Long-Term Taste Impairment after Intensity-Modulated Radiotherapy to Treat Head-and-Neck Cancer: Correlations with Glossectomy and the Mean Radiation Dose to the Oral Cavity

Therapy-Associated Saliva and Taste change Evaluation (TASTE) in head & neck cancer patients undergoing radiotherapy: a study protocol

BACKGROUND

One of the main side effects of radiation therapy to the head and neck region is altered taste sensation. This causes significant morbidity and has profound effects on the quality of life (QoL) of patients. While radiation-associated toxicities like xerostomia and dysphagia are part of large investigations, data on taste impairment is sparse. Small cohort sizes in the majority of studies and a variety of analysis methods limit our current understanding of the underlying processes. None of the studies published to date used a taste-specific QoL questionnaire with differentiation of the different taste qualities (e.g. sour, bitter). Furthermore, data regarding the correlation of taste impairment with radiation-associated change in saliva composition is currently not available. The aim of the TASTE study is to fill this gap. Based on the acquired data, a normal tissue complication probability (NTCP) model for late radiation-associated taste impairment will be developed.

METHODS

In this prospective, observational multicenter study 150 head and neck cancer patients undergoing radiation therapy will be recruited and undergo repetitive (semi-) objective and subjective assessment of their taste, smell and salivary function (questionnaires, taste and smell assessment, saliva analysis). Primary endpoint will be patient-reported taste impairment 12 months post radiation therapy using a standardized questionnaire. Secondary endpoints will include taste impairment measured using taste strips at 12 months and 2 years post radiation therapy. Differences between subgroups (radiation side, chemotherapy, etc.) and changes over time will be assessed while adjusting for confounding factors (e.g. age, sex, smoking history).

DISCUSSION

This study sets out to further our understanding of taste impairment in patients undergoing radiation therapy to the head and neck region with the goal to prevent this common side effect in future patients. The results of the study may be used to evaluate taste-preserving radiotherapy for patients with head and neck cancer, which may significantly reduce the long-term burden in this patient cohort.

Mean Oral Cavity Organ-at-Risk Dose Predicts Opioid Use and Hospitalization during Radiotherapy for Patients with Head and Neck Tumors

BACKGROUND

Approximately 75% of all head and neck cancer patients are treated with radiotherapy (RT). RT to the oral cavity results in acute and late adverse events which can be severe and detrimental to a patient's quality of life and function. The purpose of this study was to explore associations between RT dose to a defined oral cavity organ-at-risk (OAR) avoidance structure, provider- and patient-reported outcomes (PROs), opioid use, and hospitalization.

METHODS

This was a retrospective analysis of prospectively obtained outcomes using multivariable modeling. The study included 196 patients treated with RT involving the oral cavity for a head and neck tumor. A defined oral cavity OAR avoidance structure was used in all patients for RT treatment planning. Validated PROs were collected prospectively. Opioid use and hospitalization were abstracted electronically from medical records.

RESULTS

Multivariable modeling revealed the mean dose to the oral cavity OAR was significantly associated with opioid use (p = 0.0082) and hospitalization (p = 0.0356) during and within 30 days of completing RT.

CONCLUSIONS

The findings of this study may be valuable in RT treatment planning for patients with tumors of the head and neck region to reduce the need for opioid use and hospitalization during treatment.

Impact of radiation dose on patient-reported acute taste alteration in a prospective observational study cohort in head and neck squamous cell cancer (HNSCC)

PURPOSE

Taste alteration (TA) is a frequent acute side effect of radiation treatment in HNSCC patients. Principal aim of our study was to investigate dosimetric parameters in relation to patient-assessed taste impairment in a prospective cohort treated with intensity-modulated radiotherapy.

