = .01). Seven patients had impairments before the start of reRT, including hearing impairment (3/10) and facial nerve impairment (3/10). The most severe late toxicities were brain necrosis (2/10), osteoradionecrosis (1/10) and vision decreased (1/10).

CONCLUSION

Curative reRT for HNACC is possible for selected cases, but the LR rate in the irradiated field and the risk of severe toxicity remain high. Improved selection criteria and more carefully defined target volumes may improve outcome in these patients. A further study including larger cohort of patients would be useful to confirm these results.

Dosimetric and clinical aspects of head and neck cancer reirradiation with intensity modulated radiotherapy techniques over the last decade

PURPOSE

Tumor recurrence in head and neck cancer (HNC) is very common, given that locoregional disease relapse occurs in up to 50% of patients. The clinical approach towards cancer recurrence is either by surgery and/or chemo-radiotherapy. Irrespective of the treatment, the management of HNC recurrence is highly challenging and often administered with palliative intent only. The aim of this work was to analyze clinical and dosimetric aspects, such as dose prescription, organ at risk sparing, overall survival and locoregional control of HNC after reirradiation with intensity modulated radiotherapy techniques based on studies published over the last decade, due to the wide clinical implementation of the intensity modulated radiotherapy and particularly of volumetric modulated arc therapy (VMAT) for this malignancy.

METHODS

A systematic search of the literature was conducted within Pub-med/Medline databases to find relevant studies. Of the 130 articles fulfilling the initial search criteria, 15 were selected for final analysis that encompassed all set requirements.

RESULTS

Clinical studies revealed the multitude of factors influencing treatment outcome, including anatomical location, histological tumor type, patient-related factors (smoking / comorbidities), cumulative dose and fractionation schedule, reirradiated volume and time between the irradiation of primary and recurrent tumor.

CONCLUSIONS

Since the literature reports no specific data related to the type of intensity modulation used in reirradiation or any correlation with treatment outcome, IMRT and VMAT might offer comparable result after HNC reirradiation. Patient selection is potentially the main factor leading to an efficient outcome.

Reirradiation of head and neck squamous cell carcinomas: a pragmatic approach, part II: radiation technique and fractionations

INTRODUCTION

Reirradiation (reRT) of local recurrent/second primary tumors of the head and neck represents a potential curative treatment for patients not candidate to a salvage surgery. Aim of the present study is to summarize literature data on modern radiation techniques and fractionations used in this setting of patients.

MATERIALS AND METHODS

A narrative review of the literature was conducted on three topics: (1) target volume delineation (2) reRT dose and techniques and (3) ongoing studies. Patients treated with postoperative reRT and palliative intent were not considered for the current analysis.

RESULTS

Recommendations on the target volume contouring have been reported. 3D-Conformal Radiotherapy, Intensity Modulated Radiotherapy, Stereotactic body Radiotherapy Intraoperative Radiotherapy, Brachytherapy and Charged Particles have been analyzed in terms of indication and fractionation in the field of reRT. Ongoing studies on the topic have been reported for IMRT and Charged Particles. Moreover, according to literature data a stepwise approach has been proposed aiming to provide a useful tool to select patients candidate to a curative reRT in daily clinical practice. Two clinical cases were also provided for its application.

CONCLUSION

Different radiation techniques and fractionations can be used for a second course of radiotherapy in patients with recurrent/second primary tumor of head and neck region. Tumor characteristics as well as radiobiological considerations should be take into account to define the best reRT approach.

Repeat re-irradiation with interstitial HDR-brachytherapy for an in-field isolated nodal recurrence in a patient with HPV-positive squamous cell carcinoma of the head and neck

PURPOSE

Locoregionally recurrent head and neck cancer is a complex clinical scenario that often requires multimodality treatment. These patients have often previously received definitive treatment with a combination of surgery, radiation therapy, and systemic therapy, which can make further management difficult. A second isolated locoregional failure is rare and clinicians are faced with a challenge to optimize disease control while minimizing treatment-related toxicity.

METHODS AND MATERIALS

In this report, we present the diagnosis, management, and outcomes of a patient with an isolated locoregional recurrence who was previously treated with two courses of radiation. The patient was treated with a second course of reirradiation using interstitial brachytherapy as well as a discussion regarding patient selection and optimal management for recurrent head and neck cancer.

RESULTS

Repeat reirradiation using interstitial HDR-brachytherapy with the use of an alloderm spacer was successfully delivered to the patient for an in-field right neck nodal recurrence. He received a total EQD2/BED dose of 127.70/153.24 Gy. At 1-year followup, the patient was without evidence of recurrent disease or new significant side effects.

