Intensity-modulated radiotherapy in head and neck cancer: results of the prospective study GORTEC 2004-03

Quantification of beam size impact on intensity-modulated proton therapy with robust optimization in head and neck cancer-comparison with intensity-modulated radiation therapy

We assessed the effect of beam size on plan robustness for intensity-modulated proton therapy (IMPT) of head and neck cancer (HNC) and compared the plan quality including robustness with that of intensity-modulated radiation therapy (IMRT). IMPT plans were generated for six HNC patients using six beam sizes (air-sigma 3-17 mm at isocenter for a 70-230 MeV) and two optimization methods for planning target volume-based non-robust optimization (NRO) and clinical target volume (CTV)-based robust optimization (RO). Worst-case dosimetric parameters and plan robustness for CTV and organs-at-risk (OARs) were assessed under different scenarios, assuming a ± 1-5 mm setup error and a ± 3% range error. Statistical comparisons of NRO-IMPT, RO-IMPT and IMRT plans were performed. In regard to CTV-D99%, RO-IMPT with smaller beam size was more robust than RO-IMPT with larger beam sizes, whereas NRO-IMPT showed the opposite (P < 0.05). There was no significant difference in the robustness of the CTV-D99% and CTV-D95% between RO-IMPT and IMRT. The worst-case CTV coverage of IMRT (±5 mm/3%) for all patients was 96.0% ± 1.4% (D99%) and 97.9% ± 0.3% (D95%). For four out of six patients, the worst-case CTV-D95% for RO-IMPT (±1-5 mm/3%) were higher than those for IMRT. Compared with IMRT, RO-IMPT with smaller beam sizes achieved lower worst-case doses to OARs. In HNC treatment, utilizing smaller beam sizes in RO-IMPT improves plan robustness compared to larger beam sizes, achieving comparable target robustness and lower worst-case OARs doses compared to IMRT.

Toxicity and Quality of Life After Locoregional Radiotherapy in Patients With Thyroid Cancer

BACKGROUND

Locoregional external beam radiotherapy (EBRT) is selectively used in thyroid cancer patients to induce locoregional control. However, despite technological advances, EBRT remains associated with toxicities. We evaluated thyroid-cancer specific toxicities and long-term Quality of Life (QoL) post-EBRT.

METHODS

EBRT-treated thyroid cancer patients at Universal Medical Centre Groningen (2007-2023) were retrospectively evaluated (n = 66). Acute (< 6 weeks) and late (≥ 3 months) toxicities and QLQ-H&N35 results, prospectively collected as standard patient care, were analyzed (available in 24/66). Additionally, 17/66 living patients cross-sectionally completed the QLQ-H&N43 [renewed QLQ-H&N35] and SF-36-RAND-36.

RESULTS

In 24/66 patients who completed questionnaires during EBRT treatment, most severe acute toxicities occurred around week 6 (91% dermatitis, 74% pain, 70% hoarseness, 65% dysphagia). Late toxicities included persisting acute toxicities and fibrosis. Six months post-treatment, only QLQ-H&N35 domains "social eating" (p = 0.031) and "dry mouth/sticky saliva" (p = 0.025) were affected, in comparison to pre-radiation. In the 10/17 patients who completed the QLQ-H&N35 6 months post-radiation and the cross-sectionally performed QLQ-H&N43, no long-term mitigation of assessed domains was identified in a longitudinal analysis. The most advanced EBRT technique was associated with better QLQ-H&N43 scores (p = 0.047).

CONCLUSIONS

EBRT causes acute and late toxicities in most thyroid cancer patients and may be associated with a decreased QoL. As these patients generally survive for multiple years, there is a compelling need to minimize toxicities with more refined radiation techniques, such as proton therapy.

Management of unilateral neck irradiation in elderly patients with head and neck cancer: Which place for hypofractionation? A single-centre experience of 43 patients

PURPOSE OF THE STUDY

The purpose of the study was to evaluate retrospectively the acute toxicity and efficacy in terms of locoregional control of a cervical lymph node irradiation using a hypofractionated regimen in frail elderly patients.

MATERIAL AND METHODS

Patients receiving unilateral hypofractionated cervical lymph node irradiation at the Institut de cancérologie de Lorraine (France) were retrospectively included. The treatment regimen consisted of delivering 54Gy in 18 fractions to the high-risk tumour or lymph node volume and 45Gy to the prophylactic volume using the technique of simultaneous integrated-boost without concomitant systemic treatment. Toxicity data according to the Common Terminology Criteria for Adverse Events version 4 and survival data were collected.

RESULTS

Forty-three patients were treated between January 2013 and July 2021. The median age was 83 years (range: 78-86.5 years), 32 patients (74.4 %) were male and 25.6 % had WHO status ≥ 2. Histological types were cutaneous squamous cell carcinoma (39 patients), salivary gland carcinoma (three patients) and Merkel cell carcinoma (one patient). The mean duration of treatment was 27 days. Seventeen patients (39.5 %) received radiotherapy alone. Acute toxicity events of grade ≥ 2 at the end of radiotherapy in the 43 patients were described as follows: 58.1 % radiodermatitis (25 patients), 24.6 % mucositis (11 patients), and 18.1 % xerostomia (eight patients). Seven patients (16.3 %) experienced grade ≥ 2 odynodysphagia, with four patients (9.3 %) requiring enteral nutrition. No grade 3 toxicity events were reported at 3 months, 6 months or 1 year. After a median follow-up of 9.2 months (range: 6-18.5 months), 11 patients (25.6 %) of those treated by exclusive irradiation had a complete locoregional response as assessed by CT-scan 3 months. At 6 months, two of 20 patients retained grade 2 xerostomia and only four of 20 patients reported residual grade 1 pain.

CONCLUSION

Moderately hypofractionated unilateral cervical lymph node radiotherapy appears to be well tolerated in frail elderly patients with an acceptable locoregional control rate, potentially providing an alternative to palliative strategies.

Acute toxicities in proton therapy for head and neck cancer - A matched analysis of the DAHANCA 35 feasibility study

Background and purpose

As preparation for a national randomized study comparing proton radiotherapy to photon radiotherapy, DAHANCA 35, we performed a non-randomized pilot study to investigate patient selection, logistics, planning, and treatment delivery. With the present study, as a comprehensive safety analysis, we want to compare toxicity during and up to two months after therapy to a historically matched group of patients treated with photon radiotherapy.

Materials and methods

62 patients treated with protons were matched to 124 patients who received photon treatment outside a protocol. Available data were retrieved from the DAHANCA database. Patients were matched on treatment centre, concurrent chemotherapy, tumour site, stage, p16 status for oropharynx cancers. Selection of patients for proton therapy was based on comparative treatment plans with a NTCP reduction for dysphagia and xerostomia at six months.

Results

Baseline characteristics between groups were well balanced, except for the type of drug used concurrently; more photon patients received Carboplatin (21.2 % vs 5.8 %, p = 0.01). Proton therapy was associated with significantly less weight loss at the end of treatment, mean weight loss of 3 % for protons and 5 % for photons (p < 0.001). There were more grade 3 skin reactions and grade 3 mucositis after proton treatment compared with photons at the end of treatment, Risk Ratio (RR) 1.9 (95 % CI: 1.01-3.5, p = 0.04) and RR 1.5 (95 % CI: 1.3-1.7, p < 0.001), respectively. All differences resolved at follow up two months after treatment. There were no significant differences between groups on opioid use, use of feeding tubes, or hospitalization during the observation period.

Conclusion

Proton treatment resulted in excess objective mucositis and dermatitis, which was transient and did not seem to negatively influence weight or treatment compliance and intensity. Selection bias was likely especially since NTCP models were used for selection of proton treatment and photon treated patients were matched manually. We are currently including patients in a randomized controlled trial.

Does lower dose pilocarpine have a role in radiation-induced xerostomia in the modern radiotherapy era? A single-center experience based on patient-reported outcome measures

PURPOSE

This study aims to investigate the efficacy of lower dose pilocarpine in alleviating late dry mouth symptoms in head and neck cancer patients received radiotherapy.

