Norihiro Aibe

Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

BackgroundTo assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise.MethodsWe quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan.ResultsThe median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm3 (range, 7.17 - 14.3 cm3) and 1.99 for pituitary adenoma, and 6.86 cm3 (range 6.05 - 14.6 cm3) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm3 for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm3(p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm3) than group 2 (6.91 ± 0.7 cm3, p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring.ConclusionQuality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract.

Outcome and toxicity of stereotactic body radiotherapy with helical tomotherapy for inoperable lung tumor: analysis of Grade 5 radiation pneumonitis

To analyze outcomes and toxicities of stereotactic body radiotherapy with helical tomotherapy (HT-SBRT) for inoperable lung tumors, the medical records of 30 patients with 31 lung tumors treated with HT-SBRT were reviewed. The 3-year local control, cause-specific survival and overall survival rates (LC, CCS and OS, respectively) were analyzed using the Kaplan–Meier method. Toxicities were graded using Common Terminology Criteria for Adverse Events ver. 4. To investigate the factors associated with Grade 5 radiation pneumonitis (G5 RP), several parameters were analyzed: (i) patient-specific factors (age, gross tumor volume and PTV, and the interstitial pulmonary shadow on pretreatment CT); and (ii) dosimetry-specific factors (conformity index, homogeneity index, mean lung dose, and V5, V10, V15, V20 and V25 of the total lungs). The median duration of observation for all patients was 36.5 months (range, 4–67 months). The 3-year LC, CCS and OS were 82, 84 and 77%, respectively. Regarding Grade 3 or higher toxicities, two patients (6.7%) developed G5 RP. GTV was significantly associated with G5 RP (P = 0.025), and there were non-significant but slight associations with developing G5 RP for V5 (P = 0.067) and PTV (P = 0.096). HT-SBRT led to standard values of LC, CCS and OS, but also caused a markedly higher incidence of G5 RP. It is essential to optimize patient selection so as to avoid severe radiation pneumonitis in HT-SBRT.

Association between Skin Phototype and Radiation Dermatitis in Patients with Breast Cancer Treated with Breast-conserving Therapy: Suntan Reaction could be a Good Predictor for Radiation Pigmentation

Breast-conserving therapy/Breast cancer/Radiation dermatitis. The purpose of this study was to evaluate the significance of skin phototype (suntan or sunburn type) i n association with radiation dermatitis in patients with breast cancer who underwent postoperative radiotherapy after breast-conserving surgery because phototype could predict sunlight reaction. We divided patie nts into two phototypes (58 suntan/darkening and 28 sunburn/reddening types) according to selfreports before radiotherapy. We examined skin color changes in 86 patients who underwent breastconserving surgery followed by 50 Gy/25 fractions (median) of radiotherapy with or without boost radiation (10 Gy/5 fractions). Color change was assessed according to CIE L*a*b* space, which is defined by th e Commission Internationale de l’Eclairage (CIE) in 1976 for quantitative color assessment. The patients were also assessed by individual typology angle (ITA°; indicator of skin color calculated by L*a*b* space) and Common Terminology Criteria for Adverse Event v3.0 (CTCAE v3). Radiation therapy changed all values except the b* value, and the suntan type showed a greater darkening response associated with radiation dermatitis than did the sunburn type in terms of ITA° value change (p = 0.04), whereas the sunburn type did not show higher a* value (reddening). By CTCAE v3 classifications, a Grade 2 reaction appeared in 14% sunburn patients and in 31% of the suntan group, respectively (p = 0.16 ). Suntan type predicted higher pigmentation associated with radiation dermatitis. Self-reported phototype has the potential to be a good predictor of skin sensitivity to radiation exposure for clinical screening.

Potential risk of alpha-glucosidase inhibitor administration in prostate cancer external radiotherapy by exceptional rectal gas production: a case report

IntroductionRadiotherapy is a standard treatment for prostate cancer, and image-guided radiotherapy is increasingly being used to aid precision of dose delivery to targeted tissues. However, precision during radiotherapy cannot be maintained when unexpected intrafraction organ motion occurs.Case presentationWe report our experience of internal organ motion caused by persistent gas production in a patient taking an alpha-glucosidase inhibitor. A 68-year-old Japanese man with prostate cancer visited our institution for treatment with helical tomotherapy. He suffered from diabetes mellitus and took an alpha-glucosidase inhibitor. Routine treatment planning computed tomography showed a large volume of rectal gas; an enema was given to void the rectum. Subsequent treatment planning computed tomography again showed a large volume of gas. After exercise (walking) to remove the intestinal gas, a third scan was performed as a test scan without tight fixation, which showed a sufficiently empty rectum for planning. However, after only a few minutes, treatment planning computed tomography again showed extreme accumulation of gas. Therefore, we postponed treatment planning computed tomography and consulted his doctor to suspend the alpha-glucosidase inhibitor, which was the expected cause of his persistent gas. Four days after the alpha-glucosidase inhibitor regimen was suspended, we took a fourth treatment planning computed tomography and made a treatment plan without gas accumulation. Thereafter, the absence of rectal gas accumulation was confirmed using daily megavolt computed tomography before treatment, and the patient received 37 fractions of intensity-modified radiotherapy at 74Gy without rectal gas complications. In this case study, the alpha-glucosidase inhibitor induced the accumulation of intestinal gas, which may have caused unexpected organ motion, untoward reactions, and insufficient doses to clinical targets.ConclusionsWe suggest that patients who are taking an alpha-glucosidase inhibitor for diabetes should discontinue use of that particular medicine prior to beginning radiotherapy.

