Radiation Oncology Journal最新文献

Purpose: Re-irradiation is a treatment option for recurrent esophageal cancer patients with a history of radiotherapy, but there is a risk of severe late adverse effects. This study focused on the efficacy and safety of re-irradiation using hyperfractionated radiotherapy.

Materials and methods: Twenty-six patients who underwent re-irradiation by the hyperfraction technique using twice-daily irradiation of 1.2 Gy per fraction for recurrent esophageal cancer were retrospectively included in this study. The overall survival period after the start of secondary radiotherapy and the occurrence of late adverse effects were investigated.

Results: Of 26 patients, 21 (81%) received re-irradiation with definitive intention and 21 (81%) underwent concurrent chemotherapy. The median re-irradiation dose was 60 Gy in 50 fractions in 25 treatment days, and the median accumulated irradiation dose in equivalent dose in 2 Gy per fraction was 85.4 Gy with an α/β value of 3. The median interval between two courses of radiotherapy was 21.0 months. The median overall survival period was 15.8 months and the 1-year and 3-year overall survival rates were 64.3% and 28.3%, respectively. Higher dose of re-irradiation and concurrent chemotherapy significantly improved survival (p < 0.001 and p = 0.019, respectively). Severe late adverse effects with the Common Terminology Criteria for Adverse Events grade 3 or higher were observed in 5 (19.2%) patients, and 2 (7.7%) of them developed a grade 5 late adverse effect.

Conclusion: High-dose re-irradiation using a hyperfractionated schedule with concurrent chemotherapy might be related to good prognosis, while the rate of late severe adverse effects is not high compared with the rates in past reports.

Purpose: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a high-grade lung neuroendocrine tumor with a poor prognosis, similar to small cell lung cancer (SCLC). However, it remains unclear whether to treat LCNEC as non-small-cell lung cancer (NSCLC) or as SCLC. We reviewed our experiences to suggest appropriate treatment strategy for resected pulmonary LCNEC.

Materials and methods: Forty-four patients were treated for pathologically diagnosed pulmonary LCNEC during 2005‒2018. We considered curative surgery first in early-stage or some locally advanced tumors, unless medically inoperable. Adjuvant treatments were decided considering patient's clinical and pathological features. After excluding two stage I tumors with radiotherapy alone and three stage III tumors with upfront chemotherapy, we analyzed 39 patients with stage I‒III pulmonary LCNEC, who underwent curative resection first.

Results: Adjuvant chemotherapy (NSCLC-based 91%, SCLC-based 9%) was performed in 62%, and adjuvant radiotherapy was done in three patients for pN2 or positive margin. None received prophylactic cranial irradiation (PCI). With a median follow-up of 30 months, the 2- and 5-year overall survival (OS) rates were 68% and 51%, and the 2- and 5-year recurrence-free survival (RFS) rates were 49% and 43%, respectively. Aged ≥67 years and SCLC-mixed pathology were significant poor prognostic factors for OS or RFS (p < 0.05). Among 17 recurrences, regional failures were most common (n = 6), and there were five brain metastases.

Conclusions: Surgery and adjuvant treatment (without PCI) could achieve favorable outcomes in pulmonary LCNEC, which was more similar to NSCLC, although some factors worsened the prognosis. The importance of intensified adjuvant therapies with multidisciplinary approach remains high.

Purpose: Studies on de-escalation in radiation therapy (RT) for human papillomavirus-related (HPV(+)) oropharyngeal cancer (OPC) are currently ongoing. This study investigated the current practice regarding the radiation dose and field in the treatment of HPV(+) OPC.

Materials and methods: The Korean Society for Head and Neck Oncology conducted a questionnaire on the primary treatment policy. Among them, for HPV(+) OPC scenarios, radiation oncologists were questioned regarding the field and dose of RT.

Results: Forty-two radiation oncologists responded to the survey. In definitive concurrent chemoradiotherapy (CCRT) treatment for stage T2N1M0 OPC, most respondents prescribed a dose of >60 Gy to the primary tonsil and involved ipsilateral lymph nodes. However, eight of the respondents prescribed a relatively low dose of ≤54 Gy. For stage T2N1M0 OPC, postoperative adjuvant RT was prescribed by eight and nine respondents with a lower dose of ≤50 Gy for the ipsilateral tonsil and involved neck, respectively. In definitive CCRT in complete remission after induction chemotherapy for initial stage T2N3M0 OPC, de-escalation of the tonsil and involved neck were performed by eight and seven respondents, respectively. Regarding whether de-escalation is applied in radiotherapy for HPV(+) OPC, 27 (64.3%) did not do it at present, and 15 (35.7%) were doing or considering it.

Conclusion: The field and dose of prescribed treatment varied between institutions in Korea. Among them, dose de-escalation of RT in HPV(+) OPC was observed in approximately 20% of the respondents. Consensus guidelines will be set in the near future after the completion of ongoing prospective trials.