METHODS

Eighteen head and neck cancer patients experiencing persistent dry mouth were enrolled in this study. All participants started pilocarpine treatment a median of 6 months post-radiotherapy. Initially, patients received pilocarpine at 5 mg/day, with a gradual increase to the recommended dose of 15 mg/day. A Patient-Reported Outcome Measurement (PROMs) questionnaire assessed symptoms' severity related to hyposalivation.

RESULTS

All patients reported symptomatic dry mouth above grade 2 before starting the medication. Pilocarpine treatment continued based on patients' self-assessment, with a median duration of 12 months (range, 3-36 months). The median daily maintenance dose was 10 mg (range, 5 to 20 mg). Total PROMs scores significantly decreased following medication, from 13 points (range 7-18 points) to 7 points (range 4-13 points) (p = 0.001). Significant improvements were observed in questions related to dry mouth (p < 0.001), water intake during eating (p = 0.01), carrying water (p = 0.01), taste (p < 0.001), and water intake during speech (p < 0.001). Initial and maintenance doses of pilocarpine were lower, and the duration of pilocarpine usage was shorter in patients treated with intensity-modulated radiation therapy compared to conformal radiotherapy (12 months vs. 25 months, p = 0.04).

CONCLUSION

Pilocarpine may be considered at doses lower for late-term dry mouth. With modern radiotherapy techniques effectively preserving the parotid gland, short-term use may be recommended in these patients. Future studies may enhance the development of a more robust patient selection criteria model.

Long-term outcomes of stimulated salivary flow and xerostomia after definitive intensity-modulated radiation therapy for patients with head and neck cancer†

This retrospective study aimed to evaluate the time to recovery from xerostomia and analyze its predictors, along with long-term outcomes of stimulated salivary flow after intensity-modulated radiation therapy (IMRT) for head and neck cancer (HNC). We evaluated patients with HNC who had received IMRT with curative intent between 2012 and 2018 at our institution. The salivary recovery ratio (SRR) was defined as '(the stimulated salivary flow)/(pre-treatment salivary flow)'. The cutoff value of SRR in salivary recovery was estimated via the relationship between SRR and xerostomia grades. The salivary recovery time was defined as the time for SRR to exceed cutoff values from the end of radiotherapy. Fifty-seven patients were analyzed, with a 48-month median follow-up period of stimulated salivary flow. The cutoff value for SRR was 44.8%, and patients with a higher grade of xerostomia had a lower SRR (P < 0.001). The median salivary recovery time was 12 months. The cumulative incidence rates of salivary recovery at two and four years were 84 (95% confidence interval [CI]: 53-79) and 92% (95% CI: 82-97), respectively, and these were significantly lower in patients with a higher mean parotid gland dose, mean oral cavity dose and stimulated salivary flow per parotid gland volume. Stimulated salivary flow and xerostomia recover over a long period after radiotherapy.

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.

Quantification of very late xerostomia in head and neck cancer patients after irradiation

Objective

Radiation therapy (RT) for head and neck cancer (HNC) can result in severe xerostomia, or the subjective feeling of dry mouth. Characterizing xerostomia is critical to designing future clinical trials investigating how to improve HNC patients' quality of life (QoL). Few studies have investigated the very late (>5 years post-RT) effects of RT for HNC. We undertook preliminary studies quantifying very late xerostomia.

Methods

Six adults who underwent RT for HNC at least 5 years prior and reported xerostomia were enrolled. Five healthy adults without a self-reported history of HNC or xerostomia were enrolled as controls. All participants completed three validated surveys to measure xerostomia-related QoL. Salivary production rates were measured and compositional analysis of the saliva and oral microbiome was completed.

Results

The QoL survey scores for the HNC participants were significantly worse as compared to the control participants. The HNC participants produced less unstimulated saliva (p = .02) but not less stimulated saliva. The median salivary mucin significantly higher in HNC participants than in control participants (p = .02). There was no significant difference between the pH, amylase, or total protein. Microbiome analysis revealed alpha diversity to be significantly lower in the HNC participants.

Conclusion

In the survivors of HNC who suffer from late toxicities, multiple means of measuring toxicity may be useful. We found that in patients with radiation-induced xerostomia over 5 years after therapy, not only were the QoL surveys significantly worse, as expected, but other measurements such as mucin and oral microbiome diversity were also significantly different.

Level of evidence

3.

Management of clinically node-negative glottic squamous cell carcinoma patients according to risk-scoring model for occult lymph node metastases

Background

Glottic squamous cell carcinoma (GSCC) is the most prevalent type of laryngeal carcinoma. The value of prophylactic lymph node dissection (LND) in resected GSCC remains controversial. This study aims to quantitatively assess the probability of occult lymph node metastasis (LNM) for GSCC patients and devise individualized postoperative radiotherapy strategies.

Methods

A total of 1319 patients with GSCC were retrospectively analyzed.

Results

GSCC patients with T1-T2 stages showed significantly lower LNM rate than those with T3-T4 stages. For patients with T3-T4 GSCC, multivariate logistic analyses indicated that three factors-maximum tumor diameter (MTD) of more than 2.0 cm, relatively low differentiation, and tumor invasive depth of no less than 1.0 cm-were independent risk factors for the existence of LNM. A predictive nomogram was established based on these factors. The accuracy and validity of our model were verified by 0.716 and remained at 0.717 after 1000 bootstrapping. The calibration curve was also plotted and showed a favorable agreement. The patients were stratified into two groups based on their individual LNM risk points. Possible LNM rates for low-risk and high-risk subgroups were 4.7% and 25.2%, respectively.

Conclusions

A new post-operative strategy selection flow chart was established based on our newly created nomogram which can effectively predict the individualized possibility of occult LNM for GSCC patients. For clinical T3-4N0 patients in the high-risk subgroup, prophylactic dose post-operative radiation therapy is recommended. However, for all those clinically diagnosed as T1-2N0 stage, regular follow-up is sufficient in view of the low occult LNM rate.Level of Evidence: 2a.

Indication to postoperative radiotherapy for oral cavity squamous cell carcinoma: what’s new in the Depth of Infiltration (DOI) era?

Objectives:

The last edition of the American Joint Committee on Cancer (AJCC eighth) has introduced the depth of infiltration (DOI) as a new prognostic parameter in oral cavity squamous cell carcinomas (OCSCCs). Aim of this study is to analyze the impact of stage migration on the indication to postoperative radiotherapy (PORT).

Methods:

OCSCCs treated at two Institutions between 2014 and 2019 were retrieved. Per the AJCC eighth, only pT3 primarily OCSCCs were considered; availability of the pathologic specimen was a further inclusion criterion. Risk factors considered for PORT were: pT3-pT4, nodal involvement, positive/close surgical margins, perineural and lymph vascular invasion.

Results:

One-hundred forty-nine patients staged as pT3 AJCC eighth were included. A four-fold increase in the number of patients staged as pT3 from the seventh to the eighth AJCC was found. Stage migration to pT3 was equally due to the downstaging from former pT4 (38%) and upstaging of former pT1-pT2 (35%). Considering the former pT1-pT2 53 patients, 13 (25%) had no risk factors for PORT other than DOI. Among 25 cases with former pT1-pT2 and negative lymph nodes no additional risk factors were found in 11 (44%).

Conclusion:

Ninety percent of patients had at least one risk factor besides DOI and would have received PORT also according to the AJCC seventh; notably, of former pT1-pT2N0, half of them have been upstaged to pT3 in the current TNM classification. The role of PORT in this cohort of patients has not been clarified yet.

Advances in knowledge:

Other-than-DOI risk factors leading to PORT indication are highly prevalent in OCSSC patients classified as pT3 per the latest AJCC TNM staging system and should therefore be considered for a comprehensive oncological assessment.

Do grape and black mulberry molasses have an effect on oral mucositis and quality of life in patients with head and neck cancer?

OBJECTIVE

We aimed to investigate the effect of black mulberry and grape molasses on the prevention and treatment of oral mucositis and quality of life (QoL) in patients with head and neck cancer (HNC).