Evaluation of dosimetry and excess seeds in permanent brachytherapy using a modified hybrid method: a single-institution experience

Permanent prostate brachytherapy is frequently performed worldwide, and many studies have demonstrated its favorable outcomes. Implant seeds used in this procedure contain a precise amount of radionuclide and are completely sealed. Because these seeds are not manufactured in Japan, they are expensive (6300 yen per seed) and therefore need careful management as a radioisotope. The proper implantation technique requires considerable procedure time, good dosimetric outcomes and simple radioactive isotope management. To evaluate the modified hybrid interactive technique based on these considerations, we assessed 313 patients who underwent hybrid interactive brachytherapy without additional external beam radiotherapy. We evaluated the duration of the procedure, dosimetric factors and the total number of excess seeds. The dosimetric results from computed tomography on Day 30 of follow-up were: 172 Gy (range 130–194 Gy) for pD90, 97.8% (83.5–100%) for pV100, 54.6% (27.5–82.4%) for pV150, 164 Gy (120–220 Gy) for uD90, 194 Gy (126–245 Gy) for uD30, 210 Gy (156–290 Gy) for uD5, 0.02 ml (0–1.2 ml) for rV100 and 0 ml (0–0.2 ml) for rV150. The number of excess seeds was determined by subtracting the number of implanted seeds from the expected number of seeds calculated from previously proposed nomograms. As per our method, nine excess seeds were used for two patients, whereas using the nomograms, the number of excess seeds was approximately eight per patient. Our modified hybrid interactive technique reduced the number of excess seeds while maintaining treatment quality.

Local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer

Background Radiotherapy is an effective treatment for the postoperative loco-regional recurrence of esophageal cancer; however, the optimal treatment field remains controversial. This study aims to evaluate the outcome of local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer. Methods We retrospectively investigated 35 patients treated for a postoperative loco-regional recurrence of esophageal cancer with local field radiotherapy between December 2008 and March 2016. The median irradiation dose was 60 Gy (range: 50-67.5 Gy). Thirty-one (88.6%) patients received concurrent chemotherapy. Results The median follow-up period was 18 months (range: 5-94 months). The 2-year overall survival was 55.7%, with a median survival time of 29.9 months. In the univariate analysis, the maximal diameter ≤20 mm (P = 0.0383), solitary lesion (P = 0.0352), and the complete remission after treatment (P = 0.00411) had a significantly better prognosis. A total of 27 of 35 patients (77.1%) had progressive disease (loco-regional failure [n = 9], distant metastasis [n = 7], and both loco-regional failure and distant metastasis [n = 11]). No patients had Grade 3 or greater mucositis. Conclusion Local field radiotherapy is a considerable treatment option for postoperative loco-regional recurrence of esophageal cancer.

Clinical Usefulness of the Platelet-to Lymphocyte Ratio in Patients with Angiosarcoma of the Face and Scalp

Angiosarcoma of the face and scalp (ASFS) is an extremely aggressive tumor that frequently metastasizes, often leading to death. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) are inflammatory markers that predict outcome of various cancers. We aimed to examine the relationship between pretreatment inflammatory markers and ASFS outcome. We included 17 patients with ASFS and a control group of 56 age- and gender-matched healthy individuals. Total white blood counts, neutrophil, lymphocyte, monocyte, and platelet counts were recorded; NLR, PLR, and LMR were calculated. Kaplan–Meier curves were used to calculate overall survival (OS) and distant metastasis-free survival (DMFS). Optimal cut-off values for each inflammatory marker were calculated using receiver operating curve analysis. Median follow-up was 22 months (range, 6–75). There was a statistically significant difference in absolute neutrophil counts and NLR between patient and control groups. Two-year OS and DMFS rates were 41% and 35%, respectively. In patients with tumors < 10 cm, PLR was highly correlated with DMFS, with the 2-year DMFS for those with a high PLR being 50% compared with 100% for those with a low PLR (p = 0.06). This study suggests that PLR is superior to NLR and LMR, and is a clinically useful marker in patients with ASFS with small tumors.