METHODS

All patients with locally advanced HNSCC and amenable to radical treatment were included. Chemotherapy-induced taste alteration scale (CITAS), EORTC QLQ-C30 and QLQ-HN43 questionnaires at baseline (T0), 3 weeks (T1) and 3 months (T2) after radiotherapy conclusion were used to assess taste impairment. Base of tongue, submandibular glands (SG), parotid glands (PG) and taste buds, along with anterior and medium third of the tongue, were considered as organs at risk and thus delineated according to consensus guidelines. The mean dose to the above-mentioned structures was correlated with patient-reported outcomes.

RESULTS

Between September 2019 and November 2020, 33 patients were recruited, 31 of which analyzed. 71% had oropharyngeal carcinoma, mostly HPV-related (60%). All were treated with tomotherapy. 77.4% had concurrent cisplatin. Mean scores of general taste alterations, global health status and dry mouth and sticky saliva were assessed. The mean doses to the anterior third, medium third and base of the tongue were 23.85, 35.50 and 47.67 Gy, respectively. Taste buds received 32.72 Gy; right and left parotid 25 and 23 Gy; right and left submandibular glands 47.8 and 39.4 Gy. At univariate analysis, dysgeusia correlated with SG mean dose (95% CI 0-0.02 p = 0.05) and PG mean dose (95% CI 0-0.02 p = 0.05); dry mouth with mean dose to anterior (95% CI 0.03-1.47 p = 0.04) and medium third (95% CI 0.02-0.93 p = 0.04) of the tongue, to taste buds (95% CI 0.06-0.96 p = 0.03) and to SGs (95% CI 0.06-0.63 p = 0.02); pain mouth with mean dose to taste buds (95% CI 0-0.02 p = 0.04), to SGs (95% CI 0-0.03 p = 0.03) and to base tongue (95% CI 0-0.02 p = 0.02).

CONCLUSIONS

Our analysis supports the influence of dose distribution on the development of TA in HNSCC patients. The contribution of dose to taste buds and tongue subvolumes remains unclear and worthy of further investigation.

Wearing individualized 3D printed oral stent to protect normal tissues in patients with nasopharyngeal carcinoma during radiotherapy

PURPOSE

To demonstrate a new individualized 3D printed oral stent in radiotherapy of nasopharyngeal carcinoma (NPC) patients and carry out a comparative analysis combining with clinical case.

MATERIAL AND METHODS

Thirty NPC patients treated in our institution from September 2021 to October 2022 were prospectively enrolled. An individualized 3D printed oral stent was designed for each patient, and one set of computed tomography (CT) slices were obtained with /without wearing the oral stent, respectively. After delineation of target volumes and organs at risk (OARs) on the two CT slices, we finished two treatment plans by using the same target objectives, critical constraints and plan setup for each patient. Finally, the dose distribution and other dosimetric parameters of target volumes and OARs between the two plans were compared.

RESULTS

Tongue volume and tongue length outside of mouth was 10.4 ± 2.5 cm3 and 2.8 ± 0.6 cm, respectively, distance between dorsal surface of oral tongue and plate increased from 0.3 ± 0.3 cm to 2.2 ± 0.5 cm by wearing the oral stent. For the target volume, there was no significant difference. However, Dmax of tongue, tongue tip and periglottis decreased significantly from 6352.6 ± 259.9 cGy to 5994.9 ± 478.9 cGy, 3499.8 ± 250.6 cGy to 3357.7 ± 158.0 cGy and 6345.5 ± 171.0 cGy to 6133.4 ± 263.3 cGy, respectively (p = 0.000); Dmean of tongue, tongue tip and periglottis decreased significantly from 3714.7 ± 204.2 cGy to 3169.7 ± 200.9 cGy, 3060.8 ± 216.2 cGy to 2509.6 ± 196.7 cGy and 3853.3 ± 224.9 cGy to 3079.3 ± 222.0 cGy, respectively (p = 0.000).

CONCLUSION

The individualized 3D printed oral stent can reduce the dose of oral tissues and organs, so as to reduce the oral adverse reactions and improve the compliance of patients and the quality of their life. The technique can be used in radiotherapy of NPC patients.

