BACKGROUND When 3-dimensional conformal radiation therapy (3DCRT) for postoperative breast cancer is performed in the supine position, patients are required to raise their arms to spare the arms from the irradiation field. However, patients with collagen vascular disease can experience severe joint symptoms. CASE REPORT A 43-year-old woman with a history of systemic lupus erythematosus (SLE) 10 years ago received a diagnosis of invasive ductal carcinoma of the left breast. Breast-conserving surgery and sentinel lymph node biopsy were performed. The pathological stage was IA. Physical and immunological examinations indicated that SLE disease activity was stable preoperatively and postoperatively. She had difficulty holding her left arm in a raised position because of arthritis related to SLE and steroid therapy. For postoperative radiation therapy, we developed an arm-behind-the-back position, in which a platform was placed between the patient's body and couch. In this position, the patient's arm was lowered behind the back, such that the arm did not interfere with the irradiation field of 3DCRT. The treatment plan achieved an acceptable homogeneity index, low dose to the lungs and heart, and no problematic hotspots. Although the time required for position matching and irradiation tended to be longer than that in the regular supine position, scheduled irradiation was safely completed. Grade 2 radiation dermatitis was observed. The patient showed no signs of local recurrence or distant metastases after 15 months. No radiation pneumonitis was observed. CONCLUSIONS The ingenuity of positioning can achieve radiotherapy in patients with collagen vascular disease and shoulder joint symptoms.

Unusual or unexpected effect of treatment It is difficult to reduce lung toxicity in chemoradiotherapy for locally advanced lung cancer. Volume-modulated arc therapy (VMAT) is a useful lung dose-lowering radiation technique, but it is time-consuming because of its complexity. We present a case of a rapidly growing bulky lung cancer treated with VMAT and intensive adaptation to volume change. A 43-year-old man with chest pain was diagnosed with non-small cell lung cancer, cT4N3M0 stage IIIC (UICC 8th edition). Concurrent chemoradiotherapy with a VMAT of 60 Gy in 30 fractions and carboplatin/paclitaxel was performed. Despite initiating chemoradiation, monitoring with cone-beam computed tomography (CT) revealed tumor progression. The peak tumor volume was 1.5 times larger than that on CT simulation. The VMAT plan was recreated to cover the increased tumor size. After the irradiation field was enlarged, the tumor, on the contrary, shrank rapidly. Therefore, VMAT planning was performed again to further shrink the irradiation field. CT at the end of the treatment showed a good volume reduction response. Durvalumab therapy was continued for 1 year. After that, the patient was alive and showed no sign of progression. Only asymptomatic radiation pneumonitis was observed as a sub-acute adverse event. We present a case in which proper adaptive VMAT and durvalumab for dramatically progressive non-small cell lung cancer were effective, resulting in 1-year progression-free survival. Even when rapid progression of bulky lung cancer is suggested, the combination of VMAT and adaptive radiotherapy with improved target coverage and reduced lung dose can be a treatment option.

Background/Objectives: Stereotactic body radiotherapy (SBRT) is increasingly used for hepatocellular carcinoma (HCC) that is unsuitable for surgery, radiofrequency ablation (RFA), or transplantation. Although current evidence for imaging assessment after SBRT is largely based on contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), repeated contrast-enhanced imaging may be difficult to perform at every routine follow-up visit. Thus, we evaluated whether conventional abdominal ultrasound (US) can monitor tumor size after SBRT for HCC. Methods: We retrospectively reviewed 67 consecutive patients who underwent SBRT for HCC at our institution between January 2015 and October 2020. After excluding patients treated for local recurrence after RFA or transarterial chemoembolization, those whose lesions were not visible on pretreatment US, and those without follow-up US within one year, 32 patients with 32 nodules were analyzed. Tumor visibility and size changes on US were assessed before treatment and at <6, 6–12, and 12–18 months after SBRT. Results: The treated lesion was identified as a discrete nodule on US in 100% (15/15; 95% CI, 78.2–100%), 75.0% (18/24; 95% CI, 53.3–90.2%), and 50.0% (8/16; 95% CI, 24.7–75.3%) of examinations at <6, 6–12, and 12–18 months, respectively. In all cases in which the lesion was no longer measurable on US, contrast-enhanced CT/MRI showed complete or partial response. Local tumor progression occurred in one patient (3.1%) during a median follow-up of 24.1 months; in this patient, interval enlargement was first detected by US 3.7 months after SBRT and was subsequently confirmed by dynamic CT/MRI. Conclusions: These descriptive findings suggest that in selected patients with lesions clearly visible on pretreatment US, conventional abdominal US may provide complementary morphologic information during the first year after SBRT when used alongside periodic dynamic CT/MRI. Prospective validation is required before routine implementation.