METHODS

Patients treated for HNC between 2010 and 2018 in our department were divided into three groups (group 1 = control (n = 14), group 2 = grape molasses (n = 40), and group 3 = black mulberry molasses (n = 40)). Oral mucositis, pain scoring, and weight loss were evaluated weekly. The European Organization for Research and Treatment of Cancer (EORTC) General QoL Questionnaire (QLQ-C30) and EORTC Head and Neck Cancer QoL Module (QLQ-HN35) were used to evaluate QoL.

RESULTS

The mean body weight, scores of oral mucositis, and pain were similar among the groups throughout the treatment. Both groups 2 and 3 were associated with improved outcomes for swallowing, opening mouth, and weight loss in the EORTC HN35, and these parameters were not significantly different between groups 2 and 3. Global health score was higher in group 3 at the 6th week of RT compared to that of group 2. Both groups 2 and 3 had improved scores for role functioning, emotional and social functioning, fatigue, appetite loss, and pain throughout the treatment compared to group 1.

CONCLUSIONS

Both grape and black mulberry molasses improved the QoL in HNC patients. No significant difference between black mulberry and grape molasses was found with regard to the healing of oral mucositis.

Patient-Reported Toxicity and Quality-of-Life Profiles in Patients With Head and Neck Cancer Treated With Definitive Radiation Therapy or Chemoradiation

PURPOSE

Radiation therapy is an effective but burdensome treatment for head and neck cancer (HNC). We aimed to characterize the severity and time pattern of patient-reported symptoms and quality of life in a large cohort of patients with HNC treated with definitive radiation therapy, with or without systemic treatment.

METHODS AND MATERIALS

A total of 859 patients with HNC treated between 2007 and 2017 prospectively completed the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Head and Neck Cancer module (QLQ-HN35) and Core Quality of Life Questionnaire (QLQ-C30) at regular intervals during and after treatment for up to 5 years. Patients were classified into 3 subgroups: early larynx cancer, infrahyoideal cancer, and suprahyoideal cancer. Outcome scales of both questionnaires were quantified per subgroup and time point by means of average scores and the frequency distribution of categorized severity (none, mild, moderate, and severe). Time patterns and symptom severity were characterized. Toxicity profiles were compared using linear mixed model analysis. Additional toxicity profiles based on age, human papillomavirus status, treatment modality, smoking status, tumor site, and treatment period were characterized as well.

RESULTS

The study population consisted of 157 patients with early larynx cancer, 304 with infrahyoideal cancer, and 398 with suprahyoideal cancer. The overall questionnaire response rate was 83%. Generally, the EORTC QLQ-HN35 symptoms reported showed a clear time pattern, with increasing scores during treatment followed by a gradual recovery in the first 2 years. Distinct toxicity profiles were seen across subgroups (P < .001), with generally less severe symptom scores in the early larynx subgroup. The EORTC QLQ-C30 functioning, quality-of-life, and general symptoms reported showed a less evident time pattern and less pronounced differences in mean scores between subgroups, although differences were still significant (P < .001). Differences in mean scores were most pronounced for role functioning, appetite loss, fatigue, and pain.

CONCLUSIONS

We established patient-reported toxicity and quality-of-life profiles that showed different patterns for 3 subgroups of patients with HNC. These profiles provide detailed information on the severity and persistence of various symptoms as experienced by patients during and after definitive radiation therapy. These profiles can be used to inform treatment of future patients and may serve as a benchmark for future studies.

Risk stratification and corresponding postoperative treatment strategies for occult contralateral lymph node metastasis in pyriform sinus squamous cell carcinoma patients with ipsilateral node-positive necks

Background

To quantitatively predict the probability of occult contralateral lymph node metastasis (cLNM) for pyriform sinus squamous cell carcinoma (PSSC) patients with ipsilateral node-positive necks to guide postoperative adjuvant treatment.

Methods

Two hundred and twenty-seven PSSC patients with ipsilateral lymph node metastasis (iLNM) were retrospectively analyzed.

Results

Multivariate logistic analyses showed that five factors including maximum tumor diameter (MTD) of more than 4.0 cm, existence of tumor extension across the midline (EAM), internal jugular vein adhesion (IJVA), lymphovascular invasion (LVI), and lymph nodal fusion (LNF) were independent risk factors for cLNM. A predictive nomogram was created based on these factors. The accuracy and validity of our model were verified by concordance index (C-index) 0.862 [95% confidence interval (CI): 0.810–0.914] in development cohort and 0.860 (95% CI: 0.820–0.900) after 1,000 bootstrapping. The calibration curve also showed a relatively favorable agreement. We then stratified patients into three groups based on their cLNM risk scores. Possible cLNM rates for low-risk, moderate-risk, and relatively high-risk subgroups were 3.6%, 21.8%, and 60.7%, respectively.

Conclusions

A new postoperative adjuvant radiotherapy (PART) strategy selection flow chart was created for PSSC patients based on our newly built nomogram which can effectively predict the individualized possibility of cLNM. For patients in high-risk subgroup, therapeutic-dose PART is highly recommended even for those with contralateral clinical N0 neck disease. For those in moderate-risk subgroup, prophylactic-dose PART is recommended. However, for patients in low-risk subgroup, regular follow-up is sufficient given the extremely low occult cLNM rate.

Comparing the 7th and 8th editions of UICC/AJCC staging system for nasopharyngeal carcinoma in the IMRT era

Background

To compare the prognostic value of 7th and 8th editions of the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system for patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy and simultaneous integrated boost– intensity-modulated radiation therapy (SIB-IMRT).

Methods

Patients with NPC (n = 300) who received SIB-IMRT were included. Survival by T-classification, N-classification, and stage group of each staging system was assessed.

Results

For T-classification, nonsignificant difference was observed between T1 and T3 and between T2 and T3 disease (P = 0.066 and 0.106, respectively) for overall survival (OS) in the 7th staging system, whereas all these differences were significant in the 8th staging system (all P < 0.05). The survival curves for disease-free survival (DFS) and locoregional recurrence-free survival (LRRFS) in both staging systems were similar, except for the comparison of T2 and T4 disease for LRRFS (P = 0.070 for 7th edition; P = 0.011 for 8th edition). For N-classification, significant differences were observed between N2 and N3 diseases after revision (P = 0.046 and P = 0.043 for OS and DFS, respectively). For staging system, no significant difference was observed between IVA and IVB of 7th edition.

Conclusion

The 8th AJCC staging system appeared to have superior prognosis value in the SIB-IMRT era compared with the 7th edition.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08036-8.

Impact of the method chosen for the analysis of recurrences after radiotherapy for head and neck cancers: volume-based, point-based and combined methods

Intensity modulated radiation therapy for head and neck is a complex technique. Inappropriate delineation and/or dose distribution can lead to recurrences. Analysis of these recurrences should lead to improve clinical practice. For several years, different methods of analysis have been described. The purpose of this review is to describe these different methods and to discuss their advantages and limitations. The first published methods used a volume-based approach studying the entire volume of recurrence according to initial target volumes, or dose distribution. The main limitation of these methods was that the volume of recurrence studied was dependent on the delay in diagnosis of that recurrence. Subsequently, other methods used point-based approaches, conceptualizing recurrence either as a spherical expansion from a core of radioresistant cells (center of mass of recurrence volume) or using a more clinical approach, taking into account tumor expansion pathways. More recently, more precise combined methods have been described, combining the different approaches. The choice of method is decisive for conclusions on the origin of recurrence.

