Factors associated with increased incidence of severe toxicities following yttrium-90 resin microspheres in the treatment of hepatic malignancies.

AIM: To further define variables associated with increased incidences of severe toxicities following administration of yttrium-90 ((90)Y) microspheres. METHODS: Fifty-eight patients undergoing 79 treatments were retrospectively assessed for development of clinical and laboratory toxicity incidence following (90)Y administration. Severe toxicity events were defined using Common Terminology Criteria for Adverse Events version 4.03 and defined as grade ≥ 3. Univariate logistic regression analyses were used to evaluate the effect of different factors on the incidence of severe toxicity events. Multicollinearity was assessed for all factors with P < 0.1 using Pearson correlation matrices. All factors not excluded due to multicollinearity were included in a multivariate logistic regression model for each measurement of severe toxicity. RESULTS: Severe (grade ≥ 3) toxicities occurred following 21.5% of the 79 treatments included in our analysis. The most common severe laboratory toxicities were severe alkaline phosphatase (17.7%), albumin (12.7%), and total bilirubin (10.1%) toxicities. Decreased pre-treatment albumin (OR = 26.2, P = 0.010) and increased pre-treatment international normalized ratio (INR) (OR = 17.7, P = 0.048) were associated with development of severe hepatic toxicity. Increased pre-treatment aspartate aminotransferase (AST; OR = 7.4, P = 0.025) and decreased pre-treatment hemoglobin (OR = 12.5, P = 0.025) were associated with severe albumin toxicity. Increasing pre-treatment model for end-stage liver disease (MELD) score (OR = 1.8, P = 0.033) was associated with severe total bilirubin toxicity. Colorectal adenocarcinoma histology was associated with severe alkaline phosphatase toxicity (OR = 5.4, P = 0.043). CONCLUSION: Clinicians should carefully consider pre-treatment albumin, INR, AST, hemoglobin, MELD, and colorectal histology when choosing appropriate candidates for (90)Y microsphere therapy.

A novel dynamic field-matching technique for treatment of patients with para-aortic node-positive cervical cancer: Clinical experience.

AIM: To report outcomes for patients with para-aortic lymph node positive cervical cancer treated with a dynamic field-matching technique. BACKGROUND: PET staging of cervical cancer has increased identification of patients with para-aortic lymph node metastasis. IMRT enables dose escalation in this area, but matching IMRT fields with traditional whole pelvis fields presents a challenge. MATERIALS AND METHODS: From 2003 to 2012, 20 patients with cervical cancer and para-aortic lymph node metastasis were treated utilizing the dynamic field-matching technique. As opposed to single-isocenter half-beam junction techniques, this technique employs wedge-shaped dose junctions for the abutment of fields. We reviewed the records of all patients who completed treatment with the technique and abstracted treatment, toxicity, and disease-related outcome data for analysis. RESULTS: Median prescribed dose to the whole pelvis field was 45 Gy and para-aortic IMRT field 50.4 Gy. All but 3 patients underwent HDR (13 pts) or LDR (4 pts) brachytherapy. All patients developed lower GI toxicity; 10 grade 1, 9 grade 2, and 1 grade 4 (enterovaginal fistula). Median DFS was 12.4 months with 1 and 2-year DFS 60.0% and 38.1%. One-year OS was 83.7% and 2-year OS, 64.4%. A total of 10 patients developed recurrence; none occurred at the matched junction. CONCLUSIONS: The dynamic field-matching technique provides a means for joining conventional whole pelvis fields and para-aortic IMRT fields that substantially reduces dose deviations at the junction due to field mismatch. Treatment with the dynamic matching technique is simple, effective, and tolerated with no apparent increase in toxicity.

Stereotactic body radiation therapy (SBRT) for lung malignancies: preliminary toxicity results using a flattening filter-free linear accelerator operating at 2400 monitor units per minute.

BACKGROUND: Flattening filter-free (FFF) linear accelerators (linacs) are capable of delivering dose rates more than 4-times higher than conventional linacs during SBRT treatments, causing some to speculate whether the higher dose rate leads to increased toxicity owing to radiobiological dose rate effects. Despite wide clinical use of this emerging technology, clinical toxicity data for FFF SBRT are lacking. In this retrospective study, we report the acute and late toxicities observed in our lung radiosurgery experience using a FFF linac operating at 2400 MU/min. METHODS: We reviewed all flattening filter-free (FFF) lung SBRT cases treated at our institution from August 2010 through July 2012. Patients were eligible for inclusion if they had at least one clinical assessment at least 30 days following SBRT. Pulmonary, cardiac, dermatologic, neurologic, and gastrointestinal treatment related toxicities were scored according to CTCAE version 4.0. Toxicity observed within 90 days of SBRT was categorized as acute, whereas toxicity observed more than 90 days from SBRT was categorized as late. Factors thought to influence risk of toxicity were examined to assess relationship to grade > =2 toxicity. RESULTS: Sixty-four patients with >30 day follow up were eligible for inclusion. All patients were treated using 10 MV unflattened photons beams with intensity modulated radiation therapy (IMRT) inverse planning. Median SBRT dose was 48 Gy in 4 fractions (range: 30-60 Gy in 3-5 fractions). Six patients (9%) experienced > = grade 2 acute pulmonary toxicity; no non-pulmonary acute toxicities were observed. In a subset of 49 patients with greater than 90 day follow up (median 11.5 months), 11 pulmonary and three nerve related grade > =2 late toxicities were recorded. Pulmonary toxicities comprised six grade 2, three grade 3, and one each grade 4 and 5 events. Nerve related events were rare and included two cases of grade 2 chest wall pain and one grade 3 brachial plexopathy which spontaneously resolved. No grade > =2 late gastrointestinal, skin, or cardiac toxicities were observed. Tumor size, biologically effective dose (BED10, assuming α/ß of 10), and tumor location (central vs peripheral) were not significantly associated with grade > =2 toxicity. CONCLUSIONS: In this early clinical experience, lung SBRT using a FFF linac operating at 2400 MU/min yields minimal acute toxicity. Preliminary results of late treatment related toxicity suggest reasonable rates of grade > =2 toxicities. Further assessment of late effects and confirmation of the clinical efficacy of FFF SBRT is warranted.

Glaucoma after pediatric cataract surgery in a population with limited access to care.

BACKGROUND: Cataract is a leading cause of childhood blindness in eastern Africa and other resource-constrained regions around the world, and high-quality surgical centers are increasingly responding to this challenge. Despite evidence concerning the ongoing risk of postoperative glaucoma after lensectomy, little is known of the incidence of glaucoma after pediatric cataract surgery in Africa. We sought to evaluate the frequency and predictors of postoperative glaucoma in this setting. METHODS: The medical records of all children who underwent surgery for congenital or developmental cataract between 2003 and 2005 at the Kilimanjaro Christian Medical Centre were retrospectively reviewed to determine the incidence of postoperative glaucoma. Potential risk factors were evaluated by means of logistic regression. RESULTS: Cumulative incidence of glaucoma at 3 years was 6.5% (95% CI, 2.5-16.0), and the annual incidence rate was 2.0 cases per 100 operated eyes (95% confidence interval, 0.74-4.37). Total time of follow-up and absence of primary intraocular lens implantation correlated with risk for postoperative glaucoma, but multivariate analysis could not confirm independent associations. CONCLUSIONS: As cataract surgical rates continue to increase and pediatric ophthalmology centers in Africa progress toward the goals of Vision 2020: The Right to Sight, renewed efforts must be directed toward the long-term postoperative care of all children undergoing operation for pediatric cataract.