Management of radiation-induced oral mucositis in head and neck cancer patients: a real-life survey among 25 Italian radiation oncology centers.

AIM: Radiation-induced oral mucositis (RIOM) is the most frequent side effect in head and neck cancer (HNC) patients treated with curative radiotherapy (RT). A standardized strategy for preventing and treating RIOM has not been defined. Aim of this study was to perform a real-life survey on RIOM management among Italian RT centers. METHODS: A 40-question survey was administered to 25 radiation oncologists working in 25 different RT centers across Italy. RESULTS: A total of 1554 HNC patients have been treated in the participating centers in 2021, the majority (median across the centers 91%) with curative intent. Median treatment time was 41 days, with a mean percentage of interruption due to toxicity of 14.5%. Eighty percent of responders provide written oral cavity hygiene recommendations. Regarding RIOM prevention, sodium bicarbonate mouthwashes, oral mucosa barrier agents, and hyaluronic acid-based mouthwashes were the most frequent topic agents used. Regarding RIOM treatment, 14 (56%) centers relied on literature evidence, while internal guidelines were available in 13 centers (44%). Grade (G)1 mucositis is mostly treated with sodium bicarbonate mouthwashes, oral mucosa barrier agents, and steroids, while hyaluronic acid-based agents, local anesthetics, and benzydamine were the most used in mucositis G2/G3. Steroids, painkillers, and anti-inflammatory drugs were the most frequent systemic agents used independently from the RIOM severity. CONCLUSION: Great variety of strategies exist among Italian centers in RIOM management for HNC patients. Whether different strategies could impact patients' compliance and overall treatment time of the radiation course is still unclear and needs further investigation.

Significant improvement in normal tissue sparing and target coverage for head and neck cancer by means of helical tomotherapy.

PURPOSE: In order to explore the potential of helical Tomotherapy in the treatment of head and neck cancers (HNC), a planning study comparing our routinely delivered IMRT technique (dynamic MLC Varian 600CD Linac, inversely optimised by the Helios/Eclipse system) against two different Tomotherapy planning approaches was performed. MATERIALS AND METHODS: In the first Tomotherapy plan (TOMO-a), we merely applied the same constraints used for the IMRT-Linac technique; in the second one (TOMO-b), we tried to stress the sparing of parotids and mandible while keeping PTV coverage and spinal cord Dmax similar to their values in the TOMO-a plan. Five patients with locally advanced oropharinx (n=3), hypopharinx (n=1) and larynx (n=1) cancer were considered. For each patient, CTV1 including neck nodes and the tumour was defined and was expanded with a margin of 0.5 cm (PTV1); then, CTV2 including high risk nodes and CTV3 including only T were defined and the corresponding PTV2/PTV3 were defined by a 0.5 cm expansion. IMRT and Tomotherapy planning were optimised to deliver 54 Gy in 30 fractions on PTV1 and 16.2 Gy in 9 fractions on PTV3; in the case a PTV2 was defined, 15 Gy were concomitantly delivered while delivering 16.2 Gy on PTV3. Separated plans for the two phases (Phase 1: first 30 fractions; Phase 2: last 9 fractions) were compared in terms of dose-volume histograms (DVH) and dose statistics on PTVs and OARs. RESULTS: When considering Phase 1, Tomotherapy improved the homogeneity of the dose distribution within PTV1 while delivering the same prescribed dose (assessed to be the median dose to PTV): the fraction of PTV1 receiving more than 95% of the prescribed dose (V95%) increased from 90% (IMRT) to 96-97% for Tomotherapy plans. Dmax within PTV1 decreased from 60.3 Gy (IMRT) to 57.4 Gy (TOMO-a) and 58.7 Gy (TOMO-b). Spinal cord Dmax decreased from 31.6 Gy (IMRT) to 26.5 Gy (TOMO-a) and 24.6 Gy (TOMO-b). No attempts to further reduce spinal cord Dmax were done. Mean dose to the parotids decreased from 26.1 Gy (IMRT) to 25.1 Gy (TOMO-a) and 20.8 Gy (TOMO-b). Mandible was significantly better spared with Tomotherapy: mean dose decreased from 34.9 Gy (IMRT) to 34.0 Gy (TOMO-a) and 30.7 Gy (TOMO-b). When considering phase 2, the average gains (TOMO-b vs IMRT) were more modest and depended on the location of PTV2/PTV3. CONCLUSIONS: Preliminary findings obtained in a sequential approach for HNC suggest that Tomotherapy has the potential to significantly improve the therapeutic ratio with respect to a conventional IMRT delivery method.