Assessment and treatment strategies for occult contralateral lymph node metastasis in hypopharyngeal squamous cell carcinoma patients with ipsilateral node-positive necks

Hypopharyngeal squamous cell carcinoma (HSCC) is an aggressive disease with poor prognosis, yet studies have largely been more qualitatively focused. Our study aims to quantitatively predict the risk of occult contralateral lymph node metastasis (cLNM) for HSCC patients with ipsilateral lymph node metastasis (iLNM). This will be based on pre- and post-operative indexes to guide the selection of prophylactic contralateral lymph node dissection (cLND) and postoperative adjuvant treatments. Multivariate analyses of 462 primary HSCC patients with iLNM showed that the age of patients, subregions of tumor, pathological T (pT) stage, ipsiateral MLS and metastatic lymph node number (MLN), and lymph nodal necrosis were independent cLNM risk factors. These were used to construct two nomograms that can effectively predict the contralateral neck involvement in HSCC patients with ipsilateral positive lymph nodes. The first nomogram (pre-model) provides quantitative assessment on the necessity of cLND, while the second nomogram (post-model) informs regions of interest for therapeutic radiation. Overall, patients deemed high-risk of cLNM by pre-model should receive cLND. Post-operation, patients deemed high-risk of cLNM by post-model should receive therapeutic radiation targeting contralateral neck lymph nodes, moderate-risk group warrants comparatively lower dose contralaterally, while low-risk group requires only follow-up.

Results of radiotherapy in squamous cell laryngeal cancer: A tomotherapy center experience

Background

Laryngeal cancer is a common type of head and neck cancer (HNC). Radiotherapy (RT) is a mainstay for curative treatment. Intensity-modulated RT (IMRT) is a standard technique today, as it provides of higher survival and local control and lower normal tissue toxicity. One of IMRT devices is helical tomotherapy (HT). The HT treatment results of HNC patients have been reported in few studies. We aimed to investigate the results of squamous cell laryngeal carcinoma patients treated with helical tomotherapy.

Methods

Forty-five laryngeal cancer patients were selected according to the inclusion criteria. Radiotherapy (RT) plans were set in the Hi-Art HT planning system. Image-gated RT (IGRT) technique was used. Appropriate patients received simultaneous cisplatin. Treatment response rates were evaluated at the post-RT third and sixth months. Survival times were calculated with the Kaplan-Meier method. The factors affecting the treatment results were evaluated using Log-rank and Cox regression tests. A P value of less than 0.05 was accepted as statistically significant.

Results

The median age was 65 (28-84) years. The median symptom duration was 6 (1-60) months. The RT dose for the early and the locally advanced disease was median 63 Gy (60.75-66) and 66 Gy (60-70), respectively. The RT interruption was median two (0-20) days. The patients were followed up to 25 (1-45) months. Grade 2 xerostomia and dysphagia rates were 55% and 7%, respectively. The 3-year estimates of overall survival (OS), disease-free survival (DFS), metastasis-free survival (DMFS), and locoregional recurrence-free survival (RRFS) were 71.7%, 60.4%, 84.9%, and 68.5%, respectively. In univariate analysis, the presence of N2 disease was a negative prognostic for DFS (P = 0.05) and DMFS (P = 0.003). RT interruption >2 days was a negative prognostic for OS (P = 0.005), DFS (P = 0.02), and RRFS (P = 0.023). In the multivariate analysis, symptom duration >6 months was found to be the only significant factor for DFS (P < 0.05).

Conclusion

Intensity-modulated radiation with HT achieved comparable clinical outcomes with acceptable toxicity in laryngeal carcinoma.

Parotid gland stem cells: Mini yet mighty

BACKGROUND

Our aim was to evaluate the correlation between the radiation doses to parotid gland (PG) stem cells and xerostomia.

METHODS

Patients diagnosed with head and neck cancer (HNC) were retrospectively evaluated, and xerostomia inventory (XI) was applied to these patients. PG stem cells were delineated on the treatment planning CT, and the mean doses to the PG stem cells calculated.

RESULTS

The total test score and mean doses to bilateral PGs were significantly correlated (r = .34, P = .001), and the mean doses to bilateral PG stem cell niches were significantly correlated with the total test score (r = .32, P = .002).

CONCLUSIONS

In this study, we found that the mean dose to PG stem cells can predict dry mouth as much as the mean dose to the PG.

Short-term and long-term unstimulated saliva flow following unilateral vs bilateral radiotherapy for oropharyngeal carcinoma

BACKGROUND

We aimed to compare unstimulated saliva flow using 3-minute modified Schirmer test (MST) following bilateral vs unilateral radiotherapy (RT) in oropharyngeal carcinoma (OPC).

METHODS

We reviewed OPC patients treated with definitive intensity-modulated radiation therapy (IMRT) between 2011 and 2017. MST was measured at baseline, 1-/6-/12-/24-month post-RT. MST values were compared between bilateral-RT vs unilateral-RT groups. Multivariable logistic regression analysis (MVA) identified predictors of hyposalivation (MST < 25 mm).

RESULTS

Total 498 bilateral-RT and 36 unilateral-RT patients were eligible. The MST values at 1-/6-/12-/24-month post-RT were all significantly reduced from baseline for the entire cohort. Baseline unilateral-RT and bilateral-RT MST values (in mm) were similar (P = .2), but much higher for unilateral-RT 1-month (mean: 19.1 vs 13.0, P = .03), 6-month (20.5 vs 9.3, P < .001), 12-month (20.1 vs 11.9, P < .01), and 24-month post-RT (22.2 vs 13.9, P = .04). MVA confirmed that unilateral RT reduced the likelihood of hyposalivation vs bilateral RT (OR 2.36, P = .006).

CONCLUSION

Unilateral RT reduces unstimulated salivary flow in OPC patients.

Comparison of CBCT-based dose calculation methods in head and neck cancer radiotherapy: from Hounsfield unit to density calibration curve to deep learning

PURPOSE

Anatomical variations occur during head and neck (H&N) radiotherapy treatment. kV cone-beam computed tomography (CBCT) images can be used for daily dose monitoring to assess dose variations owing to anatomic changes. Deep learning methods (DLMs) have recently been proposed to generate pseudo-CT (pCT) from CBCT to perform dose calculation. This study aims to evaluate the accuracy of a DLM and to compare this method with three existing methods of dose calculation from CBCT in H&N cancer radiotherapy.

METHODS

Forty-four patients received VMAT for H&N cancer (70-63-56 Gy). For each patient, reference CT (Bigbore, Philips) and CBCT images (XVI, Elekta) were acquired. The DLM was based on a generative adversarial network. The three compared methods were: (a) a method using a density to Hounsfield Unit (HU) relation from phantom CBCT image (HU-D curve method), (b) a water-air-bone density assignment method (DAM), and iii) a method using deformable image registration (DIR). The imaging endpoints were the mean absolute error (MAE) and mean error (ME) of HU from pCT and reference CT (CT_ref ). The dosimetric endpoints were dose discrepancies and 3D gamma analyses (local, 2%/2 mm, 30% dose threshold). Dose discrepancies were defined as the mean absolute differences between DVHs calculated from the CT_ref and pCT of each method.

RESULTS

In the entire body, the MAEs and MEs of the DLM, HU-D curve method, DAM, and DIR method were 82.4 and 17.1 HU, 266.6 and 208.9 HU, 113.2 and 14.2 HU, and 95.5 and -36.6 HU, respectively. The MAE obtained using the DLM differed significantly from those of other methods (Wilcoxon, P ≤ 0.05). The DLM dose discrepancies were 7 ± 8 cGy (maximum = 44 cGy) for the ipsilateral parotid gland D_mean and 5 ± 6 cGy (max = 26 cGy) for the contralateral parotid gland mean dose (D_mean ). For the parotid gland D_mean , no significant dose difference was observed between the DLM and other methods. The mean 3D gamma pass rate ± standard deviation was 98.1 ± 1.2%, 91.0 ± 5.3%, 97.9 ± 1.6%, and 98.8 ± 0.7% for the DLM, HU-D method, DAM, and DIR method, respectively. The gamma pass rates and mean gamma results of the HU-D curve method, DAM, and DIR method differed significantly from those of the DLM.

CONCLUSIONS

For H&N radiotherapy, DIR method and DLM appears as the most appealing CBCT-based dose calculation methods among the four methods in terms of dose accuracy as well as calculation time. Using the DIR method or DLM with CBCT images enables dose monitoring in the parotid glands during the treatment course and may be used to trigger replanning.

