Toru Shibata

We evaluated retrospectively the daily target coverage using cone-beam computed tomography (CBCT) in breath-hold image-guided radiotherapy (BH-IGRT) for gastric lymphoma. BH-IGRT was performed using a prescribed dose of 30.6 Gy in 17 fractions for the whole stomach. We assessed the target coverage of the whole stomach on daily CBCT images [daily clinical target volume (CTV)], which was delineated individually by two observers. We evaluated V_95% (percentage of volume receiving ≥95% of the prescribed dose) of daily CTV. In total, 102 fractions from 6 patients were assessed. The mean V_95% of daily CTV was 97.2%, which was over 95%. In two of six patients, the V_95% of daily CTV was over 95% for either observer in all fractions. One patient had significant interobserver variation (p = 0.013). In 95 fractions (93%), the V_95% of daily CTV was over 95% for either observer. Daily target coverage for CTV in BH-IGRT for gastric lymphoma seems to be favorable, even when using CBCT. A previous study ascertained good daily target coverage in BH-IGRT for gastric lymphoma using in-room CT. Even when using CBCT in our study, daily target coverage for CTV in BH-IGRT for gastric lymphoma seems to be favorable.

Background/Aim: We retrospectively compared stereotactic body radiotherapy (SBRT) with conventionally fractionated radiotherapy (CFRT) for a solitary lung tumor after resection of a non-small cell lung cancer (NSCLC), due to a lack of data concerning whether SBRT or CFRT is more effective in this setting. Patients and Methods: SBRT using 48 Gy in 4 fractions was administered to 15 patients with a peripheral tumor (SBRT group). CFRT using 66-70 Gy in 33-35 fractions was administered to 11 patients with a central tumor (CFRT group). Results: The median follow-up time was 32 months (range: 9-79 months). The 3-year overall survival rates in SBRT and CFRT groups were 81% and 40%, respectively (p=0.008). The 3-year local control rates in SBRT and CFRT groups were 83% and 35%, respectively (p=0.035). Regarding toxicities, no significant differences were found between the two groups. Conclusion: Compared to CFRT, SBRT may be more effective in solitary-lung-tumor patients after the complete resection of an NSCLC as with inoperable-stage I-NSCLC patients.

We assessed differences in gross tumor volumes (GTVs) for pancreatic cancer between respiratory-ungated positron emission tomography (3D-PET) and contrast-enhanced four-dimensional computed tomography (CE-4DCT).

Aim: To evaluate the clinical results of two-step intensity-modulated radiation therapy (IMRT) for oropharyngeal cancer. Patients and Methods: Eighty patients were treated with two-step IMRT between 2002 and 2014. Whole-neck radiotherapy (44.0-50.0 Gy/22-25 fractions) was delivered by IMRT, followed by boost IMRT to the high-risk clinical target volume (total dose of 70.0 Gy/35 fractions). Forty-seven patients received concurrent chemotherapy. Immunohistochemistry for human papillomavirus type 16 (HPV/p16) was performed for 64 patients. Results: The 5-year overall survival and locoregional control rates for stage I, II, III, and IVA-B disease were 80.0%, 75.0%, 78.0%, and 64.0% and 100.0%, 75.0%, 92.0%, and 82.0%, respectively. Overall survival was significantly higher in HPV/p16-positive patients than in HPV/p16-negative patients (p=0.01). Xerostomia of grade 2 or more was noted in 10 patients. Conclusion: Favourable overall survival and locoregional control rates with excellent salivary preservation were obtained using the two-step IMRT method for oropharyngeal cancer.

The ideal neoadjuvant treatment protocol for patients with pancreatic cancer (PDAC) remains unclear. We evaluated the efficacy and safety of neoadjuvant hypofractionated chemoradiotherapy with S-1 for patients with resectable (R) and borderline resectable (BR) PDAC.

