Urinary infection or radiation cystitis? A prospective evaluation of urinary symptoms in patients submitted to pelvic radiotherapy.

OBJECTIVES: The purpose of this study was to evaluate the incidence of urinary tract infection (UTI) in patients with cystitis symptoms who underwent pelvic radiation therapy and identify correlated predictive factors. METHODS: A prospective cohort study was conducted of patients who met the following: primary pelvic cancer treated with curative intent, older than 18 years old, and good performance status. The exclusion criteria were patients being treated for a UTI, using a urinary catheter, in dialysis or with cystostomy or nephrostomy, and using antibiotics during treatment. Urinalysis and urine culture were collected before the beginning of radiation therapy. Weekly evaluations of urinary symptoms were subsequently performed. In cases of new or worsening symptoms, a questionnaire was applied, and new urine exams were collected. The UTI diagnosis was defined by uroculture as bacterial growth greater than 104 CFU/mL. RESULTS: From September 2014 to November 2015, 112 patients were sequentially recruited, and 72 (64%) fulfilled the inclusion criteria. During follow-up, 24 (33%) patients had new urinary symptoms or worse preexisting symptoms. A UTI was confirmed in the second urinary culture in only one (1.4%) patient. CONCLUSIONS: The incidence of UTI was much lower than expected, suggesting that asymptomatic bacteriuria develops symptoms due to radiotherapy. Due to the low rate of UTI, no predictive factor was identified.

Implementation of image-guided brachytherapy (IGBT) for patients with uterine cervix cancer: a tumor volume kinetics approach.

PURPOSE: To evaluate tumor shrinking kinetics in order to implement image-guided brachytherapy (IGBT) for the treatment of patients with cervix cancer. MATERIAL AND METHODS: This study has prospectively evaluated tumor shrinking kinetics of thirteen patients with uterine cervix cancer treated with combined chemoradiation. Four high dose rate brachytherapy fractions were delivered during the course of pelvic external beam radiation therapy (EBRT). Magnetic resonance imaging (MRI) exams were acquired at diagnosis (D), first (B1), and third (B3) brachytherapy fractions. Target volumes (GTV and HR-CTV) were calculated by both the ellipsoid formula (VE) and MRI contouring (VC), which were defined by a consensus between at least two radiation oncologists and a pelvic expert radiologist. RESULTS: Most enrolled patients had squamous cell carcinoma and FIGO stage IIB disease, and initiated brachytherapy after the third week of pelvic external beam radiation. Gross tumor volume volume reduction from diagnostic MRI to B1 represented 61.9% and 75.2% of the initial volume, when measured by VE and VC, respectively. Only a modest volume reduction (15-20%) was observed from B1 to B3. CONCLUSIONS: The most expressive tumor shrinking occurred in the first three weeks of oncological treatment and was in accordance with gynecological examination. These findings may help in IGBT implementation.

Avaliação dosimétrica de uma combinação de aplicadores para braquiterapia de tumores do colo uterino com acometimento da porção distal da vagina / Dosimetric evaluation of a combination of brachytherapy applicators for uterine cervix cancer with involvement of the distal vagina

OBJETIVO: Avaliar uma alternativa de braquiterapia para tumores do colo uterino acometendo a porção distal da vagina, sem aumentar os riscos de toxicidade. MATERIAIS E MÉTODOS: Estudo teórico comparando três diferentes aplicadores de braquiterapia intracavitária de alta taxa de dose: sonda intrauterina e cilindro vaginal (SC); sonda e anel associado ao cilindro vaginal (SA+C) e um aplicador virtual com sonda, anel e cilindro vaginal em um único conjunto (SAC). Foram prescritas doses de 7 Gy no ponto A e 5 Gy na superfície ou a 5 mm de profundidade na mucosa vaginal, mantendo as doses nos pontos de reto, bexiga e sigmoide abaixo dos limites de tolerância. Foram comparados os volumes englobados pelas isodoses de 50 por cento (V50), 100 por cento (V100), 150 por cento (V150) e 200 por cento (V200), respectivamente. RESULTADOS: Tanto SA+C quanto SAC apresentaram melhor distribuição de dose quando comparados ao aplicador SC. A distribuição de dose obtida com SA+C foi semelhante à do aplicador SAC, sendo V150 e V200 cerca de 50 por cento maiores para SA+C, todavia, dentro do cilindro. CONCLUSÃO: A utilização de SA+C em uma única aplicação em dois tempos pode ser uma alternativa de tratamento para pacientes que apresentam tumores de colo uterino com acometimento distal da vagina.

OBJECTIVE: To evaluate an alternative brachytherapy technique for uterine cervix cancer involving the distal vagina, without increasing the risk of toxicity. MATERIALS AND METHODS: Theoretical study comparing three different high-dose rate intracavitary brachytherapy applicators: intrauterine tandem and vaginal cylinder (TC); tandem/ring applicator combined with vaginal cylinder (TR+C); and a virtual applicator combining both the tandem/ring and vaginal cylinder in a single device (TRC). Prescribed doses were 7 Gy at point A, and 5 Gy on the surface or at a 5 mm depth of the vaginal mucosa. Doses delivered to the rectum, bladder and sigmoid colon were kept below the tolerance limits. Volumes covered by the isodoses, respectively, 50 percent (V50), 100 percent (V100), 150 percent (V150) and 200 percent (V200) were compared. RESULTS: Both the combined TR+C and TRC presented a better dose distribution as compared with the TC applicator. The TR+C dose distribution was similar to the TRC dose, with V150 and V200 being about 50 percent higher for TR+C (within the cylinder). CONCLUSION: Combined TR+C in a two-time single application may represent an alternative therapy technique for patients affected by uterine cervix cancer involving the distal vagina.