Intensity-Modulated Radiotherapy-Based Reirradiation for Head and Neck Cancer: A Multi-institutional Study by Korean Radiation Oncology Group (KROG 1707)

Purpose

The benefits of reirradiation for head and neck cancer (HNC) have not been determined. This study evaluated the efficacy of reirradiation using intensity-modulated radiotherapy (IMRT) for recurrent or second primary HNC (RSPHNC) and identified subgroups for whom reirradiation for RSPHNC is beneficial.

Materials and Methods

A total of 118 patients from seven Korean institutions with RSPHNC who underwent IMRT-based reirradiation between 2006 and 2015 were evaluated through retrospective review of medical records. We assessed overall survival (OS) and local control (LC) within the radiotherapy (RT) field following IMRT-based reirradiation. Additionally, the OS curve according to the recursive partitioning analysis (RPA) suggested by the Multi-Institution Reirradiation (MIRI) Collaborative was determined.

Results

At a median follow-up period of 18.5 months, OS at 2 years was 43.1%. In multivariate analysis, primary subsite, recurrent tumor size, interval between RT courses, and salvage surgery were associated with OS. With regard to the MIRI RPA model, the class I subgroup had a significantly higher OS than class II or III subgroups. LC at 2 years was 53.5%. Multivariate analyses revealed that both intervals between RT courses and salvage surgery were prognostic factors affecting LC. Grade 3 or more toxicity and grade 5 toxicity rates were 8.5% and 0.8%, respectively.

Conclusion

IMRT-based reirradiation was an effective therapeutic option for patients with RSPHNC, especially those with resectable tumors and a long interval between RT courses. Further, our patients' population validated the MIRI RPA classification by showing the difference of OS according to MIRI RPA class.

Reirradiation with intensity-modulated radiation therapy for recurrent or secondary head and neck cancer: Meta-analysis and systematic review

BACKGROUND

To summarize outcomes of reirradiation with intensity-modulated radiotherapy (IMRT) for recurrent or secondary head and neck cancer (HNC).

METHODS

Primary endpoints were 2-year local control (LC) and overall survival (OS). Studies involving only recurrent nasopharyngeal patients with cancer were excluded.

RESULTS

A total of 17 studies involving 1635 patients were included. Fourteen (82%) of those were retrospective, and 15 (88%) were from single institution. Reirradiation with IMRT produced pooled 2-year LC and OS rates of 52% (95% confidence interval [CI], 46%-57%) and 46% (95% CI, 41%-50%), respectively. In subgroup analyses, the rate of salvage surgery (<42% vs ≥42%) influenced the pooled 2-year LC rate (45.9% vs 58.5%, P = .011). The pooled rates of late grade ≥ 3 and grade 5 toxicities were 26% (95% CI, 20%-32%) and 3.1% (95% CI, 2%-5%), respectively.

CONCLUSIONS

Reirradiation with IMRT was an effective modality compared to historical outcomes in the pre-IMRT era.

Correlation of intensity-modulated radiation therapy at a specific radiation dose with the prognosis of nasal mucous damage after radiotherapy

Objective of the present study was to investigate the tolerant radiation dose of nasal mucosa by observing and analyzing patients who received intensity-modulated radiation therapy (IMRT). Patients with nasopharyngeal carcinoma (N = 66) were selected for this study. The modified saccharin assay, endoscopy test, magnetic resonance imaging, and sino-nasal outcome test-20 (SNOT-20) survey were performed for the patients before and at 0 (T0), 3 (T1), 6 (T2), and 12 (T3) months after radiotherapy. The threshold doses of IMRT before radiotherapy and at T0, T1, T2, and T3 were determined as, respectively, 37 Gy, 37 Gy, 39 Gy, and 37 Gy for the saccharin test; 38 Gy, 37 Gy, 40 Gy, and 38 Gy for the endoscopy test; and 39 Gy, 37 Gy, 39 Gy, and 39 Gy for the nasal-related symptom scoring test. The modified saccharin assay, endoscopy test, and SNOT-20 survey revealed that a low dose (< threshold dose) of IMRT was associated with higher mucocilia transport rate (MRT), better endoscopy test score, and improved SNOT-20 score. The patients who received IMRT at a dose less than the threshold had the least damaged nasal mucosa morphology, and functional impairment scores were highest at T1 of IMRT. We conclude that nasal mucosa showed the most serious damage within 3 months after IMRT. If the radiation dose can be controlled within the threshold, the nasal mucosa can recover in the following few months, but recovery will be difficult otherwise.

Individualized Prophylactic Neck Irradiation in Patients with cN0 Head and Neck Cancer Based on Sentinel Lymph Node(s) Identification: Definitive Results of a Prospective Phase 1-2 Study

PURPOSE

This prospective, nonrandomized, interventional phase 1-2 study investigated the individualization of elective node irradiation in clinically N0 head and neck squamous cell carcinoma by sentinel lymph node (SLN) mapping with single-photon emission computed tomography/computed tomography (SPECT/CT) and its impact on tumor control and radiation-related toxicity.

METHODS AND MATERIALS

Forty-four patients with clinically N0 head and neck squamous cell carcinoma treated with definitive (chemo-)radiation therapy were imaged with SPECT/CT after ^99mTc nanocolloid injection around the tumor. The neck levels containing up to the 4 hottest SLNs were selected for prophylactic irradiation. A comparative virtual planning was performed with the selection of neck levels based on the current international guidelines. Regional control was monitored as a function of the selected volume. Dosimetric data for the organs at risk were compared between the plans. Normal tissue complication probability (NTCP) rates were derived for xerostomia, dysphagia, and hypothyroidism to predict the clinical benefit and correlated to quality-of-life (QoL) assessments at 6 months.

RESULTS

Sixteen percent of patients presented unpredicted lymphatic drainage, and 48% drained unilaterally. The nodal clinical target volume based on lymphoscintigraphy was smaller than the nodal clinical target volume based on international guidelines by a factor of 2 (P < .0001). After a median follow-up of 46 months, only 1 patient experienced a regional relapse in a nonirradiated area. Significant median dose reductions to organs at risk were observed, particularly to contralateral salivary glands in patients with unilateral drainage (14.6-28.1 Gy) and to the thyroid gland in all patients (22.4-48.9 Gy). Median NTCP reductions were observed for xerostomia (0.3% to 13.7%), dysphagia (1.7% to 10.8%), and hypothyroidism (14.0% to 36.1%). QoL at 6 months was improved, particularly in patients irradiated unilaterally.

CONCLUSIONS

Neck SLN mapping with SPECT/CT individualizes and reduces the elective nodal target volumes without compromising the regional control. The NTCP rates were reduced and favorable QoL were observed in all patients, particularly in the case of unilateral irradiation.

Implementation of an optimization method for parotid gland sparing during inverse planning for head and neck cancer radiotherapy

PURPOSE

To guide parotid gland (PG) sparing at the dose planning step, a specific model based on overlap between PTV and organ at risk (Moore et al.) was developed and evaluated for VMAT in head-and-neck (H&N) cancer radiotherapy.

MATERIALS AND METHODS

One hundred and sixty patients treated for locally advanced H&N cancer were included. A model optimization was first performed (20 patients) before a model evaluation (110 patients). Thirty cases were planned with and without the model to quantify the PG dose sparing. The inter-operator variability was evaluated on one case, planned by 12 operators with and without the model. The endpoints were PG mean dose (D_mean), PTV homogeneity and number of monitor units (MU).

RESULTS

The PG D_mean predicted by the model was reached in 89% of cases. Using the model significantly reduced the PG D_mean: -6.1±4.3Gy. Plans with the model showed lower PTV dose homogeneity and more MUs (+10.5% on average). For the inter-operator variability, PG dose volume histograms without the optimized model were significantly different compared to those with the model; the D_mean standard deviation for the ipsilateral PG decreased from 2.2Gy to 1.2Gy. For the contralateral PG, this value decreased from 2.9Gy to 0.8Gy.