Clinical results of computed tomography (CT) simulations and [¹⁸F]-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET)/CT simulations were compared retrospectively. Between 2006 and 2011, [¹⁸F]-FDG PET/CT simulation was performed on 68 consecutive patients with pharyngeal cancers (PET/CT group). As an historical control, conventional CT simulation was performed on 56 consecutive patients with pharyngeal cancer between 2000 and 2006 (CT group). In the PET/CT group, the primary sites were nasopharynx (NPC), oropharynx (OPC), and hypopharynx (HPC) in 35, 20, and 13 patients, respectively; in the CT group, the primary sites were NPC, OPC, and HPC in 21, 17, and 18 patients, respectively. All but five patients in the PET/CT group were treated with intensity modulated radiation therapy (IMRT). In the PET/CT group, TNM and clinical stages changed in 11 (16 %) and eight (12 %) patients, respectively. Although the 5-year overall survival (OS) rates for the PET/CT and the CT groups were 80 and 64 %, respectively (p = 0.0420), this result may be attributable to the background difference between the two groups. Similarly, the 5-year locoregional control rates of the two groups were 82 and 70 %, respectively (p = 0.0501). Notably, marginal recurrences around the planning target volume (PTV) were only noted in four CT group patients. PET/CT simulation was useful for delineating an accurate clinical target volume (CTV) of pharyngeal cancer, and its clinical results were satisfactory.

Purpose This study evaluated the relationship between dose–volume histogram (DVH) parameters and pulmonary complications after neoadjuvant chemoradiotherapy (NACRT) followed by surgery for lung cancer. We also examined a new DVH parameter, because the unresected lung should be more spared than the later resected lung. Patients and methods Data from 43 non-small cell lung cancer patients were retrospectively analyzed. The DVH parameters of the lung were calculated from the total bilateral lung volume minus (1) the gross tumor volume (DVHg) or (2) the later resected lung volume (DVHr). Radiation pneumonitis (RP) and fistula, including bronchopleural and pulmonary fistula, were graded as the pulmonary complications. Factors affecting the incidences of grade 2 or higher RP (≥G2 RP) and fistula were analyzed. Results Sixteen patients (37 %) experienced ≥G2 RP and a V20 value of the total lung minus the later resected lung (V20r) ≥ 12 % was a significant factor affecting the incidence of ≥G2 RP (p = 0.032). Six patients (14 %) developed a fistula and a V35 value of the total lung minus the gross tumor (V35g) ≥ 19 % and a V40g ≥ 16 % were significant factors affecting the incidence of fistula (p = 0.002 and 0.009, respectively). Conclusion These DVH parameters may be related to the incidences of ≥G2 RP and fistula.

The aim of this study was to investigate the impact of pelvic rotational setup error on lymph nodal dose in the whole pelvic intensity-modulated radiation therapy using the fiducial marker. The dose differences of clinical target volume for pelvic lymph node (CTVLN) due to isocenter (IC) shift and pelvic rotation were evaluated using the radiation treatment planning system. The rotated computed tomography (CT) images were created for the simulation of the pelvic rotation. The original CT images were rotated around the IC of the original plan in the pitch and roll directions up to±3.0 deg. at 1.0 deg. intervals. As simulated plans, IC positions were shifted in the anterior-posterior and superior-inferior directions up to±10 mm at 2 mm intervals in the original and rotated CT images, and the dose distributions were calculated. The dose calculation was performed for each CT image while keeping the movement of multi leaf collimator and the monitor unit of the original plan. The differences between D98% of CTVLN in the original plan and simulated plans were calculated. In the posterior direction shifts of 4, 6, 8, and 10 mm, the dose reduction of 0.7, 2.1, 6.1, and 11.9% from the original plan were found for D98% of CTVLN, respectively. The dose reductions due to the rotation of pitch direction were greater than the rotation of roll direction. In the posterior direction shifts of 4, 6, 8, and 10 mm with 3.0 deg. rotation of pitch direction, the dose reduction of 2.2, 6.8, 12.8, and 19.0% from the original plan were found, respectively. The dose reduction of CTVLN might be occurred due to the rotational setup error of pitch direction.

Background: To report the treatment outcome of a patient with nasopharyngeal small‐cell carcinoma (SCC). Methods: The patient received concurrent chemoradiotherapy (CRT). Chemotherapy consisted of four cycles of cisplatin and etoposide. Accelerated hyperfractionated radiotherapy (RT) was performed with a dose of 45 Gy in 30 fractions over 3 weeks for the nasopharynx and upper neck region, while conventional fractionated RT was performed with a dose of 50 Gy in 25 fractions over 5 weeks for the lower neck region. Results: Complete response was achieved 1 month after the completion of CRT. Prophylactic cranial irradiation (PCI) was not performed. Isolated brain metastasis was diagnosed 18 months after the completion of CRT. Finally, the patient died due to the brain and cord metastases 32 months after the completion of CRT. Conclusions: The administration of PCI may be considered for nasopharyngeal SCC. Head Neck, 2014