Acute Taste Dysfunction in Oropharyngeal Cancer Patients after Transoral Robotic Surgery

OBJECTIVES

To compare taste changes after transoral robotic surgery (TORS) to taste changes in healthy controls.

METHODS

Oropharyngeal cancer patients receiving TORS and healthy controls were recruited. Participants underwent posterolateral and whole-mouth psychophysical taste testing (identification, intensity, and hedonics) at baseline and at 2 weeks postoperatively (patients) or follow-up (controls). Surgeons reported suspension time and glossopharyngeal nerve injury (GNI) based on the identification and sacrifice of the nerve. A Clinical Global Impression (CGI) of taste symptoms was completed at each session ("My sense of taste bothers me" on a 5-point scale from Never [1] to Always [5]). A taste disorder (TD) was a CGI of 3 (Sometimes) or worse. Within-subject changes in CGI and psychophysical scores were computed. "Worsened taste" was a CGI increase by ≥1 point at follow-up.

RESULTS

Of 69 participants, most (33/37 tumor, 31/32 controls) had normal baseline taste (CGI < 3). 14/33 (42%) TORS patients and no controls developed new TDs at follow-up. More smokers (7/9) had worsened taste than nonsmokers (19/60, difference = 46% [95% CI 16%-76%]). More patients without GNI (6/22) than with GNI (0/15) had postoperative phantogeusia (difference = 27% [95% CI 9-45%]). Tumor-ipsilateral taste identification (TI) decreased more in patients (-11.3%) than controls (0.8%, difference = 12.2% [95% CI 5.0-19.3%]). Suspension time was not associated with worsened taste symptoms or psychophysical changes.

CONCLUSIONS

Patient-reported taste changes after TORS are frequent. Compared to healthy controls, TORS patients have decreased tumor-ipsilateral TI. Suspension time and GNI are unlikely to cause symptomatic TDs. Further investigations of the etiology and long-term symptom burden of TORS-associated TDs will aid in the management of oropharyngeal cancer patients.

LEVEL OF EVIDENCE

3 (non-randomized controlled cohort study) Laryngoscope, 133:3520-3528, 2023.

Chemosensory Functions After Glossectomy-A Cross-Sectional Pilot Study

OBJECTIVE

To evaluate potential interactions and compensatory mechanisms of subjectively impaired taste function with ortho- and retronasal olfaction after glossectomy.

STUDY DESIGN

In this cross-sectional pilot study, chemosensory functions were assessed in 25 patients with tongue carcinomas after glossectomy. The orthonasal-, retronasal-, and gustatory functions were tested with a mean time of 25 months after surgery with the Sniffin' Sticks odor identification test kit (ISST), the Candy Smell-27 test (CST-27) and the Taste strip test (TST). Visual analog scales (VAS) were additionally used for self-assessment of taste, flavor perception, and odor ranging from 0 (no perception) to 10 (excellent perception) and further correlated with our psychophysical evaluated outcome measures.

RESULTS

The TST, ISST, and CST-27 tests revealed that only eight (32%) and 13 (52%) glossectomy patients had normal taste and orthonasal function, e 21 (84%) patients showed normal retronasal function. Importantly, neither extent of resection and reconstruction nor prior radiotherapy affected chemosensory functions. Contrary, 20 (80%) patients rated their taste and flavor perception as acceptable (VAS >5). Results of the TST, ISST, and CST-27 tests did not correlate with the equivalent self-assessments of taste (p = 0.260, r = 0.234), odor (p = 0.588, r = -0.114), and flavor (p = 0.728, r = 0.073) perception.

CONCLUSION

There was a significant discrepancy between self-perception of taste and flavor and assessed gustatory function after glossectomy. A contribution of the intact retronasal olfactory system could be a possible explanation of our results.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:375-382, 2023.

