Cardiac-sparing radiation therapy using positioning breast shell for patients with left-sided breast cancer who are ineligible for breath-hold techniques.

PURPOSE: Patients with left-sided breast cancer (LSBC) are at increased risk of cardiac morbidity from adjuvant breast radiation therapy (ABRT). Breath-hold (BH) techniques substantially reduce the radiation received by heart during radiation therapy for LSBC. However, a subset of patients with LSBC are ineligible for BH techniques due to an inability to breath-hold or because of other comorbidities. To reduce radiation to the heart, we routinely use a custom-made breast shell for the treatment of patients with LSBC who are ineligible for BH techniques. This study evaluates the dosimetric impact of using a breast shell for patients with LSBC undergoing ABRT. METHODS AND MATERIALS: Sixteen consecutive patients with LSBC who failed BH and underwent ABRT using a breast shell during the period of 2014 to 2016 were identified. Treatment was planned using field-in-field tangents with a prescribed dose of 42.5 Gy in 16 fractions. Comparisons between plans with and without a shell were made for each patient using a paired t test to quantify the sparing of organs at risk (OARs) and target coverage. RESULTS: There was no statistically significant difference in the planning target volume of breast coverage. A statistically significant improvement was observed in sparing the heart, left ventricle (LV), and ipsilateral lung (P-value < .001). Plans with the shell spared OARs better than the no-shell plans with a mean dose of 2.15 Gy versus 5.15 Gy (58.2% reduction) to the heart, 3.27 Gy versus 9.00 Gy (63.7% reduction) to the LV, and 5.16 Gy versus 7.95 Gy (35% reduction) to the ipsilateral lung. The irradiated volumes of OARs for plans with and without shell are 13.3 cc versus 59.5 cc (77.6% reduction) for the heart, 6.2 cc versus 33.2 cc (81.2% reduction) for the LV, and 92.8 cc versus 162.5 cc (42.9% reduction) for the ipsilateral lung. CONCLUSIONS: A positioning breast shell offers significant benefit in terms of sparing the heart for patients with LSBC who are ineligible for BH techniques. It also can be used as a simple cardiac-sparing alternative in centers without BH capability.

Patient reported quality of life after helical IMRT based concurrent chemoradiation of locally advanced anal cancer.

BACKGROUND AND PURPOSE: Concurrent chemoradiation (CCRT) is the standard treatment for locally advanced anal canal carcinoma, although treatment-related side effects can affect patient quality of life (QOL). The purpose was to prospectively evaluate the effects of Tomotherapy (HT) based CCRT on patient reported QOL in locally advanced anal cancer. PATIENTS AND METHODS: Fifty-four patients treated with HT and concurrent 5-fluorouracil/mitomycin-C underwent QOL evaluation at baseline, after treatment, and during follow-up with EORTC core (QLQ-C30) and colorectal (QLQ-CR29) questionnaires. The QOL scores at baseline and post-treatment were compared. RESULTS: All C30 functional symptoms, except emotional and cognitive functioning, were impaired end-of-treatment and recovered by 3months follow-up. The majority of symptom scores were worse end-of-treatment but recovered by 3months except for fecal incontinence (FI), diarrhea, urinary incontinence (UI), and dyspareunia which persisted. FI returned to baseline at 12months while diarrhea, UI, and dyspareunia persisted. CONCLUSIONS: Most impaired functions and symptoms following HT based CCRT were temporary and improved by 3months post-therapy. Late complications affecting QOL were FI, sexual function, UI, and diarrhea. Our observations support routine use of IMRT and emphasize the significance of precise evaluation of sexual, urinary, and anorectal functions before starting CCRT and routine incorporation of QOL evaluations.

Dosimetric effect of small bowel oral contrast on conventional radiation therapy, linear accelerator-based intensity modulated radiation therapy, and helical tomotherapy plans for rectal cancer.

PURPOSE: This study evaluated the dosimetric effect of small bowel oral contrast on conventional radiation therapy, linear accelerator-based intensity modulated radiation therapy (IMRT), and helical tomotherapy (HT) treatment plans. METHODS AND MATERIALS: Thirteen patients with rectal cancer underwent computed tomography (CT) simulation with oral contrast (CCT) in preparation for chemoradiation therapy. The contrast in the small bowel was contoured, and a noncontrast CT scan (NCCT) was simulated by reassigning a CT number of 0 Hounsfield units to the contrast volume. Conventional, IMRT, and HT plans were generated with the CCT. The plan generated on the CCT was then recalculated on the NCCT, maintaining the same number of monitor units for each field, and the plans were not renormalized. Dosimetric parameters representing coverage of the planning target volume with 45 Gy (D98%, D95%, D50%, and D2%) and sparing of the bladder and peritoneal cavity (D50%, D30%, and D10%) were recorded. The ratio of dose calculated in the presence of contrast to dose with contrast edited out was recorded for each parameter. A paired Student t test was used for comparison of plans. RESULTS: For conventional plans, there was <0.1% variance in the dose ratio for all volumes of interest. For IMRT plans, there was a 1% decrease in the mean dose ratio, and the range of dose ratios for all volumes was greater than that for HT or conventional plans. For HT plans, for all volumes of interest, the mean dose ratio was <0.2%, and the range for all patients was <1%. For all IMRT dosimetric parameters, the difference was in the order of 1% of the mean dose (P < .05). The dose difference was not statistically significant for the conventional or HT plans. CONCLUSIONS: The use of CCT during CT simulation has no clinically significant effect on dose calculations for conventional, IMRT, and HT treatment plans and may not require replacement of the contrast with a CT number of 0 Hounsfield units.