Purpose: To provide a new insight on a novel safe cardiac radioablation using deep inspiration breath-hold (DIBH) to reduce gastrointestinal dose.

Materials and methods: For treating incessant ventricular tachycardia (VT) originated from left ventricle inferior scar abutting the stomach, a target delineation and treatment planning for cardiac radioablation was performed. With four different computed tomography (CT) scan protocols-DIBH, full expiration breath-hold, four-dimensional (4D) CT without and with abdominal compression, the distances between the target and the stomach were compared.

Results: Among the protocols, the CT scan with DIBH showed largest distance between the target and the stomach and selected for the treatment planning. The prescribed dose was 25 Gy in a single fraction, and satisfactory dosimetric parameters were achieved with the DIBH. The patient was successfully treated with the DIBH, and experienced no acute toxicity.

Conclusion: To gain the best benefit from cardiac radioablation, understanding the possible toxicity in the adjacent organs is crucial. By moving the heart with thoraco-diaphragmatic movement by DIBH, the target could be physically separated from the stomach.

Purpose: The study aims to report late toxicities in locally advanced head-and-neck squamous cell carcinoma (LAHNSCC) treated with intensity-modulated radiation therapy (IMRT).

Materials and methods: A retrospective study was conducted on 103 patients of LAHNSCC treated with IMRT. We analyzed the cumulative incidence of late xerostomia, dysphagia, and aspiration at an interval of 6-month, 1-year, 2-year, and 3-year from the start of IMRT.

Results: At a median follow up of 4.2 years (interquartile range, 3.5 to 6 years), the cumulative incidence of grade ≥2 late xerostomia was 5.5%, dysphagia was 6.9%, and aspiration was 11.1%. Logistic regression showed that Dmean of ≥26 Gy to parotids had higher risk of xerostomia (hazard ratio [HR] = 5.19; 95% confidence interval [CI], 1.90-14.22; p = 0.001). Late dysphagia was associated with Dmean of ≥45 Gy to pharyngeal constrictors (PC) (HR = 7; 95% CI, 1.84-26.61; p =0.004), ≥55 Gy to larynx (HR = 3.25; 95% CI, 1.15-9.11; p = 0.025), and adjuvant RT (HR = 5.26; 95% CI, 1.85-14.87; p = 0.002). Aspiration was associated with Dmean of ≥45 Gy to larynx (HR = 6.5; 95% CI, 1.93-21.88; p = 0.003), Dmean of ≥55 Gy to PC (HR = 3.54; 95% CI, 1.25-9.98; p = 0.017), and patients having late dysphagia (HR = 4.37; 95% CI, 1.55-12.31; p = 0.005).

Conclusion: IMRT is a feasible radiation delivery technique in LAHNSCC with a decreased late toxicity profile.

Purpose: To evaluate correlation of single photon emission computed tomography-computed tomography (SPECT-CT) data on lymph flow (LF) from oral tongue cancer (OC) and the topography of lymph nodes (LN) metastases; to determine the clinical value of lymph flow guided radiotherapy (LFGRT).

Materials and methods: SPECT-CT visualization of LF from the OC lesions was performed after peritumoral injection of 99mTc-phytate in 26 primary patients with clinical stage cT1-2N0M0 disease. We determined the individual drainage (unilateral/bilateral) from the tumor, and localization of sentinel LNs according to the neck levels. Metastases in LNs were verified with histology and a 2-year follow-up.

Results: SPECT-CT detected bilateral LF in 10 (38.5%) of 26 patients; in 16 (61.5%) cases the drainage was unilateral. Histology revealed LNs metastases in three cases; regional recurrences were diagnosed in other four patients. In all seven observations metastases were located at the same site and level as the sentinel LNs. In eight (30.8%) of 26 patients sentinel LNs were visualized unilaterally at levels Ib-IIa; in five cases, unilaterally at levels I-IIa-III. In these patients, LFGRT demonstrated 59%-70% reduction of irradiated volume, and 26%-42% and 51%-70% decrease of the mean dose to the spinal cord and the contralateral parotid gland. In patients with a bilateral drainage the reduction of doses absorbed by the spinal cord and contralateral parotid gland was 19% and 6%, respectively.

Conclusion: Localization of sentinel LNs determined by SPECT-CT corresponds to the localization of metastatic LNs in terms of side and levels.

Purpose: To determine the effectiveness of salvage radiation therapy (RT) in patients with locoregional recurrence (LRR) following initial curative resection of non-small cell lung cancer (NSCLC) and identify the prognostic factors affecting survival.