CONCLUSION

During the H&N inverse planning, the optimized model guides to the lowest PG achievable mean dose, allowing a significant PG mean dose reduction of -6.1Gy. Integrating this method at the treatment-planning step significantly reduced the inter-patient and inter-operator variabilities.

Cancer Stem Cells in Head and Neck Carcinomas: Identification and Possible Therapeutic Implications

The recurrence and/or lack of response of certain tumors to radio- and chemotherapy has been attributed to a small subpopulation of cells termed cancer stem cells (CSCs). CSCs have been identified in many tumors (including solid and hematological tumors). CSCs are characterized by their capacity for self-renewal, their ability to introduce heterogeneity within a tumor mass and its metastases, genomic instability, and their insensitivity to both radiation and chemotherapy. The latter highlights the clinical importance of studying this subpopulation since their resistance to traditional treatments may lead to metastatic disease and/or tumor relapse. Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common malignancy worldwide with the highest incidence occurring in East Asia and eastern and southern Africa. Several cellular subpopulations believed to have CSC properties have been isolated from HNSCCs, but at present, identification and characterization of CSCs remains an experimental challenge with no established or standardized protocols in place to confirm their identity. In this review we discuss current approaches to the study of CSCs with a focus on HNSCCs, particularly in the context of what this might mean from a therapeutic perspective.

Very late xerostomia, dysphagia, and neck fibrosis after head and neck radiotherapy

BACKGROUND

Acute and late toxicity after intensity-modulated radiotherapy (IMRT) for head and neck cancer (HNC) impacts on patient quality of life; yet, very late toxicity data remain scarce. This study assessed dysphagia, xerostomia, and neck fibrosis 3-8 years after IMRT.

METHODS

A retrospective analysis using generalized estimated equations was performed on 60 patients with HNC treated with fractionated IMRT between 2000 and 2015 who had a follow-up ≥8 years. Toxicity was scored using LENT-SOMA scales.

RESULTS

A trend towards a nonlinear global time effect (P = .05) was noted for dysphagia with a decrease during the 5 years post-treatment and an increase thereafter. A significant decrease in xerostomia (P = .001) and an increase in neck fibrosis (P = .04) was observed until 8 years.

CONCLUSIONS

Dysphagia, xerostomia, and neck fibrosis do not appear stable over time and remain highly prevalent in the very late follow-up. Our findings support the need for prospective trials investigating very late toxicity in patients with HNC.

The effectiveness of intensity-modulated radiation therapy versus 2D-RT for the treatment of nasopharyngeal carcinoma: A systematic review and meta-analysis

BACKGROUND

At present, the management of nasopharyngeal carcinoma (NPC) is mainly based on radiotherapy, but there are many radiation delivery techniques such as intensity-modulated radiotherapy (IMRT) and 2-dimensional radiotherapy (2D-RT).

MATERIALS AND METHODS

We searched all the eligible studies through the PubMed, Cochrane Library, Medline, and Embase. The endpoint events in meta-analysis were overall survival (OS), tumor local control including local-regional free survival (LRFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS), and late toxicities.

RESULTS

A total of ten publications met the criteria and were identified through searches of the databases and references. We included 13304 patients in the meta-analysis, of whom 5212 received IMRT and 8092 were allocated to 2D-RT alone group. Compared with 2D-RT treatment, the IMRT group was associated with a better 5-year OS (OR = 1.70; 95% CI = 1.36-2.12), LRFS (OR = 2.08; 95% CI = 1.82-2.37), and PFS (OR = 1.40; 95% CI = 1.26-1.56). Additionally, the incidence of late toxicities such as late xerostomia (OR = 0.21; 95% CI = 0.09-0.51), trismus (OR = 0.16; 95% CI = 0.04-0.60), and temporal lobe neuropathy (TLN) (OR = 0.40; 95% CI = 0.24-0.67) for NPC patients in IMRT group were significantly lower than 2D-RT.

CONCLUSIONS

The meta-analysis demonstrates that IMRT provides improved long-term tumor overall survival and local control including LRFS and PFS. Additionally, IMRT yields a lower incidence of late toxicities induced by irradiation in NPC patients. Compared to 2D-RT, IMRT may be an effective treatment for patients with NPC. Further intensive studies should be pursued to examine the association.

Head and neck cancer management and cancer stem cells implication

Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal linings of the upper aerodigestive tract and are heterogeneous in nature. Risk factors for HNSCCs are smoking, excessive alcohol consumption, and the human papilloma virus. Conventional treatments are surgery, radiotherapy, chemotherapy, or a combined modality; however, no international standard mode of therapy exists. In contrast to the conventional model of clonal evolution in tumor development, there is a newly proposed theory based on the activity of cancer stem cells (CSCs) as the model for carcinogenesis. This “CSC hypothesis” may explain the high mortality rate, low response to treatments, and tendency to develop multiple tumors for HNSCC patients. We review current knowledge on HNSCC etiology and treatment, with a focus on CSCs, including their origins, identifications, and effects on therapeutic options.

Advantages of using reduced-volume intensity modulated radiation therapy for the treatment of nasopharyngeal carcinoma: a retrospective paired study

BACKGROUND

The definition of clinical target volume (CTV) in intensity modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) has not been addressed. We performed this study to assess the feasibility and efficacy of using IMRT with reduced-volume CTV for the treatment of nasopharyngeal carcinoma.

METHODS

We retrospectively reviewed 293 non-metastatic NPC patients treated with IMRT from 2002 to 2013. A total of 180 matched cases finally included with 90 received conventional-volume IMRT (CV-IMRT) and 90 received reduced-volume IMRT (RV-IMRT). Kaplan-Meier method and log-rank tests were used to compare NPC-specific survival. Multivariate analyses using the Cox proportional hazards model were conducted to detect independent predictors.

RESULTS

With a median follow-up of 70 months, the 3-year overall survival, progression-free survival, distant metastasis-free survival, local recurrence-free survival, regional recurrence-free survival, locoregional recurrence-free survival rates were 88.9, 84.4, 92.2, 91.1, 98.9, 91.1% for the CV-IMRT arm and 92.2, 85.6, 90.0, 93.3, 98.9, 93.3% for the RV-IMRT arm, respectively. None significant survival difference was observed. Additionally, RV-IMRT was associated with reduced risk of late xerostomia (P = 0.039) and hearing loss (P = 0.008), compared versus CV-IMRT.

CONCLUSIONS

The use of RV-IMRT for the treatment of NPC led to comparable survival condition and truly reduced toxicity reactions compared versus CV-IMRT.

A density assignment method for dose monitoring in head-and-neck radiotherapy

BACKGROUND AND PURPOSE

During head-and-neck (H&N) radiotherapy, the parotid glands (PGs) may be overdosed; thus, a tool is required to monitor the delivered dose. This study aimed to assess the dose accuracy of a patient-specific density assignment method (DAM) for dose calculation to monitor the dose to PGs during treatment.

PATIENTS AND METHODS

Forty patients with H&N cancer received an intensity modulated radiation therapy (IMRT), among whom 15 had weekly CTs. Dose distributions were calculated either on the CTs (CT_ref), on one-class CTs (1C-CT, water), or on three-class CTs (3C-CT, water-air-bone). The inter- and intra-patient DAM uncertainties were evaluated by the difference between doses calculated on CT_ref and 1C-CTs or 3C-CTs. PG mean dose (D_mean) and spinal cord maximum dose (D_2%) were considered. The cumulated dose to the PGs was estimated by the mean D_mean of the weekly CTs.

RESULTS

The mean (maximum) inter-patient DAM dose uncertainties for the PGs (in cGy) were 23 (75) using 1C-CTs and 12 (50) using 3C-CTs (p ≤ 0.001). For the spinal cord, these uncertainties were 118 (245) and 15 (67; p ≤ 0.001). The mean (maximum) DAM dose uncertainty between cumulated doses calculated on CTs and 3C-CTs was 7 cGy (45 cGy) for the PGs. Considering the difference between the planned and cumulated doses, 53% of the ipsilateral and 80% of the contralateral PGs were overdosed by +3.6 Gy (up to 8.2 Gy) and +1.9 Gy (up to 5.2 Gy), respectively.

