Pharyngeal Constrictor-Sparing Salvage Stereotactic Body Radiation Therapy with Tongue-Out for In-Field Recurrence after Definitive Radiation Therapy for Head & Neck Cancer: Guide to Tongue-Out Radiation Therapy (TORT).

This report details a pharyngeal constrictor muscle (PCM)-sparing stereotactic body radiation therapy (SBRT) using our institutional technique of "Tongue-out" RT (TORT) for treating a local recurrent cancer in the uvula (GTVuvula) in a patient with history of a definitive chemo-RT (70 Gy with weekly cisplatin) for a locally advanced laryngeal cancer four years ago. TORT includes optimizing the patients' reproducible tongue-out position using readily available medicine cup (30 cc) followed by sculping the thermoplastic mask with tongue-out, and real-time visual monitoring of the tongue position during the CT-simulation scan, CBCT acquisition, and treatment. Between arcs during volumetric modulated arc therapy (VMAT), time for tongue relaxation and saliva swallowing can be given to the patient. Without TORT, the patient's GTVuvula abutted the medial aspect of superior PCM (medial-sPCM) and a substantial volume of the previously irradiated sPCM would have received high radiation dose from this salvage SBRT (32.5 Gy in 5 fractions). Compared to without TORT, the shortest distance between medial-sPCM-to-GTVuvula was increased by 13 mm with TORT, which reduced radiation dose to sPCM in salvage SBRT plan. The mean dose (Dmean) to sPCM was decreased from 20.5 Gy without TORT to 12.7 Gy with TORT. With TORT, minimal sPCM volumes fell within higher isodose line: volume receiving ≥ 60% prescription dose (V60%Rx), V80%Rx, and V100%Rx to sPCM was, 4.8 vs. 0.7 cc (without vs. with TORT, respectively), 2.9 vs. 0.19 cc, and 1.6 vs. 0.04 cc, respectively. Maximum dose (Dmax) to medial-sPCM was 34.6 Gy without TORT vs. 22.7 Gy with TORT. These high doses to the sPCM and intrafractional swallowing-related geographic misses of GTVuvula were avoided through the application of TORT in this salvage re-RT setting. The patient successfully finished salvage SBRT with TORT resulting no dysphagia or mucositis and maintained complete response at 12 months after treatment.

Continuous Positive Airway Pressure-Assisted Breathing With Supine Tangential Left Breast Radiation Therapy When Deep Inspiration Breath-Hold Radiation Therapy Was Ineffective or Unsuitable: Clinical Implications for an Affordable Heart-Sparing Breast Radiation Therapy to Reduce the Health Care Disparities in Low-Resource Settings.

Purpose: To report continuous positive airway pressure (CPAP)-assisted breathing with supine tangential left breast radiation therapy (CPAP-RT) when deep inspiration breath-hold RT (DIBH-RT) was ineffective or unsuitable. Methods and Materials: Ten patients with left breast cancer underwent computed tomography simulation scan (CT-sim) under DIBH followed by CPAP-assisted breathing (15 cm H2O) to create CPAP-RT plans in authors' institute. Reasons for CPAP-RT include inability to reproduce DIBH (n = 5), DIBH-RT plan exceeded dose limits to the heart (n = 2), and unable to proceed with planned DIBH-RT due to mechanical issues (n = 3). Radiation target volumes and organs at risk were contoured according to published atlas data. For dosimetric comparison, supine tangential fields for breast only RT (Breast-RT) and wide-tangential fields for breast + internal mammary nodal RT (Breast + IMN-RT) were used with prescription of 40 Gy in 15 fractions on each patients' CT-sim with free-breathing (FB), DIBH, and CPAP-assisted breathing, respectively. Results: Planning target volume (PTV) coverage was acceptable and comparable in all RT plans. Compared with FB, both DIBH and CPAP-assisted breathing inflated the thorax and increased left lung volume on average by 46% and 51%, respectively (FB: 1230 vs DIBH: 1802 vs CPAP-assisted breathing:1860 cc, P < .01), and increased the shortest distance between PTVeval-Breast to the heart by 5.6 ± 3.0 and 11.9 ± 3.6 mm (P < .01) and to LAD by 4.9 ± 2.9 and 10.8 ± 4.3 mm, respectively (P < .01). Compared with FB, both DIBH and CPAP significantly reduced radiation dose to the heart and LAD. A mean dose to the heart (HeartDmean) was FB: 2.3 ± 0.9, DIBH: 1.2 ± 0.7, and CPAP: 0.9 ± 0.4 Gy in Breast-RT (P < .01); FB: 3.2 ± 1.7, DIBH: 1.7 ± 0.8, and CPAP: 1.3 ± 0.5 Gy in Breast + IMN-RT (P < .01). LADDmean was FB: 11 ± 4.5, DIBH: 5.4 ± 3.2, and CPAP: 2.4 ± 0.9 Gy in Breast-RT (P < .01); FB: 15.5 ± 7.8, DIBH: 7.4 ± 4.1, and CPAP: 3.5 ± 1.4 Gy in Breast + IMN-RT (P < .01). A maximum dose to LAD (LADDmax) was FB: 35.8 ± 8.7, DIBH: 22.4 ± 15.4, and CPAP: 7.8 ± 5.3 Gy in Breast-RT (P < .01); FB: 38.7 ± 5.0, DIBH: 25.3 ± 15.2, and CPAP: 10.2 ± 6.8 Gy in Breast + IMN-RT (P < .01). All patients successfully completed CPAP-RT. Conclusions: CPAP-RT provides efficient and practical heart and LAD sparing RT using simple supine tangential fields for Breast-RT or wide-tangential fields for Breast + IMN-RT when DIBH-RT was ineffective or unsuitable. With its easy accessibility and low infrastructural requirement, CPAP-RT can provide affordable heart-sparing left breast RT to reduce the health care disparities in low-resource settings.