Prognostic significance of midline shift of the olfactory or frontal lobes of the brain in canine nasal carcinomas treated by palliative radiotherapy: a pilot study

Cerebral meningioma associated with extensive calvarium osteolysis and presumed intratumoral carcinoma metastasis in a cat

Case summary

A 10-year-old male neutered domestic shorthair cat presented with a 3-month history of weight loss, dysorexia and lethargy. Neurological examination revealed decreased mentation, absent menace response bilaterally and proprioceptive deficits affecting all four limbs; these findings were consistent with a forebrain disorder. Brain CT revealed an extensive asymmetric permeative osteolysis destroying two-thirds of the circumference of the calvarium and involving the right frontal, parietal, temporal and occipital bones, as well as the left parietal bone. This extensive bone lysis was associated with a large ‘plaque-like’ extra-axial subdural/pachymeningeal lesion extending within the soft tissues surrounding the calvarium. The cat was humanely euthanased. Post-mortem MRI was performed, which revealed a T2-weighted (T2W) hypointense subdural lesion and a T2W hyperintense circumferential extracranial lesion lining the right calvarium and left parietal bone. Histopathological analysis on a post-mortem sample of the lesion revealed a fibroblastic subtype of meningioma. Epithelial neoplastic cells were observed scattered through the meningioma, calvarium and surrounding muscular tissues, corresponding with presumed metastatic carcinoma.

Relevance and novel information

To our knowledge, this is the first report of an intracranial meningioma associated with such an extensive and diffuse calvarial osteolysis in veterinary medicine. This is also the first description of presumed metastatic inclusions (adenocarcinoma in this case) inside an intracranial feline meningioma, which is a rare phenomenon known as tumour-to-tumour metastasis in human medicine.

Dose-escalated simultaneously integrated boost radiation protocol fails to result in a survival advantage for sinonasal tumors in dogs

The prognosis for canine sinonasal tumors remains rather poor despite definitive-intent radiotherapy (RT). Theoretical calculations predicted improved outcomes with simultaneously integrated boost (SIB) protocols. With the hypothesis of clinically detectable differences in outcome between groups, our retrospective study evaluated prognostic variables and outcome in dogs treated with regular versus SIB RT. Dogs with sinonasal tumors treated with either a regular (10 × 4.2 Gy) or new SIB protocol (10 × 4.83 Gy to macroscopic tumor) were included. Information regarding signalment, tumor stage, type, clinical signs, radiation toxicity, response, and outcome was collected. Forty-nine dogs were included: 27 treated regularly and 22 treated with SIB RT. A total of 69.4% showed epistaxis, 6.1% showed epileptic seizures, 46.9% showed stage IV tumors, and 6.1% showed lymph node metastases. Early toxicity was mostly mild. Late grade 1 skin toxicity (alopecia/leucotrichia) was seen in 72.1% of dogs, and a possible grade 3 ocular toxicity (blindness) was seen in one dog. Complete/partial resolution of clinical signs was seen in 95.9% of patients as best clinical response and partial remission was seen as best imaging response in 34.7%. The median progression-free survival (PFS) was 274 days (95% CI: 117-383) for regular and 300 days (95% CI: 143-451) for SIB RT, which was not significantly different (P = 0.42). Similarly, the median overall survival (OS) was 348 days (95% CI: 121-500) for regular and 381 days (95% CI: 295-634) for the SIB RT (P = 0.18). Stratified by protocol, the hazard ratio of stage IV versus stage I-III tumors was 2.29 (95% CI: 1.156-4.551, P = 0.02) for OS but not PFS. All dogs showed acceptable toxicity. In contrast to theoretical predictions, however, we could not show a statistically significant better outcome with the new protocol.

Treatment of advanced-stage canine nasal carcinomas with toceranib phosphate: 23 cases (2015-2020)

OBJECTIVE

To determine the median survival time (MST) of dogs with nasal carcinoma treated with toceranib phosphate.

MATERIAL AND METHODS

The databases of four Spanish referral hospitals were retrospectively searched for dogs with a diagnosis of nasal tumours presented between January 2015 and October 2020. Dogs treated with radiotherapy or other chemotherapies prior toceranib were excluded.