CONCLUSION

The uncertainty of the three-class DAM appears to be clinically non-significant (<0.5 Gy) compared with the PG overdose (up to 8.2 Gy). This DAM could therefore be used to monitor PG doses and trigger replanning.

Practical clinical guidelines for contouring the trigeminal nerve (V) and its branches in head and neck cancers

PURPOSE

The trigeminal nerve (V) is a major route of tumor spread in several head and neck cancers. However, only limited data are currently available for its precise contouring, although this is absolutely necessary in the era of intensity-modulated radiation therapy (IMRT). The purpose of this article is to present practical clinical guidelines for contouring the trigeminal nerve (V) in head and neck cancers at risk of spread along this nerve.

METHOD

The main types of head and neck cancers associated with risks of spread along the trigeminal nerve (V) and its branches were comprehensively reviewed based on clinical experience, literature-based patterns of failure, anatomy and radio-anatomy. A consensus for contouring was proposed based on a multidisciplinary approach among head and neck oncology experts including radiation oncologists (JBi, ML, MO, VG and JB), a radiologist (VD) and a surgeon (CS). These practical clinical guidelines have been endorsed by the GORTEC (Head and Neck Radiation Oncology Group).

RESULTS

We provided contouring and treatment guidelines, supported by detailed figures and tables to help, for the trigeminal nerve and its branches: the ophthalmic nerve (V1), the maxillary nerve (V2) and the manidibular nerve (V3). A CT- and MRI-based atlas was proposed to illustrate the whole trigeminal nerve pathway with its main branches.

CONCLUSION

Trigeminal nerve (V) invasion is an important component of the natural history of various head and neck cancers. Recognizing the radio-anatomy and potential routes of invasion is essential for optimal contouring, as presented in these guidelines.

Systematic review and meta-analyses of intensity-modulated radiation therapy versus conventional two-dimensional and/or or three-dimensional radiotherapy in curative-intent management of head and neck squamous cell carcinoma

Introduction

Technological advancements in treatment planning and delivery have propelled the use of intensity-modulated radiation therapy (IMRT) in head and neck squamous cell carcinoma (HNSCC). This review compares IMRT with conventional two-dimensional (2D) and/or three-dimensional (3D) radiotherapy (RT) in curative-intent management of HNSCC.

Methods

Only randomized controlled trials (RCTs) offering curative-intent RT in patients with non-metastatic HNSCC were included. Outcome data was extracted independently by two reviewers, pooled using the Cochrane methodology, and expressed as risk ratio (RR) or hazard ratio (HR) as appropriate with 95% confidence intervals (CIs). Xerostomia was the primary outcome of interest whereas loco-regional control, overall survival and quality-of-life (QOL) were secondary endpoints.

Results

Seven RCTs involving 1155 patients directly comparing IMRT with 2D/3D-RT in HNSCC were included. The primary objective in five of seven index RCTs was reduction in xerostomia, with only one trial each using loco-regional control and overall survival as primary endpoints for sample size calculation. The use of IMRT was associated with a 36% relative risk reduction in ≥grade 2 acute xerostomia (RR = 0.64, 95%CI = 0.49–0.84; p = 0.001) compared to 2D/3D-RT. More importantly, IMRT significantly reduced the risk of ≥grade 2 late xerostomia (RR = 0.44, 95%CI = 0.34–0.57; p = 0.00001) compared to non-IMRT techniques at all time-points. Within the limitations of inadequate sample size and low statistical power, IMRT also resulted in 24% relative reduction in the risk of loco-regional relapse (HR = 0.76, 0.57–1.01; p = 0.06) and 30% relative reduction in risk of death (HR = 0.70, 95%CI = 0.57–0.88; p = 0.002) compared to 2D/3D-RT. However, this benefit of IMRT for loco-regional control and overall survival was limited to nasopharyngeal cancer patients alone, with no significant difference in efficacy between the two techniques in patients with cancers of the laryngo-pharynx in this analysis, highlighting the inconsistency in results of subgroup analyses stratified by primary site. Inadequate reporting of data precluded statistically pooling of results for QOL outcomes.

Conclusions

There is consistent moderate-quality evidence that IMRT significantly reduces the risk of moderate to severe acute and late xerostomia compared to 2D/3D-RT in curative-intent radiotherapeutic management of HNSCC. However, the quality of evidence regarding the superiority of IMRT over conventional techniques for disease-related endpoints is rather low due to relative lack of power and inconsistency of results precluding robust conclusions.

Radiotherapy dose-volume parameters predict videofluoroscopy-detected dysphagia per DIGEST after IMRT for oropharyngeal cancer: Results of a prospective registry

PURPOSE

Our primary aim was to prospectively validate retrospective dose-response models of chronic radiation-associated dysphagia (RAD) after intensity modulated radiotherapy (IMRT) for oropharyngeal cancer (OPC). The secondary aim was to validate a grade ≥2 cut-point of the published videofluoroscopic dysphagia severity (Dynamic Imaging Grade for Swallowing Toxicity, DIGEST) as radiation dose-dependent.

MATERIAL AND METHODS

Ninety-seven patients enrolled on an IRB-approved prospective registry protocol with stage I-IV OPC underwent pre- and 3-6 month post-RT videofluoroscopy. Dose-volume histograms (DVH) for swallowing regions of interest (ROI) were calculated. Dysphagia severity was graded per DIGEST criteria (dichotomized with grade ≥2 as moderate/severe RAD). Recursive partitioning analysis (RPA) and Bayesian Information Criteria (BIC) were used to identify dose-volume effects associated with moderate/severe RAD.

RESULTS

31% developed moderate/severe RAD (i.e. DIGEST grade ≥2) at 3-6 months after RT. RPA found DVH-derived dosimetric parameters of geniohyoid/mylohyoid (GHM), superior pharyngeal constrictor (SPC), and supraglottic region were associated with DIGEST grade ≥2 RAD. V61 ≥ 18.57% of GHM demonstrated optimal model performance for prediction of DIGEST grade ≥2.

CONCLUSION

The findings from this prospective longitudinal registry validate prior observations that dose to submental musculature predicts for increased burden of dysphagia after oropharyngeal IMRT. Findings also support dichotomization of DIGEST grade ≥2 as a dose-dependent split for use as an endpoint in trials or predictive dose-response analysis of videofluoroscopy results.

Locoregional Control and Toxicity in Head and Neck Carcinoma Patients following Helical Tomotherapy-Delivered Intensity-Modulated Radiation Therapy Compared with 3D-CRT Data

OBJECTIVES

To assess the feasibility and efficacy of intensity-modulated radiation implemented with helical tomotherapy image-guided with daily megavoltage computed tomography for head and neck cancer.

METHODS

Between May 2010 and May 2013, 72 patients were treated with curative intent. The median age was 64 years, with 57% undergoing definitive and 43% postoperative radiotherapy. Primary tumour sites were oral cavity (21%), oropharynx (26%), hypopharynx (20%), larynx (22%), and others (11%). Staging included 4% stage I, 15% II, 26% III, 48% IVa, and 7% IVb. Radiotherapy was combined with chemotherapy in 64%. Primary endpoint was locoregional control, and secondary endpoints survival and toxicity.

RESULTS

Median follow-up was 20 months, with 11 locoregional recurrences. Three-year disease-free survival was 58% and overall survival 57%. In the multivariate analysis, age under 64 years, no extracapsular extension, postoperative radiotherapy, induction chemotherapy, and non-oral cavity tumour were significant favourable prognostic factors for disease-free-survival. The overall incidence of acute grade ≥3 toxicities were mucositis 32%, pain 11%, xerostomia 7%, dysphagia 53%, radiodermatitis 44%, and osteonecrosis 1%. Late grade ≥3 toxicities were fibrosis 6%, dysphagia 21%, fistula 1%, and skin necrosis 1%.

CONCLUSIONS

Intensity-modulated radiation with helical tomotherapy achieved respectable locoregional control and overall survival, with acceptable toxicity, in head and neck cancer patients.