Prospective Evaluation of Taste Function in Patients With Head and Neck Cancer Receiving Intensity-Modulated Radiotherapy

Importance

The majority of the patients with head and neck cancer (HNC) experience taste dysfunction (TD) during or after radiotherapy (RT). However, prospectively collected data for taste dysfunction have been limited, especially in the era of intensity-modulated RT (IMRT).

Objective

To evaluate the taste function in patients with HNC receiving IMRT by investigating the association between time course and recovery of TD in both acute and late phases.

Design, Setting, and Participants

From August 2017 to November 2020, patients treated at the Chang Gung Memorial Hospital with curative or postoperative IMRT for HNC were enrolled in this prospective cohort study. The data analysis was performed from March 2021 to January 2022.

Exposures

IMRT with and without concurrent chemotherapy.

Main Outcomes and Measures

Taste function was measured using the whole-mouth solution method for 4 tastes (salt, sweet, sour, and bitter). Subjective evaluations (National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.03] and Subjective Total Taste Acuity scale) were used. Patient self-reported quality of life was evaluated using European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck Module (EORTC QLQ-H&N35).

Results

A total of 87 patients (78 [90%] men and 9 [10%] women; mean [range] age, 58 [31-80] years) were enrolled. Overall TD rates were 79 of 86 (91.9%), 63 of 83 (75.9%), 27 of 81 (33.3%), 5 of 56 (8.9%), and 2 of 30 (6.7%) during RT, and 1 week, 3 months, 6 months, and 1 year after RT, respectively. Positive correlation occurred between objectively measured taste loss for the 4 taste qualities and subjective perception of taste loss. Only oral cavity mean dose 4000 cGy or greater predicted TD 3 months after RT. The mean oral cavity doses to the predicted 15% (D15), 25% (D25), and 50% (D50) probabilities were 25, 38, and 60 Gy at 3 months and 57, 60, and 64 Gy at 6 months, respectively.

Conclusions and Relevance

In this cohort study, most patients still experienced TD during and at 3 months after RT. Only a few patients experienced long-term TD. A high oral cavity dose was associated with TD in patients with HNC receiving IMRT. Reducing oral cavity dose may promote early recovery of taste function after IMRT.

State of Rehabilitation Research in the Head and Neck Cancer Population: Functional Impact vs. Impairment-Focused Outcomes

PURPOSE OF REVIEW

Management of head and neck cancer (HNC) typically involves a morbid combination of surgery, radiation, and systemic therapy. As the number of HNC survivors grows, there is growing interest in rehabilitation strategies to manage HNC-related comorbidity. In this review, we summarize the current state of HNC rehabilitation research.

RECENT FINDINGS

We have organized our review using the World Health Organization's International Classification of Function (ICF) model of impairment, activity, and participation. Specifically, we describe the current research on rehabilitation strategies to prevent and treat impairments including dysphagia, xerostomia, dysgeusia, dysosmia, odynophagia, trismus, first bite syndrome, dysarthria, dysphonia, lymphedema, shoulder syndrome, cervicalgia, cervical dystonia and dropped head syndrome, deconditioning, and fatigue. We also discuss the broader impact of HNC-related impairment by exploring the state of rehabilitation literature on activity, participation, psychosocial distress, and suicidality in HNC survivors. We demonstrate that research in HNC rehabilitation continues to focus primarily on impairment-driven interventions. There remains a dearth of HNC rehabilitation studies directly examining the impact of rehabilitation interventions on outcomes related to activity and participation. More high-quality interventional studies and reviews are needed to guide prevention and treatment of functional loss in HNC survivors.

The influence of radiation dose on taste impairment in a prospective observational study cohort of oropharyngeal cancer patients

BACKGROUND

To analyze the influence of radiation dose on late radiation-associated taste impairment in oropharyngeal cancer (OPC) patients treated with intensity-modulated radiotherapy (IMRT) using the taste bud bearing tongue mucosa as organ at risk.

