Oral mucositis (OM) is a common and debilitating adverse effect of conditioning regimens in patients undergoing hematopoietic cell transplantation (HCT). It is treated symptomatically with pain relief medications. The use of low-level laser therapy (LLLT) to prevent tissue damage has been postulated for almost forty years, however, there are only a few reports concerning old generation lasers in mucositis prophylaxis in HCT recipients. Here we hypothesized, that a new generation LLLT (Nd: YAG Fotona LightWalker®) laser may be an effective prophylaxis in shortening and reducing the severity of this complication.

This clinical trial is a prospective, randomized open-label study. All patients qualified to hematopoietic stem cell transplantation will be informed about possibility of taking part in this study. Patients who meet the inclusion criteria will be enrolled and randomized into two groups.

Patients in the first group will receive standard supportive treatment. Patients in the second group, except for the supportive treatment (as in the first group), will additionally receive prophylactic laser therapy of oral mucosa during high-dose chemotherapy conditioning before HSCT. Patients will undergo laser treatment daily from the first day of conditioning regimen till the second day after stem cell transfusion. The procedure will be carried out by trained staff at the bedside.

Severity of oral mucositis and pain will be measured in both groups on days 0, 4, 7, 11, 14, 18 and 21 after HSCT.

Severity of oral mucositis will be assessed according to five-point WHO scale Pain intensity will be measured on the basis of ten-point NRS scale.

In addition, the need for opioid analgesics and total parenteral nutrition will be evaluated.

Photographic documentation will be made on days -7, 0, 7, 14, 21. All obtained results will be collected in a database and subjected to statistical analysis. Additional analysis will be carried out during the study to evaluate whether the differences in results between studied groups reach statistical significance with less than a predetermined number of patients.

Inclusion Criteria:

• written, informed consent for participation in the study
• oral sanation
• myeloablative conditioning

Exclusion Criteria:

• lack of patient's consent
• pathological lesions in oral cavity on the first day of conditioning regimen
• renal failure
• active infection