World Workshop on Oral Medicine VIII: Development of a core outcome set for dry mouth: a systematic review of outcome domains for salivary hypofunction.

OBJECTIVE: To identify all outcome measures used to assess salivary gland hypofunction (i.e., objective measures used to determine actual changes in saliva quantity or to assess response to treatment of salivary gland hypofunction) and to group these into domains. STUDY DESIGN: A systematic review including clinical trials and prospective or retrospective observational studies involving human participants with dry mouth, with any type of intervention where the objective assessment of salivary gland hypofunction was described. RESULTS: Five hundred fifty-three studies involving 31,507 participants were identified. Most assessed salivary gland hypofunction and xerostomia (68.7%), whereas 31.3% assessed salivary gland hypofunction alone. Most studies investigated the "amount of saliva," and the highest number of outcome measures were within the domain of "clinical/objective signs of salivary gland hypofunction." CONCLUSIONS: Seven domains encompassing 30 outcome measures were identified, confirming the diversity in outcomes and outcome measures used in research regarding salivary gland hypofunction. Identified items will be used in conjunction with those identified regarding xerostomia to create a core outcome set for dry mouth quantification for use in future clinical trials, with the overall goal of improving the standardization of reporting, leading to the establishment of more robust evidence for the management of dry mouth and improving patient care.

World Workshop on Oral Medicine VIII: Development of a core outcome set for dry mouth: a systematic review of outcome domains for xerostomia.

OBJECTIVE: The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth. STUDY DESIGN: A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized. RESULTS: From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains. CONCLUSION: There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

World Workshop on Oral Medicine VIII: Development of a core outcome set for dry mouth: a consensus study.

OBJECTIVE: This study aimed to develop a consensus-based core outcome set (COS) to be used in clinical trials assessing dry mouth interventions. STUDY DESIGN: Through 2 systematic literature reviews and interviews with dry mouth patients, we identified relevant outcome domains for dry mouth assessment. A Delphi survey was presented to health care providers attending the American Academy of Oral Medicine annual meeting in Memphis, Tennessee, USA, on May 2022 (n = 104) and 10 dry mouth patients at Cork University Dental School and Hospital, Republic of Ireland. The outcome domains for which no consensus was reached were subsequently discussed in a second consensus process led by a virtual Special Interest Group of 11 oral medicine experts from the World Workshop on Oral Medicine VIII dry mouth working group. RESULTS: After the 2-step consensus process, a consensus was reached for 12 dry mouth outcome domains (i.e., salivary gland flow, signs of hyposalivation, mucosal moisture/wetness, the severity of xerostomia, duration of xerostomia, the overall impact of xerostomia, impact on physical functioning, impact of hyposalivation on general health, impact on social activities, quality of life, the economic impact of dry mouth, patient satisfaction) to be included in the final COS. CONCLUSIONS: We propose a consensus-based COS to assess dry mouth interventions in clinical trials. This COS includes the minimum but mandatory set of domains that all clinical trials evaluating dry mouth treatments should assess.

World Workshop on Oral Medicine VIII: Development of a core outcome set for dry mouth: the patient perspective.

OBJECTIVE: We conducted a qualitative study of patients' perspectives on dry mouth outcomes to explore their personal experiences and investigate which outcomes are most important to them. This work was part of the WONDER initiative (World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research) exploring Core Outcome Measures in Effectiveness Trials. STUDY DESIGN: Using a study-specific topic guide, we conducted digitally recorded, semi-structured interviews of focus groups of patients with dry mouth secondary to Sjögren syndrome and head and neck radiotherapy. We conducted interviews until data saturation had been achieved and evaluated all transcripts for accuracy before we anonymized the data. RESULTS: Two focus groups consisting of 4 participants per group identified 4 distinct themes: (1) impact on oral health and function, (2) social isolation and withdrawal, (3) frustration with dry mouth management, and (4) limited knowledge of the medical community and lack of understanding of family and friends. CONCLUSIONS: The diversity of self-reported outcomes and the complexity of patient perceptions identified in our work may represent additional barriers to successful dry mouth management that should be considered in the design of future clinical trials.