RESULTS

Twenty-three dogs with a confirmed nasal carcinoma treated with toceranib phosphate and with a CT scan for initial staging according to Adams Modified Staging System were included. Nine dogs had a stage III nasal carcinoma whereas 14 dogs had a stage IV nasal carcinoma. No dog had stages I and II nasal carcinoma. The median overall survival time was 139 days. The difference between the MST between dogs with stages III and IV was not statistically significant [P = 0.6, 140 days for stage III (range 46-401) vs 120 days for stage IV (range 23-600)]. Overall, dogs with epistaxis achieved a longer median survival (166 days) than dogs without epistaxis (83 days). Toceranib phosphate was generally well tolerated. Most dogs had an initial clinical benefit followed by progressive disease.

SIGNIFICANCE

This is the first study to report the MST in dogs with stages III and IV nasal carcinoma treated with toceranib phosphate. This retrospective study showed that toceranib phosphate decreases the clinical signs associated with nasal carcinomas.

Definitive-intent intensity modulated radiotherapy for modified-Adams' stage 4 canine sinonasal cancer: A retrospective study of 29 cases (2011-2017)

Dogs with sinonasal tumors with cribriform plate lysis (modified Adams' stage 4) treated with non-conformal definitive radiotherapy (RT) have short median survivals of 6-7 months. Intensity-modulated radiotherapy with its greater conformality and tumor dose homogeneity may result in more favorable outcomes. Dogs with epithelial or mesenchymal sinonasal tumors and CT evidence of cribriform lysis that received 10 daily fractions of 4.2 Gray using IMRT by helical tomotherapy were included in this single-institution retrospective case series study. Dogs with distant metastasis, previous treatment, or concurrent chemotherapy were excluded. Based on CT, tumors were divided into two groups: cribriform plate lysis only (stage 4a) or intracranial extension (stage 4b). Twenty-nine dogs were included, 23 with carcinoma and six with sarcoma. Eight dogs had stage 4b tumors; two presented with neurologic signs. Two dogs had lymph node metastasis at diagnosis, one confirmed and one suspected. Radiation dose distributions were standardized and patient positioning for RT was verified daily using on-board megavoltage CT. All evaluable dogs had improvement of clinical signs. Median progression free survival was 177 days (95% CI, 128-294 days). Median overall survival was 319 days (95% CI, 188-499 days). Radiotherapy was well tolerated. The most common side effect was grade 1 or 2 oral mucositis. Two dogs that received additional treatment at progression (stereotactic RT [1]; surgery [1]) developed significant late effects. Image-guided definitive-intent IMRT may improve survival in dogs with modified Adams' stage 4 sinonasal tumors and is associated with low morbidity. Intracranial tumor extension was not prognostic in this cohort of uniformly treated dogs.

MRI findings, including diffusion-weighted imaging, in seven cats with nasal lymphoma and two cats with nasal adenocarcinoma

OBJECTIVES

Primary nasal tumours in cats are rare, with lymphoma being the most common feline nasal tumour, followed by adenocarcinoma. Although CT can reliably detect feline nasal tumours, there are no specific CT features that identify each tumour type. To our knowledge, there have been no reports describing MRI findings, including diffusion-weighted imaging (DWI), for nasal lymphomas and adenocarcinomas in cats. Therefore, this retrospective study aimed to evaluate the MRI findings of nasal lymphoma and adenocarcinoma, including qualitative and quantitative analysis of DWI.

METHODS

MRI examination was performed on seven cats with histologically confirmed lymphoma and on two with adenocarcinoma. The MRI protocol included T2-weighted imaging (T2WI), T1-weighted imaging (T1WI) and DWI. Apparent diffusion coefficient (ADC) values were measured using DWI. Contrast agent was not used in one cat with lymphoma.

RESULTS

Of the cats with lymphoma, three (43%) were iso- and hyperintense on T2WI, seven (100%) were isointense on T1WI, five (83%) exhibited mild heterogeneous enhancement, including a prominent region of non-enhancement on post-contrast T1WI, and seven (100%) cats exhibited hyperintensity on DWI. The median ADC values were 0.45 × 10^-3 mm²/s (range 0.37-0.53 × 10^-3 mm²/s). For adenocarcinoma, two (100%) were iso- and hyperintense on T2WI, two (100%) were isointense on T1WI, two (100%) exhibited marked heterogeneous enhancement on post-contrast T1WI and two (100%) were isointense on DWI. The median ADC values were 1.08 × 10^-3 mm²/s (range 0.88-1.27 × 10^-3 mm²/s). The median ADC values of lymphoma tended to be lower than adenocarcinoma (P = 0.056).

CONCLUSIONS AND RELEVANCE

Determining ADC value and tumours with a large area of non-enhancement may be helpful in differentiating nasal lymphoma from nasal adenocarcinoma.