Static and rotational intensity modulated techniques for head-neck cancer radiotherapy: a planning comparison.

PURPOSE: To compare helical Tomotherapy (HT), two volumetric-modulated arc techniques and conventional fixed-field intensity modulated techniques (S-IMRT) for head-neck (HN) cancers. METHODS AND MATERIALS: Eighteen HN patients were considered. Four treatment plans were generated for each patient: HT, S-IMRT optimised with Eclipse treatment planning system and two volumetric techniques using Elekta-Oncentra approach (VMAT) and Varian-RapidArc (RA), using two full arcs. All techniques were optimised to simultaneously deliver 66Gy to PTV1 (GTV and enlarged nodes) and 54Gy to PTV2 (subclinical and electively treated nodes). Comparisons were assessed on several dosimetric parameters and, secondarily, on planned MUs and delivery time. RESULTS: Concerning PTV coverage, significantly better results were found for HT and RA. HT significantly improved the target coverage both compared to S-IMRT and VMAT. No significant differences were found between S-IMRT and volumetric techniques in terms of dose homogeneity. For OARs, all the techniques were able to satisfy all hard constraints; significantly better results were found for HT, especially in the intermediate dose range (15-30 Gy). S-IMRT reached a significantly better OARs sparing with respect to VMAT and RA. No significant differences were found for body mean dose, excepting higher values of V5-V10 for HT. A reduction of planned MUs and delivery treatment time was found with volumetric techniques. CONCLUSIONS: The objectives of satisfying target coverage and sparing of critical structures were reached with all techniques. S-IMRT techniques were found more advantageous compared to RA and VMAT for OARs sparing. HT reached the best overall treatment plan quality.

Simultaneous integrated boost (SIB) for nasopharynx cancer with helical tomotherapy. A planning study.

PURPOSE: To explore the potential of helical tomotherapy (HT) in the treatment of nasopharynx cancer. PATIENTS AND METHODS: Six T1-4 N1-3 patients were considered. A simultaneous integrated boost (SIB) technique was planned with inversely optimized conventional intensity-modulated radiotherapy (IMRT; dynamic multileaf collimator using the Eclipse-Helios Varian system) and HT. The prescribed (median) doses were 54 Gy, 61.5 Gy, and 64.5 Gy delivered in 30 fractions to PTV1 (planning target volume), PTV2, and PTV3, respectively. The same constraints for PTV coverage and for parotids, spinal cord, mandible, optic structures, and brain stem were followed in both modalities. The planner also tried to reduce the dose to other structures (mucosae outside PTV1, larynx, esophagus, inner ear, thyroid, brain, lungs, submental connective tissue, bony structures) as much as possible. RESULTS: The fraction of PTV receiving >95% of the prescribed dose (V95%) increased from 97.6% and 94.3% (IMRT) to 99.6% and 97% (HT) for PTV1 and PTV3, respectively (p<0.05); median dose to parotids decreased from 30.1 Gy for IMRT to 25.0 Gy for HT (p<0.05). Significant gains (p<0.05) were found for most organs at risk (OARs): mucosae (V30 decreased from 44 cm(3) [IMRT] to 18 cm(3) [HT]); larynx (V30: 25 cm(3) vs. 11 cm(3)); thyroid (mean dose: 48.7 Gy vs. 41.5 Gy); esophagus (V45: 4 cm(3) vs. 1 cm(3)); brain stem (D1%: 45.1 Gy vs. 37.7 Gy). CONCLUSION: HT improves the homogeneity of dose distribution within PTV and PTV coverage together with a significantly greater sparing of OARs compared to linac five-field IMRT.