Impact of medications on salivary flow rate in patients with xerostomia: a retrospective study by the Xeromeds Consortium.

OBJECTIVES: This study evaluates the impact of systemic medications and polypharmacy on unstimulated (UWS) and chewing-stimulated whole saliva (SWS) flow rates in patients with xerostomia. MATERIAL AND METHODS: This cross-sectional multicenter study is based on data of patients referred to five oral medicine outpatient practices in Europe and USA from January 2000 and April 2014. Relevant demographic, social, medical history and current medications were collected. RESULTS: The study included 1144 patients, 972 (85%) females, with a mean (SD) age of 59 (14.1) years. In unmatched patients, the UWS flow rate was lower in patients taking a medication (vs. not taking a medication) from the following drug categories: opioid analgesics, anticonvulsants, antidepressants, antihypertensives, benzodiazepines, corticosteroids, diuretics, disease-modifying antirheumatic drugs (DMARDs) and hormones. There was a greater negative effect on SWS flow rate in patients taking (vs. not taking) anticonvulsants, antidepressants, benzodiazepines, corticosteroids, and DMARDs. In matched patients, both UWS (0.22 vs. 0.19 ml/min; p = 0.03) and SWS (0.97 vs. 0.85 ml/min; p = .017) flow rates were higher in patients on non-opioid analgesics (vs. not taking). The UWS flow rate was lower in patients taking antidepressants (vs. not taking) (0.16 vs. 0.22 ml/min p = .002) and higher (and within normal range) in patients taking sex hormones (vs. not taking) (0.25 vs. 0.16 ml/min; p = .005). On the other hand, SWS was lower in patients taking corticosteroid (vs. not taking) (0.76 vs. 1.07 ml/min; p = .002), and in patients taking DMARDs (vs. not taking) (0.71 vs. 0.98 ml/min; p = .021). Finally, differences in medians of both UWS and SWS were statistically significant in patients taking 1 or more than 1 opioid analgesic (vs. not taking, p ≤ .0001 and p = .031, respectively), 1 or more than 1 anticonvulsants (vs. not taking, p = .008 and p = .007), 1 or more than 1 antidepressants (vs. not taking, p < .0001 for both), 1 or more than 1 DMARDs (vs. not taking, p = .042, and p = .003). CONCLUSIONS: A greater negative impact on UWS and SWS flow rates was seen in patients taking more than one medication from the same drug class. Intake of antidepressants, corticosteroids and DMARDs is associated with lower whole saliva flow rates. CLINICAL RELEVANCE: Salivary flow rate can be modified by some specific medications, mostly by polypharmacy.

Intraglandular mesenchymal stem cell treatment induces changes in the salivary proteome of irradiated patients.

BACKGROUND: Hyposalivation and xerostomia (dry mouth), are the leading site-effects to treatment of head and neck cancer. Currently, there are no effective therapies to alleviate radiation-induced hyposalivation. Adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) have shown potential for restoring salivary gland function. However, the mode of action is unknown. The purpose of the present study was therefore to characterize the effect of AT-MSC therapy on the salivary proteome in previously irradiated head and neck cancer patients. METHODS: Whole saliva was collected from patients with radiation-induced salivary gland hypofunction (n = 8) at baseline, and 120 days after AT-MSC treatment, and from healthy controls (n = 10). The salivary proteome was characterized with mass spectrometry based proteomics, and data was compared within the AT-MSC group (baseline versus day 120) and between AT-MSC group and healthy controls. Significance levels between groups were determined by using double-sided t-test, and visualized by means of principal component analysis, volcano plots and cluster analysis. RESULTS: Here we show that 140 human proteins are significantly differentially expressed in saliva from patients with radiation-induced hypofunction versus healthy controls. AT-MSC treatment induce a significant impact on the salivary proteome, as 99 proteins are differentially expressed at baseline vs. 120 days after treatment. However, AT-MSC treatment does not restore healthy conditions, as 212 proteins are significantly differentially expressed in saliva 120 days after AT-MSCs treatment, as compared to healthy controls. CONCLUSION: The results indicate an increase in proteins related to tissue regeneration in AT-MSCs treated patients. Our study demonstrates the impact of AT-MSCs on the salivary proteome, thereby providing insight into the potential mode of action of this novel treatment approach.