In Regard to Morganti et al

To the Editor: We read the recent study by Morganti and colleagues (1) with great interest. This important study with data on a large number of patients encourages the radiation oncologist to use postoperative chemoradiation therapy (2). However, several questions remain that require further exploration. At first, although the authors made a comparison between chemoradiation therapy (yes) versus chemoradiation therapy (no) groups in Figure 2, there may have been 4 groups (no adjuvant therapy, postoperative radiation therapy, chemotherapy, and chemoradiation therapy). The chemoradiation therapy (no) group combined 3 groups into 1 group as a control (no postoperative chemoradiation therapy group Z no adjuvant therapy þ postoperative radiation therapy þ adjuvant chemotherapy). It is difficult to draw their conclusion from this figure. We as readers would like to know the comparison of overall survival and background deviation among those 4 groups (at least the yes and no groups), inasmuch as the authors stated an existing bias in the chemotherapy group in their discussion. We thought that there were many types of treatment orders (ie the adjuvant chemotherapy group may include chemoradiation therapy then chemotherapy, radiation therapy then chemotherapy, and chemotherapyonly groups), making it difficult to summarize in Table 1. A group scheme like a Figure 1, a propensity score analysis, or both would help elucidate the value of this study. We have substantial evidence about chemotherapy in the adjuvant setting (3), as the authors cited in their discussion. On the other hand, chemoradiation therapy could not be shown to have sufficient and reproducible merit in addition to the chemotherapy arm (3-5). We are unaware of any available randomized multicenter data comparing adjuvant chemoradiation therapy with chemotherapy alone, using an appropriate study design, precise and appropriate definitions of

Utility of additional delayed post-therapeutic ¹³¹I whole-body scanning in patients with thyroid cancer.

Objective: The purpose of this study is to compare early (3 days after administration) and delayed (7–9 days after administration) post-therapeutic 131I scanning for detecting metastatic lesions from differentiated thyroid carcinoma. Methods: This study included 24 patients (10 men and 14 women) with differentiated thyroid carcinoma who underwent early and delayed whole-body scanning after 131I treatment. The early and delayed scan images were visually analyzed, and the region-to-whole-body ratio (RBR) and its variation from the early to delayed scanning (RBR variation) were calculated. Results: In the visual analysis, lung metastases in 2 patients and 1 bone metastasis could not be detected on early scanning but were classified as moderate uptake on delayed scanning. The abdomen showed definite uptake on early scanning but was washed out on delayed scanning. The RBR variation of the lung and bone metastases was significantly higher than those of the abdomen and thyroid remnants. This suggests that the distribution of 131I was more quickly washed out of the abdomen and thyroid remnants than from the metastatic lesions. Conclusions: Delayed scanning showed a higher detection rate of lung and bone metastases than early scanning because of the washout of the physiological distributions. Additional delayed scanning is recommended, especially for high-risk patients with intensive physiological distribution on early scanning.

Correlation Between Dosimetric Parameters and Acute Dermatitis of Post-operative Radiotherapy in Breast Cancer Patients

Background/Aim: To examine the correlation between dosimetric parameters and acute radiation dermatitis in early breast cancer patients subjected to post-operative radiotherapy. Patients and Methods: The data of 84 patients treated with post-operative radiotherapy were analyzed. The total prescribed dose was 50 Gy in 25 fractions over 5 weeks. Radiation dermatitis was assessed according to Common Terminology Criteria for Adverse Events v4.0. We set organ at risk whole body (from neck to abdomen examined by CT images) also as surrogate skin volume (3 mm thickness). Results: A total of 28 patients showed radiation dermatitis grade equal or higher than 2 at the 50 Gy time point. These 28 patients were compared to 56 matched pair patients with grade 0-1 radiation dermatitis during the same treatment period. The mean of V5-20 and V40 in patients whole volume and V40-50 in skin volume were significantly higher in patients who presented with acute radiation dermatitis Grades ≥2 than in the other patients who did not. The statistically most significant difference was observed for V40 for skin volume and V5 for patient whole volume. Rate of acute radiation dermatitis grade ≥2 was significantly higher for patients with V5 (whole body) >1,360 cm3 than those with V5 (whole body) <1,360 cm3 (47% vs. 27%, p=0.0353), as well as for patients with V40 (skin volume) >45 cm3 compared with those with V40 (skin volume) <45 cm3 (50% vs. 18%, p=0.0043). Conclusion: Dosimetric parameters were useful to predict radiation dermatitis grade ≥2. V5 (whole body) 1,360 cm3 and V40 (skin volume) 45 cm3 may be dose volume constrain for radiation dermatitis grade ≥2.