MATERIAL AND METHODS

This study is part of an ongoing, prospective observational study. Cancer-free OPC survivors with at least 24 months from IMRT were included in this analysis. Scores for taste impairment and dry mouth were extracted from the MD Anderson Symptom Inventory Head and Neck module (MDASI-HN) with scores of ≥5 considered as moderate-to-severe symptoms. The mean dose, minimum and maximum dose to the taste bud bearing tongue mucosa, the ipsi- and contralateral parotid and submandibular glands were extracted and analyzed for correlation with moderate-to-severe taste impairment.

RESULTS

One hundred sixteen T1-4 OPC patients were included (81% males, median age: 55). The primary tumor was in the tonsil in 92 cases (79%) and in the base of tongue in 21 cases (18%). Patients were treated with 64.2-72.0 Gy; 37 patients (32%) received concurrent chemotherapy and 22 (19%) concurrent targeted therapy. After a median of 58 months from RT (IQR: 43-68) 38 patients (33%) suffered from moderate-to-severe long-term radiation-associated taste impairment. No dose volume parameter of the taste bud bearing tongue mucosa and the salivary glands was significantly associated with moderate-to-severe taste impairment for the whole patient cohort. For patients without concurrent chemotherapy, the minimum and mean dose to the ipsilateral parotid gland, and the maximum dose to the submandibular gland was significantly associated with late taste impairment (all p < 0.05). A significant correlation was found between taste impairment and dry mouth (p < 0.001).

CONCLUSION

The dose to the ipsilateral parotid gland seems to play an important role in the development of late taste impairment. The influence of dose to the taste bud bearing tongue mucosa remains unclear and needs further investigation.

Treatment-Related Dysgeusia in Oral and Oropharyngeal Cancer: A Comprehensive Review

Oral cancer is the most common tumor of the head and neck region. Its management is based on surgical and systemic therapies. Taste disorders represent the most common side effect of these treatments; indeed, dysgeusia is noted by 70% of oral cancer patients. Despite survival remaining the primary endpoint of cancer patients, taste impairments can cause psychological distress. This comprehensive review describes the last decade’s knowledge from the literature regarding taste alterations in patients with oral and oropharyngeal squamous cell carcinoma. A total of 26 articles in English, including prospective, cross-sectional, and case–control studies, and clinical trials were evaluated. Literature analysis shows that anti-cancer treatments can destroy taste cells, decrease and alter their receptors, and interrupt nerve transmission. Furthermore, the tumour itself can destroy the oral mucosal lining, which encloses the taste buds. Dysgeusia typically occurs in 3–4 weeks of treatments, and usually taste sensation is recovered within 3–12 months. However, some patients exhibit incomplete or no recovery, even several years later. Thus, dysgeusia can become a chronic issue and negatively influence patients’ quality of life, worsening their dysphagia and their nutritional status. Physicians should be focused on preventing oncological treatment-related symptoms, offering the most suitable personalized support during therapy.

Taste and Smell Function in Head and Neck Cancer Survivors

Survivors of head and neck squamous cell cancers (HNSCC) frequently complain of taste dysfunction long after radiation therapy is completed, which contradicts findings from most sensory evaluation studies that predict dysfunction should resolve few months after treatment. Therefore, it remains unclear whether taste and smell function fully recovers in HNSCC survivors. We evaluated HNSCC survivors (n = 40; age 63 ± 12 years, mean ± standard deviation) who received radiation therapy between 6 months and 10 years before recruitment and compared their responses to those of a healthy control group (n = 20) equivalent in age, sex, race, smoking history, and body mass index. We assessed regional (tongue tip) and whole-mouth taste intensity perception using the general Labeled Magnitude Scale and smell function using the University of Pennsylvania Smell Identification Test (UPSIT). To determine possible differences between groups in retronasal smell perception, we used solutions of sucrose with strawberry extract, citric acid with lemon extract, sodium chloride in vegetable broth, and caffeine in coffee and asked participants to rate perceived smell and taste intensities with and without nose clips. We found groups had similar UPSIT and taste intensity scores when solutions were experienced in the whole mouth. However, HNSCC survivors were less likely to identify low concentrations of bitter, sweet, or salty stimuli in the tongue tip relative to healthy controls. Our findings suggest persistent and subtle localized damage to the chorda tympani or to the taste buds in the fungiform papillae of HNSCC survivors, which could explain their sensory complaints long after completion of radiotherapy.