Currently, there are no effective treatments to ease dry mouth, which is a leading long-term side effect of radiation treatment for head and neck cancer. However, treatment with stem cells has shown potential for restoring function of the salivary glands, which are damaged due to radiation. We compared proteins in saliva of previously radiation-treated patients with healthy non-irradiated persons and found differences in the levels of 140 proteins. After stem cell treatment of irradiated patients, we found changes in the salivary content of proteins related to tissue regeneration. Our study demonstrates the impact of stem cell treatment on proteins in saliva, thereby providing insight into the potential mode of action of this treatment approach for patients with radiation-induced dry mouth. Consequently, this could potentially help to improve treatment of dry mouth in the future.

Mesenchymal stromal/stem cell therapy for radiation-induced salivary gland hypofunction in animal models: a protocol for a systematic review and meta-analysis.

BACKGROUND: Salivary gland (SG) hypofunction (objectively reduced saliva flow rate) and xerostomia (subjective sensation of dry mouth) are common and burdensome side effects of radiotherapy to the head and neck region. Currently, only sparse symptomatic treatment is available to ease the discomfort of xerostomia. The objective of this study is to assess the effect of mesenchymal stem cell (MSC) therapy on SG function after radiation-induced injury. METHODS: This systematic review will include animal intervention studies assessing efficacy and safety of MSCs in treating radiation-induced SG hypofunction. The primary outcome is the effect of MSC administration on salivary flow rates (SFR), by comparing treated groups to control groups when available. Secondary outcomes are morphological and immunohistochemical effects as well as safety of MSC treatment. Electronic searches in MEDLINE (PubMed) and Embase databases will be constructed and validated according to the peer review of electronic search strategies (PRESS) and assessed by two independent researchers. Data from eligible studies will be extracted, pooled, and analyzed using random-effects models. Risk of bias will be evaluated with the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool. DISCUSSION: Thus far, critical appraisal of MSC therapy as an effective treatment for SG hypofunction caused solely by radiation injury has not been conducted. A summary of the existing literature on preclinical studies concerning this issue can provide valuable information about effectiveness, mode of action, and safety, allowing further optimization of preclinical and clinical trials. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021227336.

Intraglandular Off-the-Shelf Allogeneic Mesenchymal Stem Cell Treatment in Patients with Radiation-Induced Xerostomia: A Safety Study (MESRIX-II).

No effective therapy exists for the most common long-term side effect of radiation therapy for head and neck cancer (HNC)-xerostomia. The objective was to evaluate safety and provide proof of concept for efficacy of allogeneic adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) injected into the major salivary glands of irradiated patients. This open-label, first-in-human, phase 1b, and single-center trial was conducted with repeated measurements days 0, 1, 5, and 30 and 4 months. Eligible patients with objective and subjective signs of radiation-induced salivary gland damage after treatment of oropharyngeal squamous cell carcinoma stages I-II (UICC 8) were enrolled. Twenty-five million cryopreserved AT-MSCs were injected into each submandibular and 50 million AT-MSCs into each parotid gland. Data were collected on adverse events, unstimulated and stimulated whole saliva (UWS and SWS) flow rates and saliva composition, patient-reported outcomes (EORTC QLQ-H&N35 and Xerostomia Questionnaire [XQ]), blood samples and salivary gland scintigraphy. Data were analyzed using repeated measures linear mixed models. Ten patients (7 men, 3 women, 59.5 years [range: 45-70]) were treated in 4 glands. No treatment-related serious adverse events occurred. During 4 months, UWS flow rate increased from 0.13 mL/minute at baseline to 0.18 mL/minute with a change of 0.06 (P = .0009) mL/minute. SWS flow rate increased from 0.66 mL/minute at baseline to 0.75 mL/minute with a change of 0.09 (P = .017) mL/minute. XQ summary score decreased by 22.6 units (P = .0004), EORTC QLQ-H&N35 dry mouth domains decreased by 26.7 (P = .0013), sticky saliva 23.3 (P = .0015), and swallowing 10.0 (P = .0016). Our trial suggests treatment of the major salivary glands with allogenic AT-MSCs is safe, warranting confirmation in larger trials.

Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline.

PURPOSE: To provide evidence-based recommendations for prevention and management of salivary gland hypofunction and xerostomia induced by nonsurgical cancer therapies. METHODS: Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials published between January 2009 and June 2020. The guideline also incorporated two previous systematic reviews conducted by MASCC/ISOO, which included studies published from 1990 through 2008. RESULTS: A total of 58 publications were identified: 46 addressed preventive interventions and 12 addressed therapeutic interventions. A majority of the evidence focused on the setting of radiation therapy for head and neck cancer. For the prevention of salivary gland hypofunction and/or xerostomia in patients with head and neck cancer, there is high-quality evidence for tissue-sparing radiation modalities. Evidence is weaker or insufficient for other interventions. For the management of salivary gland hypofunction and/or xerostomia, intermediate-quality evidence supports the use of topical mucosal lubricants, saliva substitutes, and agents that stimulate the salivary reflex. RECOMMENDATIONS: For patients who receive radiation therapy for head and neck cancer, tissue-sparing radiation modalities should be used when possible to reduce the risk of salivary gland hypofunction and xerostomia. Other risk-reducing interventions that may be offered during radiation therapy for head and neck cancer include bethanechol and acupuncture. For patients who develop salivary gland hypofunction and/or xerostomia, interventions include topical mucosal lubricants, saliva substitutes, and sugar-free lozenges or chewing gum. For patients with head and neck cancer, oral pilocarpine and oral cevimeline, acupuncture, or transcutaneous electrostimulation may be offered after radiation therapy.Additional information can be found at www.asco.org/supportive-care-guidelines.

Oral symptoms and pathologies in Danish patients with chronic kidney disease- a pilot study.

The aim was to investigate oral health in randomly selected patients with chronic kidney disease (CKD). Data obtained by structured interview (self-reported lifestyle, oral symptoms and regularity of dental visits) and oral examination of patients with CKD from the Copenhagen University Hospital. Fourteen patients with CKD were screened. Only half of the patients reported regular dental visits and poor dental status was registered in half of the patients. Oral mucosal changes were registered in thirteen patients (93%). Eleven patients (79%) had gingival inflammatory disease. Twelve patients (86%) were carriers of Candida, and three (21%) had oral candidosis. Six patients (43%) had low whole saliva flow rate. Twelve patients (86%) reported at least one oral symptom. Overall, there was no differences in oral symptoms or findings related to kidney transplanted or not transplanted patients. The small sample size most likely influences the results. However, the vast majority of patients with CKD reported oral symptoms and only half consulted a dentist regularly. Poor dental status, oral mucosal changes and gingival disease were prevalent findings. Patients with CKD need focus on daily oral healthcare and regular dental visits. Interdisciplinary cooperation could encourage patients with CKD to focus on oral health.

Systematic review of natural and miscellaneous agents, for the management of oral mucositis in cancer patients and clinical practice guidelines - part 2: honey, herbal compounds, saliva stimulants, probiotics, and miscellaneous agents.

OBJECTIVE: To update the clinical practice guidelines for the management of oral mucositis (OM) that were developed by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO). This part focuses on honey, herbal compounds, saliva stimulants, probiotics, and miscellaneous agents. METHODS: A systematic review was conducted by the Mucositis Study Group of MASCC/ISOO. The body of evidence for each intervention, in each clinical setting, was assigned an evidence level. The findings were added to the database used to develop the 2014 MASCC/ISOO clinical practice guidelines. Based on the evidence level, one of the following guidelines were determined: Recommendation, Suggestion, No Guideline Possible. RESULTS: A total of 78 papers were identified within the scope of this section, of which 49 were included in this review and merged with nine publications that were reported in the previous guidelines update. A new Suggestion was made for honey (combined topical and systemic delivery) for the prevention of OM in head and neck cancer patients receiving radiotherapy with or without chemotherapy. A new Suggestion clarified that chewing gum is not effective for the prevention of OM in pediatric patients with hematological or solid cancer treated with chemotherapy. No guideline was possible for other interventions. CONCLUSIONS: Numerous natural products and herbal remedies were studied for the management of OM. Of the agents reviewed in this systematic review, a guideline in favor was made for honey (combined topical and systemic), while a guideline against was made for chewing gum. Additional research is warranted to clarify the potential of other interventions.