CONCLUSION

Recurrent head and neck cancer should be managed with a multidisciplinary approach given the complex clinical scenario. Reirradiation is a commonly used salvage measure for recurrent head and neck cancer that requires careful planning and patient selection due to prior treatment-related effects and dose constraints. We reported a case of a second course of reirradiation using interstitial HDR-brachytherapy for locoregionally recurrent head and neck cancer and showed no recurrence of disease or worsening long term side effects at 1 year.

Re-irradiation for head and neck cancer: outcome and toxicity analysis using a prospective single institution database

Purpose

Re-irradiation (re-RT) in head and neck cancer is challenging. This study prospectively explored the feasibility of re-RT in patients with loco-regionally recurrent or second primary head and neck cancer (LRR/SP HNC).

Methods

From 2004 to 2021, 61 LRR/SP HNC patients were treated with re-RT, defined as having a second course of RT with curative intent resulting in a cumulative dose of ≥100 Gy in an overlapping volume. Postoperative or definitive dynamic intensity-modulated and/or volumetric modulated re-RT was administered using twice daily hyperfractionation to 60 Gy combined with cisplatin or carboplatin/5-fluorouracil. Overall survival (OS), progression-free survival (PFS), locoregional control (LRC) and distant metastasis control (DMC) were analyzed and prognostic factors evaluated. Toxicity was prospectively recorded and graded.

Results

The median follow-up was 9.8 months. In 41 patients (67.1%), complete administration of the intended treatment was not feasible. In 9 patients (15%) re-RT was interrupted prematurely and in other 9, the complete re-RT dose was lower than 60 Gy, and 37 patients (61%) could not receive or complete chemotherapy. Two-year OS, PFS and LRC rates were 19%, 18% and 30%, respectively. 20 patients (33%) received the complete intended treatment, and 1- and 2-year OS rates were 70% and 47%, respectively. Charlson comorbidity index was an important predictor for treatment completion. Multivariate analysis revealed recurrent N stage 0-1, age, chemotherapy administration and re-RT dose of 60 Gy as prognostic factors for clinical outcomes. No grade 5 re-RT-related toxicity was observed. The most common new grade ≥3 acute toxicities were dysphagia (52%) and mucositis (46%). Late toxicity included grade ≥3 dysphagia in 5% and osteoradionecrosis in 10% of evaluable patients, respectively. 6 patients (10%) were alive after 9 years without progression and no late toxicity grade ≥3, except for 2 patients presenting with osteoradionecrosis.

Conclusion

Hyperfractionated re-RT with 60 Gy combined with platinum-based chemotherapy was a curative treatment option with acceptable toxicity in LRR/SP patients. Patients with higher comorbidity had a higher probability of failing to receive and complete the intended therapy. Consequently, they derived unsatisfactory benefits from re-RT, highlighting the importance of patient selection.

Re-Irradiation for Recurrent Head and Neck Cancer: Freedom from Cancer Recurrence Rate

Salvage re-irradiation (rRT) for patients with locoregionally recurrent head and neck cancer (rHNC) remains challenging. A retrospective analysis was performed on 49 patients who received rRT between 2011 and 2018. The co-primary endpoint of the study was 2-year freedom from cancer recurrence rate (FCRR) and overall survival (OS), and secondary endpoints were 2-year disease-free survival (DFS), local failure (LF), regional failure (RF), distant metastases (DM), and RTOG grade 3 ≥ late toxicities. Adjuvant and definitive rRT were delivered to 22 and 27 patients, respectively. A total of 91% of patients were managed with conventional re-RT and 71% of patients received concurrent chemotherapy. The median follow-up after rRT was 30 months. The 2-year FCRR, OS, DFS, LF, RF, and DM were 64%, 51%, 28%, 32%, 9%, and 39% respectively. MVA showed that poor performance status (PS: 1-2 vs. 0) and age > 52 years were predictive of worse OS. In comparison, poor PS (1-2 vs. 0) and total dose of rRT < 60 Gy were predictive of worse DFS. Late RTOG toxicity of grade 3 ≥ was reported in nine (18.3%) patients. FCRR at 2 years after salvage rRT for rHNC was higher than other traditional endpoints and could be an important endpoint to be included in future rRT studies. rRT for rHNC at our cohort was relatively successful, with a manageable level of late severe toxicity. Replacing this approach in other developing countries is a viable option.