A Mechanistic Overview of Taste Bud Maintenance and Impairment in Cancer Therapies

Since the early 20th century, progress in cancer therapies has significantly improved disease prognosis. Nonetheless, cancer treatments are often associated with side effects that can negatively affect patient well-being and disrupt the course of treatment. Among the main side effects, taste impairment is associated with depression, malnutrition, and morbid weight loss. Although relatively common, taste disruption associated with cancer therapies remains poorly understood. Here, we review the current knowledge related to the molecular mechanisms underlying taste maintenance and disruption in the context of cancer therapies.

Taste dysfunction following radiotherapy to the head and neck: A systematic review

BACKGROUND

An intact sense of taste provides pleasure, supports sustenance and alerts the body to toxins. Head and neck cancer (HNC) patients who receive radiotherapy (RT) are high-risk for developing radiation-induced taste dysfunction. Advances in RT offer opportunities for taste-preserving strategies by reducing dose to the gustatory organs-at-risk.

METHODS

PubMed, Medline and EMBASE were searched for publications reporting on taste, RT and HNC. Randomised trials, cohort studies and cross-sectional studies were included.

RESULTS

31 studies were included in this review. Meta-analysed prevalence of acute taste dysfunction following RT was approximately 96% (95% CI 64 to 100%) by objective measures and 79% (95% CI 65 to 88%) by subjective measures, with the majority of patients showing at least partial recovery. Long-term dysfunction was seen in ~25% of patients. Taste dysfunction was associated with sequalae including weight loss and reduced quality-of-life (QoL). Taste dysfunction was more common when the oral cavity, and specifically the anterior two-thirds of the tongue, was irradiated, suggesting a dose constraint for taste preservation might be feasible. Proton beam therapy and customised bite blocks reduced dose to the gustatory field and subsequent loss of taste.

CONCLUSIONS

Taste dysfunction following RT is common and negatively affects patients' nutritional status and QoL. Decisions about treatment strategies, including choice of RT modality, dose distribution across the gustatory field and the use of adjuncts like bite blocks may be beneficial. However, evidence is limited. There is a pressing need for randomised studies or large prospective cohort studies with sufficient adjustment for confounders.

Development and validation of a contouring guideline for the taste bud bearing tongue mucosa

PURPOSE

To introduce a contouring guideline for the taste bud bearing tongue mucosa for head and neck cancer patients receiving radiotherapy.

METHODS AND MATERIALS

CT simulation images of oropharyngeal cancer patients were used to delineate both the whole tongue (extrinsic/intrinsic tongue muscles, floor of mouth) and the taste bud bearing tongue mucosa (method A: adaptation of the whole tongue structure; method B: axial adaptation of a mid-sagittal contour). Volumetric and dosimetric parameters of the whole tongue and the two methods of mucosal delineation, spatial overlap between methods A and B, and inter-observer variability for method B were calculated.

RESULTS

The study cohort was comprised of 70 patients with T1-4 N0-1 tonsillar (83%) and base of tongue (17%) cancers. Most of the comparative parameters between the whole tongue and mucosa (method A) significantly differed (mean, minimum, and maximum dose, V5-V70, D40-D90). The mean dose calculated for the whole tongue deviated on average 3.77 Gy compared to method A. No significant differences were found between methods A and B of the taste bud bearing tongue mucosa structure, and none of the dosimetric parameters differed more than 1.03 Gy on average. The mean Dice similarity coefficient for both mucosal structures was 0.79 ± 0.05, and 0.63 ± 0.12 for the inter-observer analysis of method B.