Materials and methods: Between January 2009 and January 2019, 54 patients with LRR after NSCLC surgery were treated with salvage RT (83.3%) or concurrent chemoradiation therapy (16.7%). Twenty-three (42.6%), 21 (38.9%), and 10 (18.5%) patients had local, regional, and both recurrences, respectively. The median RT dose was 66 Gy (range, 37.5 to 70 Gy). The radiation target volume included recurrent lesions with or without regional lymphatics depending on the location and recurrence type.

Results: The median follow-up time from the start of RT was 28.3 months (range, 2.4 to 112.4 months) and disease-free interval (DFI) from surgery to recurrence was 21.0 months (range, 0.5 to 92.3 months). Tumor response after RT was complete response, partial response, stable disease, and progressive disease in 17, 29, 5, and 3 patients, respectively. The rates of freedom from local progression at 1 and 2 years were 77.2% and 66.0%, respectively. The median survival duration after RT was 24.8 months, and the 2-year overall survival (OS) rate was 51.1%. On univariate analysis, initial stage, recurrence site, DFI, and tumor response after RT were significant prognostic factors for OS. DFI ≥12 months and tumor response after RT were statistically significant factors on multivariate Cox analysis for OS.

Conclusion: Our results demonstrated the effectiveness of salvage RT for LRR of NSCLC following curative surgery.

Purpose: Typical doses of 45-50.4 Gy used to treat regional nodes have demonstrated inadequate control of gross nodal disease (GND) in gynecologic cancer, and accelerated repopulation may limit the efficacy of a sequential boost. We reviewed outcomes of patients treated with a simultaneous integrated boost (SIB) at 2.25 Gy per fraction to positron emission tomography (PET) avid GND to evaluate toxicity and tumor control using this dose-escalated regimen.

Materials and methods: A total of 83 patients with gynecologic cancer and PET avid inguinal, pelvic, or para-aortic lymphadenopathy were treated using intensity-modulated radiation therapy (IMRT) with SIB. Primary cancers were mostly cervical (51%) and endometrial (34%), and included patients who received concurrent chemotherapy (59%) and/or brachytherapy boost (78%).

Results: Median follow-up from radiation completion was 12.6 months (range, 2.7 to 92.9 months). Median dose to elective lymphatics was 50.4 Gy (range, 45 to 50.4 Gy) at 1.8 Gy/fraction. Median SIB dose and volume were 63 Gy (range, 56.3 to 63 Gy) and 72.8 mL (range, 6.8 to 1,134 mL) at 2-2.25 Gy/fraction. Nodal control was 97.6% in the SIB area while 90.4% in the low dose area (p = 0.013). SIB radiotherapy (RT) field failure-free, non-SIB RT field failure-free, and out of RT field failure-free survival at 4 years were 98%, 86%, and 51%, respectively. Acute and late grade ≥3 genitourinary toxicity rates were 0%. Acute and late grade ≥3 gastrointestinal toxicity rates were 7.2% and 12.0%, respectively.

Conclusion: Dose escalated SIB to PET avid adenopathy results in excellent local control with acceptable toxicity.

Purpose: Image-guided radiotherapy (IGRT) is central to the safe and effective delivery of ultrahypofractionated (UF) stereotactic body radiotherapy (SBRT) for localized prostate cancer. However, the optimal IGRT modality remains uncertain. We aim to study the safety of performing UF-SBRT using cone-beam computed tomography (CBCT) and real-time transperineal ultrasound (TPUS) monitoring.

Materials and methods: We retrospectively review the medical records of 26 patients who had received UF-SBRT for intermediate risk localized prostate cancer in our institution from October 2018 to December 2020. All patients were treated with SBRT without fiducial marker and received 35-40 Gy to the clinical target volume in 5 fractions over 2-5 weeks. CBCT was used to correct for interfraction displacement while intrafraction displacement of the prostate gland was monitored using Elekta Clarity Autoscan TPUS with 4 mm isotropic warning level. All patients also received neoadjuvant and concurrent androgen deprivation therapy for a total of 6 months. The primary endpoints were incidence of acute toxicities and patient reported urinary toxicities in terms of the International Prostate Symptom Score: before (IPSS1), at the completion of (IPSS2), and at 3-6 months (IPSS3) after SBRT.

Results: All men were treated and followed up for at least 3 months after SBRT. Patients experienced transient worsening of their urinary symptoms at the end of SBRT but they usually recovered in 3-6 months afterwards. The median IPSS1, IPSS2, and IPSS3 were 12, 12.5, and 8, respectively. One patient developed grade 3 rectal bleeding which was related to underlying hemorrhoid. No other grade 3-4 acute toxicity was observed.

Conclusion: It appears safe to deliver UF-SBRT without fiducial marker for prostate cancer patients using CBCT and non-invasive hybrid imaging modalities for positioning and tracking. Longer follow-up is necessary to monitor the treatment efficacy and long-term toxicities.