Salivary Gland Hypofunction and Xerostomia in Head and Neck Radiation Patients.

BACKGROUND: The most manifest long-term consequences of radiation therapy in the head and neck cancer patient are salivary gland hypofunction and a sensation of oral dryness (xerostomia). METHODS: This critical review addresses the consequences of radiation injury to salivary gland tissue, the clinical management of salivary gland hypofunction and xerostomia, and current and potential strategies to prevent or reduce radiation injury to salivary gland tissue or restore the function of radiation-injured salivary gland tissue. RESULTS: Salivary gland hypofunction and xerostomia have severe implications for oral functioning, maintenance of oral and general health, and quality of life. Significant progress has been made to spare salivary gland function chiefly due to advances in radiation techniques. Other strategies have also been developed, e.g., radioprotectors, identification and preservation/expansion of salivary stem cells by stimulation with cholinergic muscarinic agonists, and application of new lubricating or stimulatory agents, surgical transfer of submandibular glands, and acupuncture. CONCLUSION: Many advances to manage salivary gland hypofunction and xerostomia induced by radiation therapy still only offer partial protection since they are often of short duration, lack the protective effects of saliva, or potentially have significant adverse effects. Intensity-modulated radiation therapy (IMRT), and its next step, proton therapy, have the greatest potential as a management strategy for permanently preserving salivary gland function in head and neck cancer patients.Presently, gene transfer to supplement fluid formation and stem cell transfer to increase the regenerative potential in radiation-damaged salivary glands are promising approaches for regaining function and/or regeneration of radiation-damaged salivary gland tissue.

Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline.

PURPOSE: To provide guidance regarding best practices in the prevention and management of medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer. METHODS: Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. Guideline development involved a systematic review of the literature and a formal consensus process. PubMed and EMBASE were searched for studies of the prevention and management of MRONJ related to bone-modifying agents (BMAs) for oncologic indications published between January 2009 and December 2017. Results from an earlier systematic review (2003 to 2008) were also included. RESULTS: The systematic review identified 132 publications, only 10 of which were randomized controlled trials. Recommendations underwent two rounds of consensus voting. RECOMMENDATIONS: Currently, MRONJ is defined by (1) current or previous treatment with a BMA or angiogenic inhibitor, (2) exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks, and (3) no history of radiation therapy to the jaws or metastatic disease to the jaws. In patients who initiate a BMA, preventive care includes comprehensive dental assessments, discussion of modifiable risk factors, and avoidance of elective dentoalveolar surgery (ie, surgery that involves the teeth or contiguous alveolar bone) during BMA treatment. It remains uncertain whether BMAs should be discontinued before dentoalveolar surgery. Staging of MRONJ should be performed by a clinician with experience in the management of MRONJ. Conservative measures comprise the initial approach to MRONJ treatment. Ongoing collaboration among the dentist, dental specialist, and oncologist is essential to optimal patient care.

Systematic review of natural and miscellaneous agents for the management of oral mucositis in cancer patients and clinical practice guidelines-part 1: vitamins, minerals, and nutritional supplements.

PURPOSE: To update the clinical practice guidelines for the use of natural and miscellaneous agents for the prevention and/or treatment of oral mucositis (OM). METHODS: A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer / International Society of Oral Oncology (MASCC/ISOO). The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. The findings were added to the database used to develop the 2014 MASCC/ISOO clinical practice guidelines. Based on the evidence level, the following guidelines were determined: Recommendation, Suggestion, and No Guideline Possible. RESULTS: A total of 78 papers were identified within the scope of this section, out of which 29 were included in this part, and were analyzed with 27 previously reviewed studies. A new Suggestion was made for oral glutamine for the prevention of OM in head and neck (H&N) cancer patients receiving radiotherapy with concomitant chemotherapy. The previous Recommendation against the use of parenteral glutamine for the prevention of OM in hematopoietic stem cell transplantation (HSCT) patients was re-established. A previous Suggestion for zinc to prevent OM in H&N cancer patients treated with radiotherapy or chemo-radiotherapy was reversed to No Guideline Possible. No guideline was possible for other interventions. CONCLUSIONS: Of the vitamins, minerals, and nutritional supplements studied for the management of OM, the evidence supports a Recommendation against parenteral glutamine in HSCT patients and a Suggestion in favor of oral glutamine in H&N cancer patients for the management of OM.