CONCLUSIONS

We defined two methods for delineating the taste bud bearing mucosa and both are equally satisfactory procedures. Either method is preferable over delineation of the whole tongue as organ at risk for taste impairment.

The impact of tongue-deviating and tongue-depressing oral stents on long-term radiation-associated symptoms in oropharyngeal cancer survivors

OBJECTIVES

To evaluate whether the use of oral stents during intensity modulated radiation therapy (IMRT) for oropharyngeal cancer (OPC) is associated with long-term patient reported symptoms.

MATERIALS AND METHODS

Data was obtained from a prospective observational study of disease-free head and neck cancer survivors. Radiation-associated patient reported symptoms were assessed using the MD Anderson Symptom Inventory Head and Neck module (MDASI-HN). Scores of ≥5 (11-point Likert scale, 0-10) were considered moderate/severe. Stratification was performed regarding IMRT volume (uni- versus bilateral neck) and stent utilization, with non-parametric analyses between groups.

RESULTS

462 OPC survivors formed the cohort (54% tonsil, 46% base of tongue primaries). A tongue-deviating stent was used in 17%, tongue-depressing stent in 46%, and no stent in 37%. Median prescribed dose to the high dose clinical target volume was 66.0 Gy. Median follow-up from RT to MDASI-HN assessment was 68 months. Twenty percent had received unilateral neck RT (all had tonsil primaries), in whom a significant improvement in the proportion of patients with moderate/severe taste impairment (2% vs. 15%, p = 0.047) and lack of appetite (0% vs. 9%, p = 0.019) was associated with the use of tongue-deviating stents compared to no oral stent. In those who had received bilateral neck RT, a significant improvement in the proportion of patients with moderate/severe difficulty swallowing/chewing was associated with use of a tongue-depressing stent (21% vs. 31% without oral stent, p = 0.013).

CONCLUSION

Disease-site specific select use of oral stents during IMRT was associated with reduced long-term patient reported symptoms in OPC survivors.

Prospective observational evaluation of radiation-induced late taste impairment kinetics in oropharyngeal cancer patients: Potential for improvement over time?

•

The majority of OPC patients are affected from late taste impairment after RT.

•

Taste markedly improved in the first years from end of RT, but plateaued after year 5.

•

Treatment site, CTV1 dose and age might have an influence on taste impairment.

Background and purpose

Taste impairment is a common radiation-induced toxicity in head and neck cancer (HNC) patients acutely. However, data on the potential for recovery and the time dependent course of late taste impairment are limited.

Materials and methods

As part of an IRB-approved observational prospective study, HNC patients underwent serial surveys including the MD Anderson Symptom Inventory - Head and Neck module (MDASI-HN). For our analysis, we extracted MDASI-HN taste item results from oropharyngeal cancer patients treated with intensity-modulated radiotherapy or volumetric modulated arc therapy and at least two taste assessments after ≥1 year from end of radiotherapy (RT).

Results

1214 MDASI taste items from 326 patients between 1 and 13 years post-RT were included. Median prescribed dose to the high-dose clinical target volume (CTV1) was 66.0 Gy, with 180 patients (55%) receiving chemotherapy. Taste markedly improved in the first years from end of RT, but plateaued after year 5. In patients with taste assessment in subsequent years, a significant reduction in taste impairment was found from the second to the third year (p = 0.001) and tended towards significance from the third to the fourth year (p = 0.058). Multivariate analysis revealed treatment site as significant factor in the sixth year from RT and CTV1 dose and age in the seventh year.

Conclusion

Radiation-induced taste impairment may improve over an extended time interval, but becomes relatively stable from year 5 post-RT. Direct characterization of RT-induced taste impairment and the calculation of normal tissue complication probability should include consideration of the time-dependent course in taste recovery.