Prospective in silico study of the feasibility and dosimetric advantages of MRI-guided dose adaptation for human papillomavirus positive oropharyngeal cancer patients compared with standard IMRT

PURPOSE

We aim to determine the feasibility and dosimetric benefits of a novel MRI-guided IMRT dose-adaption strategy for human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPC).

MATERIALS/METHODS

Patients with locally advanced HPV+ OPC underwent pre-treatment and in-treatment MRIs every two weeks using RT immobilization setup. For each patient, two IMRT plans were created (i.e. standard and adaptive). The prescription dose for the standard plans was 2.12 Gy/fx for 33 fractions to the initial PTV. For adaptive plans, a new PTVadaptive was generated based on serial MRIs in case of detectable tumor shrinkage. Prescription dose to PTVadaptive was 2.12 Gy/fx to allow for maximum dose to the residual disease. Any previously involved volumes received minimally a floor dose of 50.16 Gy. Uninvolved elective nodal volumes were prescribed 50.16 Gy in 1.52 Gy/fx. Dosimetric parameters of organs at risk (OARs) were recorded for standard vs. adaptive plans. Normal tissue complication probability (NTCP) for toxicity endpoints was calculated using literature-derived multivariate logistic regression models.

RESULTS

Five patients were included in this pilot study, 3 men and 2 women. Median age was 58 years (range 45-69). Three tumors originated at the tonsillar fossa and two at the base of tongue. The average dose to 95% of initial PTV volume was 70.7 Gy (SD,0.3) for standard plans vs. 58.5 Gy (SD,2.0) for adaptive plans. The majority of OARs showed decrease in dosimetric parameters using adaptive plans vs. standard plans, particularly swallowing related structures. The average reduction in the probability of developing dysphagia ≥ grade2, feeding tube persistence at 6-month post-treatment and hypothyroidism at 1-year post-treatment was 11%, 4%, and 5%, respectively. The probability of xerostomia at 6-month was only reduced by 1% for adaptive plans vs. standard IMRT.

CONCLUSION

These in silico results showed that the proposed MRI-guided adaptive approach is technically feasible and advantageous in reducing dose to OARs, especially swallowing musculature.

Comparisons of the clinical outcomes of different postoperative radiation strategies for treatment of head and neck squamous cell carcinoma

Purpose

We previously reported unfavorable locoregional control with limited field postoperative radiotherapy for head and neck squamous cell carcinoma patients and thus revised the strategy to cover the whole neck. Head and neck squamous cell carcinoma Patients' outcomes were retrospectively analyzed to compare the efficacy of two treatments.

Material and methods

Before 2010, the clinical target volume covered the tumor bed and/or involved the neck region. Since 2011, whole-neck irradiation was planned. Univariate analysis, multivariate analysis, and propensity score matching were performed. The study included 275 patients: 186 received limited field postoperative radiotherapy and 89 received whole-neck postoperative radiotherapy. The median follow-up time for the entire cohort was 40.8 months.

Results

In univariate analysis, the radiation strategy had no significant effect on overall survival and progression-free survival. In multivariate analysis, whole-neck postoperative radiotherapy was a favorable factor for overall survival, progression-free survival, and locoregional control. Propensity score matching resulted in a cohort comprising 118 well-matched patients evenly divided between the limited field postoperative radiotherapy and whole-neck postoperative radiotherapy groups. Whole-neck postoperative radiotherapy group achieved a significantly better 2-year overall survival (56.4% vs. 78.1%; P = 0.003), 2-year progression-free survival (34.7% vs. 59.8%; P = 0.009), and 2-year locoregional control (54.4% vs. 83.2%; P < 0.001). The limited field postoperative radiotherapy group developed significantly more locoregional recurrences both in-field (35.2% vs. 15.1%, P = 0.003) and out-of-field (25.0% vs. 0%, P < 0.001) in the matched-pair cohort.

Conclusion

Whole-neck postoperative radiotherapy is a more appropriate choice than limited field postoperative radiotherapy to improve overall survival, progression-free survival and locoregional control.

Exclusive concurrent radiochemotherapy for advanced head and neck cancers with 'fractionated' 5-fluorouracil and cisplatin

Concurrent radiochemotherapy (CRC) is a standard treatment in patients with inoperable locoregionally advanced ear-nose-throat (ENT) cancer. We report the safety and efficacy of CRC with daily fractionated 5-fluorouracil and cisplatin ('F' 5FU-CDDP) in a monocentric retrospective cohort. From January 2006 to August 2012, all patients with unresectable (or inoperable) nonmetastatic locoregionally advanced ENT cancer treated curatively by means of radiotherapy (normal fractionated 70 Gy to the macroscopic tumor and prophylactic 50 Gy) with three courses (week 1-week 4-week 7) of 'F' 5FU-CDDP regimen (800 mg/m/day of 5-fluorouracil and 20 mg/m/day of CDDP from day 1 to day 4) were included. Seventy patients underwent CRC (86% men, median age 58 years old, 100% squamous cell carcinoma, 97% stage III/IV). Fifty-six patients received the three complete courses of chemotherapy with cumulative doses of CDDP of 217 mg/m/patient (dose intensity ratio of 90.5%). After a median follow-up period of 30.7 months, median overall and disease-free survivals were 34.1 [95% confidence interval (CI) (21.6-56.8)] and 50.2 months [95% CI (17.4-NA)] with 71% [95% CI (57.5-81)] and 67% [95% CI (51.8-78.5)] for locoregional control at 2 and 5 years, respectively. In all, 58.5% of grade 3 or higher mucositis and 24% of radioepithelitis were observed, but only 11.5, 3, and 1.5% of grade 3 or higher neutropenia, nephrotoxicity, and neurotoxicity were observed, respectively. No deaths from toxicity occurred. CRC with three courses of 'F' 5FU-CDDP appears effective and could be an alternative to standard CRC treatment. Randomized studies are required to be able to use this treatment regimen routinely.

Radiation Therapy for Oral Cavity and Oropharyngeal Cancers

Radiotherapy is a key therapeutic modality used in the treatment of oral cavity and oropharyngeal cancers, whether as definitive treatment or postoperatively for those with high-risk factors after surgery. Although radiotherapy is a proven, effective treatment of cancer control, it can result in significant acute and late toxicities. Pretreatment patient education, supportive care, and posttreatment adherence to rehabilitative and preventive care can help mitigate toxicities. Advances in radiation delivery, such as through continued technological advances, or novel approaches to customizing radiation dose and volume, to maximize the therapeutic efficacy while minimizing side effects, are warranted.

Development of Human Salivary Gland-Like Tissue In Vitro

The loss of salivary gland function caused by radiation therapy of the head and neck is a serious condition and it affects a patient's quality of life. The current lack of effective therapies demands new options to be explored. This study tested whether human salivary gland epithelial cells (SGECs) could be successfully cultured on a decellularized porcine gut matrix (SIS-muc) in both mono- and coculture with microvascular endothelial cells (mvECs). By performing immunofluorescence imaging, transmission as well as scanning electron microscopy (SEM), quantitative polymerase chain reaction (qPCR), and an amylase enzyme assay, it was investigated as to what extent the three-dimensional (3D)-cultured cells could maintain their molecular differentiation and the production of working α-amylase (α-AMY) compared with two-dimensional (2D) culture. In both 3D mono- and coculture, SGECs were successfully cultured and formed acinar-like structures. Those findings were confirmed by SEM imaging. Immunofluorescence imaging revealed that 3D-cultured cells expressed α-AMY, Claudin-1 (CL-1), and water channel protein aquaporin-5 (AQP-5). Two-dimensional-cultured cells only were positive for α-AMY. Real time (RT)-qPCR analysis showed that α-AMY relative gene expression was higher in both 3D mono- and coculture than in 2D culture. In α-AMY enzyme assay, cocultured SGECs showed about 25 times increased enzyme activity compared with 2D-cultured cells. In conclusion, the SIS-muc combined with endothelial coculture seems a suitable culture setting for the tissue engineering of functional human salivary gland tissue.