World Workshop on Oral Medicine VII: Prognostic biomarkers in oral leukoplakia: A systematic review of longitudinal studies.

OBJECTIVE: To identify the prognostic biomarker candidates for stratification and long-term surveillance of oral leukoplakia progressing to cancer via a systematic literature review. MATERIALS AND METHODS: Systematic searches with no date restrictions were conducted on March 29, 2018, targeting the databases PubMed (Ovid), EMBASE (Ovid), EBM (Ovid), and Web of Science (ISI). Bias was assessed using the Quality in Prognosis Studies tool. Biomarkers were stratified based on hallmarks of cancer. RESULTS: Inclusion criteria were met by 25 of 3,415 studies. A range of biomarkers were evaluated experimentally for risk stratification, prognosis, and surveillance of oral leukoplakia in tissue, blood, and saliva. However, the studies were highly heterogeneous and require further validation. Biomarkers reported in these studies included inflammatory or oxidative markers, growth factors, ion channels, genetic and cellular regulatory factors, and epigenetic biomarkers. Studies tended to include small sample sizes, under-reported or variably reported histopathological data, did not address potential confounding, reported limited/variable follow-up data, or lacked a control group. Inclusion of subsets from chemoprevention trials may have introduced bias regarding reported malignant transformation rates and accuracy of prognostic biomarkers. CONCLUSIONS: This review identified insufficient longitudinal evidence to support validated prognostic biomarkers for oral leukoplakia. Further studies are needed to identify molecular targets with the potential to mitigate risk of malignant transformation.

Safety and Efficacy of Mesenchymal Stem Cells for Radiation-Induced Xerostomia: A Randomized, Placebo-Controlled Phase 1/2 Trial (MESRIX).

BACKGROUND: Salivary gland hypofunction and xerostomia are major complications to head and neck radiotherapy. This trial assessed the safety and efficacy of adipose tissue-derived mesenchymal stem cell (ASC) therapy for radiation-induced xerostomia. PATIENT AND METHODS: This randomized, placebo-controlled phase 1/2 trial included 30 patients, randomized in a 1:1 ratio to receive ultrasound-guided transplantation of ASCs or placebo to the submandibular glands. Patients had previously received radiotherapy for a T1-2, N0-2A, human papillomavirus-positive, oropharyngeal squamous cell carcinoma. The primary outcome was the change in unstimulated whole salivary flow rate, measured before and after the intervention. All assessments were performed one month prior (baseline) and one and four months following ASC or placebo administration. RESULTS: No adverse events were detected. Unstimulated whole salivary flow rates significantly increased in the ASC-arm at one (33%; P = .048) and four months (50%; P = .003), but not in the placebo-arm (P = .6 and P = .8), compared to baseline. The ASC-arm symptom scores significantly decreased on the xerostomia and VAS questionnaires, in the domains of thirst (-22%, P = .035) and difficulties in eating solid foods (-2%, P = .008) after four months compared to baseline. The ASC-arm showed significantly improved salivary gland functions of inorganic element secretion and absorption, at baseline and four months, compared to the placebo-arm. Core-needle biopsies showed increases in serous gland tissue and decreases in adipose and connective tissues in the ASC-arm compared to the placebo-arm (P = .04 and P = .02, respectively). MRIs showed no significant differences between groups in gland size or intensity (P < .05). CONCLUSIONS: ASC therapy for radiation-induced hypofunction and xerostomia was safe and significantly improved salivary gland functions and patient-reported outcomes. These results should encourage further exploratory and confirmatory trials.